Wings of Discovery 2009-2011

2009–11 EDGEWOOD HIGH SCHOOL STUDENT SCIENCE JOURNAL

Featuring the work of: Ally Cross Connor Curliss Catherine DeGuire Clare Everts Kelsey Ford Lindsay Fulton Andrew Gisi

Lorraine Guerin Mikki Heckman Ruby Herrera Mark Holaday Manya Hose Maddie Kothe Katie Kuecker

Khuaten Maneb de Macedo Niall Martin Cassidy McDonald Sara Murphy Audrey Netzel Jessie O’Brien Claire Petchler

Julia Pinckney Marcy Prince Sam Richards Tom Richards Katie Wall

In Loving Memory of Joseph E. Zaiman, Jr.

Wings of Discovery is an annual, independent journal of original science research by Advanced Science students at Edgewood High School. All contributions constitute the students’ own work and reproduction in whole or in part of any article without permission is prohibited.

Wings of Discovery Š 2012 Edgewood High School of the Sacred Heart.

Edgewood High School, 2219 Monroe Street, Madison WI 53711.

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Foreword As President of Edgewood High School, I write today to tell you how proud I am to have our science research journal, Wings of Discovery, in your hands at this moment.

This journal is a credit to our Advanced Science students, who care so much about adding to the knowledge we have about our world, and are capable of doing so.

It is also a credit to our award-winning science teachers, who nurture in their students not only current scientific understanding, but the confidence to become part of creating it. Edgewood strives to form young scientists in the Dominican Catholic values on which we were founded — truth, compassion, justice, community and partnership — and Wings of Discovery is part of that effort.

Few high schools around the country publish a journal like the one you now hold.

For this achievement, I would like to thank our science teachers — Mrs. Mekel Wiederholt Meier, Mr. Eric Pantano, Mr. Robert Shannon, Mrs. Jessica Splitter, Mr. Jonathan Hessler and Mr. Derek Ralph — for their guidance and leadership to our students. I also want to remember that this annual journal is a tribute to our beloved teacher Mr. Joseph Zaimann, whose dream this was, a dream that has come true in his memory.

In addition, I want to thank all EHS science supporters, without whom this annual journal would not have come to fruition in its first year nor in this, its fouth edition.

Your continued support will allow this exceptional growth experience for our science students to continue into the future and become another great Edgewood tradition.

The discipline of science embodies the search for truth. But without the additional essential values we instill in our students — compassion, justice, community and partnership — new knowledge of scientific truths may add little to the quality of life for the inhabitants of God’s earth. We strive to form the whole person of our young scientists, endowing them with a complete and honorable value system that will serve to create good through science. Our prayer is that this journal has been, and will continue to be for years to come, a means to this end.

Sincerely,

Judd Schemmel President

EDGEWOOD HIGH SCHOOL STUDENT SCIENCE JOURNAL 2009-011

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In Loving Memory of Joe E. Zaiman, Jr. 1953-2003 For 23 years, Joseph E. Zaiman, Jr. was a science teacher at Edgewood High School in Madison, Wisconsin. During his time there he not only taught life science, but by his example he taught about life itself. Through his love and enthusiasm for teaching, he earned the admiration and respect of his students, colleagues, friends and family. Joe’s motto to learn constantly, laugh a lot, and love others is the best way to describe the way he lived his life.

Joe was a man who savored constant learning. Whether he was reading a scientific journal, identifying a rare aquatic insect, digging for fossils, or learning the stars and constellations, Joe wanted to know everything about the world around him. But he most enjoyed learning from his students. Likewise, his infectious desire to learn inspired his students as well. Joe always thought that the best way for students to understand nature was to teach through hands-on experiences. His students will never forget their DNA models, hiking the rain forest in Belize, bog walking on Madeline Island, marveling at newly hardened lava in Hawaii or canoeing the St. Croix River.

All of these activities made science fun and inspired students to strive to learn more.

When one thinks of Joe, one has to think of laughter. It was his trademark. A day would not go by when any student or friend of Joe’s did not hear him laugh. Joe’s sense of humor, like his love of learning, was contagious. His unforgettable jokes, pranks, and wonderful “magic tricks” brightened even the gloomiest day.

Joe emulated the Gospel teachings through his love of others. He showed an unconditional love for everyone and everything. His love for his students could be seen and felt immediately upon entering his classroom. Joe reached out to all students.

However, it seemed that he was in his glory helping those who struggled or did not quite fit in. Being around Joe and his warmth made you want to be a better person.

Joe was also a man of many dreams. Some were fulfilled in his lifetime while others were not. The publication of a scientific journal specifically designated for high school students was one dream he planned to pursue. It is our hope that this journal will in some way be a tribute to Joe, a man, a teacher, and friend who lived life to learn, love, and laugh and inspired all around him to do the same.

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Index Aquatic Plants of the St. Croix and Its Backwaters....................................................................................................6

by Ally Cross and Ruby Herrera Tracking Dissolved Oxygen and Carbon Dioxide Levels of the Head of the Rapids Group Camp Swimming Hole during Succession ....................................................................................................8

by Cassidy McDonald and Jessie O’Brien Preliminary Assessment of Functional and Family Diversity of Macroinvertebrates in the Main Channel, Side Channel, and Backwater Habitat Areas of the St. Croix River (June 2009) ..................10

by Catherine DeGuire and Katie Kuecker Preliminary Assessment of Functional and Family Diversity of Macroinvertebrates in the Kettle River Based on Substrate Composition and Water Speed (June 2010) ............................................................................13

by Catherine DeGuire, Katie Kuecker, Khuaten Maneb de Macedo Nocturnal Moth Populations in St. Croix State Park ..............................................................................................16

by Lorraine Guerin and Mark Holaday The Effect of Water Speed, Anthropogenic Influences, and Plant Density on DO, CO2, Phosphates and Nitrates in the St. Croix Tributaries and Their Backwaters ............................................................18

by Katie Wall and Marcy Prince Forest Types of St. Croix State Park and Their Respective Dominant Tree Species ..................................................21

by Claire Petchler and Manya Hose Correlation of Terrestrial Arthropod Diversity and Plant Communities of St. Croix State Park ..............................24

by Julia Pinckney and Andrew Gisi Mussel Species in the St. Croix and Kettle Rivers and Their Tributaries..................................................................27

by Kelsey Ford and Lindsay Fulton Identifying Correlation between Types of Peat and Plant Family in a Wetland........................................................29

by Niall Martin and Connor Curliss Quantitative Study of Terrestrial Arthropods in Relation to Distance from the St. Croix River ..............................31

by Clare Everts and Audrey Netzel Succession of the Populations of Zooplankton in the Swimming Hole ..................................................................33

by Maddie Kothe, Sara Murphy, and Mikki Heckman Factors Affecting the Wetland Plant Gradient in Relation to Distance from Its Source ..........................................36

by Sam Richards and Tom Richards

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Aquatic Plants of the St. Croix and Its Backwaters

by Ally Cross and Ruby Herrera Ally Cross

Ruby Herrera

Aquatic Plants are essential to the aquatic ecosystem. The plants provide not only oxygen for the water, but also shelter and food for the aquatic animals. They also protect the shorelines from erosion. Many factors can affect the abundance and species distribution of aquatic plant life. The purpose of this experiment was to determine the ideal environmental conditions for, and the abundance and type of aquatic plants in the St. Croix River and its backwaters. This was accomplished by testing the amount of light reaching the plants, the concentration of carbon dioxide and dissolved oxygen in the water, the pH level, the water depth, the sediment composition, the water clarity and the water movement at each site. It was hypothesized that aquatic plants would be more abundant where there is a greater amount of light, lower concentration of carbon dioxide, higher concentration of oxygen, low water movement, low water depth, low amount of sand in the sediment, and high water clarity. It was found that submersed plants prosper with little sunlight while emergent plants require more sunlight. Also, it was noted that higher current was a cause for less plant diversity. This shows that more plants are able to grow in areas where there is a low current and only few plants can prosper in an area with faster water movement. The data also showed that more dissolved oxygen in the water was the result of more oxygen-producing vegetation in the area. It was also shown that plants flourish in shallower water. The smaller depth of the water allowed the ability of light to reach the plant leaves. In conclusion, the research helped determine the conditions that affect the abundance of plants, plant diversity, and the species that are more likely to prosper in the St. Croix River.

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ests were done at each site visited to determine the light reaching the plants, levels of carbon dioxide and dissolved oxygen in the water, water movement and depth, sediment composition, and water clarity. The charts and graphs show the results of each test, and in some cases, the averages of three trials.

Many correlations were found in the data that contribute to plant growth and abundance in each of the sites. It was found that submersed plants prosper with little sunlight while emergent plants require more sunlight. Backwaters Site 2 was situated in the middle of the water and had little light reaching the bottom; it had many plants below the water surface. On the contrary, Backwaters Site 3, which was also in the middle of the water, received light all the way to the bottom. Only one plant was growing below the water surface in this site, and no vegetation surrounded the area. Like Backwater Site 2, many sites in the St. Croix River had an abundance of common bur-reed (Sparganium eurycarpum) which are emergent aquatic plants. Each plant was thick and tall, growing in the full sunlight.

It was also noted that higher current was a cause for less plant diversity. This shows that more plants are able to grow in areas where there is a low current and only few plants can prosper in an area with faster water movement. The slower current (or no water movement at all) allowed the plants to set strong roots in the sediment and grow in a sturdy manner. The St. Croix River, on average, had a faster current than the backwaters, and each site had only one or two different species present. Unlike the St. Croix, the backwaters showed purely stagnant waters and generally had more plant diversity than the river.

It was found that more plants thrive in sediment with the least amount of sand. Due to its permeability, sandy sediments allow more water to pass through, but plants need to retain water in order to survive. The data showed that there was more plant diversity in the

backwaters than in the St. Croix, and that the backwaters had, on average, 14 ml less sand in the sediment than the river.

The data showed that more dissolved oxygen in the water was the result of more vegetation in the area. This is due to the fact that plants produce oxygen as a result of photosynthesis. Backwaters Site 5 had the most vegetation and also had the highest level of dissolved oxygen. Likewise, St. Croix River Site 3 also had the most vegetation and the highest level of dissolved oxygen. A higher level of carbon dioxide in the water resulted in an increase in vegetation. Again, this is due to the continuous process of photosynthesis. During photosynthesis, carbon dioxide is consumed, so that areas with higher CO2 concentration were able to support a greater amount of vegetation. Backwaters Site 2 had the second largest amount of plants and the most carbon dioxide. Backwaters Site 3 had the least amount of plants and also the least amount of carbon dioxide in the water. Another part of the data that supports this idea is that St. Croix River Site 3 had the most carbon dioxide and the most vegetation.

Another correlation was between water depth and aquatic plant abundance. It was evident that plants flourish in shallower water. The smaller depth of the water secured the ability of light to reach the plant leaves. Backwaters Site 5 had the most vegetation and the shallowest water. Also, St. Croix River Site 2 had the shallowest water of all the river sites and had the second greatest amount of aquatic plants. In regards to the sediment, it was noted that the more detritus present, the more plants flourished. St. Croix River Site 2 had the most detritus and had the second greatest amount of vegetation. It also had the most diversity of plant species.

A factor that caused more plants to grow in a certain area was the decomposing matter present at some of the sites. Decomposing material provides more nutrients and causes the plants to prosper. For that reason, St. Croix River Site 3, which had many dead leaves and decomposing material throughout the area, was also the

AQUATIC PLANTS OF THE ST. CROIX AND ITS BACKWATERS

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site with the most plants. Like the small decomposing plants, leaves, and sticks, fallen trees were discovered at many of the sites. Although they are bigger than the other decomposed material and will take longer to decompose, the trees will provide more nutrients for the aquatic plants. St. Croix River Sites 2 and 3 had the most vegetation and both sites had at least two fallen/dead/decomposing trees in the water (in the site, near, or surrounding the area.)

This experiment was very important for many reasons. First, it helped establish under what conditions aquatic plants grow best in the St. Croix River and its backwaters. This is useful because it will help people know under what conditions plants grow best, and help them find what they are looking for in the St. Croix River. Furthermore, it will help people who wish to preserve endangered plants find out where a plant will grow best. Also, because we pressed the plants, the specimens can be used to identify the plants around the St. Croix River better. It will help people identify plants in future studies.

The results can also be used in future studies to determine where macroinvertebrates live best. Plants affect the habitat of macroinvertebrates. Furthermore, one could test rivers with more current because the areas that were tested did not have an overly strong current.

Another study could be done on different rivers in Minnesota to determine the difference between rivers found in Minnesota. Also, the study could be taken a step further. It could determine where specific plants are more likely to grow.

Conclusion The objective of the experiment was to determine the abundance of aquatic plants in different conditions and what factors affect their growth by testing the amount of light reaching the plants, the concentration of carbon dioxide and dissolved oxygen in the water, pH level, the water depth and clarity, sediment composition, and water movement at each site. After the research was completed, it was found that the hypothesis was partially supported by the data. It was found that the ideas stated in the hypothesis were somewhat supported by the data.

It was assumed that more light would be needed to increase plant growth, however it was concluded that emergent plants would need more light to grow while submerged plants prospered with less light. Therefore, the claims of the hypothesis about amount of light were partially supported. The beliefs in the hypothesis about the amount of carbon dioxide in the water were disproved by the data found. It was found that the more carbon dioxide in the water, the more vegetation present.

This is due to photosynthesis. Likewise with the amount of carbon dioxide, it was found that there was more dissolved oxygen in areas where there was more vegetation as supposed in the hypothesis. This is also due to photosynthesis. As stated by the hypothesis, it was concluded that more plants could prosper in areas with less water movement. Less water movement allows

the roots to set firmly in the sediment. It was also concluded that the shallower the water, the more vegetation. This data supported the claims in the hypothesis and it allowed the sunlight to reach even the submerged plants whereas deeper water would not allow sunlight to penetrate to the bottom. Finally, the data supported the hypothesis in relation to sediment composition. It was believed that less sand and more clay and detritus would lead to more plant life. This was proved correct because sand allows water to pass through it whereas clay and detritus retain water and also provide nutrients for the plants. Due to these conclusions, the hypothesis was partially supported by the data.

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Tracking Dissolved Oxygen and Carbon Dioxide Levels of the Head of the Rapids Group Camp Swimming Hole during Succession Cassidy McDonald

Jessie O’Brien Cassidy McDonald is a junior at Edgewood High School. She worked closely with Mekel Wiederholt Meier and Jerry Kelly while doing this research on an environmental field education course in St. Croix State Park. She thanks her mentors and the entire staff of the field education course for all of their support.

Jessie O’Brien is also a junior at Edgewood High School. She appreciates all of the help she received from Mekel Wiederholt Meier, Jerry Kelly, and the staff of St. Croix

by Cassidy McDonald and Jessie O’Brien Dissolved oxygen (DO) is an important indicator of aquatic plant activity. The Head of the Rapids Group Camp Swimming Hole (HRGC Swimming Hole) is emptied and refilled manually each year. The purpose of this study was to closely track the DO levels of the HRGC Swimming Hole as it refilled and went through the process of succession. Carbon dioxide (CO2) levels were also tracked, as they are indicators of respiring organism activity. It was expected that the DO levels would steadily increase to normal, oscillating behavior, as plant population began to return. As the plant life increased and photosynthesized, more oxygen would be produced. It was also expected that the CO2 levels would vary indirectly with the DO levels, because plants intake CO2 and expel O2. This hypothesis was somewhat confirmed. The DO values did steadily increase throughout the course of the study. However, the study was not performed long enough to determine when the DO levels reached a steady state. The CO2 values did not vary as indirectly with the DO levels as was anticipated.

The data from this experiment helped to determine the succession of an aquatic system.

Introduction he amount of dissolved oxygen (DO) in an aquatic system is a beneficial value to know as it is indicative of plant activity. This is because as aquatic plants go through process of photosynthesis, they intake carbon dioxide (CO2) and expire DO. Higher DO levels imply more plant life. Limnology textbooks [1,2] support the concept that DO increases with larger plant populations.

“Most lacustrine oxygen originates as a by-product of photosynthesis” [2]. Likewise, CO2 levels suggest the activity of respiring organisms, because respiration takes in oxygen and releases CO2.

Aquatic succession, in many locations, occurs naturally as seasons change from winter to spring. A study that was done in the Black Sea [3] suggests that it takes from April until August for a plant population to reach a steady state.

The Head of the Rapids Group Camp swimming hole (HRGC swimming hole) goes through succession annually, but not naturally. It is a man-made swimming hole. It is drained every autumn and filled every spring.

This swimming hole is a useful tool for studying succession, as it allows researchers to track changes from the moment it begins to fill.

DO and CO2 had not yet been tracked frequently during the filling of the HRGC swimming hole, and the intention of this study was to fill this gap in knowledge.

The aim of the study was to determine how the oxygen levels (and CO2, carbonate, and pH levels) would change after the HRGC swimming hole was refilled, using this knowledge to determine how and when the plant and respiring organism population would return, and possibly verify when each population would reach a stable, steady state.

It was hypothesized that the DO levels would steadily increase to normal, oscillating behavior, as plant population began to return. As the plant life increased and photosynthesized, more oxygen would be produced.

The CO2 levels would vary inversely with the DO levels, because plants intake CO2 and expel O2.

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Materials and Methods Materials that were used to perform this study included a water thermometer, a DO testing kit, a CO2 testing kit, a carbonate testing kit, a pH tester, two large sample bottles, three DO sample bottles, and a notebook for recording observations.

Three locations were used for sampling. The first was located beside the HRGC swimming hole input pipe.

Samples were taken at a water depth of approximately 18" by wading into the wtaer at 1:00 a.m., 5:00 a.m., 9:00 a.m., 1:00 p.m., 5:00 p.m., and 9:00 p.m. for six days. This site was chosen for its proximity to the input pipe, and because throughout the entire study, this site was underwater, unlike the second location. From this location’s samples, DO tests, CO2 tests, carbonate tests, and pH tests were run. Water temperature was also taken.

The second site was located at the end of the pier.

Samples were taken at 1:00 p.m. each of the six days, from about 12" deep, and obtained by reaching into the water from the end of the pier. This site was used as a control. The same five tests were run from the samples taken at this site. The third and final site was used as a sample of the water from which the swimming hole fills.

Samples were taken at 1:00 p.m. each day, from approximately 18" deep, by wading into the water. DO was the only test run from these samples.

Results and Discussion The results showed that the DO levels steadily increased as the week progressed while the CO2 levels dropped rapidly until 6/4/11, and then evened out (Graph 1). The backwater DO levels were generally lower than the swimming hole DO levels. The pH level of the HRGC swimming hole was consistently between 6 and 8. There were no carbonates in the swimming hole, and there were between 38 and 78 ppm of bicarbonates. After an initial peak of 93.7%, the percent saturation stayed between 40 and 81.9%. It rose throughout the sampling period (Graph 2).

TRACKING DISSOLVED OXYGEN AND CARBON DIOXIDE LEVELS OF THE HRGC SWIMMING HOLE DURING SUCCESSION

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Graph 1

These DO results likely occurred because as the swimming hole increased in size, the DO producing plants had a larger and more desirable habitat. Therefore, they were able to increase their population, producing more DO. The plant population has not yet leveled off. It continues to increase in size. The CO2 levels may have been a result of dilution. Before the swimming hole was completely filled, the Graph 2 respiring organisms had a densely populated habitat. After the volume of the swimming hole increased, the organisms were diluted. The CO2 levels were thusly also diluted, decreasing the ppm. The CO2 levels have not yet reached a steady state, indicating that the respiring organism population is still increasing. The fact that the backwater DO levels were lower than the swimming hole DO levels indicates a plant population in the swimming hole. The backwater sampling location has a current, so plant life is limited.

A plant population in the swimming hole would increase the DO levels. The pH and alkalinity levels indicate a medium to well-buffered system. Free CO2 molecules are somewhat likely to occur. The percent saturation confirms the concept that DO increased throughout the sampling period.

These results were similar to the hypothesis because the DO levels increased steadily. However, the study ended before a steady DO state could be reached. The CO2 levels were different than the hypothesis because they varied less inversely with the DO. They were much more independent and varied with the respiring organisms. The DO hypothesis was correct because as predicted, a plant population did return and begin to increase in size. The CO2 hypothesis was incorrect because the CO2 was more affected by respiring organisms than expected.

There were limitations with sampling techniques.

These limitations were human error. It would have been impossible to take samples at the same exact time each day. There were a few samples (the 1:00 p.m. sample on 6/2/11 and the 5:00 a.m. sample on 6/6/11) that were taken an hour after the scheduled sample times. Other samples may have been taken slightly later than the scheduled time for various reasons. If this error had occurred during the daytime samplings, this would cause DO levels to be higher, because plants would have been photosynthesizing for longer. If this had occurred during the night samplings, the DO levels would be lower, because plants would have stopped photosynthesizing for

REFERENCES 1. Allan, J. David., and Mariรก M. Castillo.

Stream Ecology. New York: Springer, 2007.

Print.

2. Cole, Gerald A. Textbook of Limnology.

Saint Louis: Mosby, 1975. Print.

3. Soylu, Elif N., and Arif Gonulol. "Seasonal Succession and Diversity of Phytoplankton in a Eutrophic Lagoon (Liman Lake)." Journal of Environmental Biology.

Sept. 2010. Web. <http://www.jeb.co.in/ journal_issues/201009_ sep10/paper_13.pdf>.

a longer period of time. Conversely, if the samples were taken too early (which occurred less often) the opposites would be true. An experimental error would be that the pH meter was calibrated only once (after the 9:00 p.m. sampling on 6/3/11). It would therefore be impossible to say that every reading before and after were perfect readings. A second experimental error was that the reagent in the CO2 kit became tainted some time on 6/7/11. The pH of the reagent was 9.6, while a normal pH would be much higher. It is necessary to disregard these two days of CO2 data.

Conclusion In conclusion, the purpose of this study was to determine how the oxygen levels (and CO2, carbonate, and pH levels) changed after the Head of the Rapids swimming hole was refilled. The intention was to use this data to determine how and when the plant population returned. The hypothesis was somewhat confirmed. The DO values did steadily increase throughout the course of the study. However, the study was not performed long enough to determine when the DO levels reached a steady state. The CO2 values did not vary as inversely with the DO levels as was anticipated. The data from this experiment is indicative of the populations of the respiring organisms and plants.

It is useful in determining the succession of an aquatic system.

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Preliminary Assessment of Functional and Family Diversity of Macroinvertebrates in the Main Channel, Side Channel, and Backwater Habitat Areas of the St. Croix River (June 2009)

by Catherine DeGuire and Katie Kuecker Catherine DeGuire and Katie Kuecker were both students at Edgewood High School at the time of this study. They would like to thank their research mentor Dr. Toben Lafrancois for all of his assistance.

The following summer, Catherine and Katie did a subsequent study that is published, along with their photos, as a second article, immediately following this one.

Macroinvertebrates play a significant role in their ecosystems and are important bioindicators. Different habitats within a river can affect the distribution and abundance of macroinvertebrate taxa and functional groups. The purpose of this study was to examine macroinvertebrate communities in three major sub-habitats of the upper St. Croix River. Main channel, side channel, and backwater habitat areas were defined by physical parameters. Two sites of each habitat type were sampled along the St. Croix. Macroinvertebrate taxonomic and functional diversity were measured along with basic water chemistry and water speed. Invertebrates were identified to family level and assigned a functional group. It was expected that the backwater and main channel sites would be the most different, but these areas were very similar in taxonomic diversity. The side channel areas had the lowest taxonomic diversity. There were not significant differences in the number or kind of functional groups found in the three habitat areas. Results may change at lower taxonomic resolution, if more sites are sampled, or if the survey is carried out at different times of the year. However, the finding that different habitat areas in the upper St. Croix River support similar taxonomic and functional diversity is ecologically significant.

Introduction he purpose of this study was to collect, identify, and preserve the different types of macroinvertebrates found in the main channel, side channel, and backwater areas of the St. Croix River. Additional goals included determining the different types of macroinvertebrates present in these habitats as well as identifying the different functional groups present and whether or not the functional groups differ among the three habitat areas.

In this study, three different habitats were chosen along the upper St. Croix River. The three habitat types were main channel, side channel, and backwater areas.

Each type of habitat had different characteristics. A main channel area was defined as having relatively faster water speed and being larger in size than the side channel. A side channel area was defined as a smaller divergence of the main channel with a generally slower water speed than the main channel. A backwater area was defined as having stagnant or slow-moving water, an abundance of vegetation, and water from main channel or side channel flowing into it. Examples of each habitat type are show in Image 1.

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Image 1. Main Channel, Side Channel, and Backwater Habitat Sites, St. Croix River between Hwy 48 and the confluence with the Kettle River, June 2009.

Macroinvertebrates are animals without a backbone that can be seen with the unaided eye. Studies have been performed to determine their role in ecosystems.

Macroinvertebrates are bioindicators, which means they are a sign of the quality of their ecosystem and can display certain signs if an environment changes. For example, a decrease in macroinvertebrate populations could indicate a polluted environment. The short life cycle of macroinvertebrates can indicate the current quality of their ecosystem. Macroinvertebrates provide one indication of the health of an ecosystem. The functional groups present can show what functions are necessary for the continued well-being of an ecosystem.

The distribution and abundance of macroinvertebrates and their functional groups can be affected by different habitats, changes over seasons, and disturbances, either human or naturally caused.

Seven macroinvertebrate functional groups [Bouchard, 2004] were identified and applied to determine functional diversity in this study: (1) Collector/gatherers feed on “decomposing fine particulate organic matter (FPOM) that has settled out of the water.”

(2) Collector/filterers feed on “decomposing FPOM that is filtered or strained from the water.”

(3) Parasites are “predators living in or on another organism to obtain nutrition, but without contributing to the prey.”

FUNCTIONAL AND FAMILY DIVERSITY OF MACROINVERTEBRATES IN HABITAT AREAS OF THE ST. CROIX RIVER

(4) Piercers are “predators that capture the prey, pierce the prey’s body or cells, and suck the prey’s fluids.”

(5) Predators “capture prey and consume the whole animal body or whole animal parts.”

(6) Scrapers feed by scraping tiny organisms and “associated materials attached to rocks, logs, and other solid substrates.”

(7) Shredders feed on “whole live or dead plant tissue.”

Each functional group is important because the macroinvertebrates perform the basic biological functions necessary for the success of an ecosystem.

Hypothesis It was hypothesized that the side channel habitat would have the most diverse population of macroinvertebrates and the most functional diversity because there would be a balance between the necessary dissolved oxygen levels and a structured habitat. The backwater habitat would have a moderately diverse population and moderate functional diversity because there would be a structured habitat, but there would not be enough dissolved oxygen from moving water and from too much rotting and decomposition of organic material. The main channel habitat would have the least diverse population and the least functional diversity because there would be enough dissolved oxygen from moving water, but there would be too much water flow and sediment for a structured habitat.

Image 2. The main channel habitat areas had an average of 18 macroinvertebrate families and the backwater habitat areas had an average of 18.5 macroinvertebrate families, whereas the side channel habitat areas had an average of 14 macroinvertebrate families (Figure 1). The main channel habitat areas had an average of 5 functional groups and the backwater habitat areas had an average of 5 functional groups, whereas the side channel habitat areas had an average of 4.5 functional groups (Figure 2). The range of macroinvertebrate families in both the main channel and side channel habitat areas was 6. In the backwater habitat areas, the range was 19.

Methods Two sites representing each of the three habitat types were chosen for sampling along the St. Croix River from Hwy 48 downstream to the confluence with the Kettle River. Water quality parameters of the site were tested (pH level, temperature, dissolved oxygen level, water speed, water depth), and Global Positioning System coordinates, aquatic vegetation, and substrate composition were noted. Using D-ring nets, macroinvertebrates from all microhabitats (rocky or sandy substrate, vegetation, submerged wood, etc.) found in the site were collected. Samples were taken for an estimated time of five minutes for each microhabitat. Using a dissecting scope and Guide to Aquatic Invertebrates of the Upper Midwest [Bouchard, 2004], the macroinvertebrates were classified to their families.

Results The three habitat types had distinct characteristics.

The substrate composition differed because the main channel sites were characterized by rocks and submerged wood, the side channel sites were characterized by sand, pebbles, and twigs, and the backwater sites were characterized by mud, decomposing leaves, and rotting organic materials. The average water speed also differed because the main channel, side channel and backwater sites had average water speeds of 0.30, 0.15, and 0.00 meters per second, respectively. Examples of each habitat type are shown in Image 1. An example of a specimen identified as a common skimmer dragonfly larvae, Odonata: Anisoptera: Libellulidae (Macromiidae), is shown in

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Image 2. Common Skimmer Dragonfly Larvae, Odonata: Anisoptera: Libellulidae (Macromiidae), Found in Backwater Site, June 2009.

Figure 1

Figure 2

Discussion The backwater and main channel areas were extremely similar in the average numbers of macroinvertebrate families found, possibly because the macroinvertebrates have adequate nutrients provided by the aquatic vegetation and a structured habitat created by submerged wood and rocky substrate in both areas. The side channel areas had fewer average macroinvertebrate families, which could have resulted from water levels this

EDGEWOOD HIGH SCHOOL STUDENT SCIENCE JOURNAL 2009-2011

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REFERENCES 1. Bouchard, Jr., R. W. Guide to Aquatic Invertebrates of the Upper Midwest. Ed. Leonard C. Ferrington, Jr. and Mary L. Karius. St. Paul: University of Minnesota, 2004. Print.

2. Merritt, Richard W., and Kenneth W. Cummins, eds. An Introduction to the Aquatic Insects of North America. 3rd ed.

1996. Print.

year that are much lower than previous years, possibly due to lack of rainfall. This might have affected the macroinvertebrate population in areas where lower water levels could change macroinvertebrate habitats and make the habitats less optimal for diversity of macroinvertebrates. The functional groups in all three areas were extremely similar, which shows that macroinvertebrates still perform the same functions in different areas. The data suggest that all three areas have habitats with enough structure to support the different functional groups, which shows the quality of the ecosystem in which the macroinvertebrates live.

Both sites for the main channel areas were similar in substrate composition and aquatic vegetation, as were the side channel sites, which could account for the small range of macroinvertebrate families found. The range of macroinvertebrate families in the backwater habitat areas was large, perhaps because one of the two backwater sites might not normally be counted as a backwater area.

Higher water levels would have made the area not a backwater area during a year of average precipitation.

The site was included in this study because it was consistent with the definition of a backwater area during the low water levels this year. The large range of macroinvertebrate families found in the backwater habitat sites could show the natural variation between sites classified as the same habitat type. There could be certain areas with more families of macroinvertebrates than others. The natural variation could have caused the results to range widely depending on the sampling sites chosen because there were different numbers of macroinvertebrate families in different sites of the same habitat type.

These data are important because scientists need to know the basic biology of the St. Croix River, including macroinvertebrates, in order to understand the functions of different areas along the river. The information collected would be useful to the National Park Service because the information can be used to design future studies to determine ideal habitats for macroinvertebrates. Macroinvertebrates break down material in their habitats, and it is ecologically important to know that the St. Croix River can support a diverse population of macroinvertebrates as well as many of the same functional groups in different areas.

This study is one of the first completed on the diversity of macroinvertebrates in different areas of the St. Croix River. It will establish a base for research on macroinvertebrates in different areas and it has shown that functional groups are extremely similar throughout the different locations along the St. Croix River. Future scientists could extend this study by conducting it during different seasons, which would allow collection during different parts of the life cycles of macroinvertebrates. Another study could be done allowing more time to collect macroinvertebrate samples, which would make the data more accurate because more sites of each type could be sampled. Additional research could be done along other rivers to determine if the functional groups are similar in areas along different rivers or if the St. Croix River is healthier than other rivers. In addition, results may change at lower taxonomic resolution.

Conclusion The purpose of this study was to collect, identify, and preserve macroinvertebrates found in the main channel, side channel, and backwater areas of the St. Croix River.

Another goal of this study was to determine the different types of macroinvertebrates present within these areas and to determine how the site parameters affected the diversity of the macroinvertebrates. An additional objective was to determine the different functional groups in the three areas and whether or not the functional groups differed among the areas. The backwater and main channel areas were most similar in the average numbers of macroinvertebrate families found. The side channel areas had the lowest number of average macroinvertebrate families found. The backwater habitat areas had the largest range of macroinvertebrate families found. The three habitat types had similar functional composition (approximately the same number of average functional groups and the same functional groups). The finding that different habitat areas in the upper St. Croix River support similar taxonomic and functional diversity is ecologically significant. These data are important because scientists need to know the basic biology of the St. Croix River, including macroinvertebrates, in order to understand the functions of different areas along the river.

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Preliminary Assessment of Functional and Family Diversity of Macroinvertebrates in the Kettle River Based on Substrate Composition and Water Speed (June 2010) Catherine DeGuire

by Catherine DeGuire, Katie Kuecker, Khuaten Maneb de Macedo Macroinvertebrates play a significant role in their ecosystems and are important bioindicators. Different habitats within a river can affect the distribution and abundance of macroinvertebrate taxa and functional groups. The purpose of this study was to examine macroinvertebrate communities in areas of the Kettle River (Pine Co., MN) in June of 2010 and their distribution in relation to substrate composition and water speed. Macroinvertebrate taxonomic and functional diversity were measured along with basic water chemistry and water speed, and substrate composition and vegetation were measured qualitatively. Invertebrates were identified to family level and assigned a functional group. It was expected that there would be greater family diversity in areas with more organic matter, fewer boulders, and slower water speeds, and the data showed that family diversity differed because of the varying water speeds and the subsequent changes in substrate composition. The functional diversity was similar at all nine sites, which can be explained by the fact that ecologically different sites still need to have the same functions performed by macroinvertebrates inhabiting the site. Results may change at lower taxonomic resolution, if more sites are sampled, or if the survey is carried out at different times of the year.

Introduction he goal of this project is to collect, identify to family, and preserve the macroinvertebrates in different sites found along the Kettle River.

Another aim of this study is to determine the family and functional diversity as well as the parameters of each site, including DO2 concentration, temperature, pH, water speed, and a qualitative assessment of the substrate composition and vegetation. The data collected will be used to determine if there is a relationship between the physical parameters of substrate composition and water speed and the family and functional diversity of macroinvertebrates found in sites with differing ecological conditions.

Macroinvertebrates provide one indication of the health of an ecosystem. The functional groups present can show what functions are necessary for the continued well-being of an ecosystem. The distribution and abundance of macroinvertebrates and their functional groups can be affected by different habitats, changes over seasons, and disturbances, either human or naturally caused.

Seven macroinvertebrate functional groups were identified [Bouchard, 2004] and applied to determine functional diversity in this study: (1) Collector/gatherers feed on “decomposing fine particulate organic matter (FPOM) that has settled out of the water.”

(2) Collector/filterers feed on “decomposing FPOM that is filtered or strained from the water.”

(3) Parasites are “predators living in or on another organism to obtain nutrition, but without contributing to the prey.”

(4) Piercers are “predators that capture the prey, pierce the prey’s body or cells, and suck the prey’s fluids.”

(5) Predators “capture prey and consume the whole animal body or whole animal parts.”

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(6) Scrapers feed by scraping tiny organisms and “associated materials attached to rocks, logs, and other solid substrates.”

(7) Shredders feed on “whole live or dead plant tissue.”

Each functional group is important because the macroinvertebrates perform the basic biological functions necessary for the success of an ecosystem.

Hypothesis There will be a greater amount of family and functional diversity in sites along the Kettle River that have more organic matter, fewer boulders, and slower water speeds because it is necessary for macroinvertebrates to have structured habitats and food sources provided by organic matter, fewer boulders, and slower water speeds.

Method At each site, test the parameters using appropriate instruments or kits (pH level, temperature, dissolved oxygen level, water speed, Global Positioning System coordinates) and note the type of aquatic vegetation and substrate composition present. Sample the site using Dring nets. Take samples from all microhabitats found in the site (rocky or sandy substrate, vegetation, submerged wood, etc.). Preserve the macroinvertebrates in collection bottles with isopropyl alcohol. Using a dissecting scope and the Guide to Aquatic Invertebrates of the Upper Midwest, classify the macroinvertebrates into families.

Put the macroinvertebrates into preservation vials with labels of the sampling site, common name, family, and order.

Results and Discussion For the average water speed of the nine sites found along the Kettle River (Graph 1), Site 3 had the fastest water speed with 0.535 meters/second. This site had a bottom made up entirely of a rock slab and no sand or decomposing matter. Sites 8 and 9 had the slowest two

Katie Kuecker

Khuaen Maneb de Macedo Catherine DeGuire is a recent graduate of Edgewood High School.

She hopes to major in biology and women’s studies in college.

Katie Kuecker is a 2011 graduate of Edgewood High School. She plans to attend the University of Wisconsin-Madison and study chemistry and Spanish with a prepharmacy intention.

Khuaten Maaneb de Macedo is a senior at Edgewood High School.

She plans to attend Stanford in hopes of becoming a cardiac surgeon.

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Graph 1

Graph 2

Graph 3

EDGEWOOD HIGH SCHOOL STUDENT SCIENCE JOURNAL 2009-2011

water speeds with 0.182 m/s and 0.115 m/s, respectively. Both of these sites had more decomposing matter, submerged logs, and twigs than other sites, which are essential for macroinvertebrates to create a structured habitat to survive. Sites 4, 5, and 6 were among the average water speeds with 0.304 m/s, 0.341 m/s, and 0.203 m/s respectively. All of these sites had sand, gravel, and medium sized rocks.

The family diversity of these sites ranged from six to fifteen (Graph 2). Site 3 had the lowest number of different families found with six families and Sites 8 and 9 had higher numbers of families with fifteen and thirteen respectively. Sites 4, 5, and 6 had similar family diversity with fourteen, twelve, and fifteen different families, respectively. The functional diversity was similar in all nine sites (Graph 3), with three to five different functional groups found. The five functional groups that were found were collector/gatherers, collector/filterers, scrapers, shredders, and shredders. The two functional groups that were not found were piercers and parasites. Site 3 had the lowest number of functional groups as well as Site 7 with three functional groups. Sites 4, 5, 6, 8, and 9 had between four and five different groups.

Dissolved oxygen tests were taken at each site and all tests were between 6 and 8 parts per million. At each site, pH testing was also done and the results ranged from 7.8 to 8.3. The temperature at all sites ranged from 66˚ F to 73˚ F. The reason for the significant difference in the temperature between sites was that it was raining.

Therefore the air temperature was colder, making the water temperature colder as well, for the sites with temperatures between 66˚ and 69˚ F. The hypothesis was supported by the data collected.

There was more family and functional diversity of macroinvertebrates in areas along the Kettle River that had slower water speeds, more organic matter, and fewer boulders present. In these areas, macroinvertebrates have a structured habitat because of the slower water velocity, which does not wash away their homes, and because of the organic matter, especially submerged logs and twigs, that provides materials for habitat support for the macroinvertebrates. In addition, rocks in these areas were smaller and therefore the macroinvertebrates are able to have a stable habitat and a secure home that will not be washed away. Macroinvertebrates also have a readily available food source in these areas due to organic matter and other macroinvertebrates that are present. Due to lack of pollutants and runoff into the Kettle River, it is very clean and has a high water quality. This cleanliness is shown through the many macroinvertebrates found with zero or very low tolerance levels in the Kettle River.

Because there is little human interference from pollution and runoff, only the physical parameters of a site, especially water speed and substrate composition, can determine the differences in family diversity among the different sites. Water speed greatly affects the substrate

FUNCTIONAL AND FAMILY DIVERSITY OF MACROINVERTEBRATES IN THE KETTLE RIVER BASED ON SUBSTRATE AND WATER SPEED

composition of an area by determining the presence of rocks, gravel, sand, silt, clay, and organic matter. If there is a higher water velocity, the organic matter, silt, and clay are the first to be swept away. This loss of fine particulate matter can be accompanied by loss of sand and gravel if the velocity is high enough. The substrate composition then affects the diversity of the macroinvertebrates because their structured habitat is swept away.

The family diversity differed because of the varying water speeds and the subsequent changes in substrate composition. The functional diversity was similar at all nine sites, which can be explained by the fact that ecologically different sites still need to have the same functions performed by macroinvertebrates inhabiting the site. Even though there may be different or fewer families present in some areas, the same functional groups are still present along the Kettle River.

Another study of the family and functional diversity of macroinvertebrates was completed in 2009 on the St. Croix River. The data from the previous experiment can be compared to the data found along the Kettle River.

The three different areas of the St. Croix River that were tested were the main stream, side channel, and backwater areas. The main stream and backwater areas had an average functional diversity of 5 while the side channel had an average of 4.5. These functional groups are similar to those found on the Kettle River. In addition, more macroinvertebrate families were found on the St. Croix River, which had a slower water speed than the Kettle River. This supports the conclusion that a slower water speed supports greater family diversity even in different waterways and areas.

There were some errors that could have occurred during the course of this experiment. One possible error is that it is impossible to collect all the different macroinvertebrate families found at one particular site even when sampling all microhabitats thoroughly. Water speed and dissolved oxygen could also have been marginally changed by outside factors. In addition, this experiment was performed during the late spring.

During different seasons, the water speeds in different areas of the Kettle River are subject to change and therefore the habitat and diversity of macroinvertebrates can be altered in various areas. One area might have a faster water speed during a different season, so there may be less family diversity of macroinvertebrates found during this season. While hiking and searching for possible collecting sites, it was necessary to choose sites that were accessible and safe; therefore some areas of the Kettle River were not sampled because of safety issues.

The results of this experiment are extremely important because macroinvertebrates are bioindicators, of the water quality of a river. The different tolerance levels of macroinvertebrates are also good displays of this because some macroinvertebrates are much more tolerant of pollutants than others. On the Kettle River, many macroinvertebrates were found that had tolerance levels of zero. These data can be compared with the data found on the St. Croix River in previous studies that show the higher tolerance levels of macroinvertebrates found on

the St. Croix River. These data help show that the Kettle River is generally a cleaner river than the St. Croix River, possibly because of higher water velocity. Functional groups are another important factor in this experiment because the functional groups found show that even though there are many different microhabitats in the Kettle River, the same functions must still be performed in the river. Water speed and substrate composition are extremely important physical parameters that affected the family diversity of macroinvertebrates found in this project. These data can be used by the National and State Park Services to be used as a reference and starting point for further macroinvertebrate studies as well as to show the high water quality of the Kettle River.

Future studies could be done to expand upon the data collected during this study. Research could be done on other tributaries of the St. Croix River to further explore the relationships among water speed, substrate composition, and macroinvertebrate diversity. Another study could be done to compare the data collected from the Kettle River with the data collected from the St. Croix River in June of 2009. Further research on the diversity of macroinvertebrates could be done during different seasons because this experiment only took place during the late spring because different times of year could mean different macroinvertebrate families are in larval stages as well as different physical parameters, such as water speed and the subsequent substrate compositional changes. Nine sites were sampled in this study on the Kettle River due to time constraints. Further studies could be done sampling more sites, especially further upstream and at the head of the Kettle River. The sampling sites were accessed only by hiking the Big Eddy Trail and the Two Rivers Trail, which limited some of the locations due to extremely steep banks and other safety concerns. Different access methods, such as canoeing down the Kettle River, could be used to reach sampling sites in previously inaccessible areas.

Conclusion The goal of this experiment was to collect, identify to family, and preserve macroinvertebrates found in the sites along the Kettle River and to determine the family and functional diversity at each site. Another objective was to test the physical parameters of each site, especially water speed and substrate composition to determine if there was a correlation between the water speed and substrate composition and the family and functional diversity of macroinvertebrates. The hypothesis was supported by the data; family diversity was related to the topography and physical parameters of each site. There was more family and functional diversity in areas with slower water speed, more organic matter, and fewer boulders on the Kettle River.

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Nocturnal Moth Populations in St. Croix State Park

by Lorraine Guerin and Mark Holaday Lorraine Guerin

Mark Holaday A recent graduate of Edgewood High School, Lorraine Guerin attended the field course in St. Croix as a sophomore and as a junior. Lorraine has fostered a love for nature since she was first immersed in it while backpacking in the Rocky Mountains with her family.

Fascinated by inchworms, Lorraine wished to do a project involving something related to the creatures.

A recent graduate of Edgewood High School, Mark Holaday has had a love for the outdoors since his father began to take him camping at the age of 3. Chasing moths since he could walk, Mark chose to pursue research on the insects. Mark was inspired and helped along by environmental field biologist, Dr. Toben LaFrancois, Ph.D.

The objective of the survey was to find which area, out of the deciduous forest, coniferous forest, marsh, and tornado site, has the greatest amount and diversity of nocturnal spring-time moths. After collection in all four areas, it was found that the coniferous forest contained the greatest amount and variety of moths. The deciduous forest was second, the tornado site was third, and the marsh had the least amount and diversity of moths. The greatest amount and diversity of moths was found in the coniferous forest because there is a great amount of sap and foliage in the coniferous forest for the moths to use as habitat and as food sources. The marsh contained the least amount and diversity of moths because there is not a great amount of good food source or coverage in the marsh.

Introduction octurnal moths exist in many different types of environment. Four such environments in which nocturnal moths exist in St. Croix State Park are deciduous forests, coniferous forests, marshes, and a deciduous forest area that was destroyed by a tornado in 2005. This experiment sought to determine which of these areas would contain the greatest number and variety of moth species. According to Susan Weller, moths in adult form feed on nectar, fruit juices, and tree sap, while in larval form, they feed on leaves and vegetation. Moths are important to the environment because they help in the pollination of flowers. Moths are also a very important food source.

Based on the assumption that a greater number of moths will occur in the area with the greatest food source, it was hypothesized that a deciduous forest would yield the greatest amount of nocturnal moths. With a greater number of nocturnal moths, the deciduous forest will also contain the greatest variation in genera of nocturnal moths. The coniferous forest would have the second greatest amount and variation of nocturnal moths because coniferous trees tend to contain a large amount of sap, but the area will not yield as much fruit and nectar as a deciduous forest. The site in which a deciduous forest is recovering from a tornado would contain the next greatest amount and variation of nocturnal moths because this site, very thick with plant life, contains many saplings, leafy vegetation, and possibly nectar and fruits. The marsh area, with its low variety of vegetation and not much thick or convenient daytime cover, would turn out with the least amount and variety of moths.

The greatest number of nocturnal moths and variety in moth genera was found in the coniferous forest. The second greatest amount and diversity of moths was found in the deciduous forest. The tornado site contained the next greatest amount and variety of moths and the least amount and least variety of moths were found in the marsh.

The coniferous forest contained the largest amount and diversity most likely because there is an immense amount of pine sap from coniferous trees at sap flows

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and this sap would be a great food source for the moths.

The coniferous forest would have also been a very good environment for the larvae of the nocturnal moths because it would have many food sources for the larvae as well as good protective ground cover. The larvae of moths most commonly feed off of vegetation such as grass and the leaves of shrubs and trees. The coniferous forest would have some grass, a few deciduous trees with leaves, and a large amount of leafy ground cover, such as large leaf asters, wild lilies of the valley, and bracken fern.

The marsh contained a small amount and diversity of moths because there is a small amount of food source available in the marsh and protective cover is sparse.

NOCTURNAL MOTH POPULATIONS IN ST. CROIX STATE PARK

Another factor that may have a huge effect on the activity of the moths is the temperature. More moths were collected when the weather was warmer. There were two trials taken that gathered a very significantly larger amount of moths. One of the trials was in the deciduous forest in which thirteen moths were collected at a temperature of 59.4˚F. The other trial was in the coniferous forest in which 18 moths were collected at a temperature of 54.95˚F. In the two warmer trials, much larger amounts of moths were collected than in the other trials at lower temperatures. With only two trials over 50˚F, however, it is not possible to draw a completely accurate conclusion about the temperature in relation to number of moths collected. Yet, the fact that the two trials that were over 50˚F had many more moths collected points towards the conclusion that nocturnal moths are much more active in warmer temperatures.

Other data from each trial site, such as cloud cover, wind speed, and stage of the moon, seemed not to be a factor in the activity of the moths.

An error considered is that, with some of the sites, no trials were taken when the temperature was warmer. For example, the trials taken at the marsh were between the cool temperatures of 43.85 and 45.40˚F. With all the trials of the marsh being at pretty low temperatures, it could have simply been too cold for the moths to be very active and there could, in reality, be a much larger amount of moths in comparison to other sites.

However, with all of the trials being pretty cold, it is unknown whether there would have been more moths in the marsh if it had only been a few degrees warmer for a trial. Another error that occurred was that sometimes a moth would be sighted, but it would escape before it was caught. This would make the data not entirely accurate because these escaped moths would have changed the data slightly. Another error that could have occurred was a moth being misidentified and again this would have changed the data slightly.

The data collected is significant because there have not been very many studies done on nocturnal moths in St. Croix State Park in the past. Therefore, the data collected is important in giving scientists at least a general idea of what kind of habitat nocturnal moths in

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the St. Croix area prefer. The data also gives scientists a general idea about what types of moths are present in the area and which types are the most common. Scientists could use this data to decide in which environments to perform experiments and also in what conditions (mainly considering temperature).

A future study to be executed could be to do a more extensive comparison between just the coniferous and deciduous forest because the results for both of these forests were more similar. With a more extensive experiment between deciduous and coniferous forests, a better idea would be conceived about which types of moths prefer which environment. A study could also go the opposite way and expand on different environments and even specify the registered environments more specifically, such as studying the difference in moths between the many different types of deciduous forests in St. Croix State Park to get a more detailed idea of which environments are better habitats for moths. In these future studies it would be important to attempt to eliminate the seemingly most disruptive factor—the temperature at the time of the trials. Future studies could, given more time to collect, organize collections and trials by temperature, thus giving a better view of actual factors between the sites.

The lowest amount of moths and the lowest amount of diversity were, in fact, found in the marsh, and the tornado site fell in second to last. The coniferous forest ranked highest in amount of moths found and amount of different genera found, and the deciduous forest fell in second.

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Katie Wall

The Effect of Water Speed, Anthropogenic Influences, and Plant Density on DO, CO2, Phosphates and Nitrates in the St. Croix Tributaries and Their Backwaters

by Katie Wall and Marcy Prince

Marcy Prince Katie Wall is a junior at Edgewood High School.

She has taken courses in biology, honors chemistry, and two years of environmental science at St. Croix, MN. Katie gladly returns to St. Croix each year to enjoy the beauty of the forest and river. Her scientific interests include environmental field work, genetics, and water chemistry titrations.

Marcy Prince is a junior at Edgewood High School.

Along with her two years of environmental science at Edgewood High School’s St. Croix program, Marcy has taken freshman biology and honors chemistry.

Edgewood’s St. Croix program is very close to Marcy’s heart. The beauty and friendships are unique.

Currently, Marcy plans on majoring in environmental studies in college.

Katie and Marcy did a previous study of water chemistry as it relates to time of day at the St. Croix State Park Group Camp .

hrough experimentation, the goal is to examine the effects of water speed, anthropogenic influence, and plant density on water quality, which includes dissolved oxygen (DO), carbon dioxide (CO2), phosphates, and nitrates. Water speed affects plant growth in various ways (Madsen et al, 2001). Since plants take in carbon dioxide and produce oxygen, areas with higher plant densities are likely to have lower CO2 levels and higher DO levels. Areas with higher water speed will have higher DO levels, because the fast-moving water will have more contact with the open air. Additionally, there will be more CO2 present in the higher water speed areas compared to the slower water speed areas, because the increased plant density in slow water speed decreases CO2 through the process of photosynthesis. Nitrates and phosphates are found naturally in small quantities and promote the growth of aquatic plants. However, nitrates and phosphates are often found in runoff from sites subject to agricultural and other anthropogenic influences. Therefore, test sites near areas that have been affected by human activity and have large quantities of aquatic plants will likely have lower nitrate and phosphate levels than areas that are not near any source of runoff and/or have little plant growth, because the plants use and absorb much of the phosphates and nitrates put into the water naturally. At locations distant from runoff locations, there should be very low phosphate and nitrate levels.

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Materials • Dissolved oxygen test kit • Carbon dioxide test kit • Nitrate/Phosphate test kit • Nine (9) sample bottles • Thermometer • pH meter • Notebook, calculator, and pencil • Meter stick • Orange or large stick • Secchi Disk • Alkalinity test kit Procedure 1. Locate a test site in the water. Determine the amount of anthropogenic influence such as proximity to roads, farms, or other human frequented areas. Record the time of day and the weather.

2. Mark off one square meter in the water. Estimate the percent of the surface that is covered by plants.

3. Measure the pH of the water. Find the water speed by marking off two meters of waterway and determining the time that it takes for the orange or stick to float the two full meters. Convert the measurement from seconds per meter to meters per second.

4. Take three water samples from one forearm length beneath the water’s surface. Fix one sample on-site using the DO test kit.

5. Return to a laboratory setting. Perform a DO test on the fixed sample. Record the results.

6. Perform a carbon dioxide test on an unfixed sample and record the results. Perform nitrate and phosphate tests on the remaining sample and record the results.

7. Once at each site, record the Secchi depth using a Secchi disc and a meter stick. Note if the Secchi depth is to the substrate. Also, take a water sample, return to laboratory, and analyze with an alkalinity kit.

8. Repeat Step 1 at five other sites, each with a unique combination of water speed, anthropogenic influence, and plant coverage.

9. Repeat Steps 2-7 at all sites at the same time each day for at least 3 days.

Analysis Nitrates and phosphates are almost nonexistent at all sites. The highest phosphate measurement found within the St. Croix National Park is 0.37 ppm, and nitrates all amount to less than 0.88 parts per million. Nitrates and phosphates are a product of agricultural runoff and other manmade pollutants, which are kept at a well-regulated minimum along the St. Croix National Scenic Riverway.

Human influence has no effect on dissolved gases, nitrates, or phosphates in the St. Croix area because of the regulation of pollutants.

However, locations with higher phosphate levels do have slightly higher plant density. For example, at Site C, there was high plant density (40% coverage), and phosphates were measured at 0.37 parts per million. The low levels of phosphates and the absence of nitrates make it difficult to determine whether the correlation is genuine, so the portion of the hypothesis involving phosphates and nitrates is not firmly proven. Further experimentation on sites with more pollutants would be required to definitively prove these findings, as well as show any other correlations.

EFFECT OF WATER SPEED, ANTHROPOGENIC INFLUENCES, AND PLANT DENSITY ON DO, CO2, PHOSPHATES AND NITRATES

There is no correlation between water speed, phosphates, and nitrates.

Sites with high water speed do have higher DO levels than sites with low water speed, which proves the hypothesis. Sites with low water speed have higher CO₂ levels than sites with high water speed, however.

This disproves the portion of the hypothesis which stated that slower water would have less CO₂ due to higher plant density. Since no correlations between plant density and CO₂ levels were found in this investigation, this part of the hypothesis is not supported.

The fact that areas with lower water speeds have higher CO₂ levels is supported by other findings from the experiment which show that CO₂ and DO vary inversely; sites with high DO tend to have low CO₂, and vice versa. This is also supported by Allen & Castillo, “High naturally occurring biological activity can alter the concentrations of oxygen and CO2, organic pollution can greatly increase respiratory demand for oxygen” [Allen & Castillo p. 58]. This means that where there is respiration and photosynthesis is occurring, there is an alteration in DO and CO2 saturation.

Plant density did not appear to have any effect on DO or CO₂. For example, there is high plant density at Site B and low plant density at Site A, but the DO measurements at each site are very similar. At Site A, the DO was measured at 6.20 ppm, and at Site B the DO was 6.37 ppm. When comparing CO₂ and plant densities, there was no correlation. This may be due to the recent flooding. Plants which were thought to be aquatic may have actually been submerged terrestrial plants, which would not respire or photosynthesize properly underwater. Therefore, the plant density may have been lower than anticipated, which is a possible error in the experiment.

In future studies, plant identification may be a good area to study. Another source of error was that the reagent in the CO₂ kit became severely tainted on the seventh of June when the pH suddenly changed from 12 to 9.6, causing test results to rise sharply. As a result, all CO₂ test results found on and after the seventh of June are excluded from the final tables and graphs, affecting the final results to an unknown degree. Some other tests require a judgment on the coloration of a liquid. The same person did not perform every test, which may have affected the results. The lack of nitrates and phosphates in the water was problematic. For future experiments,

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testing for other aspects of water quality, such as different minerals and elements, may yield better results.

Conclusion In the process of determining the correlation between water speed, plant density, and human influence, it was

found that human influence is so minimal in the St. Croix River and its tributaries and backwaters that it had no effect on dissolved gases, phosphates, or nitrates, which disproved the hypothesis. Nitrates were not present at any site, but the plant density was greater where more phosphates were present, proving the hypothesis.

Water speed had no effect on phosphates or nitrates, as expected. Sites with higher water speed had higher DO levels, which supported the hypothesis. However, sites with lower water speed had higher CO₂ levels, which disproved the hypothesis. The discovery that DO and CO₂ vary inversely was unexpected but interesting.

REFERENCES 1. Allen, J. David, and Maria M. Castillo. Stream Ecology: Structure and Function of Running Waters. 2nd ed. Dordecht: Springer, 2007. Print.

This source was extremely useful in understanding the basics of how rivers function and the interconnectedness of all aspects of river ecology.

2. Calle Delgado, P., Yoram Avnimelech, Rod McNeil, Delma Bratvold, Craig L. Browdy, and Paul Sandifer. “Physical, Chemical and Biological Characteristics of Distinctive Regions in Paddlewheel Aerated Shrimp Ponds.”

Aquaculture 217 (2002): 235-48. Print.

This source was useful for making a hypothesis about dissolved oxygen and water speed. It was also very informative about the effect of the time of day on dissolved oxygen levels as well.

3. Cleveland, April J. “Science Junction - Water What Ifs Nitrate & Phosphate Lessons.” North Carolina State University: Welcome to North Carolina State University.

Web. 12 Apr. 2011. <http://www.ncsu.edu/sciencejunction/depot/experiments/water/lessons/np/>.

This educational article contained useful information on the sources of waterborne nitrates and phosphates and their effects on aquatic plants. It greatly aided the formation of our hypothesis regarding nitrate and phosphate levels in the St. Croix River and its backwaters.

4. Domogalla, B. P., C. Juday, and W. H. Peterson. “The Forms of Nitrogen Found in Certain Lake Waters.” Journal of Biological Chemistry 63 (1925): 269-85. Print.

This article describes observations made about nitrogen and a mention of phosphorous cycles involving plankton. It states that not only do organic, living things need nitrogen and phosphorous, but they also produce nitrogen and phosphorus.

This source was used to formulate a hypothesis on how water speed affects the presence of these two elements.

5. Kelly, Jerry. E-mail interview. 25 Jan. 2011.

Jerry Kelly contributed information about locations to take samples and possible studies such as nutrient analysis. He also gave information about water hardness that was very useful but was excluded from our project.

6. Madsen, J. D., P. A. Chambers, W. F. James, E. W. Koch, and D. F. Westlake. “The Interaction between Water Movement, Sediment Dynamics and Submersed Macrophytes.” Hydrobiologia, 444 (2001): 71-84. Print.

This article was helpful in understanding the relationship between plants and water speed. We understood that it is extremely difficult to explain.

7. Richardson, William, Lynn Bartsch, Michelle Bartsch, Richard Kiesling, Brenda M. Lafrancois, and Kathy Lee. “Patterns of Nutrient Distributions in the St. Croix and Upper Mississippi Rivers; Preliminary Evaluation of Variation among Channels, Flowing Backwaters and Isolated Backwaters.” Speech. 2008 St. Croix River Research Rendezvous. Minnesota, St. Croix. 21 Oct. 2008. Science Museum of Minnesota. 2008. Web. 17 Apr. 2011. <www.smm.org>.

This presentation helped us to understand a project similar to our own, and their conclusions helped to form our ideas and hypotheses.

21

Forest Types of St. Croix State Park and Their Respective Dominant Tree Species

by Claire Petchler and Manya Hose Claire Petchler Forests are important to our ecosystem because they provide habitat for flora and fauna. It is expected to find thirteen different forest types within the St. Croix State Park. The forests of St. Croix were assessed using a wandering survey, taking note of defining characteristics in the surrounding location. Only seven of the thirteen were identified which may be due to lack of time, however it may also be an indicator that the forests are receding. In addition to the research conducted, a collection of pressed tree leaves was also compiled, to be used by the National Park Service and the St. Croix Field Education Program.

Introduction the Head of the Rapids boat launch trail, the oak he forests of Minnesota provide a rich savannah, the fire tower, the outlook, the two rivers trail, ecosystem for flora and fauna. They are the Head of the Rapids campground, Sand Creek, the Pine habitats that huge numbers of other life forms Barrens, the Pine Chapel, Big Eddy Trail, Little Yellow hinge and depend upon. Often forests are Banks, St. Johns, and Trail 14. grouped together into general categories, such Only seven of the 13 different forest types of the St. as coniferous versus deciduous forests. Upon further Croix State Park were identified within the limited time examination, forests hold subtle differences that make period. The forest types identified include the Central them unique biomes capable of supporting different Dry Oak-Aspen (Pine) Woodland, the Northern Wetanimals and vegetation. Studying the different forest Mesic Boreal Hardwood-Conifer Forest, the Northern types in the St. Croix State Park helps researchers better Wet-Mesic Hardwood Forest, the Central Dry-Mesic understand the diversity of animals and vegetation found Oak-Aspen Forest, the Central Mesic Hardwood Forest within the park limits. According to The Field Guide to (Eastern), and the Northern Wet Ash Swamp.

Native Plant Communities of Minnesota: The Laurentian The only Fire-Dependent forest found was the Mixed Forest Province, St. Croix State Park is expected to Central Dry Oak-Aspen (Pine) Woodlands (Chart 1). host 13 different forest types. These forests can be These types of forest need occasional burning to allow determined by the variety of trees found within a local trees to disperse their seed. Typically the Central Dry area. Over a two-week period different forest types in the Oak-Aspen (Pine) Woodlands have a patchy ground St. Croix State Park were searched for and identified. layer, with a sparse sub-canopy layer with dominant tree A topographical map of St. Croix State park was used species of quaking aspen and northern pin oak. The oak to determine where specific forest types were most likely savannah and the pine barren sites were an example of to be found based upon elevation, proximity to water, this forest. The oak savannah contained northern red and the general forest type (coniferous, deciduous, and oak, bur oak, and jack pine. The Pine Barrens included wetland). Once sites were selected, the area was visited. quaking aspen, northern red oak, bur oak, jack pine, and To determine forest type, a wandering survey was red maple. conducted, noting the different species of trees found in Of the Mesic Hardwood forest system, the Central an area both in the forest system and along the roadside. Dry Mesic Oak-Aspen forest, the Central Mesic Trees were defined as “a woody plant with an erect Hardwood forest (Eastern), Northern Wet-Mesic Boreal perennial trunk…a definitely formed crown of foliage, Hardwood-Conifer Forest, and the Northern Wet Mesic and a height of at least thirteen feet” [Little, 10].

Chart 1. Fire Dependent Forests Particularly abundant tree species in an area were Central Dry Oak-Aspen (Pine) Woodlands noted. A general Expected Species Found in Species Found in description of the area was Dominant Species Oak Savannah Pine Barren also recorded, including the Quaking Aspen None *Quaking Aspen area’s proximity to water, Northern Pin Oak None None how hilly or flat the area was, whether the soil was Expected Species Found in Species Found in moist or dry, sandy or Subdominant Species Oak Savannah Pine Barren loamy, an estimate of the Northern Red Oak *Northern Red Oak *Northern Red Oak understory and canopy Bur Oak *Bur Oak *Bur Oak percent coverage. A Jack Pine Jack Pine Jack Pine number of sites were Red Maple None *Red Maple visited, including the Red Pine None None campground boat launch,

T

Manya Hose Claire Petchler graduated from Edgewood High School in May 2010, and is studying English and science at Muhlenberg College. She has greatly enjoyed participation in the St. Croix environmental field education course for two years.

Manya Hose graduated from Edgewood High School in May 2010 and is studying biology and psychology in college.

Manya enjoyed taking part in the St. Croix field education program for two years.

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Chart 2: Mesic Hardwood Forests

Central Dry Mesic Oak-Aspen Forest Expected Species Found in Species Found in Dominant Species Sand Creek Big Eddy Northern Red Oak None Northern Red Oak Expected Species Found in Species Found in Subdominant Species Sand Creek Big Eddy Paper Birch None Paper Birch Red Maple *Red Maple Red maple Quaking Aspen Quaking Aspen Quaking Aspen American Basswood American Basswood American Basswood Sugar Maple Sugar Maple None Big Toothed Aspen Black Ash Black Ash Bur Oak Bur Oak Bur Oak Black Ash Black Ash White Swamp Oak White Swamp Oak Ironwood None Yellow Birch None Black Oak

Central Mesic Hardwood Forest (Eastern) Expected Species Found on Dominant Species Two Rivers Trail American Basswood American Basswood Northern Red Oak Northern Red Oak Sugar Maple Sugar Maple Expected Species Found on Subdominant Species Two Rivers Trail Green Ash None Paper Birch Paper Birch Red Maple Red Maple Bur Oak Bur Oak Quaking Aspen None Sugar Maple Black Ash Black Oak American Elm

Northern Wet Mesic Hardwood Forest Expected Species Found in Species Found in Dominant Species Big Eddy Trail Sand Creek Black Ash Black Ash Black Ash American Basswood American Basswood American Basswood Quaking Aspen Quaking Aspen Quaking Aspen Expected Species Found in Species Found in Subdominant Species Big Eddy Trail Sand Creek Red Maple Red Maple Red Maple Bur Oak None Bur Oak Paper Birch Paper Birch None Sugar Maple None Sugar Maple Green Ash None None Northern Red Oak Northern Red Oak None White Cedar None None Balsam Poplar None None

Northern Wet-Mesic Boreal Hardwood-Conifer Forest Expected Species Found in Dominant Species Big Eddy Trail Quaking Aspen Quaking Aspen Paper Birch Paper Birch Balsam Fir None Expected Species Found in Subdominant Species Big Eddy Trail Red Maple Red Maple White Spruce None Black Ash Black Ash Black Oak Bur Oak Altermante Leaf Dogwood American Elm American Basswood White Swamp Oak Northern Red Oak

Hardwood Forest were found. Central Dry Mesic OakAspen forests were found in Sand Creek and the Big Eddy trail. These forests are typically hardwood-conifer forests with loamy soil and northern red oak found as a dominant species in the canopy. The Central Mesic Hardwood forest (Eastern) is usually mesic hardwood forests with a loamy or sandy soil on rolling hills. The canopy is usually dominated by basswood, northern red oak, and sugar maple. This type of forest was found on the Two Rivers Trail. The Northern Wet-Mesic Boreal Hardwood-Conifer Forests are hardwood-conifer forests, most often found on level sites with clayey soil and high water tables. The dominant tree species are quaking aspen, paper birch, and balsam fir. This forest was also found within the Big Eddy Trail. The final Mesic Hardwood forest system found was the Northern Wet Mesic Hardwood forest. This type of forest is typically on well drained soil with a loamy soil composition, the canopy being dominated by sugar maple. The canopy is typically continuous for all of these forests (see Chart 2).

A third category of forest is the Floodplain Forests.

Floodplain forests lay on lower ground, close to bodies of water, typically rivers, which flood seasonally. The one floodplain forest found in the St. Croix State Park was the Northern Terrace forest. This type of forest has a typically continuous canopy cover, lying along river banks with a dominant tree species of black ash and silver maple. Northern Terrace forests were found along the St. Croix River, as well as at the Campground boat launch (See Chart 3).

The final type of forest found in the St. Croix State Park was a member of the Wet Forest System. These forests consist of hardwood forests in mucky soil, with poor drainage or proximity to water. The subcanopy is patchy, while the canopyâ&#x20AC;&#x2122;s dominant species is black ash.

This type of forest was also found at Sand Creek (See Chart 4).

The types of forest that were not found include the northern Wet Cedar Forest, the Northern Very Wet Ash Swamp, the Northern Rich Tamarack Swamp (Eastern

PURIFICATION OF THERMOSENSITIVE OLIGO(LYSINE)-B-ELASTIN-LIKE POLYPEPTIDES

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Chart 3: Floodplain Forests

Northern Terrace Forest

REFERENCES

Expected Dominant Species Black Ash Silver Maple

Species Found on St. Croix River Black Ash Silver Maple

Species Found at Campground Launch Black Ash Silver Maple

1. Forest Trees of Wisconsin, How to Know Them.

Madison: Department of Natural Resources, 1990.

Expected Subdominant Species Green Ash American Basswoood American Elm

Species Found on St. Croix River Green Ash American Basswood American Elm

Species Found at Campground Launch Green Ash American Basswood American Elm Yellow Birch

2. Little, Elbert L, comp.

National Audubon Society: Field Guide to North American Trees, Western Region.

Chanticleer Press, Inc., 1994.

Balsam Fir Swamp White Oak Quaking Aspen White Spruce Northern Red Oak Northern Wet Ash Swamp Expected Dominant Species Black Ash Expected Subdominant Species Yellow Birch Red Maple Quaking Aspen Balsam Poplar White Cedar

Chart 4: Wet Forest System

Species Found in Sand Creek Black Ash Species Found in Sand Creek Yellow Birch Red Maple Quaking Aspen None None Sugar Maple Bur Oak American Basswood Swamp White Oak Ironwood

Basin), the Northern Alder Swamp, the Northern Spruce Bog, the Northern Open Bog, and the Northern Wet Meadow/Carr.

The Minnesota Department of Natural Resources proved that all 13 forest types exist within the St. Croix State Park. However, the test conducted was unable to identify all 13 types. There are many possible explanations as to why only seven forests were found.

To begin with, forest types often have similar tree species and tend to blend gradually rather than in a sudden change. Thus, differentiating between forests is often difficult. Also, only general descriptors were used to identify the forests. Specific trees were identified, but the forest descriptions were not as accurate. Precise soil composition was not taken and ground vegetation was not identified, which is another important constraint in identifying forests. Eighteen sites ranging across the St. Croix State Park were visited, but a forest type could have been easily missed within the 34,000 acres of the park limits.

3. Norman, Aaseng, John Almendinger, Kurt Rusterholz, Daniel Wovcha, and Thomas R. Klein, comps. The Field Guide to the Native Plant Communities of Minnesota: The Laurentian Mixed Forest Province. New Brighton: Printing Enterprises Inc., 2003.

4. Petrides, George A. A Field Guide to Trees and Shrubs. Boston: Houghton Mifflin Company, 1958.

The goal of the research conducted was to identify different tree species in a site to determine forest types, to survey the diversity of the forest types in the St. Croix State Park in a two week time period. It was hypothesized that all 13 different forest types would be found in the St. Croix State Park because of the evidence given concerning their presence in The Field Guide to the Native Plant Communities of Minnesota: The Laurentian Mixed Forest Province compiled by the Minnesota Department of National Resources. The hypothesis was not supported by the data as only seven of the 13 forest types were found, which may be due to the difficulty in discerning forest types, the huge expanse of land the St. Croix State park covers and the limited time period.

24

Correlation of Terrestrial Arthropod Diversity and Plant Communities of St. Croix State Park

by Julia Pinckney and Andrew Gisi Julia Pinkney This experiment compared diversity of terrestrial arthropods in eight different sites within the St. Croix State Park and the vegetation in those spaces to conclude the relationship between terrestrial arthropod diversity and the plant communities in which terrestrial arthropods live. Less stable and more recently disturbed sites containing different micro-habitats generally had a greater diversity of terrestrial arthropods. More stable areas, with more uniformity, had decreased terrestrial arthropod diversity. The experiment concluded that plant communities and terrestrial arthropod diversity are correlated because terrestrial arthropods depend on the many factors of a plant community to survive in an area.

Andrew Gisi Julia Pinckney has grown up in Madison and has attended Edgewood since fourth grade. She thanks all of the St. Croix staff for all their work, and especially thanks Jerry, Mekel, Jess, and the second years for their help with this project.

Andrew Gisi would like to thank all the St Croix staff and students for a great time, their support, and laughs, especially Mekel, Jerry, and Jess for their help with any problems encountered, and Julia for being a partner in this project.

Introduction his experiment examined diversity of terrestrial arthropods in eight different sites in St. Croix State Park and the vegetation in those spaces to conclude the relationship between terrestrial arthropod diversity and the plant community in which they live. The experiment’s objective was to classify at the family level the terrestrial arthropods found in different plant communities within St. Croix State Park, and to identify the plant communities themselves. Arthropods are “invertebrate animals of the phylum Arthopoda, characterized by an exoskeleton made of chitin and a segmented body with pairs of jointed appendages… Arthropods include the insects, crustaceans, arachnids, myriapods, and extinct trilobites, and are the largest phylum in the animal kingdom” [Arthropod]. A terrestrial arthropod is simply an arthropod that lives on the ground.

The experiment was based on research done previously at St. Croix, including two smaller projects from the summer of 2009. One group tested the diversity of terrestrial arthropods in several areas around the Head of the Rapids Group Camp at St. Croix Park, while the other group tested for differences of diversity and number of terrestrial arthropods in two different areas by the backwaters of the St. Croix River during the day and the night.

The second experiment gave most of the history of the current experiment. Members of that team (Julia Pinckney, Clare Everts, and Audrey Netzel) concluded that the deciduous forest had a greater diversity of terrestrial arthropods than the area directly next to the backwaters. However, the experiment had many variables and did not focus enough on vegetation to be able to draw solid conclusions that relate to this experiment.

The current experiment focuses not on the general area, but the plants in each area that make one site different from the other.

It was believed that there would be a correlation between terrestrial arthropod diversity and the plant communities in which they live. The interpretation of this hypothesis was that an area with more diversity of vegetation would also have more diversity of terrestrial arthropods.

T

To conduct the experiment, eight sites were chosen and assigned to two groups, with one group tested in the first two days and the other group tested second. Pitfall traps were set up in the six sites from the first group.

Sites were by the workshop in Head of the Rapids Group Camp (labeled “cabin” on data), by the road near the Head of the Rapids Group Camp, in the Chapel Pine grove, at a site where a severe storm caused a blowdown in 2004 and was cleared of trees by park staff in 2010 (labeled “tornado” on data), at a site burned in the spring of 2010, and at a site burned in 2009 (labeled “two-year-old burn site” on data). The second group of sites was the deciduous forest by the Head of the Rapids Group Camp and a deciduous forest near the backwaters of the St. Croix River (labeled “trail” on data). To test at each site, three pairs of holes were dug on a transect line.

Each of the holes in a pair was 40 cm apart, and there was a distance of six meters between each pair of holes.

A sample of topsoil from digging at each site was saved for later use.

Two plastic cups, one nesting inside the other, were placed in each hole, and 40 mL of antifreeze and two to three drops of detergent (used to break the surface tension and facilitate drowning of the terrestrial arthropods) were put into the cups. Guide vanes were set up between the two cups in each pair: one wooden stake was attached to each end of a 4-cm by 40-cm piece of plastic, and each stake was sunk into the ground as close to the side of the cup as possible. A cover was placed over each trap, allowing terrestrial arthropods in and protecting the trap from rain.

Diagram 1. Pitfall Traps

CORRELATION OF TERRESTRIAL ARTHROPOD DIVERSITY AND PLANT COMMUNITIES OF ST. CROIX STATE PARK

Canopy Subcanopy

Deciduous Forest

Trail

Northern Pin Oak

Black Oak

White Oak Bur Oak

Bur Oak

Hazelnut

Ironwood

25

Pine Chapel

Tornado

2-Year-Old Burn

Red Pine

—

Northern Pin Oak

Northern Pin Oak

—

—

Burn

Cabin and Road

Northern Pin Oak Jack Pine

—

Cherry

—

Kentucky Bluegrass

Bracken Fern

Groundcover

Quaking Aspen

Meadow Rue

Bracken Fern

Bracken Fern

Large Leaf Aster

Large Leaf Aster

Woodland Sedge

Wild Geranium

Fescue

Woodland Sesge

Bracken Fern Blackberry Large Leaf Aster Woodland Sedge

Woodland Sedge Wild Rose

American Vetch

Bracken Fern

Aspen Shoots

Aspen Seedlings

Bracken Fern

Kentucky Bluegrass

Kentucky Bluegrass

Plantain Weed Clover Dandelion

Yarrow Bed Straw

looser, sandy ground is better for drainage and the more compacted soil would not be good for draining, the compacted soil by the cabin and road would have more standing water after it rains. This could cause terrestrial arthropods living on the ground to drown. All sites had over 50 percent of sand in the soil based on the soil composition tests. Although sandier soil would be better for water drainage and burrowing, its effects could be canceled in the cabin and road sites because the soil was extremely compacted.

The tornado site had a low amount of diversity, and this could be explained because it did not have much ground cover and had been quite recently disturbed (both by the initial blow down and the more recent clearing of the site). However, the site’s ground was sandy, leading to good drainage and a good place to live for burrowing arthropods. After the area gains more plant life, it may become more like the two-year-old burn site and then the deciduous forest, trail, and pine chapel sites.

The pine chapel, deciduous forest, and trail sites had about the same kinds of soil as the road and the trail

Number of Families and Orders

On the first day (when the traps were set up), data was recorded about the site, including: the main plants in the canopy, subcanopy, and groundcover (see Table 1); approximate percentage of sun that reached the ground on a clear day; soil composition in percentages of sand, silt, and clay from the soil collected earlier; and the pH of the soil. pH was determined by using three color pH test strips for each site that were averaged to find the approximate pH for each site.

After one day, terrestrial arthropod samples were collected and labeled from each site in the group, and cups were replaced and refilled by following the original procedure for setting them up. Daily information (date, time, weather, humidity, and temperature) was collected as well. After two days of testing, all traps were removed.

They were replaced and the procedure repeated for two more days at the second group of sites. Each day after samples were collected, specimens were put in isopropyl alcohol and classified down to family.

Data shows that the burn site and the two-year-old burn site had more terrestrial arthropod orders than the all the other sites, and therefore were more diverse. Most other sites (with the exception of the cabin) had around 8 orders. The cabin had slightly more diversity, with 9 orders.

The diversity at the burn site could be explained because the whole area was re-starting in plant life, which affected terrestrial arthropods. Different species of plants had probably come in, and the site still had to stabilize. Some of the arthropods probably would die out once the area became more stable—it is possible to see this change after one year at the two-year-old burn site. It contained less orders and families, and was becoming more stable. Once the sites became more stable, they would most likely start to look like the deciduous forest, the trail, or the pine chapel in terms of arthropod diversity: they would have fewer families and orders.

The road and cabin sites did not have as much diversity because they seemed to be more disturbed by human activity, including having more compacted soil.

This would make it more difficult for burrowing arthropods to make their homes there. Also, because

Table 1.

Main vegetation at the three levels (canopy, subcanopy, and groundcover) at each site that was tested

Graph 1

30

Number of Terrestrial Arthropod Families and Orders Found at Sites

25

Orders Families

20 15 10 5 0

Cabin

Burn

Road

Pine 2-Yr-Old Tornado Deciduous Trail Chapel Burn Forest

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REFERENCES

Burn

1. “Arthropod.” The Free Dictionary. Farlex, Inc. Web. 31 Aug. 2010. <http://www.thefreedictionary.com/arthropod>.

2. “Indicator Species.”

Department of Natural Resources and Environment.

Michigan.gov. Web. 14 Mar. 2010. <http://www.michigan. gov/dnr/0,1607,7-15310370_22664-60298-,00.html>.

3. “Insects of the Great Lakes Region.” 11 June, 2010.

4. “Insects: Their Natural History and Diversity.”

Stephen A. Marshall. 11 June, 2010.

5. Kelly, Jerry. Personal interview. 2 June – 11 June 2010.

6. “Park Info: St. Croix State Park: Minnesota DNR.” Minnesota Department of Natural Resources. Minnesota DNR, 2010. Web. 11 Apr. 2010. <http://www. dnr.state.mn.us/state_ parks/st_croix/narrative. html>.

7. “Pitfall Traps.”

Mississippi Entomological Museum.

Mississippi State University - Department of Entomology and Plant Pathology, 6 Aug. 2009. Web. 28 Apr. 2010. <http://mississippientomologicalmuseum.org. msstate.edu//collecting. preparation.methods/ Pitfalls.htm>.

8. “Spiders of North America” 11 June, 2010.

9. “Woodlands and Biodiversity - Structural Diversity.” Offwell Woodland & Wildlife Trust. Web. 11 Apr. 2010. <http://www. countrysideinfo.co.uk/ woodland_manage/ woodbio3.htm>.

Significant Groundcover

2-year-old Burn

Cabin

Road

X

Significant Subcanopy and Canopy High Light (over 50%)

X

X

X

X

X

X

X

X

X

X

9

8

Deciduous Forest

Trail

Pine Chapel

X

X

X

X

X

X

Tornado

X

Variable Compacted Soil Very Recently Disturbed/Unstable

X

X

Higher pH (above 6)

# of Families Found

12

12

X

8

8

7

7

Table 2. Families of terrestrial arthropods found under variable conditions of vegetation, soil and light conditions (compacted and less sandy), but they also had more plants that non-burrowing terrestrial arthropods could use for shelter. Altogether, these three sites were more stable, but it is possible that they simply could not sustain as many types of terrestrial arthropods. Perhaps the overall uniformity in groundcover, light, soil, and so on in each individual site and lack of different minihabitats within the area was only favorable to a smaller set of terrestrial arthropods.

Table 2 shows factors that were found at each site.

Using this, it was concluded that areas that are recovering from impact (especially the burn site and the two-year-old burn site) have the most diversity of terrestrial arthropods, probably because they have many areas for different terrestrial arthropods to live in.

Sunlight seemed similarly important to the diversity of terrestrial arthropods found in a site. As ground cover and subcanopy and canopy increased and light decreased (as well as having more types of plants overall), diversity of terrestrial arthropods decreased. The tornado site seems to not fit in with the general track of the other areas because while it was topographically similar to the sites that had greater diversity of terrestrial arthropods, it had low diversity.

Chances of error in the experiment included weather because it rained for about half of the sampling time; the terrestrial arthropods would most likely not have been as active if it were raining. There were also chances that some arthropods were misidentified, and if the cups were placed unevenly into the ground, terrestrial arthropods would have had trouble entering the trap. Some pitfall traps may have been set closer to a certain colony of terrestrial arthropods. For example, at the two-year-old burn site, the trap was near an anthill. Lastly, the sampling time was only for two days at each site, which may not have been enough time to get thorough samples in order to get a firm conclusion. Also, since there were two different times to sample sites, the variation in which day a site was sampled could have affected results.

This project shows that plant communities and terrestrial arthropods are related, which is important because the results can be used to find which terrestrial arthropods will be found depending on the area, and vice versa. Additionally, all terrestrial arthropods are indicator species, meaning that “their decline may indicate a disturbance that alters the ecosystem.

Disturbances may result from natural events…or manmade events” [Indicator Species]. Terrestrial arthropods, therefore, show the health of an area. They also decompose material, pollinate flowers, provide food for other animals, and, as an indicator species, are used to categorize communities that are alike. By using the information presented in this experiment, one can better understand terrestrial arthropod importance and relationship to their natural surroundings.

The original interpretation of the hypothesis was incorrect—plant life alone does not correlate to terrestrial arthropod diversity. However, the hypothesis itself was correct because “plant communities” does not simply mean “plants.” The soil type, sunlight percentage, and many other factors, as well as the plants themselves, create a plant community and this as a whole influences and correlates to the diversity of terrestrial arthropods.

Conclusion The objective of this experiment was to classify terrestrial arthropods to family that were found in plant communities within St. Croix State Park, and to identify the plant communities. Generally, more disturbed sites had a greater diversity of terrestrial arthropods, probably because each had different micro-habitats within them.

As sites became more stable, with greater diversity of plant life and shade, terrestrial arthropod diversity decreased. The hypothesis was supported by the data, because plant communities and terrestrial arthropod diversity are correlated. Terrestrial arthropods depend on the many factors of a plant community to survive in the area.

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Mussel Species in the St. Croix and Kettle Rivers and Their Tributaries

by Kelsey Ford and Lindsay Fulton A survey of the mussel middens was taken on the St. Croix River, the Kettle River, as well as Sand Creek, Bear Creek, and Kennedy Brook. Shell quantities, species diversity and waterway size were compared for correlation. The most mussel middens were found on the banks of the St. Croix where 3200 shells were found. The St. Croix also had the most diverse population of mussels with 14 different species found. The Kettle River had the second most numerous mussel shells. 226 shells were found on the Kettle River. The Kettle River also had the second most diverse mussel population with 9 different species found. The small tributaries had the least numerous mussel shells and shell diversity. No middens were found on Sand Creek or Kennedy Brook. Two different species and six shells total were found on Bear Creek. The most common species found were the Wabash Pigtoe (Fusconaia flava), the Mucket (Actinonaias ligamentina), and the Spike (Elliptio dilatata). It was found that the larger the size of the waterway, the more numerous and diverse mussels were found.

Introduction survey of the mussel middens were taken on the banks of the St. Croix River, the Kettle River, and the Sand Creek, Bear Creek, and Kennedy Brook. Shell quantities, species diversity and waterway size were compared for correlation. Mussels are an important part of the river way ecosystem. They filter the water, are an important source of food for many predators, and are indicators of the health of the waterway [USFWS: Americaâ&#x20AC;&#x2122;s Mussels]. However, 213 out of 297 mussel species are endangered, threatened or of special concern.

Several mussel species have also gone extinct [Mussels: Minnesota DNR]. For these reasons it is important to study mussel populations and make sure the populations do not decline. It is also important to assess any threats to the mussel populations such as water pollution, damming of waterways, and invasive species such as Zebra Mussels. The St. Croix waterway has one of the most diverse mussel populations in the United States. It is home to over 40 different mussel species including two federally endangered species: the Higginâ&#x20AC;&#x2122;s Eye and the Winged Mapleleaf [Watch This Wild River]. No species in the St. Croix have yet gone extinct, but it is important to keep track of the mussel populations to make sure that no species disappear from the river.

Studying middens is a good way to monitor the populations without disturbing the live mussels in their natural habitat. By surveying the middens, the number and distribution of the different mussel species can be gathered.

A

Results The data from this experiment indicates that more mussel middens were found on the St. Croix River than the Kettle River and the tributaries. Both the St. Croix and the Kettle River had fairly diverse mussel middens.

The tributaries produced very few mussel middens during this experiment. Several factors could be accountable for these results. The variety in substrates, the fish population, the accessibility of the banks, and the current of the waterway are possible variations that would affect these results.

Kelsey Ford

Lindsay Fulton

Total numbers of mussels of all species found at the different sites Species Number Found Wabash Pigtoe (Fusconaia flava) 992 782 Mucket (Actinonaias ligamentina) Spike (Elliptio dilatata) 740 Threeridge (Amblema plicata) 245 223 Fat Mucket (Lampsilis siliquoidea) Pimpleback (Quadrula pustulosa) 173 Black Sandshell (Ligumia recta) 170 36 Purple Wartyback (Cyclonaias tuberculata) Hickorynut (Obovaria olivaria) 27 Round Pigtoe (Pleurobema coccineum) 13 Plain Pocketbook (Lampsilis cardium) 9 Unidentifiable 8 5 Fluted Shell (Lasmigona costata) 4 Fragile Papershell (Leptodea fragilis) Creeper (Strophitus undulatus) 3 Wartyback (Quadrula nodulata) 2 TOTAL 3432

Factors that affected the number of shells found and species diversity were the substrate, the current, the fish population and accessibility to the banks. Softer substrates make better habitats for mussels. The St. Croix has a soft substrate which resulted in a higher number of, as well as more diverse species. The Kettle has a rockier substrate with sandy patches which is not a good substrate for mussels and this resulted in fewer mussels and mussel species found. The tributaries had somewhat rocky bottoms. A slower current is also better for mussels because it makes it easier for the mussels to move around in the water and siphon the water. The St. Croix has a slow current which is why more mussels were found in the St. Croix versus the Kettle River and the tributaries which have fast currents. The fish population affects mussel population because the mussels need the fish to reproduce. The St. Croix has a lot of fish making it easy for the mussels to reproduce. The Kettle

Kelsey Ford is a recent graduate of Edgewood High School. Her mentor on this research project was Dr. Toben Lafrancois, Ph.D. Kelsey did this project as a project for her second year in the environmental field education course. Her favorite mussel was the spike mussel.

Lindsay Fulton graduated from Edgewood High School in 2010. Dr. Lafrancois was also her mentor. This survey was a project of her third year in the environmental field education course. Her favorite mussel was the threeridge.

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REFERENCES 1. Hamilton, Hannah.

"Mussel Facts." U.S. Geological Survey. Web. 2 Aug. 2009. <http://fl. biology.usgs.gov/Center_ Publications/Fact_Sheets /mussel_factsheetlm. pdf>.

2. “Mussels: Minnesota DNR.” Minnesota Department of Natural Resources: Minnesota DNR. Web. 03 Aug. 2009. <http://www.dnr. state.mn.us/mussels/ index.html>.

3. “USFWS: America's Mussels.” U.S. Fish and Wildlife Service Home.

Web. 03 Aug. 2009. <http://www.fws.gov/ midwest/Endangered/ clams/mussels.html>.

4. “Watch This Wild River - Minnesota Conservation Volunteer: Minnesota DNR." Minnesota Department of Natural Resources: Minnesota DNR. Web. 03 Aug. 2009. <http://www.dnr.state. mn.us/volunteer/ julaug06/wildriver.html>.

River and tributaries have very low fish populations making it difficult for mussels to reproduce.

Accessibility to the banks affects how easily the predators can get to the water to prey on the mussels. If the banks are steep or full of brush, such as at the Kettle River and the small tributaries, it makes it hard for the predators to hunt and therefore fewer middens will be found. The St. Croix has very accessible banks, making it easier for the predators to hunt and more mussel middens are found. All of these factors affected the number of mussels living in the river and the number of middens found on the banks.

This survey was important because mussels are bio indicators of fresh water systems. They are filter feeders and they play a big role in making water healthy for other organisms. “Mussels are natural indicators of water quality. If mussels cannot live in a waterway, it is probably unsafe for humans. They filter out the impurities from the water and are an important source of food for many fish, birds and mammals” (Hamilton).

There are 40 species of mussels in the St. Croix River and these have been the same 40 species since the start of the river’s history and many of them are endangered, threatened, or of special concern. It is important for the environment as well as St. Croix’s history to keep these mussels protected and to keep the rivers free from invasive species such as zebra mussels. Many middens were found with diverse species and there were no zebra mussels which is very important information gained through this experiment.

Graph 1

Graph 2 Conclusion The St. Croix had the most numerous and diverse mussel middens, while the Kettle River and the smaller tributaries had the least numerous and diverse mussel middens. The larger the waterway size, the more numerous and diverse mussels were present. The factors which affected the results consisted of the substrates, the current speed, the fish population and the accessibility to the banks. The two most common mussel species found were the Wabash Pigtoe (Fusconaia flava) and the Mucket (Actinonaias ligamentina). It is important to monitor mussel populations because they are bio indicators of waterways, they filter the water and they provide food for several other organisms. It is especially important, for previously stated reasons, to ensure that no mussel species go extinct.

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Identifying Correlation between Types of Peat and Plant Family in a Wetland

by Niall Martin and Connor Curliss

Niall Martin

Peat is formed when dead plants are broken down to nearly nothing. The leftover result is a spongy, fibrous material that acts as a habitat for many plants and animals. The purpose of the experiment preformed was to determine if there was a correlation between the amount of peat (as well as the type of peat), and the family of plants that grow in the St. Croix Wetland. It was hypothesized that there would be a distinct correlation of the type of peat, and what families of plants are able to grow in the given type and amount of peat.

The data that was found provided no solid, conclusive evidence of a correlation other than mucky peat being more habitable for grasses.

Upon more research it was found that the family of plants that grew in an area did not rely at all on the type of peat. Furthermore, the bacteria that broke down the dead plants affected the type of peat that was found in an area. When exposed to air, aerobic bacteria decomposes the dead plants at a very fast rate, and while submerged in water, as a large fraction of the wetland was, anaerobic bacteria very slowly decomposes the dead plants. As a result, more peat was found in areas of the wetland that were exposed to the air due to the constant mixing of peat and inorganic materials, whereas in the submerged area, the peat would not mix with the clay that had gathered at the bottom of the bed. In conclusion, the experiment helped determine how the flooding of the wetland affected, or in this case did not truly affect, the growth of plants and deposition of peat.

T

he experiment that we undertook at the St. Croix State Park, in St. Croix, Minnesota, focused on the wetland area of the park. We hypothesized that a correlation between the types of peat and the families of certain plants in the St. Croix State Park wetland should exist. Previous research showed that peat acts as a preservant in a wetland, by virtue of the fairly unconcentrated acid released by the reeds that make up the peat. This finding led us to suppose that all plants growing in a wetland with peat must find a different source of nutrition other than dead organisms that decompose in the ground.

Many plants have adapted to this change in their habitat through their evolution into carnivorous plants that either feed on microorganisms, or very small macro invertebrates. However, families of plants as broad as grasses, sedges, and rushes, have not adapted so as to be mostly carnivorous. Along with this finding, we found that as recently as 1993 another experiment was done testing the nutrients in the St. Croix River. It was found that the river had been slowly, but consistently, losing nutrients. Along with these results, the St. Croix Watershed Research Station also found an excess of phosphorus in the river. Now, since the wetland gets its water from the St. Croix River, we assumed that there was an excess of phosphorus in the wetland as well. The amount of phosphorus in an area can affect how plants grow. Some plants thrive in an excess of phosphorus, while others cannot grow at all.

To gather the data that would help us accomplish the task of finding a correlation, we took a soil corer, plunged it through to the floor of the wetland, and measured the different layers of organic material (consisting of peat, mucky peat and muck). Along with this measurement we also took an estimate of the percentage of grasses, sedges, rushes, and open water in a

1-meter radius of the point that was cored. This process was carried out on 8 different transects. With the data so collected, many different deposition and concentration maps were made.

The different types of peat, as mentioned earlier, are muck, mucky peat, and peat. Muck is a very grimy, oily form of peat. Muck has been broken down by bacteria for so long that it has lost all sign of fiber, and is nearly liquid. Mucky peat, is less fibrous than peat, but still clearly solid. Peat is a very spongy, airy solid consisting solely of fibrous material. On the first three or four transects that were measured there was a notable correlation between the amount of mucky peat in the ground and the high number of sedges growing in it.

However, it has since been determined that this is less likely to be for the suspected reason (the flooding of the wetland resulting in muck) than for a different reason entirely. Instead, it is more likely that it is simply a combination of the pre-existing abundance of lake sedges (Carex lacustris) and the coincidental presence of mucky peat in the ground the lake sedge is growing in. Also, as we moved closer to the brush layer opposite the open water in the wetland, we began to see a more diverse array of plant life, including a higher number of grasses.

Some other plants that were found consisted of cinquefoil (Potentilla fruticosa), beaked willow (Salix bebbiana), and meadowsweet (Spiraea alba). However, they were usually either outside of our square meter testing area or resulted in a minimal percent coverage that was too small to be noted. The only other plant family besides sedges that was abundant enough to be noted was the Graminae, or grass family, but there was very little correlation between the presence of grass and the type of peat. Generally, grasses were found in either peat or mucky peat, although there is apparently no systematic relationship between the two factors, as those

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make up two-thirds of all the organic soil in the wetland.

It should be noted, however, that no grass was found in the heavily flooded area where all of the muck in the wetland was found.

Although no conclusive evidence was found proving that there was a correlation between the type of peat and the family of plants that grow in it, we did find through research that bacteria plays a major part in the type of peat growing in an area. And due to the flooding that left the wetland covered in standing water for the summer, it is possible that our experiment was preformed in the least ideal conditions. It was found that in wetlands there are two broad types of bacteria that eat away at dead plants and form peat in the process. These two types are aerobic and anaerobic bacteria. Aerobic bacteria can only function properly with oxygen present, which is not present in appropriate amounts when the peat is submerged. The area near the open water has long been submerged, which led to the creation of a bed of clay beneath all of the organic matter that does not mix with any of the peat layers, due to the work of anaerobic bacteria that work without the presence of air, or oxygen. Thus, there is a layer of long decomposed muck lying upon a solid (almost concrete-like) layer of clay well beneath the visible organic layer. When the corer was plunged into the ground, it stuck in the clay and was effectively plugged to stop any organic soil from falling out. The corer filled up with muck, and no other peat types stayed in the corer, which led to the conclusion that no peat was present.

In conclusion, it was found that the wetland contained three general variations of organic soil: muck, mucky peat, and peat. Also, the plant life in the wetland was largely dominated by plants from both the Cyperaceae and Graminae families; in common terms, sedges and grasses. There were no definite correlations between the presence of a certain type of organic soil and a certain family of plant, although no grasses were found in the area where the soil present was largely muck. Conversely, although grasses were found in only peat and mucky peat, there is no conclusive support of the hypothesis because these two types covered the vast majority of organic soil present in the wetland. Sedges, on the other hand, were found throughout the entire wetland in all three types of organic soil. All in all, the hypothesis was largely unsupported, but we both found how interesting and complicated plant life in a wetland can be. Plant growth and diversity are affected by a large number of factors, although it seems that soil type is not one of them, or, at least, it is not a primary factor. In further research, we discovered how aerobic and anaerobic bacteria affect what types of organic soil are present, as mentioned before. The wetland has an ecosystem that was affected greatly by the flooding that occurred just prior to the experimentation and is constantly changing. Future studies that could be done, with the information that we already have, would be to examine exactly how bacteria can affect the families of plants that grow in an area.

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Quantitative Study of Terrestrial Arthropods in Relation to Distance from the St. Croix River

by Clare Everts and Audrey Netzel Clare Everts Introduction he study of terrestrial arthropods is important because arthropods play a crucial role in the environment. Arthropods help the environment by recycling nutrients and clearing waste. The results of this study suggest that the area near the river provides a better food source, therefore, more arthropods are found there. This data can help make conclusions about the soil and general health of an area.

Terrestrial arthropods were collected using two different methods: pitfall traps and Berlese funnels.

Pitfall traps were set out for intervals of 24 hours and collected four times. Soil samples for the Berlese funnels were taken once, and sat in the Berlese funnels for 48 hours. Terrestrial arthropods were identified to family (if possible) using identification books and compound microscopes. Sites for collecting the terrestrial arthropods were set up on three transect lines, 50 meters apart, going perpendicular to the river near the Head of Rapids Boat Launch. The four sites ascending from the river on the same transect line were laid 10 meters apart. There were two pitfall traps at each site. Groups of trap sites, which were approximately the same distance from the river and yielded similar data were give a single letter designator and their data was combined for the analysis.

At each site, data about pH level, soil moisture, and soil composition was collected and averaged according to distance from the river.

T

Analysis The total quantity and diversity of terrestrial arthropods was greatest at Sites A, the sites closest to the river. Sites A yielded the most terrestrial arthropods

because of the moist soil near the river. Arthropods prefer moist soil because they can burrow into it.

Burrowing in soil helps arthropods retain water. The sandy soil that was found closer to the river also encourages burrowing by terrestrial arthropods, which is a reason why more arthropods were found there. Sandy soil is easier to move through and contains more oxygen, which arthropods prefer. The river can also be a food source to a great number of arthropod families. The data of an unpublished first year project shows that nitrogen levels are higher in soil near the St. Croix River. The project also found phosphorus near the St. Croix River.

Arthropods need nutrients to survive, so arthropods go to places with higher nutrient levels.

Sites C had the least quantity and variety of terrestrial arthropods. Soil moisture at Sites C was the second lowest, which is not preferable to arthropods. On a whole, Sites C had little undergrowth, probably because they were in a transition space between a floodplain and a deciduous forest. Sites C and D had the same diversity of arthropod families, but a many more arthropods in those families were collected at Sites D. This could be because many unique families, such as Scarabaeidae and Cerambycidae, were found at Sites D, so the diversity was large, but the bulk of arthropods found at Sites D were of a select few families, like Porcellionidae and Formicidae.

The supplementary data assisted in explaining the data collected in the pitfall traps and Berlese funnels. At all of the sites, pH was fairly consistent. Paper strips that tested pH all read either five or six. Because the margin between sites was so small, pH was not a factor in arthropod variety and abundance.

Moisture was not consistent at all of the sites. Near the river, at Sites A and B, moisture was very similar. The moisture at Sites C and D were significantly lower than the moisture at Sites A and B. This is probably because Sites C and D were on a hill, so water drained to the lower sites. Sites B had the highest moisture because they were lower than Sites A, so water drained to there. Sand content at Sites A was the highest. As the sites moved away from the river, the sand content decreased as the silt and clay contents increased.

The hypothesis was not supported by the data. The hypothesis stated that a greater variety and abundance of

Audrey Netzel

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REFERENCES 1. Dunn, Gary A. Insects of the Great Lakes Region.

Ann Arbor: University of Michigan, 1996.

Print.

2. Kelly, Jerome. Personal interview. 2 June – 11 June 2010.

3. “Pitfall Traps.”

Mississippi Entomological Museum.

Mississippi State University - Department of Entomology and Plant Pathology, 6 Aug. 2009. Web. 28 Apr. 2010. <http://mississippientomologicalmuseum.org.msstate.edu /collecting.preparation. methods/Pitfalls.htm>.

4. “Spiders of North America” 11June, 2010.

5. Zalom, Frank.

“Arthropod.” World Book Advanced. World Book, 2010. Web. 15 March 2010.

6. Netzel, Audrey N., Clare M. Everts, and Julia L. Pinckney. “Terrestrial Arthropod Diversity in Relation to Time of Day and Location.” Rep. Print.

7. Marshall, Stephen A. Insects: Their Natural History and Diversity.

Buffalo, NY: Firefly (U.S.), 2006. Print.

8. Richards, Sam and Tom. Unpublished first year project. June 2010.

terrestrial arthropods would be found as sites moved away from the river. The data completely contradicts the hypothesis. The hypothesis assumed that the food supply, soil organic content, and plant cover would be greater as sites became farther away from the St. Croix.

In reality, there was a lot of plant cover near the river, and sites farther back in the forest often had much less ground cover. One part of the hypothesis that was correct was the pH would not be a factor. The data concluded that pH is not a factor in terrestrial arthropod diversity and abundance.

The data found in this experiment conflicts with a previous project on terrestrial arthropods. The previous project compared terrestrial arthropods on a riverbank to terrestrial arthropods in a deciduous forest. The result of the project was that more terrestrial arthropods were

found in the forest because there was more plant cover there. The reason for the conflict between that data and the data from this project could be that the previous riverbank site could have been less sandy than Sites A in this project. The previous riverbank had less groundcover than Sites A in this project, which could have caused the difference.

Three types of possible errors are human error, animal interference, and weather variation. Human error could have occurred if the lip of the pit fall dish was not inserted below ground level. This would result in fewer arthropods being trapped in the dish. Another human error could have been that the plate covers were pushed too close to the ground, so larger arthropods could not reach the pit fall traps. Animal interference also caused possible errors. Animals dug up some dishes from the ground, ruining the sample. Finally, weather variation also could have caused errors. Rain was sometimes able to fill the dishes with water. Rain dilutes the anti-freeze and washes arthropods from the dish. The rain also affected the analysis of soil moisture in relationship to the arthropods found in the Berlese funnels. More rain caused the moisture to rise and change some data.

Further studies would confirm and add to the data found in this project. One possible study would be to conduct the same experiment on a different waterway, which would show if the data found in this experiment is true for rivers other than the St. Croix. A further study could also be more extensive, with more transect lines and a longer water gradient. The study could also extend further downstream or upstream.

Conclusion This experiment aimed to test which distance from the St. Croix River contained the greatest variety and quantity of terrestrial arthropods using pit fall traps and Berlese funnels. Then, data collected about soil composition, soil moisture, and pH level of the soil was used to support the arthropod data collected. The results showed that a greater quantity and diversity of terrestrial arthropods are found closer to the St. Croix River. The hypothesis was not supported by the data.

THE EFFECTS OF ELECTRON DONATING AND ACCEPTING RADICALS ON THE GEOMETRY OF TETRAPHENYLETHYLENE

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Succession of the Populations of Zooplankton in the Swimming Hole

by Maddie Kothe, Sara Murphy, and Mikki Heckman Background s the pond returns to the “standard state” from the “abnormal state,” the succession of the zooplankton population will be surveyed.

Last summer, we conducted a research project to discover where the zooplanktons were in the water. We discovered that because the secchi depth of the swimming hole went to the floor, the plankton consistently lived throughout the water.

Outside of the St. Croix River Basin, we found much research conducted on the Great Lakes and the Madison lakes. On Lake Mendota, a research project was done in 1969 to compare the effects of zooplankton and how the plankton are affected by the eutrophication of the lake and the high and low levels of nutrients during varying seasons and times. The study was enacted by a group of three from UW Madison: Arthur Davis Hasler, Mitsuo Terraguchi, and John P. Wall. The study concluded that the higher the nutrient number, the larger the populations of the plankton became. The sizes and shapes of the plankton also varied based on the time of year. The populations also grew during different parts of the year. The project also observed the effects of the natural nutrient effects and the human pollutants. It concluded that the natural substances caused the populations to flourish more than the non-natural substances. This experiment showed that that the zooplankton population vary depending on the environment’s condition.

Trends were found initially within the Copepoda population. Copepoda has three sub-orders: Calanoida, Cyclopoida, and Harpacticoida. If Cyclopoida were found, it was reasoned that the family was Copepoda Cyclopioda Cyclopidae because Cyclopidae is the only Cyclopoida family found natively. Resolution was not sufficient for classifying the Calanoida to family, so these samples were counted as a whole sub-order.

Harpacticoida were not found. Also, nauplii (immature zooplankton) were found and counted separately, noting probable sub-order. This method was used because the nauplii were not fully developed, so samples could not be classified further than order. Therefore, Copepoda were counted as Cyclopoida Cyclopidae, nauplii, or Calanoida.

The three different Copepoda groups showed patterns in population fluctuations as the pond progressed back to the standard state. A steady climb of the Cyclopoida Cyclopidae was observed in the first three samples, collected the first morning through the second. This growth could have resulted from the Cyclopoida Cyclopidae having more space to reproduce as water was

A

pumped into the pond.

A drop in the Cyclopoida Cyclopidae population occurred between the second night and third morning. This could have resulted because more predators were introduced into the pond as tadpoles and turtles were observed.

During the third night, there was a sudden increase in population. This could Figure 1. be due to the increases in Cladocera Bosminidae, light and temperature which is strictly characobserved that day, causing terized by the two tuska phytoplankton bloom, like antennae protruding resulting in more food for from the front of the the Cyclopoida Cyclopidae. zooplankton. The “Phytoplankton thrive Bosminidae sub-order with direct sunlight and was the most populous nutrients. The warmer the sub-order in the water, the more phytoCladocera order. The plankton,” says Susan Cladocera Bosminidae Sylvester of the Wisconsin showed that the trend of Department of Natural the Cladocera Resources. A steady population changes the increase for the rest of the most dramatically to days was found. This could really emphasize the be a result of more space succession of the for the Cyclopoida population of the Cyclopidae. Nauplii were zooplankton. observed in the first collection. The nauplii population steadily increased until the third night. This indicates that a new Copepoda generation was being introduced. Calanoida were not observed until the fourth day. This implies that the ecosystem was progressing towards the standard state because there was variety in the population.

The other main order found in the pond was Cladocera. The first Cladocera family found was Bosminidae; characterized by the two tusk-like firstantenna protruding from the head. Bosminidae were the most common Cladocera found throughout the four days. Daphniadae were also found; characterized by the two branched second antennae, short first antennae, and a small beak. In the Daphniadae family, two genus were found: Daphnia and Ceriodaphnia. Sididae were rarely observed; characterized by two second antennae branched to the side, and a large eye. Chydoridae were also present; characterized by a very round body

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Graph 1

Graph 2

Graph 3

(Pennak). Finally, Cladocera nauplii, of unknown families, were observed.

Trends were found over the sampling period. The first trend was found in the Cladocera populations.

On the first day, there were only Bosminidae and one Chydoridae found. The Bosminidae population decreased during the first night and reached a low the

second morning, but the change was not significant.

Chydoridae were not observed again. The second morning no Cladocera were found. Bosminidae populations increased in size the second night, and an exponential spike occurred the third morning. Nauplii were also observed. This spike could possibly be due to the fact that there is more water filling the pond, so there was more space to grow and reproduce. There was also lack of predators because the environment was not stable. The third night predators were observed, though, and there was a notable drop in the populationsâ&#x20AC;&#x2122; sizes.

Another spike was observed after the fourth morning.

The spike was greatest in nauplii, which implies a Cladocera generation was in the pond as the habitat returns to the standard state. Daphidae and Sididae were observed as well. This growth was probably because the third day was extremely hot and sunny, causing more phytoplankton to be produced, so the Cladocera showed growth a day later. More phytoplankton means more food for Cladocera, and more populations can expand.

Following the boom of Cladocera the fourth morning, there was a drop the fourth night, only Bosminidae were observed. This could possibly be a result of more and more predators entering the area. Predators entered the pond with plentiful zooplankton to eat, allowing the predators to grow, consuming more zooplankton, resulting in the population drop.

In addition to the two other orders, Copepoda and Cladocera, two other orders were found. In the Rotifera order, two families were detected. Branchionidae were most common. Branchionidae have an appearance like an oval with the top cut off jaggedly with short stem attached to the bottom. Rotifera Lyndidae were also found. Lyndidae are longer and thinner. Rotifera were difficult due to insufficient equipment and resolution.

Thus, Rotifera were not significant in the data, because they were difficult to find. Ostracoda were also found.

Ostracoda are small seed-like zooplankton. Ostracoda were disregarded in the data calculations because they were rare and difficult to count.

This study could lead to many future studies. A longer future study could be done using the same procedure to yield more accurate data. Another study may occur based on zooplankton as water quality indicators, in a different environment. Studies could also be done in water bodies with of different water quality to see the direct correlation between water chemistry and the zooplankton populations. Research shows that nitrates and phosphates are the major limiting nutrients for phytoplankton, zooplanktonâ&#x20AC;&#x2122;s food. Chemical analysis could be done to determine the correlation between nutrient levels and zooplankton populations.

Another possible study would look at observing zooplankton populations in different habitats with different biological communities. Zooplankton are good environmental indicators because zooplankton are early in the food chain. This means that the environmental changes are reflected early in the zooplankton populations.

SUCCESSION OF POPULATIONS OF ZOOPLANKTON IN THE SWIMMING HOLE

Possible errors included human, experimental, and procedural. Experimental errors were mainly due to broken and flawed equipment. On the second day, the Van Dorn bottle broke during the evening collection. Initial repairs worked, but the bottle had some leaking. This leaking could have lost some sample, causing skewed data and showing less zooplankton concentration per liter. Also, this leaking would cause the data to appear to have a lower number of zooplankton for samples collected after the first day, which would misrepresent the data.

Procedural errors could have occurred in the zooplankton transfer process. The first transfer is from Van Dorn bottle into plankton tow, followed into sample bottle. Next, is the transfer from bottle to Petri dish. Finally, to identify a sample down to family, or sub-class, another transfer from Petri dish into a well-tray, and finally onto a well-slide and viewed with a compound microscope. Zooplankton may have been lost during transfers. The same eyedroppers and forceps were used, so Zooplankton could have also been counted incorrectly, if specimens that remained inside the eyedropper fell into a different sample’s slide. These instances could cause data to be counted in the wrong samples, or lost entirely, misrepresenting the data. Human errors included spills, relying on guess estimates for overall weather and percent cloud coverage, and varying lengths in arms of the researchers, causing the water temperature collection to be at varying depths.

Zooplankton are first order consumers; therefore, they affect the rest of the food chain.

This occurrence causes the condition of zooplankton to be influential to the condition of their environment. However, this study determines how the zooplankton are affected by their environment rather than how they affect it. This effect resulted from the pond’s draining. As a result of the poor environmental condition, one Cladocera found had produced a nesting egg.

The nesting egg is only created as a “last resort” survival mechanism for a zooplankton’s offspring.

The nesting egg indicates that pond’s condition at the “abnormal” state resulted in the previous community’s destruction, and a new generation’s succession. This new generation’s development was observed as time progressed, and as the pond returned to the standard state. The samples collected generally contained few zooplankton, compared to the samples collected last year at the standard state that contained as many as 125 individuals of one order in a single collection. As conditions improved, the number of individuals increased overall; however, the numbers never reached the defined standard state. The samples collected also generally contained zooplankton significantly smaller in size, at least one-tenth in size, than those of the standard community. In the first samplings, mostly nauplii and small adults were collected. As the conditions improved, larger adults were collected along with more nauplii; however, the samples again never reached the standard levels. Finally, in the first samples, only Cladoceras and one Copepoda sub-order were present. As the conditions improved, a second Copepoda sub-order was found, though few in number, and variation was increased in the Cladocera population. Few Rotifers and no Ostracods were collected in the early samples, but as conditions improved, two Ostracods and an increased number of Rotifers were recorded. This rapid increase in size, number, and variation over four days of sampling after the environmental devastation occurred, demonstrates the importance of zooplankton as indicators of the environment. Moreover, zooplankton indicate their environment’s conditions quickly and dramatically. It is helpful in determining the future effect an event can have on all other inhabitants of an altered environment, and it is extremely important that the environment can return to stability.

The objective was to survey the zooplankton populations as the pond returned to a stable community. The experiment’s results partly supported the hypothesis, which was that the zooplankton population would start at a high density and would decrease due to the increased water volume. Next, it was thought that the population would increase once the pond was filled and became more stable. Therefore, the hypothesis states that the zooplankton population would change resembling a “U-shaped curve” as the pond stabilized. The experiment yielded results that did change, but not in the expected “U-shaped” curve. The zooplankton population started at a low concentration per liter of water probably due to the low water volume remaining in the pond and the poor environment. Low water levels provided minimal space thereby decreasing phytoplankton, the zooplankton’s food. This decrease would make it more difficult for the zooplankton to survive, resulting in a reduced population. Next, the rapid increases in the number of zooplankton were most likely due to the lack of predators in the pond and the bright sun that produced excellent phytoplankton growth and bloom. Then, the zooplankton population’s decrease was a result of the pond’s return to the standard water level, allowing other predators to return and more zooplankton to be consumed. The zooplankton did not reach the defined standard state of about 125 individuals per liter, as defined by last year’s data.

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REFERENCES Professionals 1. Wisconsin Department of Natural Resources: Michael A. Miller, Paul Garrison, Susan Sylvester, and Carolyn Betz 2. Toben Lafrancois, St. Croix Staff Written 3. Pennak, Robert W. Freshwater Invertebrates of the United States. Second ed. New York: John Wiley & Sons, 1978.

General informational guide to help us understand the behaviors and characteristics of various types of zooplankton; also, contains a great taxonomic guide 4. Cerullo, Mary M., and Bill Curtsinger. Sea Soup: Zooplankton. Gardiner, Me.: Tilbury House, 2001.

Information on marine and fresh-water zooplanktons about their sizes types of locomotion, and other general information in simple terms.

5. Upper and Lower Willow Watershed: 2010 Water Quality Management Plan Update.

Bartilson, Kathy, Cahow, Jim, Cunningham, Joe, Helmuth, Lisa, Lederer, Amanda, Binder, Mark. Wisconsin Department of Natural Resources Publication, 2010 Maps out and gives important information regarding the St. Croix River Basin on the Wisconsin side.

6. Hasler, Arthur D., Mitsuo Terraguchi, and John P. Wall. Biological Aspects of Eutrophication in Lakes Mendota, Crystal, Trout and Green. Madison: University of Wisconsin, Water Resources Center, 1969.

Great background examples of similar projects with zooplankton in Madison; helped with finding collection methods and writing procedure 7. The St. Croix River Basin areawide water quality management plan. Wisconsin Department of Natural Resources Publication, WI docs. no.: Nat.6/2:W 2/S 3/1982. Revised and reprinted 1982.

Maps of the St. Croix river basin, charts and information on water quality 8. Kiørbe, Thomas. A Mechanistic Approach to Plankton Ecology. Princeton: Princeton University Press, 2008.

9. Suthers, Ian M., and Rissik, David. Plankton: A Guide to their Ecology and Monitoring for Water Quality. Australia: CSIRO, 2009.

10/ Thorp, James H., and Covich, Alan P. Ecology and Classification of North American Freshwater Invertebrates. Second Edition. San Diego, Academic Press: 2001, 1991.

Zooplankton in the Great Lakes.

Web Sources 11. www.dnr.wi.gov: Surface Water Data Viewer Great tool that helped us find test sites and learn more about the area.

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Factors Affecting the Wetland Plant Gradient in Relation to Distance from Its Source

by Sam Richards and Tom Richards Sam Richards

Tom Richards

Graph 1

The purpose was to do a survey of five different habitats and record at each site the amount of sunlight, the relative humidity, the amount of plant litter, temperature, and the soil composition and then analyze the data and see what seemed to be the best habitat for the mushrooms surveyed. It was found that there is a direct correlation between the amount of sunlight and number of mushrooms; i.e. the less sunlight, the more mushrooms. However, this was not followed on the riverbank, where there were a great deal of mushrooms and sunlight together. We believe this to be so because of the great amount of water on the river bank that makes this area a good place for mushroom growth.. Based on the number of different species and the number of different sites in each area, the coniferous forest has a more diverse population compared to the deciduous forest. Ultimately all the different mushrooms have too many individual factors and have individual preferences so we couldn’t determine one place that would be the best habitat for optimal growth.

T

he central focus of the experiment was to determine which factor is most important in determining the plant gradient from the runoff pipe through the wetland. There are many different types of wetlands that can be distinguished in the Minnesota/Wisconsin area. They are characterized by various sets of criteria such as vegetation, soil type, nutrient concentration of the water or soil, and others. These factors also go into separation of zones within the individual wetland. The wetland as a whole is generally specified as to which type it is; whether forested floodplain, swamp, scrub/shrub, wet meadow, deep or shallow marsh, or aquatic bed. Even within the wetland there are changes as the ground goes from dry land to open water. These changes separate overlapping zones that have certain characteristics of different wetland types. “Plant species zonation occurs in response to variations in environmental conditions, particularly water depth. A species habitat along a water depth gradient is a result of its individual adaptations” (Cronk, 69) These adaptations essentially show stages of a hydrosere, or gradual change from body of freshwater to wooded area, between which is the wetland. Because these zones of plant life generally reflect the hydrosere stages, or the transition from body of water to landmass, the hypothesis was that the largest factor affect the plant distribution would be the depth of water.

The first step in this experiment was to identify plants throughout the wetland, moving away from the runoff pipe. This defined the plant gradient around which the rest of the experiment would be based. The next step was to test the water depth along the same line, as water depth was hypothesized to be the factor that would correlate with the plant distribution. Finally, other variables were tested to rule them out as having an equal or greater impact on the plant life than water depth.

Graph 1 shows that as the transect line moved away from the road runoff, water depth steadily decreased.

The depth of the organic mat drops rapidly during the first four samples, but seems to plateau after that with a depth of about 50cm. The plant type and diversity also changes as the plots continue through the wetland.

As Graph 2 shows, certain species of plants are found exclusively in the deeper or shallower part of the wetland. The entire plant density also rises as the water depth decreases. Sedges are the only plant found throughout the entire wetland observed in this test. The first three species found were sedges, bladderwort, and duckweed. The depth of the water at the first site (69cm) makes a prime habitat for aquatic plants such as these, the duckweed and bladderwort. The amount of duckweed found was mostly insignificant, but it was there through the sixth plot, never with coverage of more than 5%. The bladderwort was found in fairly large

FACTORS AFFECTING THE WETAND PLANT GRADIENT ON RELATION TO DISTANCE FROM ITS SOURCE

amounts near the beginning of the transect line, up to 30% in one plot. It too was found through the sixth plot, which seems to indicate a change in zone around this area. The idea that the zone changes around the sixth plot is supported by the introduction of grass.

Grasses were not present in the first four sites, but covered 55% of the square at the fifth plot, and were then present throughout the rest of the transect line, except at sites 8 and 9. This suggests that there was a gradual transition from deep marsh to shallow marsh at this point.

The first shrub was found in plot 7, but another was not found again until plot 11. This suggests that the transition from sedge meadow to shrubby meadow was somewhat gradual. There were scattered spiraea (which was the first shrub) outside the transect line between these points, but they did not reach any high density until the eleventh or twelfth plot, when the two varieties of willow were introduced to the shrub population.

From the eleventh plot through plot 20, shrubs took up anywhere from 15%-55% of surface coverage, so the transition to shrub/scrub began around the eleventh plot point.

With the plant gradient defined, variables needed to be tested to find which variable most influences this gradient. Because the hypothesis states that water depth would have the greatest influence on plant distribution, the first variable tested was water depth. At the first point the water depth was around 70 cm. Over the next three plots, the water depth dropped to around 50cm.

Between plot 4 and plot 5 the water depth dropped 16cm in one interval. This was the most drastic drop in the whole set of data. This was also the area in the wetland where the aquatic plants became less prevalent and grasses began thriving. Making the connection between these two big changes is unavoidable, but one common change cannot fully support our hypothesis.

The water depth constantly dropped as the line continued, until the depth reached 3 inches at site 11, and basically hit a plateau, rising and falling at each plot, but staying between 3 cm and 9 cm the whole time.

This area is where moss was first exposed and where the

shrubs/scrubs zone started, so there is an obvious correlation between the water depth and the zonation of wetland plants.

With this information, part of the hypothesis is already supported; that water depth does play an important role in the plant gradient. The other part of the hypothesis, however, is that no other factor plays a more important role in plant distribution than water depth. To try to prove this, other variables were tested, mostly having to do with the soil. The first measurement, however, was the plant root mat depth, which was found by feeling when the corer fell easily through the bottom of the mat, into the sediment below.

As Graph 1 shows, the root matâ&#x20AC;&#x2122;s depth decreased steadily from about 76cm thick to about 50cm thick at plot 5, at which point the thickness remained stable for the remainder of the transect. It is possible that the presence of only sedges would create a thicker mat, but it does not seem that a thicker mat would result in less plant diversity. At the last few points the mat thickness increased more, which is also the location of the greatest plant diversity.

Next we tested different variables relating to the soil such as type and nutrient content. The nutrient tests took up a great deal of time, but yielded results suggesting that the nutrient levels hardly fluctuated through the wetland. The only nutrient that seemed to change at all was potassium, the concentration of which was found using a titration. And the difference was only that near the open water 12 drops of test solution were required whereas 13 or 14 drops were usually required to titrate samples taken farther away from the open water.

This means that the potassium content near the water is slightly higher, but because the difference is less than 50 lbs/acre, the difference is negligible. The nitrogen was also a bit hard to decipher, because the color of the indicator solution turned into a peach hue as opposed to the pink which was on the indicator key card. So it was decided that the color most resembled the first square, which is just trace, meaning there was hardly any nitrogen throughout the wetland. The phosphorous stayed the same light blue color no matter where the

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Graph 2

EDGEWOOD HIGH SCHOOL STUDENT SCIENCE JOURNAL 2009-2011

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REFERENCES 1. Cronk, J. K., and M. Siobhan. Fennessy.

Wetland Plants: Biology and Ecology. Boca Raton, FL: Lewis, 2001.

Print.

2. “Plant Zonation in Wetlands.” Offwell Woodland & Wildlife Trust. Web. 22 Jan. 2011. <http://www. countrysideinfo.co.uk/ wetland_survey/ zones.htm>.

3. Wetland Functional Values. Madison, WI: Wisconsin Department of Natural Resources.

Print.

4. “Wetland Plants and Plant Communities of Minnesota and Wisconsin.” U.S. Geological Survey. 3 Aug. 2006. Web. 25 Jan. 2011. <http://www. npwrc.usgs.gov/resource/ plants/mnplant/ marsh.htm>.

5. Curliss, Connor; Martin, Niall. Personal correspondence. 6/7/116/10/11 6. Kelly, Jerry. Personal Correspondence.

6/1/11-6/10/11

sample was taken, indicative of low, but present phosphorous of around 50lbs/acre. The pH was slightly acidic, between 6 and 7, which is often indicative of peatlands with sphagnum moss, but as was suspected stayed relatively constant throughout the duration of testing.

The soil structure experiment did not work as suspected because of the soil type present in the wetlands. The wetlands’ sediment was not mineral soil, but was in fact organic soil, meaning it was made primarily, if not exclusively of decomposing plant fibers, which become a dark oily soil called peat, then if it decomposes even further will eventually become a slippery, watery soil called muck. As another study found this year, more muck was found closer to the open water than deeper into the wetland, where most of the soil was peat (Curliss, Martin). This is one variable that also changed in conjunction with the zonation, but because organic soil is so closely associated with the plants which decompose to constitute it, the soil type is more likely a result of the plants than the inverse. As the other project explained, the peat and muck deposition may also be a result of the clay bed found in the deeper part of the wetland, which is not found in the shallower water, so soil type likely did not have as much of an impact as water depth on plant distribution.

Some of the errors that may have occurred during the course of the experiment were the inconsistency of the water depth and the fact that the experiment dealt largely with organic soils. The experiment had three separate field days to collect data and soil samples, and so the water depth was inconsistent, dropping a total of 10 cm from the first day to the last day. This created an inaccurate representation of the water depths on the transect line. In addition, the soil in the experiment was organic soil, meaning the soil was more mucky and peaty and filled with organic matter in contrast to mineral soil which just contains sand, silt and clay. The soil nutrient testing kits were designed to test the

nutrient levels of inorganic soil, not organic soil, so the tests done on the soil collected in this experiment may not be accurate. Even if these tests do work the same on organic soil as they do on mineral soil, they required a very long time to settle. In inorganic soil the small grains of mineral settle quickly when performing these tests, but when the tests are on peat or muck, the organic fibers stay suspended in the testing solution long after the kit’s suggested wait time is finished. This took a day to understand, so tests were delayed, plus further delay from having to wait hours instead of minutes to get test results. If any fibers remained, it was nearly impossible to get an accurate reading because the organic fibers made the indicator solution greener than whatever color it truly should be.

Because the plant zonation and water depth gradient fluctuated in such close conjunction, and no other variable seemed to have a sizeable impact on plant species distribution, the hypothesis seems to be supported by this experiment. Though the hypothesis is supported by the data found in this experiment, more trials on different variables would need to be done to fully support such a wide-scoped objective. To determine whether water depth truly is the most important factor in determining the plant gradient, every other factor (such as water chemistry, sunlight, water flow, macroinvertebrate life) would need to be tested. Other changes or additions that would support the findings of this experiment would be a longer transect line reaching the clear opposite bank, which marks the end of the wetland and beginning of the forest. Another affective method would be to create more transects to get a more accurate depiction by having a larger sample size.

Wetlands are important in cleaning ecosystems of toxins and creating habitats for many flora and fauna.

Understanding how wetlands work is important in preserving them, both for their environmental importance and for appreciating their beauty.

Acknowledgements Managing Editors Eric Pantano and Mekel Wiederholt Meier Editorial Team Kristin DeLorme, Maureen Moravchik, Eric Pantano, Mekel Wiederholt Meier, Jim Ottney Lead Research Teachers Eric Pantano, Mekel Wiederholt Meier, Toben Lafrancois, Jerry Kelly, Jessica Splitter and Mary Bridget Samson Layout Jim Ottney â&#x20AC;&#x201C; OpenWindow Design Cover Image Clare Everts and Audrey Netzel, photo taken through microscope Printing and Production Manager Michael Elliot â&#x20AC;&#x201C; Suttle-Straus, Inc.

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