Chelse Prather, PhD
• Grew up in Northern Kentucky • BS, biology, University of Kentucky • PhD, biology, University of Notre Dame, research in the rainforest in Puerto Rico • Previous Postdoc, biology/history/philosophy, Florida State University • Now Research Faculty at University of Houston
Prairie restoration and management • Focus on restoring and managing for diverse native plant communities or creating habitat for game, migratory and threatened species. • What about the smaller animals—the invertebrates? • Butterflies, the “pretty” invertebrates have been mentioned. • What about all the others?
Outline 1. Why care about invertebrates? Invertebrates and humans 2. Research question: What determines invertebrate herbivore community structure in coastal tallgrass prairies? 3. Other projects 4. How to use this information?
Outline 1. Why care about invertebrates? Invertebrates and humans 2. Research question: What determines invertebrate herbivore community structure in coastal tallgrass prairies? 3. Other projects 4. How to use this information?
Invertebrates: • Represent over 80% of all known eukaryotic species • Fill a vast array of ecological niches • Attain high biomass in most ecosystems.
Do insects affect humans? Ecosystem services: Benefits from ecosystems that support human life and wellbeing
Some%invertebrates%cause% problema2c%disservices%
The little things that run the world E. O. Wilson
Invertebrates, ecosystem services, climate change Chelse M. Prather, Shannon Pelini, Angela Laws, Emily Rivest, Megan Woltz, Christopher P. Bloch, Izzy Del Torro, Chuan-Kai Ho, John Kominoski, T. A. Scott Newbold, Sheena Parsons. 2012. Biological Reviews, in press.
“…If invertebrates were to disappear, I doubt that the human species would last more than a few months.”%
Goal: Evaluate invertebrate influences on ecosystem services and how these influences may be altered by climate change
Invertebrate effects on ecosystem services -On the National Bison range, it’s estimated that grasshoppers eat more vegetation than all the large vertebrates combined (Belovsky 2002). - Can eat 0-100% of plant biomass in an ecosystem
- 11,000 species of myrmechores
-3/4 of all plants and 1/3 of all crops by volume are pollinatordependent
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!Dung&beetles&that&decompose&feces&are&worth& es6mated&at&$454&million&in&the&US&
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!Emerging&insect&cause& !Invertebrate&frass&can& huge&changes&in& increase&or&decrease& available&nutrients% nutrients&to&plants%
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Invertebrate effects on ecosystem services%
Food web stability
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In summary: • Invertebrates provide or indirectly influence all ecosystem services. • They are the major providers of a few services, and influence most of the others to a great degree. • BUT: the basic science has not been done to evaluate their relative importance.
Outline 1. Why care about invertebrates? Invertebrates and humans 2. Research question: What determines invertebrate herbivore community structure in coastal tallgrass prairies? 3. Other projects 4. How to use this information?
Fundamental question in ecology: What is the relative importance of factors that affect the abundance and diversity of organisms?
Why grasshoppers?
• One of the major herbivores in most prairies across the US • Can eat more than ungulate herbivores combined • Relatively easy to sample
Top down controls Predator pressure & Parasite load Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics
Plant biomass
Plant diversity
X
Plant micronutrients
Plant macronutrients
P L A N T
Q U A L I T Y
Site characteristics
Precipitation & temperature
CLIMATE
Soil macronutrients
X
Soil micronutrients
GEOLOGY
Land use & management
Fragment size
HUMAN
Time since restoration
INFLUENCES
Top down controls Predator pressure & Parasite load Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics
Plant biomass
Plant diversity
X
Plant micronutrients
Plant macronutrients
P L A N T
Q U A L I T Y
Site characteristics
Precipitation & temperature
CLIMATE
Soil macronutrients
X
Soil micronutrients
GEOLOGY
Land use & management
Fragment size
HUMAN
Time since restoration
INFLUENCES
Pristine prairie
Restored prairie
Measured grasshopper diversity and density, and possible predictors across 3 habitats (n=12). Plant community Biomass Diversity Water Plant height Macro-nutrients (N, P) Micro-nutrients (Ca, Cu, Fe, K, Mg, Mn, Na, S, Zn) Root biomass Root moisture
Shell-rich area
Predators Wolf spider density Soil Moisture Oyster shell content pH
Invasive forest
Density of food web members Number of individuals per m2
0.16% 0.08%
Shell-rich areas
Predators%(wolf%spiders)%
0% 1% 2%
2%
df%=%22% t%=%5.79% P%=%<%0.001%%%
Herbivores%(orthopterans)%
0% 5%
df%=%22% t%=%=6.92% P%=%%0.496%%%
Omnivores%(crayďŹ sh)%
1% 0% 2%
Pristine prairie
1%
df%=%22% t%=%=2.54% P%=%<%0.019%%%
2%
Detri2vores%(isopods)%
0% 1%
df%=%22% t%=%=2.00% P%=%<%0.058%%%
2%
Results
Top down controls
Single-factor, bivariate relationships; build up to multiple factors.
Predator pressure & Parasite load
Soil moisture
Herbivore community characteristics Herbivore abundance
Herbivore diversity
Significant drought event in 2011 Plant community characteristics
Plant biomass
Plant diversity
X
Plant micronutrients
Plant macronutrients
Site characteristics
Precipitation & temperature
CLIMATE
Soil macronutrients
X
Soil micronutrients
GEOLOGY
Land use & management
Fragment size
HUMAN
Time since restoration
INFLUENCES
Results
Top down controls Predator Predator pressure pressure & & Parasite Parasite load load Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics
Plant biomass
Plant diversity
X
Plant micronutrients
Plant macronutrients
Site characteristics
Precipitation & temperature
CLIMATE
Soil macronutrients
X
Soil micronutrients
GEOLOGY
Land use & management
Fragment size
HUMAN
Time since restoration
INFLUENCES
Results
Top down controls Predator pressure & Parasite load
Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics
Plant biomass biomass Plant
Plant diversity
X
Plant micronutrients
Plant macronutrients
Site characteristics
Precipitation & temperature
CLIMATE
Soil macronutrients
X
Soil micronutrients
GEOLOGY
Land use & management
Fragment size
HUMAN
Time since restoration
INFLUENCES
Results
Top down controls Predator pressure & Parasite load
Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics Plant biomass
Plant diversity diversity Plant
X
Plant micronutrients
Plant macronutrients
Site characteristics
Precipitation & temperature
CLIMATE
Soil macronutrients
X
Soil micronutrients
GEOLOGY
Land use & management
Fragment size
HUMAN
Time since restoration
INFLUENCES
Results
Top down controls Predator pressure & Parasite load
Phosphorus Nitrogen
Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics Plant biomass
Plant diversity
X
Plant micronutrients
Plant macronurients nutrients
Site characteristics
Precipitation & temperature
CLIMATE
Soil macronutrients
X
Soil micronutrients
GEOLOGY
Land use & management
Fragment size
HUMAN
Time since restoration
INFLUENCES
Results
Top down controls Predator pressure & Parasite load
Calcium Potassium Sodium Sulfur
Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics Plant biomass
Plant diversity
Plant macronutrients
X
Plant Plant micromicronutrients nutrients
Site characteristics
Precipitation & temperature
CLIMATE
Soil macronutrients
X
Soil micronutrients
GEOLOGY
Land use & management
Fragment size
HUMAN
Time since restoration
INFLUENCES
Results
Top down controls Predator pressure & Parasite load
Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics Plant biomass
Plant diversity
Plant macronutrients
Plant micronutrients
Site characteristics
Precipitation & temperature
CLIMATE
Soil macronutrients
X
Soil micronutrients
GEOLOGY
Land use & management
Fragment size
HUMAN
Time since restoration
INFLUENCES
Results
Top down controls Predator pressure & Parasite load
Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics Plant biomass
Precipitation & temperature CLIMATE
Soil macronutrients
Plant diversity
Soil micronutrients
GEOLOGY
Plant macronutrients
Land use & management
Plant micronutrients
Fragment size
HUMAN
Time since restoration
INFLUENCES
Results
Top down controls Predator pressure & Parasite load
Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics Plant biomass
Precipitation & temperature CLIMATE
Soil macronutrients
Plant diversity
Soil micronutrients
GEOLOGY
Plant macronutrients
Land use & management
Plant micronutrients
Fragment size
HUMAN
Time since restoration
INFLUENCES
Results
Top down controls
Dependent variable Dependent variable Density Grass-feeder density Mixed-feeder densityPlant biomass
Predator pressure & Parasite load
Predictors (coefficent)
R2
F
P
F
Herbivore community characteristics Herbivore Predictors Herbivore R2 abundance (coefficent) P (0.456) diversity0.48
Soil moisture (-0.866) 0.221 N:P Fe (-0.564) N (-0.649) Plant community characteristics Veg height (-0.219) Ca diversity (0.014) (0.501) 0.732 Plant Plant Plant macroRoots (-0.229) Ca (0.478)nutrients diversity Zn (0.734)
Richness K(0.920) 0.35 S (-0.687) Forb-feeder Ca (1.453) 0.791 density P (-0.561) Soil Precipitation Na Soil (0.475) Land use & & macro- Znmicromanage(-0.322) temperature nutrients nutrients ment CLIMATE
P
GEOLOGY
<0.001
11.59
0.006
5.105
<0.001 30.755 Plant micronutrients <0.001 <0.001 Fragment size
HUMAN
7.653 4.763 Time since restoration
INFLUENCES
CONCLUSION: What is the relative importance of factors that affect the abundance and distribution of prairie herbivores? Top down controls Predator pressure & Parasite load
Herbivore community characteristics Herbivore abundance
Herbivore diversity
Plant community characteristics
Plant biomass
Precipitation & temperature CLIMATE
Soil macronutrients
Plant diversity
Soil micronutrients
GEOLOGY
Plant macronutrients
Land use & management H U M A N
Plant micronutrients
Fragment size
Time since restoration
I N F L U E N C E S
Conclusions: If you build it, will they come?
Katydid: Orchelimum vulgaris
Grasshopper: Melanoplus femurrubrum
Grasshopper: Metataplea brevicornis
Katydid: Concephalus strictus
Species%specific%effects%
100%
Mixed%feeders%
Grass%feeders%
50% 0% =50% =100% 100% 50% 0% =50% =100%
2%Grass%
Both%
2%Mixed%
Grasshopper%diversity%conclusions% • The%number%of%species%doesn’t%necessarily% maSer,%but%the%iden2ty%of%the%species%you% have%maSers.% • Next—bigger%experiment%at%more%sites.%
**Disclaimer: understanding of what controls communities, not to be used to manage insects with current results**