Research Essay: Katherine Sales

(Friends of Warner Parks)

How do the Emerald Ash Borer and invasive plants affect parks on a local and national scale?

With climate change and the expansionist mindset of the world, public parks are some of the most important parts of society Public parks encourage connecting with the outdoors; whether it be a hike, a walk, or a friendly game of football; public parks give all people a space to be one with nature. The organization I chose to spend my service hours with was Friends of Warner Parks. Friends of Warner Parks provides services such as clean-up and restoration, community outreach events, and environmental education.

The first Warner Park opened in 1910 thanks to Luke Lea. Luke Lea bought the land at the end of Belle Meade Boulevard and donated it to the City of Nashville for a public park comprised of 543 acres. Flash forward to 1987 and the nonprofit group Friends of Warner Parks was established and in 2000 the Nature Center-HQ of Friends of Warner Parks was built. Today Friends of Warner Parks looks over 3100 acres of land. While the parks may be a place of comfort, many environmental problems afflict the parks today. Two of the problems I noticed and got to learn about in my experience were the effects of Emerald Ash Borer and Invasive Plant species on the parks(Friends of Warner Parks).

The Emerald Ash Beetle or Emerald Ash Borer (EAB) is a wood-boring beetle from northeast Asia. The adult beetles are mostly harmless but the larvae feed on ash trees causing them to die by disrupting their ability to take in nutrients and water(Emerald Ash Borer). Their eating pattern is described by Tim Phelps, Tennessee Department of Agriculture, Division of Forestry Public Information Officer, [as] “ a serpentine style eating or feeding pattern that these larvae do inside the trunk of the tree. That in and of itself weakens the tree. But, ultimately, these larvae completely encircle the stem of the tree or a branch”(Davis). The Emerald Ash Borer was introduced to the United States in 2001 and since then, has killed forty million ash trees.

The Emerald Ash Borer (EAB) was first introduced to America in 2001 and has caused problems in the Northwest and Northeast states. Nature specialists first noticed the decline of Ash trees in Detroit in 2001. They believed at first the trees had a disease, but by 2003, five to seven million trees were dead or dying in Michigan. Since there was really no information about what was happening, they were not able to stop the infestation so the EAB spread to other states. Now the EAB can be found in 31 different states. The EAB is one of the most destructive “non-native forest pests”(Houping). In infested areas, the EAB can kill up to 99% of ash trees in that area within a few years. The graph of “Ash Tree update 2017” shows the mortality rate of ash trees in the national parks. From 2016-2017, the number of living ash trees decreased as the number of dead ash trees increased. As of 2017, 67% of the original amount of ash trees in National Parks had died due to the Emerald Ash Borer. The National Parks article warns that if something is not done quickly then even more death can occur(Ash Tree Update 2017).

The infestation of EAB is an environmental crisis and also an economic problem. There are roughly eight billion ash trees valued at about 282 billion dollars. If all of these ash trees are destroyed, 282 billion dollars will be lost. Not only is the loss of ash trees a problem, but also the cost to treat the invasive species. “The projected economic cost of the area where the invasive species was found was roughly 12 5 billion dollars to mitigate spread and another 10 7 billion dollars for removal and treatment” along with “The estimated impact of EAB for the 30-yr time horizon ranged from $265 million to $1.2 billion depending on the combination of spread, treatment, and discount rates”(Ash Tree Update 2017). The cost to treat the ash trees would be a financial burden on most states.

Ash trees provide resources for animals, and the destruction of these ash trees would be detrimental to the animals’ ecosystems. Ash seeds are consumed by smaller animals such as ducks, birds, and insects, and “21 species of moth rely on the ash tree”(Ash Tree Update) Not only that but 43 species of arthropods, invertebrates with an exoskeleton, use ash trees for feeding. The opening from the lack of ash trees will increase invasive species.“This, in turn, will lead to habitat alteration and species displacement in the ecosystems, which most likely will result in landscape homogenization from the loss of species diversity”(Ash Tree Update 2017). This means that due to the environmental changes, some species will either die off or have to migrate because they no longer have the ash trees to survive off of. Looking locally at Nashville the EAB was first discovered in 2014 Tim Phelps says, “The white flag has been thrown up, the Emerald Ash Borer is here to stay. And, there are things that homeowners need to know about how to protect a tree, as well as landowners”(Ash Tree Update 2017).

The Emerald Ash Borer affects the nation and has specifically affected Warner Parks. Ash Trees compose 15% of the Warner Parks Canopy, and Warner Parks will have to take down 3600 Ash trees in the next five years. These removals pose a threat to park goers and the whole of Nashville Metro expects the borer will ultimately kill all of Nashville’s thousands of ash trees by the year 2026 The city says the insect arrived in Nashville in 2014 and is already responsible for killing tens of millions of trees across North America(Gonzalez). Phase 1 of ash tree removal will begin with taking out 128 ash trees along trails. Warner Parks has been lucky enough to have started replanting and hopes to replenish the loss of the ash trees. Warner Parks have planted 4000 native trees with blue tubes around them for protection and to promote the growth of new trees(Friends of Warner Parks).

A big part of my time over the summer was spent pulling various invasive species around the park. An invasive species is defined in National Geographic as “ an organism that is not indigenous, or native, to a particular area.”Invasive species are a threat economically and environmentally. Invasive species are able to adapt to their new environment quickly, reproduce, and then take over entire ecosystems. Oftentimes, invasive species are spread around the world due to anthropogenic causes. Invasive species can attach themselves to things being shipped around the world. Also with climate change, some invasive plants are capitalizing on the change in weather to allow them to move into new climates Many big problems come with this introduction of invasive species into environments. When invasive species are introduced into environments, they are often able to breed and reproduce quickly due to the lack of a natural predator. They can also prey on native species, outcompete them for food and other resources, cause or carry disease, and prevent native species from reproducing or killing a native species’ youth(National Wildlife Federation. Economic problems also follow invasive plant species. Conservation authorities are estimated to spend 50.8 million on invasive species per year in Ontario alone Invasive species cause management costs, research, and monitoring problems, reduced crop yield, job losses, damage to infrastructure, and negative impacts to international trades and tariffs(Invasive Species Center)

There are nine particularly prevalent Tennessee invasive species: Tree-of-Heaven, Royal Paulownia, Mimosa, Privet, Amur and Japanese Honeysuckle, Kudzu, Chinese Lespedeza, and Japanese Grass(Kincannon). The main way that the invasive plant species affect the Nashville area is by pushing out native plant species. This, therefore, alters ecosystems and has been prominent in many of the trails in the Warner Parks area. These invasive plants devastate landscapes, and many universities conduct research to find solutions.

North Dakota State University’s students did research on the Emerald Ash Borer problem and came up with three solutions. Two solutions, diversification, and isolation, are the most effective. One of the solutions to the destruction of ash trees through the Emerald Ash Beetle is by diversifying the plants and trees in that ecosystem. In most areas where ash trees reside, overplanting occurs. Overplanting is very dangerous to ecosystems. American elm trees were originally planted largely in the great plains, and Dutch elm disease wiped out a majority of the elm trees. The Dutch Elm trees were replaced with green ash trees because these trees grew large and fast(North Dakota State University) The same problem occurred when the Emerald Ash Beetles were introduced into the American environment. This over planting of trees caused the biodiversity of systems to go down and in turn, allowed the areas to be more susceptible to attacks such as these. Biodiversity yields benefits as well as a solution. One good example of this is farmers who use this practice of biodiversity in day-to-day life. Oftentimes, farmers use something called monoculture, which is the growth of one crop. This leads to the same problem as the ash trees: one pest or disease is able to come in and wipe out a majority of the crop Many farmers have switched over to polycultures because of this. Polyculture is the growth of multiple crops, and it makes pests spread more slowly. This is seen through sunflowers being planted with tomato crops. Stanley Rice, a professor of biological sciences at Oklahoma State University writes, “Sunflowers impede movements of sphinx moths through tomato fields, causing them to lay fewer eggs, which hatch into voracious tomato hornworms”(Stanley). Due to the planting of sunflowers within the tomato crops, the moths are not able to destroy the tomato plants as much If fewer ash trees were planted, trees such as “cottonwood or boxelder” will have the same kind of effect as planting sunflowers in with tomatoes and will slow the spread of the EAB(North Dakota State University). Not only will they decrease the spread of ash beetles, but they will also ensure that if the ash tree population in one area is destroyed then the ecosystem will be diverse enough to recover. The second solution to the Emerald Ash beetle crisis is isolation. One of the ways that the Emerald Ash beetle is able to spread across countries and states is through the transportation of wood. A couple of states have put restrictions on what can be done with firewood at campsites or the sale of firewood in general, for example, “The Indiana Department of Natural Resources recommends burning all firewood to avoid spreading the insect”(Suellen) Quarantine is an easy and cheap way to stop the spread of the Emerald Ash Borer. Research into the treatment of invasive plant species has differed. The department of energy and environment categorizes the three broad categories that cover treatment for invasive plants: mechanical, chemical, and biological. Mechanical treatment is actually pulling invasive species from the ground This could be pulling, digging, suffocating, cutting, and mowing Chemical treatment is the use of herbicides to prohibit and control growth Biological treatment is using natural predators to try to eradicate invasive species(Department of Energy and Environment). Although the research for eradicating invasive plants is fairly straightforward, there is a clear crossover between what has been done for invasive plants and what should be done about the Emerald Ash Borer

Friends of Warner Parks is doing significant work to help save the Nashville community from the devastation of both the Emerald Ash Borer and various invasive plants. The first thing Friends of Warner Parks is doing is educating the wider Nashville community. When walking in the park various signs will be on display with a warning about what the Emerald Ash Borer is. These signs also include what to do if an Emerald Ash Borer is seen and where to go to find more information. Friends of Warner Parks also encourages and offers many volunteer and educational opportunities These opportunities range from “pick and pull days” where volunteers actually get to go out and pull invasive species, to exhibits in the Nature Center on the current climate of the Warner Parks. Finally, Friends of Warner Parks is taking action. Friends of Warner Parks is going in and destroying 4000 Ash trees. Removing these Ash Trees stops the spread of the Emerald Ash Borer to other regions across Tennessee and the United States. Friends of Warner Parks is also planting new trees that will hopefully grow and replace the prominent Ash tree population. These new trees can be seen throughout the parks in blue tubes These blue tubes help with monitoring the growth of the new trees but also create a sort of greenhouse that will facilitate growth.

Works Cited:

“Ash Tree Update 2017 (U.S. National Park Service).” National Parks Service, U.S. Department of the Interior, Web.Jan 30 2023 https://www.nps.gov/articles/ash-tree-update.htm.

“EAB Network - Home.” EAB Network - Home, Web. Jan 27 2023 https://www.emeraldashborer.info/

Friends. “Metro Parks to Remove Eab Infested Ash Trees This Fall.” Friends of Warner Parks, 6 Oct. 2022, Web. Jan 10 2023 https://warnerparks.org/eab-infested-ash-trees/.

Gonzalez, Tony. “'It's Time.' Nashville Begins Chopping down Trees Damaged by Emerald Ash Borer.” WPLN News, 3 Oct. 2022, Web. Jan 10 2023 https://wpln.org/post/its-time-nashville-begins-chopping-down-trees-damaged-by-emerald-ash-b orer/.

Invasive Plant Control Methods, Web. Jan 27 2023 https://doee.dc.gov/page/invasive-plant-control-methods#:~:text=Herbicides%20are%20among% 20the%20most,BGone%E2%84%A2%20and%20Garlon%E2%84%A2.

“Invasive Species Economic Impacts.” Invasive Species Centre, 12 Oct. 2022, Web. Jan 27 2023 https://www.invasivespeciescentre.ca/invasive-species/what-is-at-risk/invasive-species-economicimpacts/.

“Invasive Species.” National Wildlife Federation, Web. Jan 10 2023 https://www.nwf.org/Educational-Resources/Wildlife-Guide/Threats-to-Wildlife/Invasive-Species

Liu, Houping. "Under Siege: Ash Management in the Wake of the Emerald Ash Borer." Journal of Integrated Pest Management, vol. 9, Annual 2018, pp. 1d+. Gale Academic OneFile, Web. Jan 27 2023 link.gale.com/apps/doc/A687753915/AONE?u=tel_a_es&sid=bookmark-AONE&xid=987a1d07.

Accessed 31 Jan. 2023.

May, Suellen. “Invasive Terrestrial Animals: Emerald Ash Borer.” Invasive Terrestrial Animals, Chelsea House, 2006. Science Online, Web. 12 December 2022 online.infobase.com/Auth/Index?aid=103456&itemid=WE40&articleId=371541. Accessed 31 Jan. 2023.

Nolan, Davis. “Emerald Ash Borers Destroying Tn Ash Trees.” WKRN News 2, WKRN News 2, 22 Apr. 2022, Web. 27 January 2023 https://www.wkrn.com/special-reports/emerald-ash-borers-destroying-tn-ash-trees/.

“Preparing Trees for Winter.” NDSU Agriculture and Extension, 28 Sept. 2022, Web. 12 December 2022 https://www.ndsu.edu/agriculture/extension/extension-topics/gardening-and-horticulture/treesand-shrubs/preparing-trees-winter.

Rice, Stanley A. “Importance of Biodiversity to Agriculture.” Encyclopedia of Biodiversity, Revised Edition, Facts On File, 2020. Science Online, Web. J10 January 2023 online.infobase.com/Auth/Index?aid=103456&itemid=WE40&articleId=285346. Accessed 31 Jan. 2023.

“Tennessee Invasive Species.” City of Knoxville, Tennessee, Web. 12 December 2022 https://www.knoxvilletn.gov/government/city_departments_offices/public_service/urban_forestr y/tennessee_invasive_species#:~:text=In%20addition%2C%20it%20focuses%20on,%2C%20sapli ngs%2C%20and%20seedlings.