Course:CONS200/2024WT1/A review of climate change impacts on the Everglades

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Location of Florida's Everglades

The Everglades is a vast area of freshwater marshland that lies in Southern Florida, in the United States. It contains a vast network of interconnected ecosystems and habitats, which are home to a myriad of unique plant and animal species.[1] The Everglades include 8 unique soil and plant communities, each with its own unique conditions and associated species, some also contain multiple subgroups with even more specific conditions and species.[2] These diverse ecosystems also provide many important benefits for the surrounding communities due to the unique environment and its features. Those unique features allow the Everglades to act as a buffer to the flood season, dampening its effects and protecting local communities.[3] The unique water ways and vegetation types are also perfect for filtering out most particles from water passing through the Everglades basin, providing clean drinking water for surrounding communities.[4] In perhaps what is a double edged sword, that filtered water is vital for surrounding farmlands and livestock, sustaining more than 25% of Florida's citrus production and half a million cattle.[3] The Everglades also provide the perfect conditions for a thriving commercial fishing scene as well as a world destination for sport fishing.[5] The rich biodiversity and unique ecosystems also attract a huge amount of tourists from all over the world.[3] In essence, the Everglades is an indispensable part of Southern Florida, supporting not only one of the most unique environments in the world, but also the surrounding communities and businesses. However, within the century this awe inspiring, yet fragile ecosystem will not look the same or even exist at all, as the rapidly changing climate has played a critical role in its decline.

Based on radiocarbon dating and past vegetation, the Everglades are approximately 7,000 years old. They exist because of a unique combination of sea level rise, hydrology, and a limestone platform formed in the Pleistocene age along the southern tip of Florida.[6] The limestone platform provided an impenetrable barrier for the buildup of peat and marine sediments that were brought in via sea level rise. This resulted in the geological makeup of the Everglades today, which is a combination of Marl and Peat soils. Peat is a product of long-term flooding that compresses the organic remains of plants and Marl is the product of periphyton which is a mix of cyanobacteria, microbes, and detritus. Marl is a calcitic mud and occurs in the short term flooding area of the Everglades while peat is formed in the long term flooded areas.[7]

Historically the Everglades were estimated to occupy 4,000 square miles, covering most of the Florida Peninsula south of Lake Okeechobee. However, human intervention in the Everglades significantly changed that area. Beginning in 1880, canals and levees were created to divert water from the Everglades to utilize the once-flooded land for agricultural purposes.[8]This led to issues in the 1930's when major hurricanes overwhelmed the canals and destroyed homes and farms. Human impacts on the Everglades have now reduced the total area to less than half of the historical area.[9] The alteration of the Everglades increased the risks of flooding significantly by reducing the capacity of flood mitigation that the Everglade wetland system provides.[10] Wetlands act as a sponge and absorb excess water; wetlands such as the Everglades retain and slowly release water, which greatly reduces the peak flood levels and acts as a buffer for flood waters.[11] Wetlands such as the Everglades have become increasingly important in the face of climate change, due to the fact that climate change has been the cause of increasing frequency of extreme weather events.[12]

The Impacts of Climate Change on the Everglades

The Everglades freshwater peatland in Southern Florida

Climate change has become a significant cause of harm on this delicate ecosystem. Some of the biggest changes associated with climate change include changes in temperature, sea level, and the increasing loss of the essential peatlands that it is made up of. Each of these is associated with a series of drastic changes to the ecosystem, habitat, and biodiversity which alters the foundations and basic constitutions of the Everglades, and causes harm to all living things inhabiting and using the vast resources the Everglades offers.

Temperature Rise

The primary consequence associated with climate change is most commonly due to changes in temperature. In the case of the Florida Everglades, the worry lies mostly in a rising of temperature. Studies by Obeysekera et al., have shown that a 1.5 °C increase in temperature is associated with increased evapotranspiration as well as changes in rainfall patterns.[13] This coupled with an increase in water demand from domestic and agricultural sources places a huge strain on water supply and results in a drier environment. [13]

This drier environment will result in droughts which will affect both inland and coastal wetland areas. In inland areas, drought will reduce the recharge of the freshwater wetlands, drying them up and lowering the water table.[14] This is especially true in regards to the Everglade's massive reserves of peat, which are an important carbon sink. In what is called a "Drydown" event, resulting from a lack of water, peat will begin to decompose, as lower water levels expose it to oxygen and as a result, allowing decomposition in previously anerobic conditions, and releasing stored carbon into the atmosphere.[5] In the coastal regions the resulting drier climate and lowering of the water table allows for increased inundation of saltwater.[13] This again affects the peat environments which are primarily freshwater, and will be destroyed with an influx of salt water.[5]

While much of what has been discussed here focuses on the effects of a rise in temperature on the peat, the associated land and organism composition is also greatly affected. The drier land means that the aquatic, amphibious, and terrestrial species composition will change drastically. For example, changes in temperature affect plant cycles and blooming and bearing periods, therefore, when a change to these is made, thousands of organisms are also greatly affected. Changes to a plants growth cycles can cause loss of habitats, food sources, and disruption for pollinators. [14] Different types of water and lower levels of water also mean that the land itself changes, microtopography is flattened, reducing the lands ability to hold on to water, and wetland habitats turn into terrestrial ones.[13]

Sea Level Rise

One of the biggest impacts our changing climate is having on the Everglades is rising sea levels. Changes in climate and temperature means that as the oceans heat up, they expand and raise sea levels, which is then coupled with a lowering of the freshwater water table, and as previously discussed the resulting effects on an ecosystem are drastic.[14] One of the major changes we have already seen are an invasion of more exotic and invasive species. Exotic species are a species that are introduced accidentally or intentionally to an area outside their normal distribution. [15] On the other hand, invasive species carry a vast array of troubles for the ecosystem they invade, as they can destroy habitats, displace native species, and alter food webs. [16] When an invasive species is introduced to an ecosystem, many native species are affected directly through loss of habitat, predation, and disease, as well as indirectly through resource competition, or nutrient consumption. [17] This crisis is affecting the Everglades no differently than any other ecosystem. As the environment changes due to climate change, new and invasive species are quick to move in. For example the Burmese Python (Python bivittatus) is recognized as an invasive species within the Everglades National Park. Introduced during or before the pet trades in the 1990's, pythons populations have grown significantly, affecting the natural flow of the Everglades ecosystem. This specific species preys upon 40 native species of vertebrates and has been linked to declines and local disappearances of several prey populations. [18] According to a research article on the impacts of pythons on the Everglades biodiversity, their findings demonstrated that, "Before 2000, mammals were encountered frequently during nocturnal road surveys within ENP. In contrast, road surveys totaling 56,971 km from 2003–2011 documented a 99.3% decrease in the frequency of raccoon observations, decreases of 98.9% and 87.5% for opossum and bobcat observations, respectively, and failed to detect rabbits. Road surveys also revealed that these species are more common in areas where pythons have been discovered only recently and are most abundant outside the python's current introduced range. These findings suggest that predation by pythons has resulted in dramatic declines in mammals within ENP (M E Dorcas et al, 2011, p. 1)." [19] The impacts just this one python species has on the Everglades animal life are devastating to the native species there, and clearly demonstrates the consequences that an invasive or exotic species can have on an ecosystem.

Another major impact with rising sea levels is the changes to the physical environment, through the loss of the distinctive ridges and sloughs. Sea level rise is affecting the landscape through erosion, changes in the pH of the water through addition of saltwater, which alters the lifestyle and habitat of many species, and increasing carbon emissions. While ridges are mostly inhabited by sawgrass, the troughs play a crucial role in providing habitats for the diverse range of species in the Everglades. Another important feature of the Everglades is the hydrological functions it possesses. Ridges and troughs are important in dispersal of water around the marshland, and troughs can be a site of stored water during dry periods, necessary for wildlife survival. Finally, a function of the material that makes up the landscape is soil and organic material, which plays a role in storing carbon, so with rising sea levels and shifting landscapes, carbon is being released back into the atmosphere, exacerbating climate change. [20]

Loss of Peatlands

As mentioned before, one of the ramifications of temperature and sea level rise is a loss in the peatlands. Peatlands only cover three percent of the world's total area but store one-third of the world's total soil carbon, double the amount that all forests around the world hold.[21]The Everglades are an ideal circumstance for the formation of peat, peat is formed from the decomposition of organic matter, primarily plant matter. Peat can only form under anaerobic conditions meaning it must be underwater to form.[22]A coastal ridge on the eastern tip of the Everglades forms a barrier that contains water within the Everglades. Paired with the wet climate of Florida and an abundance of plant life, the Everglades have been building up peat at a rate of 12 centimeters per century during the last millennia. Based on a collective of researchers from the Kennedy Space Center, Florida International University, and the Florida Water Management District, the Florida Everglades historically contained 20 billion cubic meters of peat. Due to anthropogenic changes (Systematic drainage for agriculture) and climate change contributing to the drainage of peatlands, the Everglades presently only contain a quarter of the historical amount(4.7 billion cubic meters). These researchers estimated that due to this peat loss starting in 1880, over 1.3 billion metric tons of carbon dioxide had been emitted.[23]

Climate change causing rising temperatures will continue to dry up peatlands through evapotranspiration, releasing more carbon into the atmosphere as climate change persists. The loss of peatlands is an example of a climate change amplifying biological feedback loop. An amplifying feedback loop is defined as a process in which the end products of an action cause more of that action to occur in the loop.[24] With temperatures continuing to rise, causing peatland loss, more and more carbon dioxide will be released, amplifying climate change risks and resulting in a never-ending amplifying biological feedback loop. Research indicates that a better understanding of feedback loops that amplify climate change needs to be understood in more depth for future climate change mitigation.[25]

Actions Being Taken to Address Climate Change in the Everglades

The Everglades are an amazing yet fragile ecosystem that must be protected. The first step to protecting the Everglades was to re-evaluate the way the ecosystem has been managed in the past. In the past, scientists and managers did not take into account the increasing forces of climate change, but in the present day, they do. [26] One step being taken by ecologists is to restore the natural flow of freshwater to the Everglades by installing bridges along the Tamiami Highway, which has been blocking freshwater flow for decades.[27] Another step to aid this crisis is to utilize our knowledge of climate change to adapt and take action to prevent further worsening of climate related impacts on the Everglades and all other natural ecosystems that are affected by these changes.[27] During the past twenty years, scientists have been aiming to restore the Everglades to their former glory, but scientists agree we must pivot sustainably managing the Everglades while taking into account the effects of climate change. With this taken into account, The Nature Conservancy Project has set bold goals for the next ten years, such as; permanently protecting 300,000 more acres of privately/publicly owned lands allowing for the movement of wide-ranging wildlife, and for the preservation of economically sustainable ranching in the region and maintaining ranching or other low-intensity agricultural uses across at least 90 percent of the 2011 footprint of 1.1 million acres to retain the long-term potential to expand both protection and restoration efforts.[28]

Conclusion

The Everglades is one of the most iconic and ecologically vital systems to a wide range of natural occurrences and biodiversity. The vast marshland is crucial for much more beyond its borders, through social benefits like water purification and flood control. It has also provided a space for practices that assist our economy, such as agriculture, fishing, and tourism. On the inside, the huge ecosystem provides homes to over 2000 species of plants and animals. [29] On top of the biodiversity it protects and the endangered species that require this ecosystem, carbon sequestration, something that is vital to our Earth's functionality, occurs at a high rate in this ecological community due to the large amounts of accumulated organic material in the form of peat moss. The Everglades face an uncertain, changing future through impacts of climate change, a few major ones in the form of rising temperatures and sea levels, and the loss of critically important peat moss. Despite these challenges, there are many restoration projects, laws, and sustainable practices being implemented around the Everglades to preserve them and tackle the damages caused by human impacts and climate change. Ultimately, the Everglades are so much more than a marshland, as they are an essential line to economic success, as well as species biodiversity and climate control. Ensuring the survival of this fragile ecosystem is paramount for it to continue to benefit all living organisms in the future generations, and doing so requires collaboration, sustainable practices and a commitment to conservation. As such an important ecosystem that is falling apart, saving it through any and all conservational mechanisms will be a testament to humanities ability to prioritize and preserve an environment from the impacts of climate change and other environmental impacts.

References

  1. ↑ Lodge, T.E. (2019). Overview of the Everglades. In: D. Pollman, C., Rumbold, D., Axelrad, D. (eds) Mercury and the Everglades. A Synthesis and Model for Complex Ecosystem Restoration . Springer, Cham. https://doi.org/10.1007/978-3-030-20070-1_1
  2. ↑ Ledge, T. E. (2019). Overview of the Everglades. Mercury and the Everglades. A Synthesis and Model for Complex Ecosystem Restoration,1-35. https://doi.org/10.1007/978-3-030-20070-1_1
  3. ↑ 3.0 3.1 3.2 Schade-Poole, K., Möller, G. (2016). Impact and Mitigation of Nutrient Pollution and Overland Water Flow Change on the Florida Everglades, USA. Sustainability, 8(9), 940.https://doi.org/10.3390/su8090940
  4. ↑ Huang, Y. H., Saiers, J. E., Harvey, J. W., Noe, G. B., Mylon, S. (2008). Advection, dispersion, and filtration of fine particles within emergent vegetation of the Florida Everglades. Water Resources Research, 44(4). https://doi.org/10.1029/2007WR006290
  5. ↑ 5.0 5.1 5.2 Richardson, L., Keefe, K., Huber, C., Racevski, L., Reynolds, G., Thourot, S., Miller, I. (2014).   Assessing the value of the Central Everglades Planning Project (CEPP) in Everglades restoration: An ecosystem service approach. Ecological Economics, 107, 366-377. https://doi.org/10.1016/j.ecolecon.2014.09.011
  6. ↑ Willard, D. A., & Bernhardt, C. E. (2011). Impacts of past climate and sea level change on Everglades Wetlands: Placing a century of anthropogenic change into a late-holocene context. Climatic Change 107, 59–80. https://doi.org/10.1007/s10584-011-0078-9
  7. ↑ U.S. Department of the Interior. (2022). Geology. National Park Service. https://www.nps.gov/ever/learn/nature/evergeology.htm
  8. ↑ Blythe, R. W. (2017). Wilderness on the edge: A history of Everglades National Park. Everglades Wilderness on the Edge. https://evergladeswildernessontheedge.com/
  9. ↑ South Florida Aquatic Environments. (2018). Florida Everglades. Florida Museum of Natural History. https://www.floridamuseum.ufl.edu/southflorida/regions/everglades/
  10. ↑ Solecki, W. D., Long, J., Harwell, C. C., Myers, V., Zubrow, E., Ankersen, T., Deren, C., Feanny, C., Hamann, R., Hornung, L., Murphy, C., & Snyder, G. (1999). Human–environment interactions in South Florida’s Everglades region: Systems of ecological degradation and restoration. Urban Ecosystems, 3(4), 305–343. https://doi.org/10.1023/A:1009560702266
  11. ↑ Finna, J. (2024). Understanding the role of natural wetlands in flood mitigation. Hydrology: Current Research, 12(3), 45–60. https://www.hilarispublisher.com/open-access/understanding-the-role-of-natural-wetlands-in-flood-mitigation-and-water-storage.pdf
  12. ↑ Brooks, H. E. (2012). Severe thunderstorms and climate change. Atmospheric Research, 123, 129–138.https://doi.org/10.1016/j.atmosres.2012.04.002
  13. ↑ 13.0 13.1 13.2 13.3 Obeysekera, J., Barnes, J. & Nungesser, M. (2015). Climate Sensitivity Runs and Regional Hydrologic Modeling for Predicting the Response of the Greater Florida Everglades Ecosystem to Climate Change. Environmental Management, 55, 749–762. https://doi.org/10.1007/s00267-014-0315-x
  14. ↑ 14.0 14.1 14.2 Pearlstine, L. G. (2010). A review of the ecological consequences and management implications of climate change for the Everglades. Journal of the North American Benthological Society 29(4), 1510-1526. https://doi.org/10.1899/10-045.1
  15. ↑ Root, T. L., Schneider, S. H., Warren, R., Price, J. R., & Mastrandrea, P. R. (2013). Climate Change and Wild Species. Encyclopedia of Biodiversity 2, 79-99. https://doi.org/10.1016/B978-0-12-384719-5.00394-4
  16. ↑ "Invasive Species". National Wildlife Federation. Retrieved December 6, 2024.
  17. ↑ National Invasive Species Information Center. (n.d). Environmental and Ecological Impacts. https://www.invasivespeciesinfo.gov/subject/environmental-and-ecological-impacts
  18. ↑ Falk, B. G., Snow, R. W., Reed, R. N. (2016). Prospects and Limitations of Citizen Science in Invasive Species Management: A Case Study with Burmese Pythons in Everglades National Park. Southeastern Naturalist, 15, 89-102. https://doi.org/10.1656/058.015.sp806
  19. ↑ Dorcas, M. E., Willson, J. D., Reed, R. N., Snow, R. W., Rochford, M. R., Miller, M. A., Meshaka, W. E., Andreadis, P. T., Mazzotti F. J., Romagosa, C. M., Hart, K. M. (2012). Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park. Biological Sciences, 109(7), 2418-2422. https://doi.org/10.1073/pnas.1115226109
  20. ↑ Nungesser, M., Saunders, C., Coronado-Molina, C., Obeysekara, J., Johnson J., McVoy, C., Benscoter, B. (2015). Potential Effects of Climate Change on Florida’s Everglades. Environmental Management, 55, 824–835. https://doi.org/10.1007/s00267-014-0417-5
  21. ↑ Palmer, J. (2024). Bog power: How restoring peatlands can sustain biodiversity and mitigate climate change. BioScience, 74(10), 671–676. https://doi.org/10.1093/biosci/biae028
  22. ↑ Kopp, O. C. (2024). Peat. Encyclopædia Britannica. https://www.britannica.com/technology/peat
  23. ↑ Dreschel, T., Hohner, S., Aich, S., McVoy, C. (2018). Peat soils of the Everglades of Florida, USA. IntechOpen. https://doi.org/10.5772/intechopen.72925
  24. ↑ Editors, B. (2019). Positive feedback - definition and examples. Biology Dictionary. https://biologydictionary.net/positive-feedback/
  25. ↑ Ripple, W. J., Wolf, C., Lenton, T. M., Gregg, J. W., Natali, S. M., Duffy, P. B., Rockström, J., & Schellnhuber, H. J. (2023). Many risky feedback loops amplify the need for climate action. One Earth, 6(2), 86–91. https://doi.org/10.1016/j.oneear.2023.01.004
  26. ↑ Saha, A. K., Saha, S., Sadle, J., Jiang, J., Price, R. M., Sternberg, L. S. L., Wendelberger, K. S. (2011). Sea level rise and South Florida coastal forests. Climate Change, 107, 81–108. https://doi.org/10.1007/s10584-011-0082-0
  27. ↑ 27.0 27.1 Encyclopedia Britannica. (2019). Climate change alters what's possible in restoring Florida's Everglades. Saving Earth. https://www.britannica.com/explore/savingearth/climate-change-alters-whats-possible-in-restoring-floridas-everglades
  28. ↑ The Nature Conservancy. (n.d.). The Everglades: America’s wetland. The Nature Conservancy. https://www.nature.org/en-us/about-us/where-we-work/united-states/florida/stories-in-florida/everglades/
  29. ↑ "THE SCIENCE OF EVERGLADES ECOLOGY". The Everglades Foundation. December 2024. Retrieved December 6, 2024. line feed character in |title= at position 15 (help)


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