Recovery Methods of Endangered Plant Species
Written by Margaret Wei
Recovery is the process of restoring threatened species to a point in which they no longer qualify under the protection of the Endangered Species Act. Due to the yearly increase in the number of endangered species, habitat restoration rose to priority among conservationists. According to the International Union of the Conservation of Nature, a species is classified as endangered when they meet at least one of the following criteria: decrease of over half of the population over 10 years, a total geographic area less than 5,000 km2, a restricted population size and area, or a statistical prediction that it will go extinct within the next 20 years. As a result of human activities, the factors that push these species to extinction include loss of habitat, the introduction of a foreign species into the environment, hunting, pollution, disease, and loss of genetic variation. Currently, there are least 40,000 endangered species which include animals, plants, and insects. To prevent this number from growing, new and innovative methods of habitat recovery are introduced to prevent species from going extinct.
Framework for Habitat Recovery
Monitoring is essential to track the long-term recovery of endangered species. Greater emphasis on habitat monitoring is especially important for taxa whose populations may be difficult to quantify, such as insects, or when true recovery requires continuous species specific habitat management. The recovery process begins with the final ruling from the Endangered Species Act. After that process, an organization that can immediately move forward with recovery-work develops a process for each species, such organizations can include state parks, research institutions, and universities. The recovery plan functions as a map for the species is able to sustain itself in the wild, and it must include an estimate of time and cost, measurable criteria so that when they are met, there is a clear distinction to which the species can be removed from the list. If successfully implemented, recovery plans result in a listed species being reclassified from endangered to threatened status, or result in the delisting and removal of the species from ESA protection.
The Endangered Texas Star Cactus Recovery
Among plant species, recovery includes identifying the long term threats of the population and determining which threat is most critical the population’s persistence; however, this can be difficult because there are a wide variety of potential threats. For arid-land cacti, these threats include over-collection for the horticultural trade, habitat disturbance, and disease or predation. The prime concern for plants is identifying what the risk is- this being because of a lack of observation and documentation, and predation is not a very widespread concern among these types of species.
A case study in Texas of the endangered Star Cactus (A. asterias) in depth displays the causes to the endangerment and the proper procedure to restore habitat. The recovery plan established that the main cause of the endangerment was a result of habitat destruction from over-collecting by enthusiasts, inadequate regulatory protection, and a limited amount of genetic variability, and invasive speciation and animals. In the study, they were able to determine how the regional variation in the different threats impacted the recovery plan by documenting the herbivores posing a threat to A. asterias in Texas, examining the rates of mortality among different sites of A. asterias in Texas, and relating herbivore-induced mortality to environmental variables and life-stages of A. asterias.
By highlighting differences in herbivore-induced mortality among geographically disparate populations, suggests that the population variability in mortality rates at both a local and regional scale exists. Looking at the study from an objective standpoint will lead to the development of more thorough recovery plans for endangered arid-lands plants such as A. asterias. Through statistical analysis and imaging, the study discovered that there was a variety of mammalian herbivores preying upon A. asterias.
Because this study focused on environmental factors, future studies require a more diverse investigation on the factors influencing mortality rates, including the connection between surrounding habitats and current land-use practices.
Conclusion
In order to successfully recover an endangered species from extinction, based on the experimental results from the Star Cactus, it is crucial to thoroughly examine the environmental stimuli and their internal and external interactions. Before a restoration plan was established, the habitat was examined to pinpoint exactly what were the threats to cause the endangerment due to the wide possibilities. These possibilities include weather conditions, predatory implications, invasive species, diseases, competition, habitat destruction due to humans, etc. In the observation and environmental manipulation, the study discovered that the main cause of the extinction was due to an excessive amount of herbivore predation. Because the study did not consider the weather (temperature, rainfall, etc) as a cause of endangerment, it would be beneficial to implement more foundational guidelines in future examinations to improve comprehensiveness in restoring endangered species. Additionally, futures studies should implement a more controlled environment by manipulating the experiment to test the effects of specific variables. However, the process of restoration is far from completed. Recovery is a lengthy process that can take up to hundreds of years that requires cooperative efforts from its partners, state legislation, local tribes, not-for-profit organizations, researchers, private individuals, and other federal agencies.
References
Bried, J., Tear, T., Shirer, R., Zimmerman, C., Gifford, N., Campbell, S., & O’Brien, K. (2014).
A framework to integrate habitat monitoring and restoration with endangered insect recovery. Environmental Management, 54(6), 1385–1398. https://doi.org/10.1007/s00267-014-0351-6
Adam W. Ferguson, Richard E. Strauss, Anna W. Strong, Sandra J. Birnbaum, Jackie M. Poole, Gena K. Janssen, Paula S. Williamson. (2013). Assessing regional differences in predation of endangered species: Implications from Texas populations of the endangered star cactus (Astrophytum asterias), Volume 97, Journal of Arid Environments, https://doi.org/10.1016/j.jaridenv.2013.05.018.
What makes a species endangered? (n.d.). Retrieved February 25, 2021, from
Fisheries, N. (2020, July 10). Recovery of species under the endangered species act. Retrieved
February 25, 2021, from https://www.fisheries.noaa.gov/national/endangered-species-conservation/recovery-species-under-endangered-species-act.