Rich Get Richer Hypothesis

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The Rich Get Richer Hypothesis: Plant Invasions in the Pisgah Forest Marina Nemshon Introduction Global biological diversity is threatened when natural habitats have low plant diversity versus those with higher diversity, according to the “Rich get Richer” theory, as stated by C. Elton. Previous studies have shown that the more diverse a habitat, the less it is exposed to invasion of exotic plant species .The focus of this theory within the context of community ecology is the reproductive abilities of invasive species, particularly in the Pisgah Forest over the last two years. The study sites of fifteen blocks of 3, 4 x 4 m plots, were evaluated in order to sample plant diversity in the Pisgah Forest from Summer 2014 to Fall 2015. These…show more content…
His theory suggests that an exotic species would face strong resistance from many native species that dominate the available resources and create a stable community. This theory has generally been supported until lately, where it is believed that the opposite of Elton’s theory is true. Espinosa-García F, Villaseñor J, Vibrans H. The rich generally get richer, but there are exceptions: Correlations between species richness of native plant species and alien weeds in Mexico. Diversity and Distributions. 2004;10(5-6):399-407. doi:10.1111/j.1366-9516.2004.00099.x. This study applies Elton’s notion of biotic resistance and found that their result is consistent with his findings. This study used the beta diversity equation to quantify their results. They found a positive correlation between the number of native and exotic species. Factors that affect the spread of exotic species is human population density, which has been shown to be an important predictor variable for exotic plant species. Simpson A, Jarnevich C, Madsen J et al. Invasive species information networks: collaboration at multiple scales for prevention, early detection, and rapid response to invasive alien species. Biodiversity. 2009;10(2-3):5-13.…show more content…
This study seeks to understand and determine factors correlated with invasibility in Colorado and how to predict and prevent loss of biodiversity by modeling invasions. Jarnovich claims that riparian habitats as well as rare habitats are more heavily invaded than upland sites. Stohlgren T, Barnett D, Kartesz J. The rich get richer: plant invasions in the United States and Canada. Frontiers in Ecology and the Environment. 2003;1(1):11-14. doi:10.1890/1540-9295(2003)001[0011:trgrpo];2. This study compared plant diversity at two different sites, similar to our lab, and found that the opposite of Elton’s theory to be true. Hot spots of native plant diversity were being more invaded than the less diverse habitats. Some factors that may have affected their data is the presence of roads in terrestrial systems, where they found Russian thistle covered the newly graded roadsides. The same can be true for Pisgah Forest, where the hiking/running path can serve as a conduit for seed dispersal for exotic plants. Stohlgren T, Barnett D, Kartesz J. The Rich Get Richer: Patterns of Plant Invasions in the United States. Frontiers in Ecology and the Environment. 2003;1(1):11.

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