Biodiversity is the variation among organisms and ecological systems at each environmental level. However, the easiest way to study these organisms is to look at species richness. Species richness involves looking at the number of species found within a given area (Ricklefs 2008). Species dispersal involves organisms moving in and out of areas to inhabit another area. Dispersal can affect organismal distribution or overall population fitness, thereby harming species richness or increasing richness (Ricklefs 2008). There are multiple factors that can influence the species richness of an organism, known as anthropogenic ecological stressors ( Thompson and Shurin 2012 ). There are a wide variety of these ecological stressors ranging from pollution, climate change and the introduction of invasive species, to habitat destruction and changing environmental conditions locally and globally (Thompson and Shurin 2012). These ecological stressors can occur individually or more simultaneously, interacting with each other and causing changes in resident species. Multiple applied ecological stressors can have a large impact on biodiversity and overall ecosystem function (Christensen et al. 2006). Stressors can be predicted due to environmental changes, but there is no control over how strongly they are applied and when they will occur (Christensen et al. 2006). Biodiversity in freshwater is known to be extremely vulnerable to climate. In response to rising temperatures due to climate change, organisms are expanding their ranges to higher latitudes and altitudes (Heino et al 2009). Therefore they are moving their overall distribution...... to the center of the paper...... which is undergoing continuous changes, thus linking back to the spatial insurance hypothesis. Works Cited Christensen, M.R., Graham, M.D., Vinebrooke, R.D., Findlay, D.L., Paterson, M.J., Turner, M.A. 2006. Numerous anthropogenic stressors cause ecological surprises in boreal lakes. Global Change Biology, 12: 2316-2322. Heino, J., Virkkala, R. and Toivonen, H. 2009. Climate change and freshwater biodiversity: detected patterns, future trends and adaptations in northern regions. Biological Reviews, 84: 39-54. Ricklefs, R. E. 2008. Community structure. Pages 376, 413 in J. Correa and S. Moran, editors. The Economy of Nature. WH Freeman and Company, New York, USA.Thompson, PL and Shurin, JB 2012. Regional zooplankton biodiversity provides limited buffering of pond ecosystems against climate change. Journal of Animal Ecology, 81: 251-259.