25 quality forest in Illinois and 250 acres in the Fox River Area.14 Similarly, presettlement vegetation maps of the Fox River Area show savannas were a common feature of the Fox River Area, but are no longer. Of the 1,299.2 acres of savanna in Illinois, one high-quality savanna occurs in the Fox River Area today.15 About 53,401 acres of wetland occur in the Fox River Area and a total of 1,655 acres are undegraded and high-quality.16 The status of the different natural communities in Illinois and the Fox River Area was the same — prevalent in 1820 but seldom occurring today. From the pattern of population change seen across the Fox River Area natural communities, it is clear that land cover changes, which moved in tangent with human activities, rendered the decline in health of the Fox River Area. By virtue of the widespread land conversions since 1820, habitat fragmentation occurred in the Fox River Area. A few distinguishable characteristics of fragmented habitats make them more prone to environmental conditions and risk factors. Due to reduced area, the habitat can only support species at lower population levels, which are more susceptible to extirpation.17 Increased isolation decreases the frequency of migration among fragments, thus reducing recolonization after degradation.18 The creation of edges results in soil moisture conditions and levels of solar radiation.19 In the long term, fragmentation can reduce species richness and abundance, and decrease the restoration potential of an environment. The effects of industrial pollution on grasslands in the Fox River Area demonstrate how perturbations impact the adaptation capacity of a fragmented habitat compared to an unfragmented habitat. In 1970, the spillage of oil in grasslands caused a small 14 Ibid. 15 Ibid. 16 Ibid. 17 Ibid. 18 Haddad, Nick. “Habitat Fragmentation and its Lasting Impact on Earth’s Ecosystems.” Science Advances, March 20, 2015. https://www.science.org/doi/10.1126/sciadv.1500052; Illinois Department of Natural Resources. Fox River Area Assessment. Office of Scientific Research and Analysis, 1998. https://friendsofthefoxriver.org/wpcontent/uploads/2018/03/fox-3-Living-Resources.pdf. 19 Ibid.
RkJQdWJsaXNoZXIy Mjg3OTMy