The Bluegrass Region is an area in north-central Kentucky with unique natural and cultural significance, which possesses some of the most fertile soils in the world. Over recent decades, land use and land cover changes have threatened the protection of the unique natural, scenic, and historic resources in this region. In this study, we applied a fragmentation model and a set of landscape metrics together with the satellite-derived USDA Cropland Data Layer to examine the shrinkage and fragmentation of grassland in the Bluegrass Region, Kentucky during 2008–2018. Our results showed that recent land use change across the Bluegrass Region is characterized by grassland decline, cropland expansion, forest spread, and suburban sprawl. The grassland area decreased by 14.4%, with an interior (or intact) grassland shrinkage of 5%, during the study period. Land conversion from grassland to other land cover types has been widespread, with major grassland shrinkage occurring in the west and northeast of the Outer Bluegrass Region and relatively minor grassland conversion in the Inner Bluegrass Region. The number of patches increased from 108,338 to 126,874. The effective mesh size, which represents the degree of landscape fragmentation in a system, decreased from 6629.84 to 1816.58 for the entire Bluegrass Region. This study is the first attempt to quantify recent grassland shrinkage and fragmentation in the Bluegrass Region. Therefore, we call for more intensive monitoring and further conservation efforts to preserve the ecosystem services provided by the Bluegrass Region, which has both local and regional implications for climate mitigation, carbon sequestration, diversity conservation, and culture protection.
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This study was supported by the NASA Kentucky Space Grant Consortium and EPSCoR Programs (NNX15AR69H), a collaboration project between UKY and NASA GISS. Alex C. Ruane acknowledges support from the NASA Earth Science Division through the NASA Goddard Institute for Space Studies Climate Impacts Group.
The following are available online at http://www.mdpi.com/2072-4292/12/11/1815/s1, Figure S1: Groundwater sensitivity regions of the Bluegrass Region (modified from the map of Groundwater Sensitivity Regions of Kentucky), Figure S2: Map of physiographic regions in Kentucky, Table S1: Conversions between various fragmentation categories between 2008–2018.
Tao, Bo; Yang, Yanjun; Yang, Jia; Smith, S. Ray; Fox, James F.; Ruane, Alex C.; Liu, Jinze; and Ren, Wei, "Recent Shrinkage and Fragmentation of Bluegrass Landscape in Kentucky" (2020). Plant and Soil Sciences Faculty Publications. 146.