XVI International Botanical Congess
Since European agricultural practices began on the Great Plains, the tall-grass prairie has declined in area between 82-99%. Additionally, species numbers in the remaining prairie may also have declined as a result of habitat fragmentation. Further species loss and alteration of plant communities may result from the invasion of prairie fragments by non-native plant species. A study of 24 tall-grass prairie fragments ranging from Minnesota and Wisconsin to Oklahoma and Missouri (ranging in size from 0.5 ha to 12,000 ha) addresses these questions: 1) do numbers of non-native plant species increase as prairie unit size decreases, 2) do naturally fragmented units (in woodlands) have lower numbers of non-native invaders than human fragmented units (in agricultural settings) of the same size, and 3) will prairie fragments clustered in space have more similar non-native species assemblages than like size fragments from more distant locations?