Ecosystem classification in a flat, highly fragmented region of Indiana, USA

A multifactor ecosystem classification of the Bluffton Till Plain Subsection of Indiana was created to characterize and organize ecosystem units within the Framework for Hierarchical Ecosystem Classification, which is used in forests throughout the eastern United States. The Bluffton Till Plain is a relatively flat landscape, typified by an undulating plain comprised of glacial till. The region is largely agrarian with forests scattered as distinct woodlots. Through examination of relationships among vegetation, soil, and landform characteristics, the Bluffton Till Plain has been organized into 3 ecological land-types (ELT) and 12 ecological land-type phases (ELTP). Nine herbaceous plant communities were described in the region, and they have been used to indicate site characteristics distinctive of each ELTP. Plant communities were found to be strongly related to landform topography, soil horizon depths, and soil texture through a process that identified communities with cluster analysis and related them to site characteristics with Classification and Regression Tree analysis. The most important factors in determining differences between plant community composition were the landform and landform component, which are related to the swell-and-swale topography of the till plain.