PARENT SESSION
Poster Session #15: Vegetation Analysis.
Tuesday, August 7, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall
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Ordination analysis of remnant cemetery prairies in Illinois.
Corbett, Erica1, Corbett, Gail2, 1 2
ABSTRACT- In Illinois, cemetery prairies represent some of the best prairie remnants on sites that would otherwise have been converted to agriculture. These sites are typically thought of as being mainly mesic, blacksoil prairie. In summer 2000, we examined the vegetation composition of 13 remnant Illinois cemetery prairies. In addition, we examined vegetation data collected from cemetery prairies as part of the 1970s Illinois Natural Areas Inventory (INAI). A detrended correspondence analysis of the 13 sites sampled in 2000 showed five clusters or isolated points. Two isolated points represented a site on dry sand and a gravel hill prairie. Two sites currently undergoing shrub invasion also formed a separate cluster. The "typical" blacksoil cemetery prairies formed two clusters: one of sites generally located in central or east-central Illinois, and one of sites in northwestern or western Illinois. Examination of sites from the 1970s INAI showed a pattern of separation of three hill prairies with tight clustering of the remaining sites. When the hill prairies were removed from analysis, the first ordination axis corresponded to a moisture gradient, with mesic prairies receiving low Axis 1 scores and dry-mesic prairies receiving high Axis 1 socres. This pattern was reinforced by the results of an ordination analysis of species data.
KEY WORDS: cemetery prairie, prairie vegetation, detrended correspondence analysis, Illinois prairie