A Measurement of Historical and Contemporary Function

Document Type

Graduate Research

Publication Date





In 1984 a portion of the Monahan, a PSU Biology field site, was reclaimed in order to establish a native grassland community and to prevent runoff of acidic groundwater. In the years since then, several student projects have analyzed the vegetation community on the site, estimating the species diversity found there. In this study, conducted in 2014, the biodiversity of the Monahan was measured using four indices of function diversity. Functional diversity describes the variety of ecological functions in a community; functional diversity indices measure and describe these functions instead of individual species. Results from two past graduate theses were included in this analysis and compared to the 2014 findings. The results of this comparison showed that the Monahan reclaimed grassland had generally increased in functional diversity (and by extension biodiversity) over time, but the dominant facets of diversity have been variable in each sample. In the first samples taken after the reclamation (Vickers, 1989) the community became more functionally even and divergent; that is, the species found were evenly spread across the community functional groups. A sample taken in 1994 revealed that the grassland had become less functionally even and divergent but more functionally dispersed, or were more widely spread across the functional groups (Yates, 1996). The survey conducted for this thesis in 2014 reveal that the grassland is at the highest level of functional richness ever recorded, but is less functionally diverse than 1994 by all other indices. Overall, since the initial 1984 reclamation, the grassland has actually increased in all areas of functional diversity.


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