Tallgrass prairie streams occupy a minute fraction of their historical range and are under continuous pressure from agricultural development. Without an understanding of the basic community structure and distributional pattern of the taxa inhabiting these streams, it is impossible to gauge the health of these increasingly threatened habitats. This study aims to increase our knowledge of macroinvertebrate community structure in headwater prairie streams to aid future conservation and restoration activities.
Specifically, our objective was to evaluate similarities and differences in taxonomic composition and community metrics among the headwater systems of several Missouri prairies. Macroinvertebrate samples and corresponding environmental measures were collected from streams in five Missouri prairies in March 2015. Nonmetric multidimensional scaling (NMS) identified the main gradients of variation structuring the communities. Multi-response permutation procedure (MRPP) statistically verified groups evident in the ordination. A joint biplot revealed correlations between environmental variables and prairie communities, and indicator species analysis identified species unique to individual prairies. Differences in various community measures among prairies were analyzed using ANOVA.
Preliminary results compare two of the five prairies, Schwartz and Golden. We interpreted a significant NMS solution with a final stress of 15 that captured 68.8% of the variation present in the original dataset. Invertebrate communities were separated in ordination space by prairie and differed significantly in composition (MRPP, p< 0.001, A= 0.07).
A joint biplot of community data and environmental variables revealed a correlation between axis two and the percent cover of periphyton (r2= 0.411). Axis three correlated with pH (r2= 0.421). Schwartz Prairie was associated with a lower pH than was Golden Prairie.
Indicator species analysis identified that four species, two non-insects and two subfamilies of flies, were indicators of Schwartz Prairie (p< 0.01). The amphipod Synurella bifurca (Hay) was indicative of Golden Prairie (p< 0.01).
No statistical difference (ANOVA) in total abundance (p=0.1304) or Shannon diversity (p= 0.1101) was evident between the two prairies. However, invertebrate richness was significantly higher in Schwartz Prairie than in Golden Prairie (p= 0.0009).
These results suggest that prairies harbor unique aquatic macroinvertebrate communities. In order to preserve a diversity of these prairie communities, conservation efforts should maximize the number of prairies in which stream habitats are preserved.