Vegetation Associations With Environmental Features in the Black Hills and Great Plains: Temperature, Precipitation, Soil Texture and Trace Elements — 53p — Madison Reichert, April Dunn, Sage Robinson, Tara Ramsey, Justin Ramsey

Terrestrial plants are strongly impacted by abiotic features of the environment; vegetation associations often mirror climate factors like precipitation and temperature, and conversely, community composition can be used to infer localized geological processes and soil attributes. Floristics and plant community assembly remain poorly studied in western South Dakota, despite the region’s botanical diversity and complex physical landscape. Here we report on in-progress studies of vegetation patterns and environmental associations at 138 locations in the Black Hills and adjoining Great Plains, based on species inventories (presence/absence data), percent cover estimates (quadrat data), canopy structure (where trees are present), physical and chemical traits of soil, GIS-inferred climate data, and geology parent materials. In total, the data set comprises ~700 vascular plant species and >600 quadrat measurements. 

In summer 2024, our efforts focused on percent cover estimates in quadrats at prairies, badlands, montane grasslands, forests and mountain summits across Harding, Lawrence and Pennington counties; specimen identification in several complex taxonomic groups found in our study sites (especially grasses in the genera Bromus, Calamagrostis, Festuca, Poa, Schedonorus); and the measurement of soil particle size distribution, pH and electroconductivity at selected locations. Preliminary ordinations suggest that temperature and precipitation (both strongly correlated with site elevation) are primary factors associated with site community composition, whereas canopy structure, soil texture, and trace element composition play a secondary role. In general, sites of the same habitat type (as defined by geography and gross environmental features) have similar community composition, and plant diversity (species richness, phylogenetic diversity) increases with elevation. Identifying community composition and diversity trends across the landscape is important for prioritizing conservation efforts and development of land management practices. Results from this project highlight complexities of the Black Hills flora and the need to develop new terminology and descriptions for these communities.

Black Hills State University
Tara Ramsey