Aquatic Vegetation of Springs at Buffalo National River, Arkansas

Abstract

The biodiversity of freshwater springs in the Arkansas Ozarks is poorly described and has received relatively little attention from researchers. Information on the biodiversity of springs is crucial for their management and conservation. This study describes the aquatic and semi-aquatic plant communities and key habitat features of several springs located at Buffalo National River, Arkansas. We report 58 taxa from among all springs, including eight genera of algae, one species of horsetail, three marchantiophytes, and one bryophyte. Among angiosperms, we found 21 species of monocots and 24 species of eudicots. Six non-native species occur among the springs and none are considered to be invasive. Data show that impounded springs tend to have higher plant diversity than springs with primarily lotic geomorphologies. Cluster analysis showed that the springs with a prominent lentic structure were most similar to each other with respect to shared taxa, while the springs with well defined, long spring-runs and no functional impoundments shared the most taxa. Geographic proximity in the watershed does not appear to play a substantial role in similarity of plant populations, indicating other factors are involved. An NMDS analysis of habitat and water chemistry data corroborated the cluster analysis and showed that habit structure plays a key role in plant community composition. Springs at Buffalo National River occurring within the Boston Mountains and Springfield Plateau appear to have lower taxonomic diversity compared to the larger springs occurring on the adjacent Salem Plateau, which is likely because of their low magnesium concentrations.