Temporal and spatial dynamics in a northern tallgrass prairie

Abstract

It is well established that plants and soil properties are interdependent. What is less known is the degree to which the distribution of plant and soil properties, in both space and time, match one another. We assessed plant community and soil conditions in permanent sample plots in a tallgrass prairie community from 2002 to 2008. Redundancy analysis showed that the dominant grass species were associated with changes in elevation, soil pH, and gravimetric water content, but not nitrogen or phosphate. Indicator species analysis suggested the community is best described by four cluster types, with half of the plots changing community type over the 6-year sampling period. These cluster types were generally spatially aggregated, with semivariograms showing a range from 80 to 346 m. This degree of spatial structuring was observed in the elevation and soil water content data, but not in measures of soil inorganic N or P. This suggests that natural plant communities do not necessarily show a strong correspondence to all soil variables, especially those that vary rapidly in time and space. The dynamic nature of vegetation patch distribution, combined with their size, may contribute to the loss of species from small tallgrass prairie reserves.