Species-sorting in a 10-year old mesic prairie restoration
Meta-community theory has as a main criterion the dispersal of species. To distinguish between the species species-sorting and mass-effects paradigms, the number of propagules is also important. However, there are few experimental examinations of these paradigms. We report on twenty-three 30m diameter circular plots within a 500 ha restoration landscape. By using identically seeded plots, we tested for evidence of species-sorting. Each plot was planted with a 48-species mesic prairie seed mix over a general mix at the landscape scale. Wet and dry plots were planted as well but we focus here only on the mesic plots. Plots were sampled 10 years after initial planting, recording establishment within each plot and recruitment outside the plot up to 15m beyond the plot boundary. Species were ranked on seed dispersal potential, with wind dispersal being the greatest and gravity dispersal the least. Plots were ordinated and species abundances examined for evidence of species sorting.
Eleven planted species were not found within any plot. Nine species that established did not disperse beyond plot boundary. Of the species that dispersed beyond the plot edge, most dispersed less than 5m and there was no difference among the dispersal potential types. Several species demonstrated species sorting, showing either increases or decreases along an ordination axis corresponding with a moisture gradient. In this example of mesic grassland restoration, species-sorting occurred within 10 years.