Co‐occurring bunchgrasses are associated with different plant species in dry pine savannas

Abstract

Grass species are often included during restoration to reinstate feedbacks with fire. In biodiverse pine savannas of the southeastern United States, wiregrass (Aristida beyrichiana) is the preferred candidate for restoring low‐intensity fires through the understory. Less common but locally co‐dominant in dry pine savannas, pineywoods dropseed (Sporobolus junceus) is another bunchgrass candidate for restoration. If two bunchgrass species associate with different suites of plants in the understory, restoring both could support a twofold goal of restoring fire regimes and plant biodiversity. To guide restoration goals, we tested the hypothesis that in natural (i.e. not recently restored) dry pine savannas in North Florida where wiregrass and dropseed are co‐dominant, they are associated with different understory plant species richness, occurrence, and abundance under or adjacent to their canopies. Species richness of associated plants did not differ between bunchgrass species or with distance from bunchgrass (i.e. under vs. adjacent). Some associated plant species, however, were more likely to occur and had greater abundance with one or the other bunchgrass species irrespective of distance. Our results suggest that including more than one bunchgrass species in restoration plantings could increase dry pine savanna biodiversity while also reinstating plant‐fire feedbacks.