Species introductions in longleaf pine groundcover vegetation

Abstract

Longleaf pine groundcover vegetation is uniquely species rich at small to medium spatial scales. However, species richness has been reduced in many locations by a history of fire suppression and soil disturbance. It is therefore of interest to determine whether groundcover species can be successfully introduced into appropriate habitats without intensive site preparation which might further damage those habitats. We have been testing two methods for introducing species into longleaf pine groundcover vegetation in the Francis Marion National Forest: (1) as seeds, collected by machine from several sites inside and outside of the National Forest. (2) as nursery grown seedlings. The only site preparation is fire. Results indicate that wiregrass (Aristida beyrichiana) is readily introduced from seed (i.e., seedlings are present and increasing in size 2 years after the initial introductions), particular1y in high light microhabitats without excessive woody competition. However, seed introductions are rarely successful for other species. In contrast to the seed introduction treatments, we have had good success introducing 1-2 year old seedlings. In addition to nursery grown seedlings of wiregrass, we have also outplanted toothache grass (Ctenium aromaticum), lndiangrass (Sorghastrum nutans) and the rare forb Pamassia caroliniana. In all cases, seedlings have shown good survival (generally > 80%). Pamassia seedlings have demonstrated the capacity to withstand periods of flooding lasting > 7 days and are Increasing rapidly in size (i.e., measured as clump basal area). We conclude (1) that seedling introductions may be a useful method for enhancing species richness of longleaf pine groundcover, and (2) sites managed with frequent fire and minimal soil disturbance may serve as refugia for artificially established populations of rare groundcover plants.

Citation

Giltzenstein, Jeff S.; Streng, Donna R.; Wade, Dale D. 1996. Species introductions in longleaf pine groundcover vegetation. In: Proceedings First Longleaf Alliance Conference; 1996 Sept. 17-19; Mobile, AL: 79-81.