Can Managers Bank on Seed Banks When Restoring Pinus taeda L. Plantations in Southwest Georgia?

摘要

In the southeastern United States, private forestland managers are under increased pressure to provide wildlife habitat and biodiversity in addition to commercial products such as timber. This study used a stand classification scheme based on vegetation biodiversity from Hedman et al. to compare seed bank composition of benchmark (BM) and nonbenchmark (NBM) Loblolly pine (Pinus taeda) stands. In the Hedman et al. study, BM stands contained species associated with Longleaf pine (P. palust-ris)/Wiregrass (Aristida stricta) communities, whereas NBM stands contained species associated with disturbed sites. The current vegetation of the BM and NBM stands had an average cover of 7.9%/m~2 and an average richness of 11 species/m~2. The intent for this study was to assist in understanding the potential role of the seed bank during stand development and restoration. We collected seedrnbank samples from six pine plantations in the winter of 2006. Seed bank samples yielded 2,885 germinants representing 56 unique species but only 4 were found in both current herbaceous vegetation plots and seed bank. The seed bank was dominated by native dicots. In BM stands, 76% of species were native, whereas in NBM stands, 69% were native. Seed bank samples from NBM stands had greater species richness (p=0.03) and total germinants (p = 0.03) than BM stands. Although the seed bank in all stands was dominated by native species, our data suggest that the seed bank under P. taeda stands should not be viewed as the sole source of native species for most restoration goals.