Seed longevity of 12 native herbaceous species in a fire-maintained pine savanna after 8 years of burial

Abstract

Restoring the fire-maintained longleaf pine (Pinus palustris Mill.) ecosystem in the southeastern United States has become a regional conservation priority in recent years and development of cost-effective approaches to restoration is a major objective. An improved understanding of the potential role of persistent seed banks in the longleaf pine ecosystem and reliance on the seed bank for restoration efforts could contribute to reduced costs associated with restoration. We used a buried seed bag method to determine seed banking potential of species within three common families (Poaceae, Fabaceae, and Asteraceae) and a rare, endangered member of the Orobanchaceae family native to the longleaf pine ecosystem. Seeds were exhumed 1, 2, 4, and 8years after burial and tested for viability. Species within the Fabaceae showed the greatest potential for forming long-term persistent seed banks with seed viability 50% or greater after 8years of burial. Some species in the Poaceae, Asteraceae, and Orobanchaceae form transient or short-term persistent seeds banks. The ability of some species to form short- or long-term persistent seed banks may in some cases make it possible to rely on the seed bank for native species re-introductions on sites scheduled for restoration.