Herbaceous Plants and Grasses in a Mountain Longleaf Pine Forest Undergoing Restoration: A Survey and Comparative Study

The Berry College Longleaf Pine Management Area consists of old-growth fire-suppressed mountain Pinus palustris (Longleaf Pine) stands embedded within an encroaching matrix of mixed pines and hardwoods. Since 2001, portions of this area have been subjected to restoration efforts involving logging followed by burning, foliar herbicide application, and planting, as well as burning and hardwood control using herbicides in unlogged old-growth stands. To document the herbaceous plants and grasses of this site and to begin to address questions concerning the short-term impacts of management practices on these species, flowering specimens were systematically collected in managed and unmanaged stands in 2008 and 2009. We recorded 201 species in 35 families, including 70 species of Asteraceae, 35 species of Poaceae, 17 species of Fabaceae, and 10 grass-like species other than Poaceae (Cyperaceae, Iridaceae, and Juncaceae). Native herbaceous plants most commonly found included: Houstonia caerulea, Hypoxis hirsuta, Solidago odora, Oxalis stricta, Coreopsis major, Hypericum hypericoides, Lespedeza procumbens, Hieracium venosum, and Packera paupercula. While only 14 species were found in unmanaged old growth, 127 were found in managed old growth, and 167 in logged areas. Fire suppressed old-growth mountain Longleaf Pine forests are generally virtually devoid of understory plant diversity; these results suggest that reduction in canopy density and leaf litter can substantially recover herbaceous and grass species diversity. However, the extent to which understory diversity can be fully recovered in any specific site remains in question, particularly if local propagule sources have vanished during the period of fire suppression. A comparison with historical species lists at our site, and with other mountain Longleaf Pine forests in various stages of fire maintenance, is presented to help define characteristic understory species for mountain Longleaf Pine forests.