Mechanistic controls of community assembly and biodiversity

The deceptively uniform bilayer structure of longleaf pine (Pinus palustris) ecosystems, featuring forests, woodlands, and savannas of canopy longleaf pines and grass-dominated ground cover, belies the exceptional floristic diversity associated with the herbaceous ground cover. Most notably, this ground cover harbors the highest levels of plant species richness in North America and globally rivals other species-rich herbaceous-dominated plant communities (Walker and Peet 1983; Peet and Allard 1993). Not only does high species richness occur at local scales (Table 5.1), but regionally, the species-rich ground cover is also characterized by many species endemic to the southeastern Coastal Plain. In addition, the entire North American Coastal Plain, which encompasses the former range of the longleaf pine, has been proposed as a global biodiversity hotspot (Noss et al. 2015).