SPATIAL-DISTRIBUTION OF FORBS AND GRASSES IN A SOUTH-CAROLINA OLDFIELD

Determined whether grasses could influence dynamics of wet and dry sites in a midsuccessional oldfield (abandoned for 35 yr) in South Carolina. Neither the distribution of seeds, soil resources nor flowering annual plants deviated from random in plots where grasses were present. In plots with grasses removed, the distribution of flowering annual forbs did not differ significantly from random. Some 37-73% of random points in 2 × 2-m plots hit only bare ground or litter. The large amount of space indicated a site open to colonization. Persistence of annual forbs and successional dynamics in this field are probably not determined by lack of space for colonization, nor are they influenced by perennial grasses. Rather, forb dynamics and succession may be influenced by broad-scale influences (eg general soil resource levels or seasonal rainfall distribution) on germination and seedling establishment. -from Authors