PARENT SESSION
Oral Session #30: Landscape Ecology: Dynamics and patterns. Presiding: A. Hansen.
Tuesday, August 7, 2001. 1:00 PM to 5:00 PM. Madison Ballroom D.
Vegetation patterns along the Kalahari transect.
Caylor, Kelly1, Shugart, Herman1, 1
ABSTRACT- Spatial pattern in tree distribution is examined at 10 sites along the IGBP Kalahari transect in southern Africa in order to examine the effect of a large climatic gradient on community structure. Analysis indicates significant aggregation among all individuals in the vegetation communities at most sites, but random spatial distributions of individuals at the most southern arid sites. The spatial distribution of large individuals is random across the entire transect. The uniform distributions commonly hypothesized to exist in savanna environments are rarely observed at all but the most arid sites. An investigation of the density of understory vegetation beneath large trees shows significantly lower than expected values at both northern and southern sites in the transect, and much higher than expected values at intermediate sites. The high degree of significant variation in the spatial distribution of small individuals with respect to large canopy individuals suggests that distribution of suitable regeneration sites and subsequent patterns of establishment may be critical phenomena in determining the spatial pattern of vegetation.
KEY WORDS: savanna, spatial pattern, kalahari, competition