PARENT SESSION
Oral Session #104: Plant Communities: Vegetation Analysis.
Presiding: S. Will-Wolf
Friday, August 9. 9:00 AM to 12:00 PM. Grand Ballroom West, Radisson.

Plant strategies, spatial patterns, and succession in a sand dune plant community.

Feagin, R^*,1, Wu, X¹, ¹ Texas A&M University, College Station, TX

ABSTRACT- Plant types, such as competitors and colonizers, and their strategies, such as competitive superiority and stress tolerance, were ascribed with spatial properties in a successional sand dune plant community on Galveston Island, Texas, USA. Spatial patterns of plant types responded to biotic interactions of competition and facilitation and an environmental stress gradient; these patterns reflected facilitative community advancement. Spatial patterns were quantified at multiple scales using univariate and bivariate Ripley's K point pattern analysis to assess the functional correlation between plant types. Spatial patterns were then examined for the dependency of plant locations in one season upon those of the previous season to discern directional interactions and successional mechanisms among plant types. It was found that each plant type uniquely forced direction in the successional process by altering clumping intensity, resulting in a shift in the balance of competition and facilitation along the environmental stress gradient. It is argued that by isolating the spatial pattern of each plant type from its directional force upon the formation of other patterns, the successional dynamics of a sand dune plant community can be attributed to simple plant strategies.

KEY WORDS: spatial, succession, Ripley's, strategy