PARENT SESSION
Poster Session # 21: Biogeography, Biodiversity, Populations, and Genetics.
Thursday, August 7 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.
Constancy in community measures through time in a tropical forest.
Price, Charles*,1, Turner, Will1, Rosenzweig, Michael1, Enquist, Brian1, 1 Department of Ecology and Evolutionary Biology, Tucson, Az
ABSTRACT- A central goal of ecology is the identification of patterns and processes responsible for generating patterns of diversity across varying scales and landscapes. There have been two general approaches, which appear to offer the ability to provide a mechanistic and quantitative framework for ecology. The first approach has focused on the mathematical properties of species-area relationships. Species-area relationships have been examined at scales ranging from within small biotas to among continents and the biotic and abiotic factors thought to influence species-area patterns are numerous. A second approach has focused on elucidating the fundamental role of organism size and abundance. Body size has been observed to be strongly correlated with a suite of physiological and life history characteristics such as: population size, abundance, generation time, growth rate, home range size and metabolic rate. Surprisingly, few studies have explored how size and area are fundamentally linked; namely, how organismal size, abundance and area combine to influence patterns of diversity across differing spatial scales or though time. Here we explore how tree density, aggregation and size in the form of basal stem diameter measures influence the scaling of diversity in a 12 ha, dry tropical forest plot through time. Despite significant turnover, shifts in species proportional abundance, shifts in centroid position, and marked aggregation; species-area, individual-area, species-individual and body-size abundance relationships remain constant following twenty years of change. These results highlight several invariant community-level scaling relationships. Further, our results point to links between allometric (or body mass) scaling rules and species-area scaling rules. Together, these patterns show that despite local change in species dominance and composition, ecological communities display highly robust patterns that are revealed by scaling across size and area.
Key words: species-area, allometry, community, body size