PARENT SESSION
Contributed Oral Session 85: Mutualism: Pollination
Wednesday, August 10, 8:00 AM - 11:30 AM, Meeting Room 520 C, Level 5, Palais des congrès de Montréal

Latitudinal gradients in the frequency of mutualisms in woody plant communities.

Stegen, James^*,1, Enquist, Brian¹, ¹ Univeristy of Arizona, Tucson, AZ

ABSTRACT- It is becoming increasingly apparent that mutualistic interactions are integral features of ecological communities. Furthermore, mutualisms are increasingly viewed as important in the establishment and maintenance of biodiversity. Thus, determining where mutualisms are rare and where they are common across large spatial scales should provide insight into the forces generating community structure. With this goal in mind, we quantified the latitudinal gradient in the frequency of three plant/animal mutualisms in woody plant communities. We first compiled species lists from 0.1ha plots in the SALVIAS database from across North and South America. We then extracted information from available literature on the presence of biotic versus abiotic pollination, the presence of biotic versus abiotic seed dispersal, and the presence/absence of extra-floral nectaries for the species in our samples. From these data we plotted the proportional abundance (in terms of number of species) of each type of mutualism against latitude. Woody plant communities in North America showed an increasing proportion of biotic pollination with a decrease in latitude. However, there was no parallel relationship between latitude and the proportion of plants with biotic pollination in South America. Patterns of seed dispersal mechanisms and extra-floral nectaries are also described.

Key words: Latitude, Mutualism, Biodiversity, Pollination