The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)

Environmental instability and functional traits explain lemur ecological community structure


Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University

March 28, 2015 , Gateway Ballroom 2/3/4/5 Add to calendar

Community ecology predicts how species assemblages are shaped by abiotic and biotic factors. The phylogenetic structure of communities (PSC) integrates evolutionary and ecological data to tease apart subtle differences in the mechanisms of community assembly. Communities consisting of species which are more closely related than expected by chance and share similar functional traits (clustered) are predicted in environments that filter species assembly. Over-dispersed communities are predicted when competition and niche partitioning limit the co-existence of closely related species. Disturbance randomizes species assembly as local extinctions create opportunities for colonizing species. I surveyed lemur abundance along environmental gradients of elevation and anthropogenic disturbance using distance sampling techniques in southeast Madagascar between 2011 and 2014. I tested if functional traits (group size, diet, life history) are related to environmental adaptation and niche partitioning to elucidate patterns in PSC. Community structure in disturbed habitats did not differ from random expectation (mean Nearest Taxon Index, NTI = - 0.6 permutation tests of PSC, p>0.05), likely because environmental stochasticity created frequent opportunities for invasion by colonizing species. In contrast, the PSC in pristine forests was significantly clustered (mean NTI = -1.5, p <0.05) because closely related species with similar functional traits (large group size and frugivory) had high relative abundance. Elevation and disturbance explained ~50% of variation in PSC (ANCOVA, F=4.147, p<0.05). In sum, lemur PSC is shaped by environmental instability and the ability of some species to dominate communities.

I thank the Leakey Foundation, NSF, SBU, PCI, CI, MBZ, Rufford.