Impact of landscape spatial pattern on liana communities in tropical rainforests at Los Tuxtlas, Mexico

Questions: What are the species composition and species and stein densities of liana communities in tropical landscapes of different deforestation levels? Which spatial attributes (forest cover, patch area, shape and isolation) have the strongest influence on liana communities in these landscapes? Location: Forty-five rainforest patches in Los Tuxtlas Biosphere Reserve, Mexico. Methods: In three landscapes with different deforestation levels (HDL = 4%; IDL = 11%; and LDL = 24% of remaining forest cover) liana communities (DBH >= 2.5 cm) were characterized in 15 randomly selected patches per landscape (10 50 mx2 m transects per patch = 0.1 ha), and evaluated the effects of patch area, shape and isolation on liana species and stein density (number of species and stems per 0.1 ha). Results: A total of 64 taxa and 24 families were sampled. Species composition differed highly among landscapes, with HDL being the most dissimilar landscape. The response of lianas to landscape spatial pattern differed significantly among landscapes. Proximity to villages had a strong positive effect on species and stem densities in LDL and IDL. There was a sharp decrease in liana stein density in HDL, with four patches (27%) found to be unoccupied by lianas. Conclusions: Fragmentation may have a positive effect oil lianas, partly because of edge effects. This positive effect seems to be limited by the proportion of remaining forest cover in the landscape, as the liana communities had collapsed in the most deforested landscape.