Liana Abundance Diversity and Distribution on Barro Colorado Island Panama
Schnitzer SA; Mangan SA; Dalling JW; Baldeck CA; Hubbell SP; Ledo A; Muller-Landau H; Tobin MF; Aguilar S; Brassfield D; Hernandez A; Lao S; Perez R; Valdez O; Yorke SR
Lianas are a key component of tropical forests; however most surveys are too small to accurately quantify liana community composition diversity abundance and spatial distribution – critical components for measuring the contribution of lianas to forest processes. In 2007 we tagged mapped measured the diameter and identified all lianas =1 cm rooted in a 50-ha plot on Barro Colorado Island Panama (BCI). We calculated liana density basal area and species richness for both independently rooted lianas and all rooted liana stems (genets plus clones). We compared spatial aggregation patterns of liana and tree species and among liana species that varied in the amount of clonal reproduction. We also tested whether liana and tree densities have increased on BCI compared to surveys conducted 30-years earlier. This study represents the most comprehensive spatially contiguous sampling of lianas ever conducted and over the 50 ha area we found 67447 rooted liana stems comprising 162 species. Rooted lianas composed nearly 25% of the woody stems (trees and lianas) 35% of woody species richness and 3% of woody basal area. Lianas were spatially aggregated within the 50-ha plot and the liana species with the highest proportion of clonal stems more spatially aggregated than the least clonal species possibly indicating clonal stem recruitment following canopy disturbance. Over the past 30 years liana density increased by 75% for stems =1 cm diameter and nearly 140% for stems =5 cm diameter while tree density on BCI decreased 11.5%; a finding consistent with other neotropical forests. Our data confirm that lianas contribute substantially to tropical forest stem density and diversity they have highly clumped distributions that appear to be driven by clonal stem recruitment into treefall gaps and they are increasing relative to trees thus indicating that lianas will play a greater role in the future dynamics of BCI and other neotropical forests.