Liana-tree interactions in a subtropical montane forest of NW Argentina

MALIZIA, A,; GRAU, H.R.

Miami, Usa

Congreso; ATBC: Geographic and conceptual frontiers of tropical biology; 2004

Association for Tropical Biology and Conservation

Lianas are life forms (usually light demanding) that rely mostly on trees for support in order to reach light. Several studies have shown that tree species differ in susceptibility to lianas’ infestation due to their morphological – functional characteristics. In this study, we analyzed the association between the liana community and tree species in six hectares of subtropical montane forests in the Sierra de San Javier, Tucumán, Argentina. All lianas > 2 cm diameter were measured on standing trees > 5 cm (canopy species) or 10 cm (subcanopy species) diameter at breast height (dbh). Tree species, dbh, crown illumination and crown form indexes, foliar phenology and position into the forest strata (as canopy or sub-canopy) were registered per tree individual. Liana stem abundance and basal area were estimated per tree and also per 20x20 m quadrants within the plot. Despite that tree community had a wide variety of morphological features and a moderate species richness (32 spp), none of the tree features considered was associated to liana density or basal area. Instead, lianas were significantly spatially autocorrelated at 20 and 40 m of radial distance. Our results suggest that tree features play a relatively minor role in structuring liana communities. Instead, factors contributing to original establishment (e.g. light gaps, microenvironment) as well as dispersal limitation strongly condition lianas distribution and community spatial structure.