Biological interactions in woodlands in the Monte Desert

VALERIA CAMPOS; PATRICIA BALMACEDA; STELLA GIANNONI

Mendoza

Congreso; XXXI Reunión Anual de la Sociedad de Biología de Cuyo; 2013

In arid and semi-arid ecosystems, woody plants produce changes in microclimate and soil properties. Ramorinoa girolae is a woody species, endemic of western Argentina and its morphology characteristics make it able to maintain different biological interactions. In this work we evaluate the diversity of plants under canopy of R. girolae and inter-canopy microhabitats, and fitted models to assess if the species richness under canopy was explained by different morphology characteristics of R. girolae. We recorded presence-absence data for plant species under canopy and inter-canopy in 29 individuals of R. girolae in the Ischigualasto Provincial Park, San Juan province, Argentina. For each individual we measured: area of canopy, density of branches, maximum high, cover percentage of shrubs and herbs under its canopy. The diversity index was higher under canopy (D=14.43) than inter-canopy (D=13.58), but there was not a significant difference (W=10.00; p=0.99). The best models to explain species richness included area of canopy (weight=0.14), density of branches (w=0.11) and both variables (w=0.08). The parameter likelihood was higher for area of canopy (0.51) than for density of branches (0.39). The microenvironments created by large and dense canopy facilitate the establishment and growth of different plant species.