Tuesday, August 7, 2007

PS 30-150: Effects of two treatments aimed at eliminating Pteridium aquilinum in sites with arrested succession in the Lacandon Tropical Forest, Chiapas, México

Cristina B. Peñaloza-Guerrero and Diego R. Pérez-Salicrup. Universidad Nacional Autónoma de México

P. aquilinum creates monospecific patches in areas intensively used under slash and burn agriculture. Once P. aquilinum dominates fields succession is inhibited. One morphological attribute that makes P. aquilinum difficult to eradicate, is its persistent rhizome. In this study we evaluated the effects of casting shade and mechanically cutting the rhizome on above and belowground biomass of P. aquilinum in invaded fields in Chiapas. For the shade experiment we established six plots of 7 x 7 m in two different sites, each plot had a central sub-plot of 3 x 3 m hereafter called sample area. Three plots were covered with an 80 % shade net in each site. For the mechanical damage experiment we established eight plots of 4 x 4 m in each site, with a sample area of 3 x 3 m. In both experiments we estimated mean frond height, density and biomass, and rhizome biomass as response variables. Response variables were measured before and 12 months after shade treatment, and before and six months after root damage treatment. Neither treatment had an effect on the response variables. Hence, these treatments might be insufficient to eliminate P. aquilinum and restore forest succession.