Changes in plant functional diversity along eucalypt forest cycle and their association with environmental conditions

RODRIGUEZ, E.; ACEÑOLAZA, P.; PAIRO, P.; BELLOCQ, M.I.

Curitiba

Congreso; XXV World Congress IUFRO (Inter. Union of Forest Res. Organizations); 2019

Tree plantations have become one of the fastest growing land uses in recent decades, mainly to attend high demands for timber and pulp production. Eucalypt is the primary tree species planted in ¨Pampean grasslands of Argentina, where our understanding on the effects on biodiversity and ecosystem functioning is limited. We assess the responses of plant functional diversity and similarity (relative to the native habitat) along eucalypt forest cycles and identify the environmental variables associated with functional characteristics of plants. We selected nine ages with three replicates (sites) per age and three protected grasslands (as reference habitat). At each site, three plots were established to measure environmental variables expected to change with plantation age. We calculated functional diversity (FDis) and similarity (FSor) indices based on life history traits (related to dispersal, establishment and persistence). We used fourth-corner analysis to identify associations between life history traits and environmental variables. Results showed a decline in FDis with increasing plantation age associated with increasing leaf litter depth (LITTER) and canopy cover, and a decline in FSor associated with LITTER.. Results of fourth corner analysis revealed a positive and strong association between plantation density with annual herbaceous plants and zoochory as dispersion syndrome; and a negative and strong association with barochorous species. Also, plants with high dispersal potential were negative and strong associated with LITTER. Eucalypt forest cycle had a negative impact on plant functional diversity, in Pampean grasslands of Argentina.