INVESTIGADORES
LOYDI Alejandro
congresos y reuniones científicas
Título:
Vegetation change in response to grazing exclusion in montane grasslands, Argentina
Autor/es:
ALEJANDRO LOYDI
Lugar:
Budweiss
Reunión:
Conferencia; The 8th European Conference on Ecological Restoration; 2012
Institución organizadora:
SER Europe Chapter
Resumen:
Montane grasslands in the Southern Pampas of Argentina are expected to show a high potential for recovery after heavy grazing due to their evolutionary history in the presence of large herbivores and their high productivity. Biodiversity in the area is mostly preserved through landscape heterogeneity (e.g. rocky outcrops, different altitude and exposition), but grassland recovery is necessary to avoid erosion and maintain ecosystem functionality. The objective of this work is to compare plant diversity, biomass and botanical composition among grazed and non-grazed areas at different times following grazing exclusion. Vegetation was assessed on exclosures established in 2006 and on nearby areas open to grazing by feral horses in December 2006, 2007, 2008 and 2009. In 2009 we added 15 year old exclosures to the analysis. Species richness declined 24 months after grazing exclusion, mainly due to a decrease in the abundance of forb species. Above-ground biomass showed a 3-fold increase 12 months after grazing exclusion. After three years of grazing exclusion, species richness and biomass were similar to those corresponding to older exclosures (15 years old). The composition of plant communities also changed following horse exclusion, with three and 15 years old exclosures dominated by perennial grasses typical of late seral stages. Our results support the hypothesis that montane grasslands in the Southern Pampas of Argentina may recover fast from grazing by large herbivores without application of specific restoration techniques.