INVASIVE PLANTS IN CHACO FORESTS: RELATIONSHIPS BETWEEN PLANT DENSITY AND SURVIVAL, LIVESTOCK, AND FOREST FRAGMENTATION

SORIA, N.; TORRES, C.; GALETTO, L.

Mar del Plata

Congreso; World Conference on Biological Invasions and Ecosystem Functioning; 2011

BIOLEF

Invasive species have been considered one of the greatest threats to biodiversity. Those can produce significant changes in the composition, structure and several processes of natural ecosystems, threatening native biodiversity. Landscape fragmentation can aldo reduce biodiversity and represents one of the main factors associated with the introduction of invasive species that generally simplify natural communities. Furthermore, livestock can have a direct influence on the dynamics of plant communities, modifying their susceptibility to establishment and spread of invasive plant species. In this study, we evaluated invasibility on 18 forest fragments with different sizes and livestock grazing intensities, in Córdoba Province (31º S, 64º W). We compared density (richness and abundance) and survival of all exotic plant species (considering 10 transects per site) between fragments of different sizes (small, medium, and large) and livestock grazing intensity (low and high). No significant differences were found in these variables. A total of 32 exotic species were found (10 in all sites and 17 only present in medium and large fragments). Twenty of these species were very common in all sites, the remaining 12 showed low abundance. We obtained high survival values ​​(>50%) for most of the species registered. Results suggest that, regarding the analyzed variables, responses of invasive plants would be species-specific in the studied system.