Landscape plant diversity distribution related to environmental gradients and human impact activities in South Patagonia

JM CELLINI; G MARTÍNEZ PASTUR; E BASSINO; MV LENCINAS; M BARRERA

PORTUGAL

Conferencia; Landscape ecology conference; 2010

Composition and distribution of plant communities at landscape level are related to environmental gradients, and their conservation status or impacts. The objective was to evaluate changes in plant diversity at landscape level in a mountain basin located in Tierra del Fuego (Argentina), and to determine the influence of human impacts and conservation value of different vegetation types along environmental gradients. The study was located in Andorra Valley (129 km²) where 139 landscape units were identified according their vegetation types (Nothofagus betuloides forests-NB, N. pumilio forests-NP, upper-valley grasslands-UVG, bottom-valley grasslands-BVG and peatlands-P). Floristic surveys (ferns, dicotiledons and monocots) and forest structure were sampled, while environmental variables quantification was performed into a GIS. We found differences in diversity related to aspect, altitude, vegetation types and forest site quality when ANOVAS, classifications and ordination analyses were performed. The most diverse vegetation types were NP and UVG compared to P, BVG and NB, where exotic species were related to the degree of human impact in the studied units. The knowledge of distribution and composition of plant diversity in the different vegetation types and environmental gradients allow us to propose conservation strategies according to the status of the units and their distribution at landscape level.