INVESTIGADORES
IZQUIERDO Andrea Elisa
congresos y reuniones científicas
Título:
Agriculture adjustment, population urbanization and nature conservation in NW
Autor/es:
GRAU,GASPARRI, GRAU,MORALES,CARILLA,ARAOZ, IZQUIERDO
Lugar:
Morelia, Mexico
Reunión:
Congreso; ATBC 2007: Linking tropical biology with human dimension; 2007
Institución organizadora:
Association for Tropical Biology and Conservation
Resumen:
We analyzed government statistics and published case studies to assess the trends in
human demography and land use change during the last 50 years in NW Argentina, a
subtropical region (>50 million ha), which includes different life zones: dry forests
(Chaco), montane humid forests (Yungas), high elevation grasslands and shrublands
(Puna), and middle elevation desserts (Monte). And, to assess the impacts of these
changes on nature conservation. Agriculture intensified and expanded in mesic lowland
ecosytems and middle elevation irrigated desserts, favored by international demand for
commodity products (soybean, sugar, wine). In these areas, population grew fast and
became concentrated in urban centers. In contrast, in the different mountain
ecosystems, marginal agriculture and extensive grazing decreased in association to a
reduction in rural population. This process favored the recovery of different forest types
and the expansion of population of once threatened large mammals (e.g. Vicugnas in the
Puna). These opportunities for ecosystem recovery, however, where limited by the
existence of different stable and low diversity plant communtities. For example in Yungas
ecosystems, peri-urban secondary forests are often dominated by highly resilient
monodominant exotic tree stands; and fire-maintained degraded grasslands are not
invaded by trees even when grazing pressure decreases. Dry forests combine both
expansion of modern agriculture and reduction in extensive grazing over non-deforested
areas. Balancing these two processes is the key to ensure the conservation of the
Chaco, one of the largest continuous remaining neotropical dry forest ecosystems.
Overall, this analysis indicates that ecosystem recovery associated to agriculture
adjustment to the most productive soils allows growing food production in association to
increasing regional opportunities for nature conservation. However, complex interactions
between social and natural systems need to be considered to take advantage of these
opportunities and to minimize the threats associated to rapid land use change.