Disturbances in the desert and threats to conservation

BORGHI CARLOS; CAMPOS CLAUDIA; ANDINO NATALIA; REUS LAURA; GIANNONI STELLA

Congreso; Segunda Reunión Conjunta de Sociedades de Biología de la República Argentina; 2011

The desert is a system of low species richness at the local level. However, because of the ecological characteristics (e.g., low primary productivity), high environmental heterogeneity and great climate severity (e.g., extreme temperatures, low water availability, and high radiation) of this system, species of low density (rare species) and endemism at genus and species levels are frequently found. Because of these features, biological diversity of arid zones becomes highly sensitive to disturbances. Although these characteristics would place those species in a high threat category, few works have evaluated the impact of different disturbances on diversity of arid zones in Argentina. On the one hand, among the disturbances affecting biological diversity that have traditionally received most attention are overgrazing, deforestation, agricultural frontier expansion, and petroleum and mineral exploitation. On the other hand, a number of anthropogenic activities that have been poorly studied in South America include road construction and use, urban expansion, tourism development, and the use and contamination of rivers and streams; these activities, which have increased as a consequence of the im- provement in the economic situation, disturb our deserts. Besides those factors, there are also some problems that have been poorly or not evaluated, such as the effect of the spread of exotic species on biodiversity, the destruction of biological crusts and natural corridors, the effect of dam construction, and the effect of the introduction of exotic fishes. Hence, the high vulnerability of desert systems, with a high rate of endemisms, is stressed, as well as the scarce knowledge of the effect of traditional and new anthropogenic disturbances on these systems.