El papel de la (des)conectividad ecohidrológica en el funcionamiento y el manejo de las zonas áridas

Resumen

Connectivity is defined as the degree to which the spatial structure of the landscape facilitates the flow of organisms and materials. Various conceptual models and empirical evidence attribute a key role to hydrological connectivity in the functioning of dryland ecosystems and landscapes, yet an integrated perspective on the different facets and processes that link connectivity with the degradation and recovery of drylands is still lacking. Here, we describe ecohydrological connectivity as an emergent property of ecosystems and landscapes that captures the interaction between hydrological connectivity and ecological proceses, and discuss how ecohydrological connectivity controls dryland ecosystem functioning, underlies the dynamics of desertification, and can be managed to facilitate the recovery of degraded drylands. A dysfunctional ecohydrological connectivity would be one in which most of the resource flow associated with bare soil connectivity at the slope or landscape scale cannot be retained and exploited by the sink effect of vegetation. Actions for the recovery of the degraded system would be aimed at interrupting the general connectivity of the bare soil matrix, promoting source-sink dynamics and enhancing the sink capacity of the vegetation patches or tiles. At the landscape scale, the disruption of hydrological connectivity can, in turn, create habitat patches and corridors for a wide variety of species, facilitating their movements and thus their conservation and adaptation to climate change.