Eco-geomorphological connectivity and coupling interactions at hillslope scale in drylands: Concepts and critical examples

The diagnosis of land degradation requires a deep understanding of ecosystem functioning and evolution. In dryland systems, in particular, research efforts must address the redistribution of scarce resources for vegetation, in a context of high spatial heterogeneity and non-linear response. This fact explains the prevalence of ecohydrological perspectives interested in runoff processes and, the more recent, focused on connectivity as an indicator of system resource optimisation. From a geomorphological perspective and reviewing the concepts of eco-hydro-geomorphological interactions operating in ecosystems, this paper explores the effects of erosion on vegetation configuration through two case studies at different spatio-temporal scales. We focus on the structure function linkage, specifically on how morphological traits relate with different stages in the erosional sequence, both in the abiotic and the biotic domain. Results suggest that vegetation dynamics are affected by structural boundary conditions at both scales, i.e. by surface armouring related with rock fragments at the patch scale, and by the degree of hillslope-channel coupling at the hillslope scale. Our preliminary results can serve as new working hypotheses about the structure-function interplay on hillslopes. All this, taking advantage of the recent technological achievements for acquiring very high-resolution geospatial data that offer new analytical possibilities in a range of scales.

Automated summary

Understanding ecosystem functioning and evolution is crucial for diagnosing land degradation, especially in dryland systems. Research on resource redistribution for vegetation in these areas must consider spatial heterogeneity and non-linear responses, often focusing on ecohydrological perspectives and connectivity indicators. This study explores erosion effects on vegetation through geomorphological, eco-hydro-geomorphological interactions, with preliminary results suggesting that vegetation dynamics are influenced by structural boundary conditions at various scales. New analytical possibilities are made possible by recent technological advancements in acquiring high-resolution geospatial data.