VEGDESERT · Vegetation shifts in desert environments: a multi-scale ecogeomorphic approach for the analysis of grassland-shrubland transitions

Climate change and the massive alteration of natural habitats are major drivers of land degradation. Their effects may be especially significant in drylands, where ecosystems are particularly sensitive to degradation, usually involving irreversible landscape changes (i.e. desertification). A common form of desertification in drylands includes the encroachment of shrub species into historic productive desert grasslands. An array of mechanisms are involved in shrub encroachment processes, including external triggering factors such as climate and land-use variations, and endogenous amplifying mechanisms brought about by soil erosion-vegetation feedbacks. Within this context, the present mobility project will investigate grassland-shrubland transitions in desert environments. The ambitious objective of this project is to develop an ecogeomorphic framework for the analysis and prediction of rapid vegetation shifts in semi-arid grasslands threatened by shrub encroachment processes. The project will be hosted by Durham University (UK) and will focus on grassland-shrubland transitions in the Chihuahuan desert, taking advantage of the information and facilities available at the Sevilleta Long Term Ecological Research Station (New Mexico, USA). The influence of a variety of triggering factors (i.e. precipitation variations and grazing) and the impact of soil erosion-vegetation amplifying feedbacks on these vegetation changes will be studied using an innovative approach that will integrate both remote sensing information of vegetation phenology and experimental data across different scales