Over the past decades, the frequency and severity of droughts have been increasing across extensive parts of the world. In southern Israel, long-term droughts have been prevalent since the turn of the 21st century. In the northwestern Negev, droughts have caused the mass mortality of shrubs, particularly impacting Noaea mucronata (Forssk.) Asch. & Schweinf, which is a dominant shrub species across the region. Recent studies revealed that this mass mortality is confined to low-geodiversity hillslopes, characterized by a thick (>1 m) and non-stony soil layer. Meanwhile, high-geodiversity hillslopes, characterized by a thin (~10 cm to the underlying bedrock) and very stony soil layer, were not adversely affected. In this project, we employed a wide range of procedures and methodologies, including soil sampling and analyses, remote sensing, 3-dimensional underground geophysical mapping, and mathematical models, to investigate the mechanisms underlying these marked differences. Overall, the datasets converge to suggest that the high-geodiversity hillslopes present generally better habitat conditions than the low-geodiversity counterparts, in terms of soil-water content, soil quality, and strata properties. Specifically, greater soil-water content in the high-geodiversity hillslopes stimulates biogeochemical cycles, resulting in improved living conditions for the shrubby vegetation as well as for the entire ecosystem. This study aims to gain better knowledge of the factors shaping drylands resilience under climate change. Climatic forecasts – including rising temperatures and increasing aridity in low-to-mid latitudes, resulting in dryland aggravation and expansion – emphasize the relevance of this study.
