In a dryland ecosystem, the sparse vegetation usually incurs frequent drought stress, inducing topsoil erosion and land degradation. The degradation may become irreversible because of inappropriate practices and/or climate change, which in turn deteriorates the natural hydro-ecosystem, leading to more frequent and severer floods and droughts, damaged biocrusts as a living cover, and further soil erosion and vegetation degradation. Consequently, such an ecosystem may be shifted from a sink to a source of green-house gases (e.g., CO₂), accelerating climate change. To increase the sustainability and resilience of dryland ecosystems as well as to confront global climate change, it is required to have a complete understanding of how hydrologic processes, biocrust and topsoil dynamics, and vegetation physiologies are interrelated, with climate and human activity as two extrinsic factors. This session cordially invites presentations of theoretical, experimental, and modeling studies that tackle the whole or fractional interrelations mentioned above.