Arid Dune Ecosystems The Nizzana Sands in the Negev Desert

Sand dune dynamics plays a key role in many arid deserts. This volume provides a synthesis of a specific sand dune ecosystem, the Nizzana site in the Negev Desert. Describing its climate and geophysical/geochemical properties of soils, geological history, flora and fauna, and past/present land-use patterns, it elucidates ecological and geomorphological processes and their interrelations, based on long-term monitoring, in situ experiments and satellite imagery. Particular attention is drawn to the impact of the topsoil biological crust in controlling water availability at local/regional scales. The interdisciplinary approach adopted in this case study offers a good example of a highly complex and dynamic system, which could easily be applied to other sandy ecosystems.

This is a valuable source of information for soil ecologists and microbiologists, conservation biologists, desert ecologists and geographers, geomorphologists, soil scientists and climatologists, lecturers, policy makers and others interested in deserts and desertification.

The North-Western Negev.- Geological Background of the Nizzana Area.- Geo-Ecology of the North-Western Negev Sand Field.- Formation and Geomorphology of the North-Western Negev Sand Dunes.- The Regional Climatic Setting.- Soil Characteristicsand Pattern of the Nizzana Research Site.- Land Use and its Effect on the Mobilization and Stabilization of the North-Western Negev Sand Dunes.- Ecosystem Patterns.- The Flora of the Nizzana Research Site.- The Vegetation of the Nizzana Research Site.- A Glance on the Fauna of Nizzana.- Biological Crusts.- Land Cover in the Nizzana Sandy Arid Ecosystem. Mapping Surface Properties with Multi-Spectral Remote Sensing Data.- Ecosystem Processes.- Topoclimate and Microclimate.- Evapotranspiration, Transpiration and Dewfall.- Morphological Changes at Active Dune Crests.- Aeolian Sand Transport and Vegetation Cover.- Soil Processes and Salt Dynamics in Dune Soils.- Runoff and Erosion Processes Within a Dune System.- Effects of Surface Runoff and Subsurface Flow on the Spatial Variability of Water Resources in Longitudinal Dunes.- Atmospheric Input of Nutrient Elements and Dust into the Sand Dune Field of the North-Western Negev.- Succession Stages in the Recovery Processes of the Topsoil Crust in a Disturbed Sandy Arid Area.- Dew Formation and Activity of Biological Soil Crusts.- Nitrogen Input Pathways into Sand Dunes: Biological Fixation and Atmospheric Nitrogen Deposition.- Vascular Plant Response to Microbiotic Soil Surface Crusts.- Ion Relations of Plants and Soil Patterns.- Temporal and Spatial Variability of Plant Water Status and Leaf Gas Exchange.- Standing Biomass and its Modelling.- Effects of Shrubs on Annual Plant Populations.- Demography of Annual Plants: The Role of Habitat Heterogeneity and Competition.- Research Perspectives / Synthesis and General Conclusions.- Sensitivity of a Sandy Area to Climate Change Along a Rainfall Gradient at a Desert Fringe.- General Conclusions – Sand Dune Deserts, Desertification, Rehabilitation and Conservation.