Park Shaked (PSK), LTSER Northern Negev - Israel

Designation: Ecosystem research and management under land-use and climate change. Climate: Mean annual precipitation 150-200mm between November and April; mean maximum summer temperature 34° C, mean minimum winter temperature 6° C. (Data avialable for 15-min interval meteorological measurements and daily summaries for rainfall, air and soil humidity and temperature, wind velocity and direction, from 1997 to the present.) Principal biomes: Semiarid shrub land (shrub-grass steppe), rocky and loessial watersheds, ephemeral streams. Vegetation is dominated by patch-forming dwarf shrubs (Noaea mucronata, Atractylis serratuloides and Thymelea hirsuta) with species-rich annual winter vegetation in the inter shrub (dominated by Stipa capensis and other grasses) and shrub patch understory (dominated by Anagallis arvensis and other forbs). As a result of drought there are also two new sub biomes: crust land and grass land. Management: Livestock grazing excluded in central watershed (20 ha) since 1987; restricted/controlled grazing by Bedouin sheep herds in surroundings; in the outer parts of the area native and exotic trees were planted in 1985-87 in contour dykes (‘shikhim’) on the slopes and in terraces in the riverbed. Research: 1. Long-term experiments (up to 20 years) for monitoring changes in abundance, diversity, species composition and distribution, and development of biological soil crusts (BSC), perennial plants (dwarf shrubs) and winter annuals in relation to rainfall, soil disturbance, patch distribution, and livestock grazing. 2. long term hydrological studies on rainfall-runoff relationship under natural and manipulation experiments. 3. Short-term experiments and surveys (1 to 5 years) A. for testing hypotheses about the detailed processes, mechanisms and interactions involved in the development, dynamics and stability of shrub- and BSC-dominated patches, their landscape mosaic patterns and their feed-back relationships with flows of materials through the landscape; B. for testing hypothesis on the effect of geodiversity on the stability of shrub land to extreme drought and understanding state changes in drylands. 4. Long term studies on cross scale-cross level interactions in natural and human modified landscape. 5. Network-related research including regional comparisons of herbaceous plant productivity in open rangeland along the Israeli North-South rainfall gradient, and global comparison of woody plant diversity effects on ecosystem functionality of most dryland regions of the world.