Related by context. Frequent words. (Click for all words.) 67 arid 64 semi arid 55 irrigated agriculture 53 temperate regions 53 soils 53 desertification 52 Droughts 52 climatic conditions 51 river basins 51 Desertification 51 subtropics 51 temperate climates 50 prolonged drought 50 grasslands 50 crop yields 50 irrigated 49 droughts 49 arid desert 49 underground aquifers 49 climates 49 arable land 48 rangelands 48 Sahel 48 tamarisk 48 tropical climates 48 Arid 48 sandy soils 48 freshwater 48 groundwater pumping 47 drought tolerant 47 freshwater lakes 47 biofuel crops 47 salt cedar 47 mid latitudes 47 cropland 47 atmospheric circulation 47 Soil moisture 46 drought resistant 46 drier 46 overgrazing 46 basins 46 cheatgrass 46 habitats 46 drought stricken 46 cold climates 46 aquifers 46 Mediterranean basin 45 clay soils 45 cereal crops 45 tropics 45 croplands 45 ecosystems 45 grasses 45 salinity 45 mountain glaciers 45 latitudes 45 warm climates 44 species 44 river basin 44 deserts 44 wetter 44 parched 44 drought parched 44 carbon sinks 44 sandy soil 44 groundwater recharge 44 pikas 44 rangeland 44 Tibetan Plateau 44 Sub Saharan Africa 44 boreal forests 44 Kalahari Desert 44 woody plants 44 biodiverse 44 transboundary 44 eastern Corn Belt 44 soil moisture 44 sub Saharan Africa 43 urbanization 43 grassland 43 diatoms 43 habitat 43 carbon sequestration 43 aquatic ecosystems 43 Deserts 43 nitrogen fertilizers 43 colder climates 43 moist soil 43 forage 43 soil fertility 43 fungal spores 43 Aral Sea 43 biologically diverse 43 temperate 43 Sahel region 43 forest ecosystems 42 groundwater 42 irrigation 42 basin 42 tropical forests 42 Ogallala Aquifer