Related by context. Frequent words. (Click for all words.) 53 aquatic ecosystem 52 aquatic habitat 50 aquatic ecosystems 50 forest ecosystems 49 watersheds 49 fragile ecology 49 irrigated agriculture 49 freshwater ecosystems 48 aquatic habitats 48 aquifer recharge 47 riparian habitat 47 groundwater recharge 47 ecosystems 47 lynx habitat 46 wildlife habitat 46 bio diversity 46 wildlife habitats 45 Yellowstone ecosystem 45 ecological 45 terrestrial ecosystems 45 headwater 45 riparian 45 headwaters 44 wetland habitats 44 biodiversity 44 Salinity 44 semi arid 44 aquifer 44 soils 44 streamflows 44 alluvial deposits 44 CO2 sequestration 44 aquifers 44 fragile ecosystem 44 ecosystem 43 ecology 43 wetland habitat 43 fertile soils 43 marine ecosystem 43 marine ecosystems 43 salinity 43 viewshed 43 spawning habitat 43 Cerrado 43 underground aquifer 43 karst 43 woodland caribou 42 coastal ecosystems 42 fragile ecosystems 42 biosphere reserve 42 seagrasses 42 biota 42 tidal wetlands 42 habitat 42 bull trout 42 groundwater 42 habitat fragmentation 42 rangelands 42 Boreal Forest 42 arid lands 42 biosphere 42 ecologies 42 Book Cliffs 42 boreal forest 41 hydrologic 41 Vegetation 41 Suisun Marsh 41 freshwater wetlands 41 underground aquifers 41 groundwater pumping 41 southern Appalachians 41 coral reef ecosystems 41 airshed 41 river basins 41 overgrazed 41 aquatic organisms 41 marine biodiversity 41 rangeland 41 ecologically fragile 41 tallgrass prairie 41 caribou herds 41 lake sediments 41 waterfowl habitat 41 drylands 41 biologically diverse 41 geomorphology 41 arid regions 41 river basin 41 hydrogeological 41 boreal 40 sediment runoff 40 ecological degradation 40 soil fertility 40 whirling disease 40 drainage basin 40 federally endangered 40 groundwater basin 40 carbon dioxide sequestration 40 Great Basin 40 phosphate mining 40 wetlands