Related by context. Frequent words. (Click for all words.) 70 Soil erosion 66 overgrazing 62 salination 61 overgrazed 58 Invasive plants 57 soil erosion 57 intensively farmed 56 bioenergy crops 56 ecological degradation 56 soil fertility 55 nutrient runoff 55 Severe drought 55 habitat fragmentation 55 cropland 54 croplands 54 wolf predation 54 grassland habitat 54 arable crops 53 livestock rearing 53 irrigated crops 53 prolonged droughts 53 arable farming 53 habitat degradation 53 periodic droughts 53 Droughts 52 cereal crops 52 frequent droughts 52 deforesting 52 grassland 52 overhunting 52 deciduous forests 52 crop yields 52 hay meadows 52 Feral hogs 52 overexploitation 52 drylands 52 shelterbelts 51 cerrado 51 deforestation 51 species extinctions 51 grazing 51 grasslands 51 rampant poaching 51 rampant deforestation 51 forbs 51 prolonged drought 51 overfishing pollution 51 scanty rains 51 cattle rearing 51 environmental degradation 51 rangelands 51 saturated soils 51 forage crops 50 insect populations 50 fertile soils 50 lowland forests 50 rainfed 50 bollworms 50 soil compaction 50 Amazon deforestation 50 semi arid 50 monocultures 50 pastoralism 50 crops 50 moorlands 50 erratic monsoon 50 forest ecosystems 49 superweeds 49 Suburban sprawl 49 nitrous oxide emissions 49 wetland ecosystems 49 biofuel crops 49 rotting vegetation 49 arable land 49 desertification 49 acidic soils 49 arable lands 49 crop residues 49 insect infestations 49 farmland 48 Rapid urbanization 48 arid lands 48 pasture 48 Deforestation 48 Illegal logging 48 sagebrush habitat 48 sown crops 48 nutrient loading 48 horticultural crops 48 nutritional deficiency 48 Invasive species 48 forage 48 soils 48 aridity 48 perennial grasses 48 nutrient absorption 48 leafy spurge 48 nutrient uptake 48 freshwater ecosystems 48 scanty rainfall 48 sorghum crop