Related by context. Frequent words. (Click for all words.) 67 mountain pine beetles 64 lodgepole 64 lodgepole pine 62 whitebark pine 61 temperate forests 60 aspen trees 60 aspen 60 beetle infestation 59 amphibian populations 58 lichens 58 jack pine 58 habitat fragmentation 58 lodgepole pines 58 Yellowstone ecosystem 58 sequoias 58 pine beetle infestation 58 lichen 58 grassland birds 57 pine beetles 57 sagebrush habitat 57 grassland habitat 57 species extinctions 57 terrestrial ecosystems 57 warmer winters 57 ponderosa pines 56 dieback 56 hemlock trees 56 winterkill 56 conifer trees 56 evergreen forests 56 hemlocks 56 Warming temperatures 56 boreal forests 56 ponderosa 56 species 56 adelgids 55 desiccation 55 caribou herds 55 bee populations 55 giant sequoias 55 forbs 55 junipers 55 aspens 55 hickories 55 fireweed 55 habitat degradation 55 amphibian species 55 forest ecosystems 55 bark beetle 54 insect infestations 54 retreating glaciers 54 Bighorn sheep 54 woody plants 54 mountain pine beetle 54 caribou herd 54 adelgid 54 temperate zones 54 spotted knapweed 54 milder winters 54 beech trees 54 mountain caribou 53 Gypsy moths 53 prolonged droughts 53 overhunting 53 herbaceous plants 53 insect populations 53 pollinating insects 53 loosestrife 53 grizzly bears 53 boreal 53 bark beetles 53 thawing permafrost 53 oak woodlands 53 avian species 53 conifers 53 elk herds 53 Mountain Pine Beetle 52 Infestations 52 ponderosa pine 52 chytrid fungus 52 cankers 52 vegetation 52 vertebrate species 52 understory 52 conifer 52 temperate regions 52 cheatgrass 52 woodland caribou 52 cottonwoods 52 birches 52 Grizzly bears 52 ungulates 52 Phytophthora 52 leafless 52 ptarmigan 52 seagrasses 52 eucalypts 52 bamboo forests 52 hardwood forests 52 timberline 52 pine beetle