Related by context. Frequent words. (Click for all words.) 65 aquatic ecosystems 64 forest ecosystems 64 ecosystems 63 marine ecosystems 62 biota 59 atmospheric carbon dioxide 59 species 59 lake sediments 59 diatoms 58 atmospheric CO2 58 habitats 58 marine ecosystem 58 coastal ecosystems 58 mammals 58 phytoplankton 57 coral reefs 57 atmospheric circulation 57 biodiversity 57 ocean ecosystems 56 marine organisms 56 anthropogenic 56 ocean acidification 56 acidification 56 biosphere 56 biomes 56 megafauna 55 temperate regions 55 boreal forests 55 landforms 55 albedo 54 mountain glaciers 54 glaciers 54 insect populations 54 biodiversity hotspots 54 corals 54 vertebrates 53 oceans 53 carbon sinks 53 wetland habitats 53 photosynthetic 53 greenhouse warming 53 cyanobacteria 53 lichens 53 ecologies 53 sediments 53 harmful algal blooms 53 CO2 concentrations 53 mid latitudes 53 polar regions 52 soils 52 zooplankton 52 amphibian species 52 marine biodiversity 52 ENSO 52 taxa 52 aquatic insects 52 habitat 52 coral species 52 volcanism 52 plankton 52 reefs 52 vertebrate 52 extinctions 52 herbivores 52 biochemical processes 52 Coral reefs 52 mass extinctions 52 invertebrates 52 bee populations 51 keystone species 51 landmasses 51 photosynthesis 51 oceanic 51 microscopic organisms 51 polar caps 51 steroid hormones 51 flora 51 organisms 51 Late Cretaceous 51 metabolic processes 51 boreal forest 51 aquatic organisms 51 sediment cores 51 peatlands 51 benthic 50 drylands 50 intestinal bacteria 50 olivine 50 speciation 50 ecology 50 abundances 50 mammalian species 50 tropical forests 50 fauna 50 atmospheric chemistry 50 tropical rainforests 50 glacial melt 50 ozone depletion 50 vegetation 50 boreal 50 nesting habitat