Biodiversity 315 Ecology-- Biodiversity-- Conservation 174 Ecology-- Biodiversity-- Conservation-- Ecosystems 135 Biodiversity conservation 82 Ecology 40 BIODIVERSITY 22 biodiversity 17 Biotechnology 15 Economics 14 Nature conservation 14 Ecology-- Biodiversity-- Conservation-- Ecosystems - Encyclopedia-- Dictionary 13 Biological Resources (Plant) 12 Environment 12 Sustainable development 11 Biodiversity-Kerala 10 Climate change 10 Forests and Forest Trees (Biology and Ecology) 10 Natural resources 10 Pollution 10 Sustainability 10 Environmental economics 9 India 9 Climatic changes 8 Forests 8 Agriculture 7 Ecology-- Biodiversity-- Conservation-- Ecosystems-Study and teaching 7 Ecosystem services 7 Forest management 7 Human ecology 7 Natural Resource Economics, (New March 2000) 7