Trees 97 Forestry 68 Forests and Forest Trees (Biology and Ecology) 44 Botany 39 Forests 35 Plants 34 Forest management 24 Forest ecology 22 Silviculture and Forest Management 22 Agroforestry 20 Agriculture 19 Biological Resources (Plant) 17 Silviculture 17 Sustainability 17 United States 16 History 15 Biodiversity 14 Forests and forestry 14 Nature conservation 14 Plant Ecology 14 Woody plants 14 Forest policy 13 India 13 Policy and Planning 13 TREES 13 Botany, Medical 12 Forestry Economics, (New March 2000) 12 Materia medica, Vegetable 12 Natural Resource Economics, (New March 2000) 12 Forest trees 11