Nature tourism Tourism and Travel 8 Leisure, Recreation and Tourism Economics, (New March 2000) 7 Natural Resource Economics, (New March 2000) 7 Ecotourism 5 Sustainability 5 Land Resources 4 Nature conservation 4 Tourism development 4 Biological Resources (General) 3 Case studies 3 Environmental impact 3 National parks 3 Biological Resources (Animal) 2 Community Participation and Development, (New March 2000) 2 Community development 2 Conservation areas 2 Management 2 Policy and Planning 2 Protected areas 2 Social Psychology and Social Anthropology, (New March 2000) 2 Social impact 2 Tourism 2 Tourism impact 2 Tourism policy 2 Accommodation 1 Acquired immune deficiency syndrome 1 Aquatic Biology and Ecology 1 Biodiversity 1 Biology 1