human ecology Sociology 5 ecology 3 social organization 3 Field biology 2 Food supply 2 ecosystem 2 Animal Nutrition 1 Closed ecological systems 1 Crops and climate 1 Ecology 1 Ecology of population 1 Economics 1 Environmental science 1 Human geography 1 Landscape assessment 1 Social culture 1 bio geo chemical cycles 1 biochemical cycles - ecosystems 1 crops - climate 1 energy 1 environmental history 1 environmental policy 1 environmental protection 1 natural resources 1 non energy materials 1 population ecology 1 social organizations 1 society 1 sustainable development 1