- Ecology 22
- Freshwater & Marine Ecology 15
- Plant Sciences 12
- Zoology 12
- Environment, general 10
- Atmospheric Protection/Air Quality Control/Air Pollution 8
- Plant Physiology 8
- Plant Pathology 7
- Soil Science & Conservation 7
- Climate Change/Climate Change Impacts 6
- Environmental Health 5
- Life Sciences, general 5
- Ecotoxicology 4
- Hydrogeology 4
- Monitoring/Environmental Analysis 4
- Plant Ecology 4
- Water Quality/Water Pollution 4
- Agriculture 3
- Atmospheric Sciences 3
- Biochemistry, general 3