- Ecology 6
- Biochemistry, general 3
- Biotechnology 3
- Cell Biology 3
- Microbial Ecology 3
- Microbiology 3
- Agriculture 2
- Plant Physiology 2
- Plant Sciences 2
- Soil Science & Conservation 2
- Atmospheric Protection/Air Quality Control/Air Pollution 1
- Ecotoxicology 1
- Environmental Management 1
- Monitoring/Environmental Analysis 1