Subject
ecosystem
69
plant ecology
28
ecology
27
forest
26
forestry
18
forest decline
16
biotope
14
climatology
11
pollution control
11
climatic change
10
vegetation
10
agriculture
7
carbon dioxide
7
wetland
7
biodiversity
6
climatic effect
6
environmental balance
6
plant physiology
6
soil biology
6
botany
5
carbon dioxide cycle
5
environmental effect
5
environmental protection
5
nutrition
5
environmental impact
4
global change
4
nitrogen cycle
4
root
4
animal
3
biosphere
3
ecophysiology
3
ecotoxicology
3
environment
3
environmental monitoring
3
environmental pollution
3
evolution
3
hydrology
3
insect
3
nature conservation
3
nitrogen
3
photosynthesis
3
plant growth
3
rain forest
3
rhizosphere
3
soil pollution
3
symbiosis
3
agricultural use
2
anthropology
2
aquatic ecosystem
2
biogeochemical cycle
2
more ...