Environmental Management
Environmental Management tests ecosystems, food chains, energy flow, biodiversity, pollution and sustainable waste management. The exam often links a local environmental problem to a scientific principle.
Core rules
- An ecosystem includes biotic communities and abiotic factors interacting. Producers make food, consumers eat it, and decomposers break down dead matter.
- Food chains show one path of energy transfer; food webs show interconnected chains. Energy decreases at each trophic level, roughly by the ten percent law, so top consumers receive less energy.
- Biodiversity is variety of species, genes and ecosystems. Conservation may be in situ, such as national parks, or ex situ, such as seed banks and zoos.
- Pollution includes air, water, soil and noise pollution. Biomagnification can concentrate non-degradable pollutants in top consumers.
- Sustainable management uses reduce, reuse and recycle, waste segregation, treatment of effluents and renewable alternatives.
Worked example
In the chain grass -> grasshopper -> frog -> snake, suppose grass has 10000 J of energy. Using the ten percent law, grasshoppers receive about 1000 J, frogs about 100 J and snakes about 10 J. The reasoning is that most energy is lost as heat and used in life processes at each transfer, so fewer trophic levels can support more energy for top consumers.
Traps
Energy decreases along a food chain, but biomass does not always follow the same simple pattern. Decomposers are not consumers at the top of a food chain. Biomagnification increases pollutant concentration upward. Conservation is not just locking land away; it includes sustainable use. The ten percent law is an approximation, not an exact rule.