back to Wildlife Ecology and Management
elective course
2. Dynamics
Energy flows one-way
Trophic levels:
(Trophos = "feeder", food chain )
(1) Producers (autotrophs)
(2) Primary consumers
(3) Secondary consumers
(4) Tertiary consumers
Detritivores
Primary productivity
1-5% of solar energy is bond
NPP: produced by heterotrophs
Productivity in bioms (click on thumbnail)
Why only four levels?
70-90 % of energy is lost at each level
0.1% energy reaches last level
Such a system cannot support extra levels
BBC: S Africa to allow elephant cull
The South African government has said it will allow elephants to be culled for the first time in 13 years.
The elephant population is thought to have grown from 8,000 to 18,000 since the government banned culls in 1995.
http://news.bbc.co.uk/1/hi/world/africa/7262951.stm