Sustainability based on ecosystem processes • 1. A recycling of elements • 2. Sunlight as a source of energy • 3. Carrying capacities are realized and maintained • 4. Biodiversity is maintained
1. A recycling of elements a. change the one-directional flow characteristic of pollution streams to a cycling and recycling of nutrients. b. recycling will improve soil health and stability. c. e.g. organic farming, green manuring, not using animal dung as a fuel, green belts or fences along streams, minimum or no-till cultivation, contour plantings etc.
2. Sunlight as a source of energy a. the increase in mechanization is connected to the limited capacity of the bioshpere to absorb waste byproducts from fossil fuel burning. b. e.g. urban smog, acid rain, global warming, fear of crude oil depletion c. Alternative like wind and solar power and animal power when appropriate. d. using the front yards to grow fruits and vegetables instead of lawns.
3. Carrying capacities are realized and maintained a. maintaining a suitable standing biomass to assure future production while confronted with increasing per capita consumption, losses in biodiversity, rainforest destruction, overfishing, etc. b. Thermodynamic considerations. c. Pest management: not all of them pests are bad but sometimes eradication methods can’t tell the difference between the good, bad, and ugly.
4. Biodiversity is maintained a. crop rotations:changing the crops to green manure, nitrogen fixation, pest control, disease control, agroforestry, energy plantations, beans and corn, a buffer against economic considerations b. plant breeding that maintains a large germ plasm base:elimination of monocultures.
Biological Control 1. Is it consistent with principles of sustainability 2. Are the introductions controllable, harmful etc. 3. Other
Alternative Pest Control • Cultural control • Control by natural enemies • Genetic control • Natural chemical control
Cultural control Cultural control of pests affecting humans. • sanitation in food handling • sanitation in personal hygiene • sanitation in water quality Cultural control of pest affecting lawns, gardens, etc. • dutch elm disease • marigolds, chrysanthemums • crop rotation • alternative host elimination
Control by natural enemies Use of parasitoids Ladybugs BT changes the flow of energy and cycling of nutrients by changing the list of who eats who
Genetic control Genetic barriers • chemical barriers: phenolic glycosides, cyanogenic glycosides • Physical barriers: tough leaves, hirsuteness • Sterile males:screwworm flies • Biotechnology: BT
Natural chemical control Hormones/phermones • highly specific • nontoxic? • e.g. molting stimulation • trapping/confusion