• One-way flow of energy through the trophic levels • A cycling of materials from abiotic to biotic and back
Biotic Energy Heat/Motion
Abiotic
Primary Production Community Net PP Total Area World NPP (g/m^2) (mill. Km^2) (bill. tons/yr) • Initial capture of Desert 90 18 1.6 energy into the Temperate 1240 12 14.8 ecosystem Forest Trop.Rain 2200 17 37.8 • Photosynthesis Forest • Two types of PP Lakes/ 250 2 0.5 Streams – Gross Open 125 332 41.5 – Net Ocean Reefs/ 2500 0.6 1.6 Algal Beds
What limits primary production in Bottom-up Model ecosystems?
Increased Productivity: • increased trophic levels supported • Marine: light and nutrients • higher biomass at all • Freshwater: light, nutrients, trophic levels pollution • Terrestrial: light, water
1 Secondary Production
• Energy flow •Rate • Ecological efficiency
Three hundred trout are needed to support one person for a year. The trout, in turn, must consume 90,000 frogs, that must consume 27 million grasshoppers that live off of 1,000 tons of grass. -- G. Tyler Miller, Jr., American Chemist (1971)
2 Where does this energy/biomass go? Energy pyramid For example: CATERPILLAR Digest/Absorb: 1/2 of what they eat. Of this: • 2/3 absorbed goes to cellular respiration (CO2,H2O, heat) • 1/3 absorbed is added BIOMASS at that level
Energy pyramid
Energy lost
3 Biogeochemical cycles
• Water, nitrogen, carbon, phosphorous, etc… • Involve geological (atmosphere, lithosphere, hydrosphere) and biological (trophic levels) components
Carbon Water cycle
Nitrogen cycle
4 Direct values
• Private goods or commodity values • Harvested – Meat – Fuelwood/timber – Edible/medicinal plants • Consumptive and productive use
Indirect values Example: River vegetation
• Public goods, nonconsumptive use value • Benefits from biodiversity not involving harvesting or destroying – Ecosystem productivity – Water quality – Soil protection – Climate – Flood control – Waste treatment and nutrient retention
Ecosystem productivity Soil and water resources
• Primary productivity- • Buffering ecosystems energy –Flood • Terrestrial and – Drought aquatic – Water quality • Diversity-productivity • Logging, farming, development affect soil relationship erosion – Useless for farming – Kill aquatic life – Water undrinkable – Loss of electrical output
5 Climate regulation Waste treatment/nutrient retention
• Local: shade, water • Aquatic communities transpiration, (fungi and bacteria) windbreaks • Break down/immobilize pollutants (2.4 trill) • Regional: • Store sewage and deforestation -> lower nutrient runoff for rainfall, lower uptake photosynthetic organisms of CO2 (global & nitrogen fixing warming) • New York Bight
Species relationships Recreation and ecotourism
• Predation (bottom-up • Enjoyment! and top-down) • Hiking, fishing, camping, rock climbing, • Pollination bird watching • Microorganisms • Ecotourism- to experience unusual communities
Option value Existence value
• Future potential to provide an economic • Value attached to preventing extinction of benefit to human society species, habitat destruction, genetic • Genetic improvement to crops- disease degredation resistance, harvest increase… • Use of flagship species (charismatic • Biological control megafauna) • Medicinal
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