GEOB 102 Lecture Notes - Lecture 4: Biocoenosis, Heterotroph

• School: UBC
• Department: Geographical Biogeosciences
• Course: GEOB 102
• Professor: Pamela O

Document Summary

Process by which plants (+ other organisms) convert solar e to chemical e. Opposite of photosynthesis, chemical break down of chos: gross photosynthesis. Total amount of carbohydrate produced by photosynthesis: net photosynthesis. Net photosynthesis depends on light intensity and temperature: production, net primary productivity (npp) Amount of stored chemical energy produced by photosynthesis. Yield of useful energy in the ecosystem. Measured as biomass = dry weight of organic matter. Expressed as kg of biomass per m2 per year. At global scales, npp varies with latitude and precipitation. Varies between ecosystem types: secondary productivity. Amount of new biomass produced by consumers and decomposers: energy flow, food chains and food webs. A network of e links among ecosystem components. Illustrates the potential pathways of e flow. A simple conceptual model of e flow that traces carbon compounds through the ecosystem. Each layer = trophic (feeding) level: autotrophs (primary producers, heterotrophs (consumers)