Biology 2483A Lecture 19: 19-Production.docx
2 Jan 2015
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Document Summary
The term ecosystem was first used by tansley (1935) to refer to all the components of an ecological system, biotic and abiotic, that influence the flow of energy and elements: broad scale science that extends beyond biology. The ecosystem concept integrates ecology with other disciplines such as geochemistry, hydrology, and atmospheric science. Total amount of carbon fixed by autotrophs: gpp depends on photosynthetic rate, photosynthetic rate is influenced by climate and leaf area index (lai) leaf area per unit of ground area. Less than 0. 1 in arctic tundra (less than 10% of the ground surface has leaf cover). 12 in boreal and tropical forests (12 layers of leaves between the canopy and the ground, on average). Trees tend to have higher respiratory losses: respiration rate increases with temperature, so tropical forests have higher respiratory losses. Wouldn"t be profitable for plant to grow leaves beyond bottom layer.
