Biology 2483A Study Guide - Final Guide: Normalized Difference Vegetation Index, Spectral Signature, Chlorophyll
15 Dec 2017
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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. The ecosystem concept integrates ecology with other disciplines such as geochemistry, hydrology, and atmospheric science. Primary production is the chemical energy generated by autotrophs during photosynthesis and chemosynthesis: primary productivity is the rate of primary production. Energy assimilated by autotrophs is stored as carbon compounds in plant tissues, thus carbon is the currency used to measure primary production. Gross primary production (gpp) 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. Layer 1 is the top of the canopy and layer 15 is the bottom. Incremental carbon gain decreases with each additional leaf layer. This may because leaves in the bottom layer become shaded.
