Biology 2483A Lecture Notes - Lecture 3: Ecological Pyramid, Estuary, Autotroph
9 Jun 2016
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Document Summary
Ecological roles determined by trophic interactions (what they eat/what eats them) All organisms are consumed by other organisms or enter a pool of dead organic matter. On land, most of the energy flow passes through the detritus (small portion consumed) Detritus is considered part of the 1st trophic level, detritivores part of the second level. Most detritus in streams, estuaries and lakes derived from land organic matter. Importance of autochthonous energy inputs increases from the head waters toward lower reaches of a river. Water velocity decreases and nutrient concentration increases as you go downstream. 2nd law of thermodynamics: during any energy transfer, some is dispersed and becomes unuseable energy decreases with each trophic level. Inverted pyramids are more common where productivity is lowest such as nutrient poor regions of the open ocean phytoplankton turnover high compared to phytoplankton of nutrient rich waters.
