ENVS 1126 Lecture : Lecture 4 Ecosystems Energy Patterns Disturbances
Document Summary
Breaks down glucose in the absence of oxygen. Releases methane gas (ch4), ethyl alcohol, acetic acid. First order consumers, herbivores, feed on plants, omnivores. Living organisms ecologically categorized based on how they get their energy. Break down dead organic matter ad are major source of nutrients in most ecosystems. Fermentation: a modified form of respiration of some decomposers (bacteria and yeasts) Anearobic (oxygen-free) respiration in sediments of lakes, marshes, swamps, and in animal guts. When food and energy moves to the next higher trophic level, total energy/biomass decreases. Terrestrial ecosystems usually have three or four trophic levels. If one acre of grassland has 907kg (2000lbs) In most ecosystems, sunlight is the initial source of energy. Primary production uses only 2% of the solar energy. There is a huge inefficiency at each trophic level. These systems have two main differences compared to terrestrial systems. Biomass of large fish is greater than biomass of small fish.
