CAS BI 107 Lecture Notes - Lecture 2: Herbivore, Keystone Species, Heterotroph
Document Summary
An assemblage of populations of various species living close enough for potential interaction. A group of interacting organisms sharing an environment. Leaf cutter ants farm fungus for food with the collection of leaf foliage, however, multiple fungi and bacteria also interact. Rate at which primary producers in a community turn solar energy into stored chemical energy via photosynthesis. The amount of primary producer biomass (weight of organic matter) available for consumption by heterotrophs. Gpp - energy used for respiration = npp. Food chain: links the trophic levels from producers to top carnivores. Most communities look like a food web, but are organized in a similar fashion. Dashed lines represent feeding on dead animals. Only about 10% of energy available in a trophic level is transferred to the next level. Results from heat loss, biomass availability, indigestibility. Ecological efficiency - overall transfer between trophic levels. Proportion of energy used is relatively high for carnivores and relatively low for producers.
