BISC 120Lg Lecture Notes - Lecture 18: Trophic Cascade, Keystone Species, Foundation Species
Document Summary
Bisc 120: general biology: organismal and evolutionary biology- lecture 18: ecology. Species diversity- a community that is the variety of organisms that make up the community. Diversity is a good thing- higher diversity communities are more resistnat to stress, more productive, and more resistant to invasions. Species richness- the total number of different species in a community. Relative abundance- the proportion each species represents of the total individuals in the community. Shannon diversity index (don"t need to write it out, but just know that this is a metric from determining varying diversity across communities) Trophic structure- flow of energy through different organisms in a community. Food chains- link trophic levels from producers to top carnivores. Food web- branching food chain with complex trophic interactions. Takes into account that different animals can be active at multiple levels of the food chain. The energetic hypothesis- suggests that length is limited by inefficient energy transfer.
