BIO 262 Lecture Notes - Lecture 3: Keystone Species, List Of Places In The Chronicles Of Narnia, Pollination
18 Apr 2019
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Document Summary
Species that occur naturally in a community. Occur nowhere except that community then endemic. Migrate, introduced purposely or accidentally into a community. Also known as invasive, alien or exotic species. Many nonnative species have drastically changed communities. Serve as early warnings of damage to a community. Species that have a more important role in a community than suggested by their abundance (sea stars, littorinasnails, sea otters) Species that play pivotal roles in a community. Strong interactions with other species affect survival of other species. Process material out of proportion with their biomass. Pollination of flowering plants (bees hummingbirds, bats) Dispersion of seeds by fruit-eating animals (bats, birds) Predation by top carnivores that affect prey populations. Starfish, kangaroo rats - when removed species diversity declined. Improving ability of plants to obtain nutrients and water. A characteristic of all communities is that their structures change constantly in response to changing environmental conditions they are dynamic.
