Biology Final Study Guide Strauss

Biology Final Study Guide Strauss - Sea urchins B iology...

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Whales?? Otters: keystone species Sea urchins (Dominant competitor) Kelp (foundation species) Filter feeding bivalves algae Planktivorous fish Herbivores & crustaceans Biology Final Study Guide Strauss 1. Draw a graph describing the intermediate disturbance hypothesis (IDH) and describe what determines diversity at low, intermediate, and high frequency of disturbance under this hypothesis. Give an example of a community that appears to conform to the IDH and describe the evidence that makes you think this. a. Competitive exclusion can be prevented by the following i. When species partition resources: intraspecific species is strong relative to interspecific competition 1. Interspecific interactions between individuals of different species 2. When species specialize on different resources to limit resource competition; this is an example of more resource type not more resources ii. Environment change— disturbance happens faster than time required for competitive exclusion iii. Resources can refer to food, nutrients: iv. Portioning of space i.e. on a tree, high v.s low 1. when species specialize in particular type of habitat or time of year this is an example of more resource type not more resources v. Portioning of time: different seasons, different years, stages of succession vi. More resources does not mean more species: adding resources decreases biodiversity; it’s a paradox of enrichment, more biomass fewer species and increased dominance (of one species) b. Competitive exclusion can also be prevented by disturbance / environmental change. i. Intermediate Disturbance Hypothesis inverted U, x-axis = disturbance frequency; y-axis = diversity 1. There is competitive exclusion happens at low diversity and low disturbance frequencies 2. At HIGH disturbance frequency and LOW diversity, there is disturbance caused extinctions 3. In the middle of disturbance frequency and diversity, at the top of the inverted U, there is disturbance-mediated coexistence ii. Plankton paradox many species of plankton despite a homologous habitat and competing for the same resources 1. The conditions by which plankton live, are dynamic and these conditions rarely last long enough to favor one species over another 2. A. What is meant by indirect effects in food webs? B. Describe two types of indirect effects (do not use an example for these). C. Now, provide one real example of an indirect effect . a. Indirect effects in food webs When species A affects species B via its effects on species C ; affect of one species on another species via its affect on another species i. i.e. the effect of b. Two types of indirect effects
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i. Trophic cascade are an example of top down regulation of community composition and plant biomass (biomass of producers affected by the presence of consumers) ii. Trophic level all the organisms whose energy source has passed through the same number of steps to reach them iii. Keystone predation 1. Keystone species a species that has a disproportionate affect on its
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This note was uploaded on 03/02/2011 for the course BIO SCI 2A taught by Professor Appleman during the Spring '08 term at UC Davis.

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Biology Final Study Guide Strauss - Sea urchins B iology...

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