Final Study Guide - Principles of Ecology Lab | BIOL 4254, Study notes of Biology

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Biol 4254 Principles of Ecology Final Exam Study Guide In addition to understanding the basic experimental design for each lab, you should know how to: Stats Determine what analysis and figures to use given a data set Use all analyses discussed – t-test, ANOVA, regression Make all figures discussed – scatter plot, bar graph Identify a mistake in a figure such as a missing figure caption, etc. Interpret a figure and statistical analysis (if confidence intervals overlap, but the p-value is 0.1, are the treatments different?) p > 0.05; Same = fail to reject null Invertebrate Diversity Describe advantages and disadvantages of diversity vs. richness = abundance – total # of individuals but not an index like; richness - # of species, simplest measure of a community; diversity takes abundance and richness into account to picture the full community composition, richness provides an incomplete picture of the composition of a community Explain niche partitioning = (area where overlap is minimized) to allow diversity, sectioning off niches so as to promote diversity Explain habitat complexity and how it relates to diversity = provides more niches so increase in diversity, low disturbance causes competitive exclusion Explain the intermediate disturbance hypothesis = diversity peaks at intermediate disturbance levels; low disturbance – competitive exclusion; high disturbance – rough environment for species to handle, prevents organisms from successfully colonizing area, less available niches Shannon-Weiner diversity index – used to calculate diversity, more widely used among ecologists; H’ = - Ʃpi ln pi or H’ = log N – 1/N(Ʃni log ni); pi = proportion of total # of individuals that belong to species I, N = total # of individuals collected, ni = # of individuals in species i, when H’ = 0, the community is at its least diverse – there is only 1 species present (also high information content); the higher H’ is, the more diverse the community (and the less information it offers) Island Biogeography, Metacommunities = common sense idea created by MacArthur & Wilson; tested in mangroves Explain the theory of island biogeography in detail and reproduce the figure with your explanation. You should be able to explain why diversity increases with patch size and decreased distance from the mainland. What is the equilibrium number of species on an island? = islands closer and larger – greater diversity; lots of species – competitive exclusion (higher extinction rate on small island); more species – lesser immigration rate bc niches full, but more successful immigration closer to mainland than far; lines intersect – equilibrium # of species (richness); SM far < LG near Define the terms metapopulation and metacommunity = group of small populations linked by migration; bunch of connected communities; multiples species that are interacting Explain how habitat fragmentation influences population size and species diversity = harder to migrate and make smaller (reduce total area of habitat) Design a park using the principles of island biogeography to maximize species richness Lake Food Webs Identify the different trophic levels in a food web = 1. Primary producers – convert inorganic forms of energy, principally light, into biomass (autotrophs), 2. Primary consumers – feed on primary producers (herbivores and detritivores – eat detritus [dead or decaying organic material]),3. Secondary consumers – feed on herbivores and detritivores (carnivores), 4. Tertiary consumers – predators that feed on carnivores Explain how ecologists develop food webs = food web – a summary of feeding relationships or interactions; reveals descriptions of community structure and helps determine how groups of organisms are regulated within a community; very complex; some ecologists try to determine which factors limit the abundance and distribution of organisms, including primary producers Explain top-down vs bottom-up control and name a variable that we tested to account for each = 1. top- down – predation or herbivory limits abundance and distribution of organism on trophic level (phytoplankton limited by zooplankton grazing [abundance of zooplankton]), grazing, the influence of consumers and predators on organisms; we tested zooplankton density 2. bottom-up – nutrients, limited by resource availability (limited abundance and distribution) (nutrients, primary producer [nitrates, nitrites, phosphates, ammonium]); tolerance can also have an affect (heat stress, osmotic balance, desiccation stress, O2 levels); dispersal also limits abundance and distribution; we tested phosphate levels Explain trophic cascades = usually top-down control; indirect effects of one trophic level on another; ex: killer whales – sea otters – sea urchin – kelp; alternates in increase and decrease of population (sea otters and kelp go down, killer whales and sea urchin go up) Explain how physiological tolerance can limit the distribution of organisms and give examples of tolerance variables we tested = organisms have a certain range that they can tolerate for each physiological factor, this can limit niche breadth; we tested variables such as salinity, dissolved oxygen, pH, temperature, total dissolved solids, nitrates, ammonium, phosphates, etc. Competition and Behavior = theme – costs/benefits