WFSC 403 6th Edition Lecture 23 Outline of Last Lecture I Basic Concepts of Population Regulation and a simple model a The Question i Figure 14 1 page 257 b 1st principle and the reverse i Page 259 nd c 2 principle i Page 260 d 2 essays i Page 258 page 260 e Biotic School versus Climate School i Predator and parasite Biotic Density dependent ii Weather climate Density independent Outline of Current Lecture I Synthesis of Population Regulation a Equilibrium b Spatial scale II Allee effect and compensation III Source and sink populations IV Evolutionary implications of population regulation a Behavior b Stress c Genetic d Dispersal Current Lecture These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute 10 Extrinsic and intrinsic processesof population regulation Figure 14 4 11 o Schematic relationship of population regulation processes that are extrinsic to the population and those that are intrinsic Extrinsic processes for example disease interact with the properties of individuals that make up the population intrinsic processes so that population regulation results from interplay between Ecological systems along a continuum these two kinds of factors Figure 14 5 Characteristics of a population giving attributes to the population Differences and collective interactions Intraspecific density 12 o Schematic representation of ecological systems along a continuum from stable to unstable Unstable or fluctuating populations can result from either biotic instability caused by internal feedbacks or by stochastic domination caused by strong environmental fluctuations or by a combination of both kinds of disruption Stochastic domination Unpredictable changes in the environment mortality events abiotic limitation Species independence o Community doesn t have time to coevolve o Limit cycle and chaos Edge of chaos on this continuum go from super stability deterministically on the way to chaos the middle zone there is the most adaptive place before hitting chaos Before hitting chaos where things are everywhere before at the other end inflexible Do you expect ecological systems to be near or at equilibrium most of the time o No they are usually wandering around state space but they don t get too close to the boundaries Source population o Net excess of reproduction o Emigration exceeds immigration Sink population o Net excess of mortality o Immigration exceeds emigration o Why bother keeping these Good for genetic variation Don t have all eggs in one basket hurricanes don t wipe out whole population
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