REM 311 Chapter Notes - Chapter 3: Scramble Competition, Exponential Growth, Mortality Rate
13 Apr 2018
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In chapter 1: exponential growth happens under favorable environmental conditions. In chapter 2: environment can turn unfavorable and causes population decline. In chapter 3: extrinsic factors (i. e. climate) can remain favorable but area can be overcrowded and causes population decline. Mortality rate increase as more individuals share limited space, water or other resources. Density-dependent mortality -> decline of population density -> remaining survivors are well off. Compensated by increased size of surviving individuals: compensation of mortality with growth in size of individuals has a pattern = self- thinning curve, log-log scale (x = density, y=mass) An area of habitat defended by an individual or pair & excludes others. Increase density causes individuals to be pushed out of their territories = larger number of individuals may be excluded from all territories. 3. 2 types of density dependence low densities = enough resources for everyone -> increase density. High densities = not enough resources -> competition.
