BIOL 1020U Lecture Notes - Lecture 7: Population Ecology, Logistic Function, Exponential Growth
Document Summary
Population ecology: the study of how and why the number of individuals in a population changes over time or space. Populations density: number of individuals of a species per unit area at a given time. Population dispersion (spacing): gives clues about population processes and relation with local environment. May depend on: density; interaction between conspecifics; the distribution of other species that are competitors, predators, or prey; environmental features such as moisture, temperature, soil type, wind direction etc. Clumped dispersion: animals like wolves live in groups to hunt and defend a territory from other packs. Uniform dispersion: king penguins spread themselves out to a distance where neighbours can t peck each other. Random dispersion: dandelions have their seeds dispersed by wind and grow wherever they land. Population growth, size, and composition is affected by 4 important processes: natality (birth rate b, mortality (death rate d, immigration (i, emigration (e) Often assume i=e so they cancel out to make things simpler.
