1. organism population community ecosystem biosphere Population Ecology

2. Life takes place in populations • Population • group of individuals of same species in same area at same time • rely on same resources • interact • interbreed Population Ecology: What factors affect a population?

3. Why Population Ecology? • Scientific goal • understanding the factors that influence the size of populations • general principles • specific cases • Practical goal • management of populations • increase population size • endangered species • decrease population size • pests • maintain population size • fisheries management • maintain & maximize sustained yield

4. Factors that affect Population Size • Abiotic factors • sunlight & temperature • precipitation / water • soil / nutrients • Biotic factors • other living organisms • prey (food) • competitors • predators, parasites, disease • Intrinsic factors • adaptations

5. 1970 1966 1960 1964 1965 1943 1951 1961 Equator 1958 1937 1956 Immigration from Africa ~1900 1970 Characterizing a Population • Describing a population • population range • pattern of spacing • density • size of population range density

6. Population Range • Geographical limitations • abiotic & biotic factors • temperature, rainfall, food, predators, etc. • habitat adaptations topolar biome adaptations torainforest biome

7. aspen oak, maple sequoia white birch 15,000 years ago glacial period Present Alpine tundra Alpine tundra Spruce-fir forests 3 km Mixed conifer forest Spruce-fir forests Woodlands 2 km Elevation (km) Mixed conifer forest Grassland, chaparral, and desert scrub 1 km Woodlands Grassland, chaparral, and desert scrub 0 km Changes in range • Range expansions & contractions • changing environment result of competition

8. Devil’s hole pupfish Iiwi Hawaiian bird Iriomote cat Socorro isopod New Guinea tree kangaroo Catalina Island mahogany tree Northern white rhinoceros At risk populations • Endangered species • limitations to range / habitat • places species at risk

9. Population Spacing • Dispersal patterns within a population Provides insight into the environmental associations & social interactions of individuals in population clumped random uniform

10. Clumped Pattern (most common)