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Chapter 14. Population Ecology. Population Ecology. What is a population? A group of individuals of the same species that live in a given area Area is defined. Ex. Voter population could be just Spearfish or United States Population Ecology
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Chapter 14 Population Ecology
Population Ecology • What is a population? • A group of individuals of the same species that live in a given area • Area is defined. Ex. Voter population could be just Spearfish or United States • Population Ecology • Changes in a population and the biotic and abiotic factors that influence those changes
Organism Population Community Ecosystem
Population Dispersion patterns • Population density • # ind of a population/ unit area or volume • Clumped dispersion • Uniform dispersion • Random dispersion
Clumped Uniform Random What dispersion pattern would you predict for a territorial chipmunk species?
Maximized rate with perfect • conditions • Growth rate (G) = rN = average • rate of increase per individual • in the population X pop size • Population size increases • exponentially • Population can outstrip its • resources and crash
Resource availability limits population growth. • Population growth following the logistic model stabilizes around the carrying capacity (K) of the environment. • G = rN(K-N)/K • (K-N)/K = the closer N comes to the carrying capacity, the slower the rate of growth
A) all of the microorganisms on your skin B) all of the species of cichlid fish in Lake Victoria C) all of the students in your classroom D) all students attending colleges and universities in your state E) the various plants found in prairies in the western United States Which of the following is an example of a population?
A) geologists. B) ecologists. C) population ecologists. D) geographers. E) population geneticists. The decline of the Nile perch in Lake Victoria in east Africa and the reemergence of cichlids is an excellent situation for study by
Harvesting crops and hunted species without damaging the resource. • Maintain healthy populations at population sizes that can replace the harvested individuals • Half the carrying capacity is ideal • Very difficult to do, because it is hard to determine K and N • Using water at a rate that allows for recharging and keeping it clean • Again this is very difficult to figure out • Finding renewable energy sources • Integrated pest management • Recycle and reused materials Sustainable Resource Management
Cockroach population - influenced by short generation time - high reproductive rate (females lay lots of eggs) Sustainability research helps give insight into how to control populations. - mature female individuals contribute most to population growth - target females for biggest impact
Life Tables and survivorship Types of survivorship curves: I = most individuals live to old age II = equal probability of dying through out life span III = rapid die off of young, few individuals live to old age
A) 0 B) 2 C) 10 to 20 D) 100 E) more than 100 Consider a stable frog population living at carrying capacity in a pond. If an average female produces 6,000 eggs during her lifetime and an average of 300 tadpoles hatch from these eggs, how many of these tadpoles will, on average, survive to reproduce?
A) It will decrease by 70%. B) It will increase by 1%. C) It will increase by 5%. D) It will increase by 70%. E) It will increase by 100%. If a population has a birth rate of 40 individuals per 1,000 per year and a death rate of 30 individuals per 1,000 per year, how will the population change each year? (Assume that the population is below carrying capacity and that there is no immigration or emigration.)
