Презентация на тему: " Population Ecology Prepared by:Assanbayeva L Group CT-16-4k1 Checked by Dosbayeva A." — Транскрипт:
Population Ecology Prepared by:Assanbayeva L Group CT-16-4k1 Checked by Dosbayeva A
Plan 1 Population ecology 2 The definition of population 3 Population Dynamics 4 Three Key Features of Populations 5 How Do Populations Grow? 6 Human Population Growth 7 The Human Population
Population ecology is the study of populations in relation to their environment, including environmental influences on density and distribution, age structure, and population size
Population Dynamics Population: All the individuals of a species that live together in an area Demography: The statistical study of populations, allows predictions to be made about how a population will change
Three Key Features of Populations Size: number of individuals in an area
Three Key Features of Populations Growth Rate: Birth Rate (natality) - Death Rate (mortality) How many individuals are born vs. how many die Birth rate (b) death rate (d) = rate of natural increase (r)
Dispersion: describes the spacing of organisms relative to each other Clumped Uniform Random Three Key Features of Populations
Population density = number of individuals in a given area or volume Count all the individuals in a population Estimate by sampling Mark-Recapture Method How Are Populations Measured?
Idealized models describe two kinds of population growth: 1.Exponential Growth 2. Logistic Growth How Do Populations Grow?
Human Population Growth J curve growth Grows at a rate of about 80 million yearly r =1.3% Why doesnt environmental resistance take effect? Altering their environment Technological advances The cultural revolution The agricultural revolution The industrial-medical revolution
Doubled three times in the last three centuries About 6.1 billion and may reach 9.3 billion by the year 2050 Improved health and technology have lowered death rates The Human Population