DYNAMICS POPULATION Mariana Chavarriaga V 8a
DynamicPopulation Vocabulary: • Population: All the individuals of a species that live together in an area. • Demography: The statiscalstudy of populations, make predictions about how a populationwillchange. • Size: Number of individuals in a area
DynamicPopulation Threekeyfeatures of population • Growthrate. Birth rate (natality) death rate (mortality) • How manyindividuals are born vs. How many die • Birth rathe (b)- Death rate (d)= rate of natural increase(r)
DynamicPopulation 4 factors that affectdensity • Immigration: Movement of individuals into a population. • Emigration: Movement of individualsout of a population. • Density-Dependentfactors: Bioticfactors in the environment that have an increasingeffect as populationsizeincreases. Ex: Disease, Competition, Parasites. • Density-Independetfactors: Abioticfactors in the environment that affectpopulationsregardiess of their density. Ex: Temperature, Storms, Drought.
DynamicPopulation Some images are very specific
DynamicPopulation Population dynamics is the branch of life sciences that studies short-term and long-term changes in the size and age composition of populations
DynamicPopulation The biological and environmental processes influencing those changes. Population dynamics deals with the way populations are affected by birth and death rates, by immigration and emigration, and studies topics such as ageing
DynamicPopulation One common mathematical model for population dynamics is the exponential growth model.Withthe exponential model, the rate of change of any given population is proportional to the already existing population.
DynamicPopulation Limited space for territories may often put a cap on the size of bird populations. In his well-known study of Florida Scrub jays, we found that the density of breeding pairs remained quite constant. In a stretch of about 550 acres of prime habitat, there was very close to one pair per 25 acres for each of the nine years In contrast, at the start of the breeding season in those same years, the overall density of jays in the area was three to four times as great.
DynamicPopulation An example with the animals and the territory
DynamicPopulation A population is a group of individuals who live together in the same habitat and are likely to interbreed. Each population has a unique physical distribution in time and space.