Populations
Population – a group of organisms of one species living in a given area at the same time
Factors Affecting Population Geographical Distribution –
Factors Affecting Population Geographical Distribution – range inhabited by a species
Factors Affecting Population Geographical Distribution – range inhabited by a species Density –
Factors Affecting Population Geographical Distribution – range inhabited by a species Density – number of individuals per unit area
Factors Affecting Population Geographical Distribution – range inhabited by a species Density – number of individuals per unit area Growth Rate –
Factors Affecting Population Geographical Distribution – range inhabited by a species Density – number of individuals per unit area Growth Rate – how fast a population is able to increase in number
Factors Affecting Population Geographical Distribution – range inhabited by a species Density – number of individuals per unit area Growth Rate – how fast a population is able to increase in number Birth rate – total number of live births per 1,000 per year
Factors Affecting Population Geographical Distribution – range inhabited by a species Density – number of individuals per unit area Growth Rate – how fast a population is able to increase in number Birth rate – total number of live births per 1,000 people per year Death rate – number of deaths per 1,000 people per year
Factors Affecting Population Geographical Distribution – range inhabited by a species Density – number of individuals per unit area Growth Rate – how fast a population is able to increase in number Birth rate – total number of live births per 1,000 people per year Death rate – number of deaths per 1,000 people per year Immigration – migration INTO a population
Factors Affecting Population Geographical Distribution – range inhabited by a species Density – number of individuals per unit area Growth Rate – how fast a population is able to increase in number Birth rate – total number of live births per 1,000 people per year Death rate – number of deaths per 1,000 people per year Immigration – migration INTO a population Emigration – migration OUT OF a population
Limiting Factor –
Limiting Factor – something that causes a population to decrease or prevents it from growing limitlessly
Limiting Factor – something that causes a population to decrease or prevents it from growing limitlessly Carrying Capacity (K) –
Limiting Factor – something that causes a population to decrease or prevents it from growing limitlessly Carrying Capacity (K) – the maximum number of individuals an environment can sustain without detrimental effects
Limiting Factor – something that causes a population to decrease or prevents it from growing limitlessly Carrying Capacity (K) – the maximum number of individuals an environment can sustain without detrimental effects
2 Types of Limiting Factors Density-dependent –
2 Types of Limiting Factors Density-dependent – factors that depend on the size of the population
2 Types of Limiting Factors Density-dependent – factors that depend on the size of the population Only become limiting when the population density becomes very high
2 Types of Limiting Factors Density-dependent – factors that depend on the size of the population Only become limiting when the population density becomes very high Effects are intensified as the population density increases
2 Types of Limiting Factors Density-dependent – factors that depend on the size of the population Only become limiting when the population density becomes very high Effects are intensified as the population density increases Density-independent –
2 Types of Limiting Factors Density-dependent – factors that depend on the size of the population Only become limiting when the population density becomes very high Effects are intensified as the population density increases Density-independent – factors that do not depend on the size of the population
2 Types of Limiting Factors Density-dependent – factors that depend on the size of the population Only become limiting when the population density becomes very high Effects are intensified as the population density increases Density-independent – factors that do not depend on the size of the population Are limiting regardless of the size of the population
2 Types of Limiting Factors Density-dependent – factors that depend on the size of the population Only become limiting when the population density becomes very high Effects are intensified as the population density increases Density-independent – factors that do not depend on the size of the population Are limiting regardless of the size of the population Affect all populations in similar ways
Density Dependent Factors
Density Dependent Factors Predation
Density Dependent Factors Predation The effect of predation intensifies as the population density of predators increases
Density Dependent Factors Predation The effect of predation intensifies as the population density of predators increases Disease
Density Dependent Factors Predation The effect of predation intensifies as the population density of predators increases Disease High population densities make the spread of disease easier to transmit
Density Dependent Factors Predation The effect of predation intensifies as the population density of predators increases Disease High population densities make the spread of disease easier to transmit Parasitism
Density Dependent Factors Predation The effect of predation intensifies as the population density of predators increases Disease High population densities make the spread of disease easier to transmit Parasitism High densities make it easier for parasites to find hosts, and spread diseases
Density Dependent Factors Predation The effect of predation intensifies as the population density of predators increases Disease High population densities make the spread of disease easier to transmit Parasitism High densities make it easier for parasites to find hosts, and spread diseases Competition
Density Dependent Factors Predation The effect of predation intensifies as the population density of predators increases Disease High population densities make the spread of disease easier to transmit Parasitism High densities make it easier for parasites to find hosts, and spread diseases Competition More members of a population = Less Available resources = More competition
Density Dependent Factors Predation The effect of predation intensifies as the population density of predators increases Disease High population densities make the spread of disease easier to transmit Parasitism High densities make it easier for parasites to find hosts, and spread diseases Competition More members of a population = Less Available resources = More competition Less members of a population = More available resources = Less competition
Density-Independent Factors
Density-Independent Factors Human Activities
Density-Independent Factors Human Activities Deforestation Over-hunting/fishing
Density-Independent Factors Human Activities Deforestation Over-hunting/fishing Natural Disasters
Density-Independent Factors Human Activities Deforestation Over-hunting/fishing Natural Disasters Hurricane, tornado, flood, severe drought Equally devastating to populations regardless of size
Density-Independent Factors Human Activities Deforestation Over-hunting/fishing Natural Disasters Hurricane, tornado, flood, severe drought Equally devastating to populations regardless of size Weather
Density-Independent Factors Human Activities Deforestation Over-hunting/fishing Natural Disasters Hurricane, tornado, flood, severe drought Equally devastating to populations regardless of size Weather Extremely hot/cold temperatures; frost Adversely effects all populations regardless of their size
Types of Growth Logistic Growth – population growth ↑ as resources ↑, and population growth ↓ as resources ↓ Population reaches a carrying capacity
Types of Growth Exponential Growth – individuals in a population reproduce at a constant rate Appears to be unlimited growth