Unit 7: Ecology

Left Side Pg # Right Side Pg #

Unit Page 34 Table of Contents 35

Levels of Organization 36 C.N. – Ecology Part 1 37

Sources of Energy Tree Map 38 C.N. – Energy Flow 39

Food Chain Activity 40 Food Chain/Web Worksheet 41

Community Interactions Tree Map

42 C.N. – Community Interactions

43

Population Growth 44 C.N. – Populations 45

PopulationsPopulations

Chapter 5-1

Population EcologyPopulation Ecology

PopulationPopulation: group of individuals of the same species living in an area.

The size of a population can effect its interactions within an ecosystem.

There are several factors that determine the size of a population.

Characteristics of Populations

3 Characteristics of a Population 1) Geographic DistributionGeographic Distribution: describes

the area inhabited by a population 2) Population Density: Population Density: the number of

individuals in a given area 3) Growth Rate: Growth Rate: rate at which a

population increases or decreases

Population SizePopulation Size

Population size is affected by: Things that cause a population to

GROWGROW: 1) BirthsBirths 2) Immigration Immigration (new individuals

join a population)

Things that cause a population to DECLINE DECLINE (decrease): 1) DeathsDeaths 2) Emigration Emigration (individuals move

out of the the population)

Limiting Factors

2 Types of Factors limit population growth (result in deaths & population decline): 1) Density-dependent1) Density-dependent

The larger the populationlarger the population, the faster faster resources are used. resources are used.

This results in limiting factors such as: Competition for food, water, space, & matesCompetition for food, water, space, & mates Disease and PredationDisease and Predation

2) Density-Independent2) Density-Independent Limiting factors like natural disasters, natural disasters,

climate changes, and temperatureclimate changes, and temperature can affect any population, regardless of its regardless of its sizesize

Lynx & Hare Populations

Patterns of Growth

1) Exponential Growth2) Logistic Growth

1) Exponential Growth

Under ideal conditions, individuals in Under ideal conditions, individuals in a population reproduce at a constant a population reproduce at a constant raterate Many births & few deaths Must have:

unlimited resources unlimited resources no predators or diseaseno predators or disease

Produces J-shaped curveJ-shaped curve Exponential Growth Curve

Model for Exponential Growth In natural

conditions, exponential growth exponential growth does not last longdoes not last long.

Limiting factors Limiting factors control how large a population can grow.

Logistic Growth

Logistic Growth: as Logistic Growth: as resources become limited, a resources become limited, a population’s growth slows population’s growth slows or stopsor stops The population reaches the

limit the environment can support

Produces a S-shaped curveS-shaped curveLogistical Growth Curve

Carrying CapacityCarrying Capacity: the maximum # of individuals the environment can support The population size has leveled off

Birth rate = death rateBirth rate = death rate # of immigrants = # of emigrants# of immigrants = # of emigrants

Human PopulationHuman Population

Currently, the human population is growing at an exponential rate.

With more people on the planet, we require more resources to keep us alive and produce more waste with our activities.

Most ecological Most ecological problems are caused by problems are caused by human activities.human activities. Habitat destruction,

pollution, global warming, ozone depletion, and endangered species