Abiotic Factors Abiotic Factors Affect EcosystemsAffect Ecosystems

The animals that live in an ecosystem rely on the The animals that live in an ecosystem rely on the abiotic factors in that ecosystem. These factors abiotic factors in that ecosystem. These factors help determine the ways the animals look, the help determine the ways the animals look, the

ways they behave and the adaptations they have ways they behave and the adaptations they have to their environment.to their environment.

Limiting Factors of an Limiting Factors of an EcosystemEcosystem• Limiting factors are abiotic factors that limit the amount Limiting factors are abiotic factors that limit the amount

of organisms that live in that particular ecosystem. of organisms that live in that particular ecosystem. • For example a desert is going to have a limited amount For example a desert is going to have a limited amount

of organisms compared to a rainforest due to the lack of of organisms compared to a rainforest due to the lack of water. The following are the most important abiotic water. The following are the most important abiotic factors that affect an ecosystem.factors that affect an ecosystem.

• Water Water • SunlightSunlight• TemperatureTemperature• Soil CompositionSoil Composition

Limited Fresh WaterLimited Fresh Water

• Water is one of the most important factors for an ecosystems ability to Water is one of the most important factors for an ecosystems ability to sustain life.sustain life.

• All organisms need water to survive.All organisms need water to survive.• Only animals with special adaptations can survive in environments Only animals with special adaptations can survive in environments

with little fresh water. The less fresh water in a place, the less animals with little fresh water. The less fresh water in a place, the less animals will survive there.will survive there.

• ExamplesExamples• Rainforests receive fresh water everyday and a large number of Rainforests receive fresh water everyday and a large number of

organisms live there.organisms live there.• Deserts receive very little rainfall so much fewer organisms live there Deserts receive very little rainfall so much fewer organisms live there

compared to areas that receive a lot of rain.compared to areas that receive a lot of rain.

Limited SunlightLimited Sunlight

• The amount of sunlight a place receives has a large affect on the The amount of sunlight a place receives has a large affect on the amount of life that lives there.amount of life that lives there.

• A great deal of insolation (amount of sunlight reaching the surface of A great deal of insolation (amount of sunlight reaching the surface of the earth) throughout the year means that the environment will be the earth) throughout the year means that the environment will be warmer.warmer.

• A good amount of sunlight also means there will be plenty of energy A good amount of sunlight also means there will be plenty of energy available for plants to grow and therefore lots of energy for animals in available for plants to grow and therefore lots of energy for animals in that ecosystem. that ecosystem.

• Examples:Examples:• Tropical Forests receive a lot of sunlight. So they are warm and Tropical Forests receive a lot of sunlight. So they are warm and

contain a huge amount of plants and animals.contain a huge amount of plants and animals.• The Tundra receives much less sunlight throughout the year. It is The Tundra receives much less sunlight throughout the year. It is

much colder and has fewer plants and animals.much colder and has fewer plants and animals.

Limited TemperatureLimited Temperature

• Temperature affects the amount of organisms that live in Temperature affects the amount of organisms that live in an area because many organisms cannot survive in frigid an area because many organisms cannot survive in frigid conditions.conditions.

• Only organisms with special adaptations to the cold can Only organisms with special adaptations to the cold can live in freezing places.live in freezing places.

• Colder places have a fewer variety of animals living there.Colder places have a fewer variety of animals living there.• Examples:Examples:• Deciduous trees lose their leaves when it is very cold. Deciduous trees lose their leaves when it is very cold.

Conifer trees have needles that can survive in freezing Conifer trees have needles that can survive in freezing weather. Polar Bears have thick layers of fat to survive on weather. Polar Bears have thick layers of fat to survive on the arctic tundra.the arctic tundra.

Soil CompositionSoil Composition

• Soil contains nutrients for plants to eat.Soil contains nutrients for plants to eat.• Environments with poor soil do not sustain as Environments with poor soil do not sustain as

much life as places with a lot of nutrients.much life as places with a lot of nutrients.• Examples:Examples:• The Tundra and Deserts have poor soil and The Tundra and Deserts have poor soil and

sustain less plants and animals.sustain less plants and animals.• Forests contain good soil and support a large Forests contain good soil and support a large

amount of life.amount of life.

Identify What Factors Affect Identify What Factors Affect Each Ecosystem.Each Ecosystem.• TundraTundra• RainforestRainforest• Arctic OceanArctic Ocean• Coral ReefCoral Reef• Coniferous ForestConiferous Forest• Tropical ForestTropical Forest• Tropical Desert Tropical Desert

Important Questions to Important Questions to StudyStudy• Are you able to define the term Are you able to define the term

limiting factor.limiting factor.• Are you able to list the 4 main limiting Are you able to list the 4 main limiting

factors that affect an ecosystem.factors that affect an ecosystem.• Are you able to describe how certain Are you able to describe how certain

limiting factors affect specific limiting factors affect specific ecosystems.ecosystems.