• SB4. Students will assess the dependence of all organisms on one another and the flow of energy and matter within their ecosystems.

• c. Relate environmental conditions to successional changes in ecosystems

The change in an ecosystem that happens when one community replaces another as a result of changing abiotic and biotic factors.

• Primary Succession – bare rock to climax community. Soil must be created.

• Secondary Succession – replacement of a devastated community. Soil is already present.

• The end result of Succession is a Climax Community

• A climax community is a community that has reached a mature stage and has little or no species change over time.

Primary Succession

Communities, Biomes, and EcosystemsChapter 3

Secondary Succession

• A biome is a large group of ecosystems that share the same type of climax community.

• Biomes are classified by their plants, temperature, and precipitation.

Terrestrial Biomes of the World

Three factors that influence:• Latitude• Altitude • Precipitation

• Plants are the best indicator of different biomes

Latitude• Distance of any point

on the surface of Earth north or south of the equator.

• Earth’s surface is heated differently in different areas to the angle of sunlight.

Altitude• The distance from the Earth

• As you increase altitude temperature and rainfall usually decrease.

Two types

• Marine Biomes

• Freshwater Biomes

Oceans and Estuaries

Marine Biomes (oceans) contain the largest amount of biomass, or living material, of any biome on Earth.

Most of this biomass is made up of extremely small, often microscopic organisms

Zones of Marine Biomes

• Aphotic Zones – Deeper water that never receives sunlight

– 90% of ocean

– May extend many kilometers deep

Photic Zones –shallow enough for sunlight to penetrate

Intertidal Zone

• Area between high and low tide lines.

Examples - Lakes, Rivers, Streams

Things that effect life in Freshwater Biomes

• Water temperatures

• Light

• Nutrients

Lakes, Ponds, and Water Temperature

• Water temperatures vary by season

• Summer has the greatest differences - decrease the deeper you go because cold water is more dense than warm water

Lakes, Ponds and Light

• Affects the amount of plant/algae present.

• Deeper you go the less light penetrates therefore less plants/algae.

• Oligotrophic lakes – Nutrient poor lakes – often found in mountain regions – little to no organic material– Little to no life

• Eutrophic lakes – Nutrient rich lakes – found in lower regions– Abundance of organic materials– Abundance of life