Ecosystems of the World

AP Study Review

Naming Ecosystems

• Terrestrial Ecosystems = Biomes– Separated based upon their climate, which involves average

temperatures and rainfall• Aquatic Ecosystems = Aquatic Life Zones– Separated based upon light availability, nutrient availability

and water temperature• Ecozones / Ecoregions:– Areas within an ecosystem which share similar characteristics

• Ecotone:– Area where two different ecosystems meet

Biomes: Deciduous Forest

• Temperate and Tropical variety• 75-250cm of rain• Rich soil with a high level of organic material• Major vegetation = Hardwood Trees• Locations:– North America, Europe, Australia, East Asia

Biomes: Tropical Rainforest• 200-400cm of rainfall• There is poor soil quality, why??– Dead organic matter is processed so efficiently and plants

are so efficient at taking in nutrients that any nutrients which enter the soil are almost immediately taken up and stored

– Soil of most rainforests is greater than 100 million years old, it rains a lot = nutrient leaching

• Major Vegetation: Tall trees, vines, ferns, plants adapted to lower light intensity

• >>>>> biodiversity• Locations:– South America, West Africa, and Southeast Asia

Biomes: Grasslands

• Includes savanna and prairies• 10-60cm of rain per year• Most areas have very rich soil• Major vegetation: grasses and shrubs• Locations:– North American plains and prairies, Russian

steppes, South African veld, Argentinian pampas

Biomes: Coniferous Forest

• AKA: Taiga• 20-60cm in the summer• The soil is very acidic because of the

vegetation present• Major vegetation: Conifers (“pine trees”)• Locations:– Northern North America, northern Eurasia

Biomes: Tundra

• < 25cm of precipitation per year• Soil is permanently frozen– Current problem is that the permafrost is melting

due to the increasing global temperature• Major vegetation: herbaceous plants• Locations:– Northern latitudes of North America, Europe, and

Asia

Biomes: Chaparral

• AKA: Scrub Forest• 50-75cm of precipitation mostly in the winter• Soil is shallow and not fertile• Major Vegetation: small trees with hard

leaves, and spiny shrubs• Locations:– Western North America, and Mediterranean

region

Biomes: Deserts

• Could be cold or hot• < 25cm of precipitation per year• Soil is sandy• Major vegetation: cacti and other plants that

are adapted to low water conditions• Locations:– 30 degrees north and south of the equator

Biome Characteristics

• Every single biome contains certain characteristics unique to itself– Determine which organisms are capable in living within

the biome• Characteristics include:– Availability of nutrients and water– Temperature– Precipitation– Light availability– # and type of disturbances, if present

Biome Laws

• Law of Tolerance– Living organisms exhibit a range of tolerance

toward the condition in their habitat and the surrounding environment

• Law of the Minimum– Living organisms will continue to live in a biome,

habitat, or environment as long as there is a supply of consumable/usable resources

Diversity

• Biodiversity– Describes the number and variety of different species

in a specific geographic region• Why is biodiversity important?– Used to measure how ‘healthy’ an ecosystem is– The more biodiversity within species in an ecosystem

means that there is a larger gene pool through which adaptation can occur = survival