17- 3 Major Biological Communities (pg. 371)

Climate’s Effect on Where Species Live

Climate – the average weather conditions in an area over a long period of time

Biome – a large region characterized by a specific type of climate and certain types of plant and animal communities

Tropical Rainforests - biome in which the temperatures stay warm and rain falls year round

Found: equatorial regions (0o)

Most Characteristic Abiotic factors: warm temperatures year round rainfall year round (200-400 cm/yr) ***thin, nutrient-poor soil

**Home to MORE species than all other land biomes combined!

Dominant plants:Broad-leaf evergreens, ferns, large, woody vines, orchids, bromeliads

Savanna - characterized by perennial grasses, spotted with isolated trees and/or small groves of trees

Found: tropical areas on either side of the equator

Abiotic factors: warm temperatures year round seasonal rainfall (wet and dry seasons)

Animals - Herds of grazing animals (giraffes, wildebeasts, zebras, gazelles), large carnivores (lions, cheetahs)

Plants – grasses, scattered trees

Taiga (or Boreal Forest) – biome dominated by great coniferous (cone-bearing, with needles) forests

Found: across northern N. America, N. Europe, N. Asia

Abiotic factors: long, cold winters and mild summers

moderate precipitation (50-100 cm/yr)

Dominant plants: coniferous forests (pines, spruces, firs)

Animals – black bears, moose, wolves, birds, etc.

Tundra – northernmost land biome covered by mosses, lichens and grasses and characterized by permafrost

Abiotic factors

Permafrost – layer of permanently frozen subsoil

“Frozen desert” 10-15 cm/yr precipitation

Arctic moss

Arctic willow

Reindeer lichenTundra

Dominant plants: lichens, mosses, perennial grasses, stunted shrubs

Arctic fox Polar bear Caribou (reindeer)

Snowy Owl

Tundra swans

Mosquito larva

Lemming

Animals

3rd T.L.

2nd T.L.

1st T.L.

Desert – biome that receives less than 25 cm of rainfall per year

Found: 30o N & S of equator and leeward side of mountains

Abiotic factors:

LOW precipitation extreme temperature variations from day to night

Desert life MUST adapt to very low precipitation

Kangaroo rat

Armadillo Lizard

Kit Fox

Grasslands – biome consisting of vast area covered with grasses and small leafy plants

Found: interior portions of continents

Abiotic factors: cold winters, warm summers

moderate rainfall (25-75 cm/yr)

* Deep, rich soils

Dominant plants: perennial grasses, herbs and flowers

Animals: prairie dogs, rabbits, coyotes, ferrets,antelope, birds

Temperate Deciduous Forest – biome characterized by changing seasons and leaf fall

Found: E. U.S., SE Canada, most of Europe, parts ofJapan, China and Australia

Abiotic factors:

hot summers, cold winters

year-round precipitation (75-150 cm/yr)

fertile soils

Dominant plants: broad leaf deciduous trees (maples, oaks), flowering ground plants, ferns and moss

Aquatic Ecosystems (pg. 106)

Nearly 75% of Earth’s surface covered with water

Aquatic Biomes: Freshwater, Estuary, Marine

A. Freshwater Ecosystems – only 3% of surface water on Earth is fresh water Affected more by seasonal variations

1. Flowing-Water Ecosystems

Types: rivers, streams, creeks and brooks flow over land

Yukon River, Alaska

2. Standing-water Ecosystems

Lakes and ponds

Piseco Lake, N.Y.

3. Freshwater Wetlands

wetlands – ecosystems in which water either covers the soil or is present at or near the surface of the soil for at least part of the year

Water may be: flowing or standing fresh, salty or brackish

Many wetlands are very productive ecosystems serving as breeding grounds for: insects, fishes and other aquatic animals, amphibians and migratory birds

3 main types of freshwater wetlands are:Bogs, Marshes, Swamps

Great Swamp National Wildlife Refuge, New Jersey

B. Estuaries – wetlands formed where rivers meet the ocean; contain a mixture of fresh water and salt water and are affected by ocean tides (brackish water)

Many are shallow so: sunlight reaches bottom (lots of photosynthesis)

Estuaries support an astonishing amount of biomass

Serves as spawning and nursery ground for fish, shellfish

Waterfowl use fornesting, feeding and resting migration

Chesapeake Bay

Florida Everglades - Mangrove Swamps

A great egret gliding along the high grass on the Hackensack River

Hackensack Meadowlands, N.J.

Fresh-water and estuary

De Korte Park, The Meadowlands

Tree Swallow

C. Marine Ecosystems - Oceans Photic zone –

Typically to a depth of about 200 mAlgae and other producers can grow

Aphotic zone – Chemosynthetic autotrophs the only producers

Lavallette, N.J.