Environmental Science 2012 Biomes Source: University of California Museum of Paleontology

Desert Deserts cover about one fifth of the Earth’s surface Rainfall is less than 50cm/year Most deserts occur at low latitudes Soils often have abundant nutrients because they need only water to become very productive and have little or no organic matter

Deserts Disturbances are common Fires, cold weather, sudden infrequent flooding Few large mammals due to incapable of storing sufficient water and withstanding heat Dominant animals are reptiles Four types: hot and arid, semiarid, coastal, cold

Deserts Sand dunes in Death Valley National Monument, California. Horned Viper Egypt Castle Valley, Utah, east of Arches National Park. From left: Baja, Mexico desert; desert in Uluru National Park, Australia; desert near the Kofa Mountains, Arizona.

Tundra Coldest of all of the biomes Tundra means treeless plain Two types of tundra: Arctic tundra: located in northern hemisphere Alpine tundra: located on mountains throughout the world at high altitudes where trees cannot grow

Tundra Characterized by: Frost-molded landscapes Extremely low temperatures Little precipitation Poor nutrients Short growing season and reproductive season Low biotic diversity Limitation of drainage- boggy Energy and nutrients in the form of dead organic matter

Tundra From left: alpine tundra in Mt. Rainier National Park, Washington; Dall Sheep in the Arctic National Wildlife Refuge, Alaska. Tundra along the Colville River, Alaska. From left: tundra near Churchill, Manitoba, Canada; tundra in the Arctic National Wildlife Refuge, Alaska. Pica: native to alpine tundra

Grasslands Characterized as lands dominated by grasses rather than large shrubs or trees Hotter and dryer climates Two main divisions: Temperate grasslands Savannas Fires are important in maintaining grasslands

Grasslands- Savannas Savannas are grasslands scattered with individual trees Cover almost half the surface of Africa Also located in Australia, South America, and India Found in warm or hot climates where annual rainfall is from 50.8 to 127cm per year Rainfall is concentrated in six or eight months of the year, followed by a long period of drought

Grasslands- Temperate Temperate grasslands have grasses as their dominant vegetation, trees and large shrubs are absent Temperatures vary from summer to winter Rainfall is less in temperate grasslands than savannas Major temperate grassland regions: Veldts- South Africa Puszta- Hungary Pampas- Argentina Steppes- former Soviet Union Plains and prairies- central North America

Grasslands A grassland west of Coalinga, California. Savanna in the Samburu Game Preserve, Kenya. Zebra and Wildebeest African savanna. Russian steppes.

Chaparral Can consist of several different types of terrain: flat plains, hills, mountain terrain Created when cool water from an ocean merges with a landmass that is at a high temperature Found at about 30 to 40 degrees below and above the equator Major chaparral biomes found: Coast of Baja and California Areas around Mediterranean Sea

Chaparral Characteristics: Wet winter Dry summer Periods of droughts and fire Temperature is about 30 degrees F in the winter and up to 100 degrees F in summer 10 – 17 inches of rainfall annually

Chaparral Chaparral California.

Forests Forests occupy one-third of Earth’s land area Forests account for two-thirds of the leaf area of land plants Contain about 70% of carbon present in living things Forests are dominated by trees and other woody vegetation: Rainforests Deciduous (aka temperate) Coniferous (aka boreal or taiga)

Deciduous Forest Deciduous: trees that have broad leaves that are lost annually Occur in eastern North America, northeastern Asia, and western and central Europe Well defined seasons with a distinct winter Moderate climate and growing season Left: Wisconsin woods. Right: The forested hills of the Adirondacks, New York.

Deciduous Forest Temp. -30*C – 30*C Precipitation 75-100cm distributed evenly throughout the year Soil is fertile with decaying litter Canopy is moderate to dense and allows light to penetrate, allowing well developed understory

Coniferous Forest Coniferous: evergreen trees, with needle like leaves, do not shed leaves Represent the largest terrestrial biome Between 50 and 60 degrees north latitudes Found in broad belt of Eurasia and North America: two-thirds in Siberia, with the rest in Scandinavia, Alaska, and Canada Seasons are divided into short, moist, and moderately warm summers and long, cold, and dry winters

Coniferous Forest Low temps. Precipitation mainly in form of snow, 40-100cm annually Soil is thin, nutrient-poor and acidic Canopy permits low light penetration, understory is limited From left: taiga in Jasper National Park, Alberta, Canada; forest west of Stockholm, Sweden.

Rainforest Occur near the equation, within the area bounded by latitudes 23.5 degrees N and 23.5 degrees S More than one half of rainforests have already been destroyed From left: Olympic Peninsula rain forest, Washington; Patria River, Costa Rica; Ranomafana National Park, Madagascar; Hawaiian forest.

Rainforest Characteristics: Great diversity of species Winter is absent, two seasons (rainy and dry) Length of daylight is 12 h and varies little Temperature 20-25* C Precipitation is evenly distributed throughout the year, over 2000mm annually Soil is nutrient poor and acidic Canopy is layered, little light penetration

Freshwater Freshwater is defined as having a low salt concentration (less than 1%) 3 different types: Ponds and lakes Streams and rivers Wetlands A lake at Acadia National Park, Maine.

Ponds and Lakes Scattered throughout the Earth Many ponds are seasonal, lakes can exist for hundreds of years or more Temperatures vary Summers: 4*C near bottom, 22*C at tope Winter: 4*C near bottom, 0*C at top (with ice) Spring and fall: there is a mixing of the layers From left: a view across Manzanita Lake toward Mt. Lassen, California; a forest pond near Donnelly, Idaho; a Great Blue Heron; Paranagat Lake, southeastern Nevada.

Ponds and Lakes Littoral zone: topmost zone near the shore Warmest, shallow Diverse community Limnetic zone: near-surface open water surrounded by the littoral zone Well-lighted Freshwater fish dominate Profundal zone: Deep-water part of lake Colder and denser, with little light

Lakes and Ponds Littoral Zone Profundal Zone Limnetic Zone

Streams and Rivers Bodies of flowing water moving in one direction Can be found anywhere Get their starts at headwaters, which may be springs, snowmelt or lakes, and travel all the way to their mouths, usually another water channel or ocean Temperature is cooler, clearer, and higher oxygen levels at the source than the mouth

Streams and Rivers From left: McArthur-Burney Falls State Park, California; trout; Green River, Utah; Brooks River, Alaska.

Wetlands Areas of standing water, support aquatic plants, include marshes, swamps, and bogs Moist and humid conditions Highest species diversity of all ecosystems Not all wetlands are freshwater, some have high salt concentrations such as salt marshes From left: Pescadero Marsh, California; coastal marsh at Umpqua Dunes, Oregon; trees and bogs on Esther Island, Alaska.

Marine Marine regions cover about three-fourths of the Earth’s surface Include ocean’s, coral reefs, and estuaries Marine algae supply much of the world’s oxygen supply and take in a huge amount of atmospheric carbon dioxide Reef fish and coral off Eniwetok atoll in the central Pacific.

Oceans Largest of all ecosystems Ocean zones: Intertidal- where ocean meets land, sometimes exposed Pelagic- water further from the land, open ocean Benthic- area below pelagic, temperatures and light decreases Abyssal- deep ocean, very cold water, highly pressured, high in oxygen, low in nutrients

Oceans

Coral Reefs Widely distributed in warm shallow waters Found as barriers along continents, fringing islands, and atolls Waters are nutritionally poor, obtain nutrients from algae and plankton Diverse in species From left: reef life in the Gulf of Aqaba, Red Sea; a reef at Fanning Island atoll in the central Pacific; a reef in the Florida Keys National Marine Sanctuary.

Estuaries Areas where freshwater streams or rivers merge with the ocean The mixing of waters with such different salt concentrates creates a very interesting and unique ecosystem Support diverse species From left: Mangrove roots, south Florida; wetlands and tidal streams in the Ashe Island area, ACE Basin National Estuarine Research Reserve, South Carolina; a salt marsh in Winyah Bay National Estuarine Research Reserve, South Carolina.

Biomes! https://www.youtube.com/watch?v=ZouWWVyz9v8