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

2. 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

3. 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

4. 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.

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

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

12. 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

13. 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

14. Chaparral
Chaparral California.

15. 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)

16. 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.

17. Deciduous Forest Temp. -30*C – 30*C
Precipitation cm 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

18. 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

19. Coniferous Forest Low temps.
Precipitation mainly in form of snow, cm 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.

20. 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.

21. 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

22. 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.

23. 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.

24. 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

25. Lakes and Ponds
Littoral Zone
Profundal Zone
Limnetic Zone

26. 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

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

28. 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.

29. 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.

30. 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

31. Oceans

32. 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.

33. 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.

34. Biomes!