Chapter 10: Geography of Terrestrial Life

© 2013 Pearson Education, Inc. Interstate Biogeography Human activities can alter distribution of plants and animals –Roads and highways block access for plants and animals –Fire suppression halts cyclical succession –Removal of animal species Bison Wolves –Exotic species

© 2013 Pearson Education, Inc Terrestrial Biomes and Climate Biomes –Communities of similar organisms in a particular climate –Determined by atmosphere and climate Temperature and precipitation –May be grouped into three climatic zones Tropical zone Temperate zone Polar zone

© 2013 Pearson Education, Inc Terrestrial Biomes and Climate Tropical zone –Equator to 25 o north and south latitude Temperate zone –Falls between 25 o and 60 o north and south latitude Polar zone –Above 60 o north and south latitude

Terrestrial Types Deserts Grasslands (Prairies and Savannas) Tundra Conifer Forests Broad Leaf Deciduous Forests Mediterranean Tropical Moist Forests Tropical Seasonal Forests

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© 2013 Pearson Education, Inc Terrestrial Biomes and Climate Depicting the climate of biomes Climatograph –Shows pattern of seasonal change in temperature and precipitation –Moisture availability not directly indicated but may be inferred

© 2013 Pearson Education, Inc Tropical Biomes Tropical rain forest –Annual rainfall greater than 2,000 mm (80 in.) –Plentiful rainfall, warm climate –Enormous plant and animal diversity –Net primary production greater than any other terrestrial biome Nutrients rapidly cycled Many unique niches and endemic species

© 2013 Pearson Education, Inc Tropical Biomes Tropical seasonal forest –Annual rainfall 1,500–2,500 mm (60–98 in.) –Wet and dry seasons Months with little or no rain common –Ranges from tall tree canopy in wettest extreme to scrubby woodlands in driest extreme

© 2013 Pearson Education, Inc Tropical Biomes Tropical savanna –Occurs where rainfall is highly seasonal Drought persists more than half the year –Dominated by grasses Supports massive herds of grazing animals –Climate overlaps with seasonal tropical forest

© 2013 Pearson Education, Inc Temperate Biomes Temperate zone –Over 60% Earth land mass in temperate zone –Annual precipitation ranges from 200 to over 2,000 mm –Annual temperature ranges 5–20 o C –Dominated by deciduous forest –Growing seasons range 4–10 months

© 2013 Pearson Education, Inc Temperate Biomes Temperate deciduous forest –Dominated by broadleaf trees –Moderate summers and cold winters –Growing seasons last between last and first hard frosts –Little remains undisturbed

© 2013 Pearson Education, Inc Temperate Biomes Temperate evergreen forest –Dominant trees keep leaves Evergreen conifers –Generally less precipitation and warmer winters than temperate deciduous forest –Summer drier than winter Some regions are temperate rain forests –Mild temperatures year round

© 2013 Pearson Education, Inc Temperate Biomes Chaparral –Dominated by summer drought –Evergreen shrubland and low woodlands –"Mediterranean" climate –Shrubs are sclerophyllous "Stony leafed" Adaptations to resist water loss and wilting –Fire adapted

© 2013 Pearson Education, Inc Temperate Biomes Temperate grasslands –90% have been altered by agriculture and cattle grazing –Too dry for forests –Wet enough to not form deserts –Winters long and cold –Summers hot

© 2013 Pearson Education, Inc Polar Biomes Polar biomes –Generally above 60 o north and south latitude –Very cold, less than 5 o C –Short growing seasons –Limited abundance and diversity of life

© 2013 Pearson Education, Inc Polar Biomes Boreal forest –Cold and wet –Growing season less than 4 months –Winters long, dry, and bitterly cold –Forests dominated by conifers –Permafrost Layer of permanently frozen soil 30–100 cm below surface

© 2013 Pearson Education, Inc Polar Biomes Tundra –Treeless landscapes –Dry, only 100–500 mm annual precipitation –Permafrost –Growing season shorter than 3 months –Winters are most harsh

© 2013 Pearson Education, Inc Deserts Deserts –Occur worldwide –Extremely arid –Typically below 250 mm annual rainfall –Wide variation in daily temperature –May be cold or hot –Plants adapted for little water Succulents

© 2013 Pearson Education, Inc Mountains and Coastlines Not biomes Contain features found in all climatic zones Have gradients of environmental change Changes in elevation produce variety of climates Particularly vulnerable to human activities and global warning

© 2013 Pearson Education, Inc Mountains and Coastlines Mountains –Mountain side may experience same climatic change as all of North America Air temperature drops as altitude increases Mountains experience same biome transitions in altitude as continent does in latitude –Mountains may have different climate on either side Rain shadow –Rain falls on mountain as air climbs windward side; other side (leeward) of mountain dry

© 2013 Pearson Education, Inc Mountains and Coastlines Coastlines –Occur in narrow transition of terrestrial biomes and oceans –Saltwater and wave action create harsh environments Plants and animals adapted to high salt, low fresh water –Human actions have lead to significant damage to coastal areas

Aquatic Ecosystems Cover more than 2/3 of earth’s surface Influenced by local climate, soil, resident organisms, adjacent terrestrial ecosystem, physical characteristics of water

Aquatic Considerations Basic needs (CO2, H2O, sunlight, oxygen, food and minerals) influenced by: –Dissolved Substances –Suspended Matter –Water Depth –Temperature –Flow Rate –Bottom Characteristics –Internal Convective Currents –Connectivity to Other Aquatic Ecosystems

Vertical Stratification Light, Temperature, Nutrients, and Oxygen Gradients Vertical Sub-communities –Plankton float freely –Bottom Dwellers = Benthos Benthic = on the bottom –Epilimnion, Hypolimnion, Thermocline

28 Vertical Component Vertical stratification is an important aspect of many aquatic ecosystems. –Organisms tend to form distinctive vertical sub-communities. Benthos - Bottom sub-community. –Low oxygen levels Thermocline - Distinctive temperature transition zone that separates warm upper layer and deeper cold layer.

29 Water Gradients

Freshwater vs. Saline Freshwater = low salt concentration Saltwater cover more area and contain greater volume

32 Freshwater Ecosystems Include standing waters of ponds and lakes, as well as flowing waters of rivers and streams. Cover relatively little total area, but biologically distinctive. Extremely varied due to individual site influences.

33 Wetlands Land surface is saturated or covered with water at least part of the year. –Swamps - Wetlands with trees. –Marshes - Wetlands without trees. –Bogs and Fens - Waterlogged soils that tend to accumulate peat. Water usually shallow enough to allow full sunlight penetration. Trap and filter water, and store runoff.

Ecological Functions of Wetlands Habitat for breeding, nesting, migration Filter water, trap contaminants Reduce flooding Neutralize and detoxify substances Recharge Succession – to terrestrial community through sedimentation, eutrophication, stream cutting and draining

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37 Estuaries Estuaries - Bays or semi-enclosed bodies of brackish water that form where rivers enter the ocean. –Usually carry rich sediments. Fan-shaped sediment deposit (delta) formed on shallow continental shelves.

Shorelines and Barrier Islands Rocky coasts, sandy beaches Barrier islands = low, narrow, sandy islands offshore –Protect inland shores from surf –Human development

Coral Reefs Accumulated calcareous skeletons of colonial corals Form along edges of shallow, submerged banks or shelves Depth limited by light penetration High diversity Endangered!

40 Marine Ecosystems Marine ecosystems have as much variability as those on land. –Food webs and communities off-shore are intricately connected to those onshore. Coral Reefs - Accumulated calcareous skeletons of colonial organisms (coral). –Depth limited by light penetration. –Among most endangered communities.