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Chapter 10: Geography of Terrestrial Life 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. 10.1 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. 10.1 Terrestrial Biomes and Climate • Tropical zone – Equator to 25o north and south latitude • Temperate zone – Falls between 25o and 60o north and south latitude • Polar zone – Above 60o north and south latitude © 2013 Pearson Education, Inc. Terrestrial Types • • • • • • • • Deserts Grasslands (Prairies and Savannas) Tundra Conifer Forests Broad Leaf Deciduous Forests Mediterranean Tropical Moist Forests Tropical Seasonal Forests © 2013 Pearson Education, Inc. © 2013 Pearson Education, Inc. ADD FIG. 5.4 8 10.1 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. 10.2 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. 10.2 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. 10.2 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. 10.3 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 5–20o C – Dominated by deciduous forest – Growing seasons range 4–10 months © 2013 Pearson Education, Inc. 10.3 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. 10.3 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. 10.3 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. 10.3 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. 10.4 Polar Biomes • Polar biomes – Generally above 60o north and south latitude – Very cold, less than 5o C – Short growing seasons – Limited abundance and diversity of life © 2013 Pearson Education, Inc. 10.4 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. 10.4 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. 10.5 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. 10.6 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. 10.6 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. 10.6 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 © 2013 Pearson Education, Inc. 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 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. 28 Water Gradients 29 Freshwater vs. Saline • Freshwater = low salt concentration • Saltwater cover more area and contain greater volume 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. 32 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. 33 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 35 36 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. 37 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! 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. 40