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Ecosystems. Types and Human Impacts. Ecosystems. Biomes and their Distribution Biome - a terrestrial region with characteristic types of natural, undisturbed plant communities adapted to the climate of an area. Ecosystems. Biomes and their Distribution
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Ecosystems Types and Human Impacts
Ecosystems • Biomes and their Distribution • Biome - a terrestrial region with characteristic types of natural, undisturbed plant communities adapted to the climate of an area
Ecosystems • Biomes and their Distribution • Climate - condition of the atmosphere over a long period of time in a geographic locale
Ecosystems • Biomes and their Distribution • Climatic Factors • Temperature (MAT) • Precipitation (MAP) • The limiting factor in determining the type and distribution of biome(s)
Global Air Circulation and Biomes Hadley Cells
Ecosystems • Desert Biomes • Desert - an area where evaporation exceeds precipitation and in which MAP < 10 inches
Ecosystems • Desert Biomes • Types • Tropical Desert • Southern Sahara • High year-round temperatures • Little variation in MAT and MAP
Ecosystems • Desert Biomes • Types • Temperate Desert • Mojave • High daytime summer temperatures • Cold daytime winter temperatures • Higher MAP than tropical deserts
Ecosystems • Desert Biomes • Types • Polar Desert • Gobi • Cold winters; warm summers • Low MAP
Ecosystems • Desert Biomes • Survival Strategies • Plants • Needle-type leaves with wax coatings (creosote) • Deep tap roots (mesquite) • Fleshy stems and shallow root systems (cacti) • Store biomass in seeds during dry periods
Ecosystems • Desert Biomes • Human Impacts • Livestock overgrazing • Off-road activities • Rapid urban growth • Irrigation - salinization • Groundwater depletion
Ecosystems • Grassland Biomes • Grassland - areas where MAP is sufficient to support grasses and small plants, but not enough to support large stands of trees
Ecosystems • Grassland Biomes • Types • Tropical Grasslands • High MAT • Low-moderate MAP • Prolonged dry season
Ecosystems • Grassland Biomes • Types • Tropical Grasslands • Savanna • Deciduous shrubs and small trees • Two prolonged dry spells • Grazers (e.g. Wildebeests) • Browsers (e.g. Giraffes)
Ecosystems • Grassland Biomes • Types • Temperate Grasslands • Cold winters • Hot, dry summers • Drought and fire • Deep, nutrient-rich soils • Thick, intertwined root systems • Agricultural breadbasket
Ecosystems • Grassland Biomes • Types • Temperate Grasslands • North America -tall-grass, short-grass prairies • South America - pampas • Africa- veldt • Europe/Asia - steppe
Ecosystems • Grassland Biomes • Types • Polar Grasslands (Tundra) • Low MAT and MAP • Most precipitation falls as snow • Long, dark winters • Permafrost • Spongy mat of grasses, mosses, shrubs • Most plant growth occurs in 6-8 week summer • Bogs and marshes form when permafrost melts
Ecosystems • Grassland Biomes • Human Impacts • Conversion to agricultural land • Releases CO2 • Soil erosion • Overgrazing and soil compaction • Oil exploration in tundra
Ecosystems • Forest Biomes • Forest - areas where MAP is sufficient to support growth of various species of tress and smaller forms of vegetation
Ecosystems • Forest Biomes • Types • Tropical Rain Forests • High MAP and MAT • Evergreen broadleafs • Leaves have large surface areas to maximize photosynthesis
Ecosystems • Forest Biomes • Types • Tropical Rain Forests • Soil nutrient level is limiting factor • High biodiversity • Stratification of plant and animal niches to minimize interspecific competition
Ecosystems • Forest Biomes • Types • Temperate Deciduous Forests • Long, warm summers • Cold winters • Abundant precipitation that is evenly distributed • Broadleaf deciduous trees • Oak • Maple • Hickory
Ecosystems • Forest Biomes • Types • Temperate Deciduous Forests • Drop leaves in fall to survive winter temperatures • Thick litter layer on forest floor
Ecosystems • Forest Biomes • Types • Polar Evergreen Coniferous Forests (Taigas) • Long, cold, dry winters • Little sunlight • Short summers
Ecosystems • Forest Biomes • Types • Evergreen Coniferous Forests (Taigas) • Spruce, Pine, Hemlock • Needle-shaped leaves with waxy coatings to withstand intense winter cold and drought • Low plant diversity
Ecosystems • Grassland Biomes • Human Impacts • Clearing for agriculture, urban growth, export logging, grazing • Soil erosion • Plant nutrient depletion • Water pollution • Loss of biodiversity
Ecosystems • Grassland Biomes • Human Impacts • Clearing of temperature deciduous forests for timber, agriculture, urban development • > 99% original stands have been cleared
Ecosystems • Aquatic Ecosystems • Classified based on salinity • Freshwater • Marine
Ecosystems • Aquatic Life Zones • Benefits of living in aquatic environments • Buoyancy provides physical support • Limited temperature fluctuations • Abundant nutrients
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Open Ocean • Coastal Zone
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Open Ocean • Regulates Earth’s climate • Distribution of heat in currents • Evaporation - Hydrologic Cycle • Reservoir for CO2 • Habitat for > 250,000 species of plants and animals
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Coastal Zone • Warm, nutrient-rich waters • Contains > 90% of marine species • High NPP
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Coastal Zone • Estuary - partially-enclosed area where seawater mixes with fresh water (brackish water) • Coastal Wetlands • Habitat for waterfowl • Remove toxic chemicals, sediment, nutrients • Absorb and store floodwaters
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Coastal Zone • Mangrove swamps • Found along warm, tropical coasts • Salt-tolerant mangrove trees • Protect shoreline from erosion
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Coastal Zone • Rocky Shorelines (Pacific Northwest, USA) • Sandy Shorelines (Gulf Coast) • Barrier Islands(Atlantic Coast; Gulf Coast) • Thin offshore islands parallel to shoreline • Protect mainland from erosion • Atlantic City, Miami Beach
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Coastal Zone • Coral Reefs • “Rainforests” of the ocean • Polyps - soft-bodied organisms that secrete a protective shell of calcium carbonate • Mutualistic relationship between photosynthetic algae and polyps
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Human Impacts • Open Ocean • Dumping • Oil drilling
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Human Impacts • Coastal Zones • Development • Dredging and filling of wetlands • Discharge of raw sewage and heavy metals in estuaries
Ecosystems • Aquatic Life Zones • Marine Ecosystems • Human Impacts • Coastal Zones • Cutting of mangroves for timber • Coral reef destruction
Ecosystems • Aquatic Life Zones • Freshwater Ecosystems • Lake - large, natural body of standing fresh water • Origins • Glaciers (Lake Michigan) • Depressions in lithosphere • Volcanic activity (Crater Lake, Oregon) • Dams (every lake in Texas!)
Ecosystems • Aquatic Life Zones • Freshwater Ecosystems • Lakes • Classified based on nutrient content and NPP • Oligotrophic • Eutrophic