Ecosystems

1
Ecosystems

• Types and Human Impacts

2
Ecosystems

• Biomes and their Distribution
• Biome - a terrestrial region with characteristic
  types of natural, undisturbed plant communities
  adapted to the climate of an area

3
Ecosystems

• Biomes and their Distribution
• Climate - condition of the atmosphere over a long
  period of time in a geographic locale

4
Ecosystems

• Biomes and their Distribution
• Climatic Factors
• Temperature (MAT)
• Precipitation (MAP)
• The limiting factor in determining the type and
  distribution of biome(s)

5
Effects of Earths Tilted Axis
6
Global Air Circulation
7
Convective Heat Transfer in Atmosphere
8
Global Air Circulation and Biomes
Hadley Cells
9
Ecosystems

• Desert Biomes
• Desert - an area where evaporation exceeds
  precipitation and in which MAP lt 10 inches

10
MAT and MAP in the Desert Biome
11
Ecosystems

• Desert Biomes
• Types
• Tropical Desert
• Southern Sahara
• High year-round temperatures
• Little variation in MAT and MAP

12
Ecosystems

• Desert Biomes
• Types
• Temperate Desert
• Mojave
• High daytime summer temperatures
• Cold daytime winter temperatures
• Higher MAP than tropical deserts

13
Ecosystems

• Desert Biomes
• Types
• Polar Desert
• Gobi
• Cold winters warm summers
• Low MAP

14
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

15
Ecosystems

• Desert Biomes
• Human Impacts
• Livestock overgrazing
• Off-road activities
• Rapid urban growth
• Irrigation - salinization
• Groundwater depletion

16
Ecosystems

• Grassland Biomes
• Grassland - areas where MAP is sufficient to
  support grasses and small plants, but not enough
  to support large stands of trees

17
MAT and MAP in the Grassland Biome
18
Ecosystems

• Grassland Biomes
• Types
• Tropical Grasslands
• High MAT
• Low-moderate MAP
• Prolonged dry season

19
Ecosystems

• Grassland Biomes
• Types
• Tropical Grasslands
• Savanna
• Deciduous shrubs and small trees
• Two prolonged dry spells
• Grazers (e.g. Wildebeests)
• Browsers (e.g. Giraffes)

20
Ecosystems

• Grassland Biomes
• Types
• Temperate Grasslands
• Cold winters
• Hot, dry summers
• Drought and fire
• Deep, nutrient-rich soils
• Thick, intertwined root systems
• Agricultural breadbasket

21
Ecosystems

• Grassland Biomes
• Types
• Temperate Grasslands
• North America -tall-grass, short-grass prairies
• South America - pampas
• Africa- veldt
• Europe/Asia - steppe

22
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

23
Ecosystems

• Grassland Biomes
• Human Impacts
• Conversion to agricultural land
• Releases CO2
• Soil erosion
• Overgrazing and soil compaction
• Oil exploration in tundra

24
Ecosystems

• Forest Biomes
• Forest - areas where MAP is sufficient to support
  growth of various species of tress and smaller
  forms of vegetation

25
MAT and MAP in the Forest Biome
26
Ecosystems

• Forest Biomes
• Types
• Tropical Rain Forests
• High MAP and MAT
• Evergreen broadleafs
• Leaves have large surface areas to maximize
  photosynthesis

27
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

28
Ecosystems

• Forest Biomes
• Types
• Temperate Deciduous Forests
• Long, warm summers
• Cold winters
• Abundant precipitation that is evenly distributed
  
• Broadleaf deciduous trees
• Oak
• Maple
• Hickory

29
Ecosystems

• Forest Biomes
• Types
• Temperate Deciduous Forests
• Drop leaves in fall to survive winter
  temperatures
• Thick litter layer on forest floor

30
Ecosystems

• Forest Biomes
• Types
• Polar Evergreen Coniferous Forests (Taigas)
• Long, cold, dry winters
• Little sunlight
• Short summers

31
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

32
Ecosystems

• Grassland Biomes
• Human Impacts
• Clearing for agriculture, urban growth, export
  logging, grazing
• Soil erosion
• Plant nutrient depletion
• Water pollution
• Loss of biodiversity

33
Ecosystems

• Grassland Biomes
• Human Impacts
• Clearing of temperature deciduous forests for
  timber, agriculture, urban development
• gt 99 original stands have been cleared

34
Ecosystems

• Aquatic Ecosystems
• Classified based on salinity
• Freshwater
• Marine

35
Ecosystems

• Aquatic Life Zones
• Benefits of living in aquatic environments
• Buoyancy provides physical support
• Limited temperature fluctuations
• Abundant nutrients

36
Ecosystems

• Aquatic Life Zones
• Marine Ecosystems
• Open Ocean
• Coastal Zone

37
Ecosystems

• Aquatic Life Zones
• Marine Ecosystems
• Open Ocean
• Regulates Earths climate
• Distribution of heat in currents
• Evaporation - Hydrologic Cycle
• Reservoir for CO2
• Habitat for gt 250,000 species of plants and
  animals

38
Ecosystems

• Aquatic Life Zones
• Marine Ecosystems
• Coastal Zone
• Warm, nutrient-rich waters
• Contains gt 90 of marine species
• High NPP

39
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

40
Ecosystems

• Aquatic Life Zones
• Marine Ecosystems
• Coastal Zone
• Mangrove swamps
• Found along warm, tropical coasts
• Salt-tolerant mangrove trees
• Protect shoreline from erosion

41
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

42
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

43
Ecosystems

• Aquatic Life Zones
• Marine Ecosystems
• Human Impacts
• Open Ocean
• Dumping
• Oil drilling

44
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

45
Ecosystems

• Aquatic Life Zones
• Marine Ecosystems
• Human Impacts
• Coastal Zones
• Cutting of mangroves for timber
• Coral reef destruction

46
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!)

47
Ecosystems

• Aquatic Life Zones
• Freshwater Ecosystems
• Lakes
• Classified based on nutrient content and NPP
• Oligotrophic
• Eutrophic

48
Temperate Zone Lakes