Transcript Chapter 10 - Geography of Terrestrial Life_AT SP16x

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
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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
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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
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Terrestrial Types
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Deserts
Grasslands (Prairies and Savannas)
Tundra
Conifer Forests
Broad Leaf Deciduous Forests
Mediterranean
Tropical Moist Forests
Tropical Seasonal Forests
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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:
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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.
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Water Gradients
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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.
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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.
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Ecological Functions of Wetlands
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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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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.
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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.
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