The Biosphere
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Transcript of The Biosphere
![Page 1: The Biosphere](https://reader038.fdocuments.in/reader038/viewer/2022110405/5681320a550346895d985eff/html5/thumbnails/1.jpg)
The Biosphere
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The Order of Things….
Subatomic Particles Atoms molecules macromolecules Organelles Cells tissues Organs Organisms
(Ecological Order…) Populations Communities Ecosystems Biomes Biosphere
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Biogeography
The study of the distribution of
organisms and the processes that
underlie distribution patterns (a
central question – evolutionary
and ecological answer -
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Biogeographic Realms
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Factors that Affect Distribution
Geologic history
Topography
Climate
Species
interactions
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Biosphere
Sum total of the places in which
organisms live
Includes portions of the
hydrosphere, lithosphere, and
atmosphere
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Climate
Average weather condition in a region
Affected by: amount of incoming solar radiation
prevailing winds
elevation
precipitation
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Climagraph, San Diego, CA
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More Climagraphs
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Fig. 5.4
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The Atmosphere
Three layers
Outer mesosphere
Middle stratosphere (includes ozone layer)
Inner troposphere (where air is warmed by
the greenhouse effect)
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Earth’s Atmosphere
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Ozone Layer
Region 17 to 27 kilometers above
sea level in the stratosphere
Molecules of ozone absorb most
layers of ultraviolet light
Protects living organisms from
excess exposure to UV light3O2 - 2O3 (ozone)
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Warming the Atmosphere
Solar energy warms the atmosphere and sets global air circulation patterns in motion
Figure 49.4Page 890
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Rotation and Wind Direction
Earth rotates faster under the air at the equator than it does at the poles
Deflection east and west
Figure 49.4Page 890
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Global Wind Patterns
Red Arrows Indicate Very Strong Winds
Trade winds, doldrums, and horse latitudes
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Seasonal Variation
Northern end of Earth’s axis tilts toward sun in June and away in December
Difference in tilt causes differences in sunlight intensity and day length
The greater the distance from the equator, the more pronounced the seasonal changes
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Earth’s Axis Tilts
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Ocean Currents
Upper waters move in currents that distribute
nutrients and affect regional climates
Figure 49.6Page 892
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Rain Shadow
Air rises on the windward side, loses
moisture before passing over the
mountain
Figure 49.7Page 893
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Monsoons
A monsoon is defined as a seasonal shift
in wind direction, being derived from the
Arabic word "mausim", meaning season.
Affect continents north and south of warm-
water oceans
Can cause seasonal variation in rains
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Air Moves from Cool to Warm Regions
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Coastal Breezes Breeze blows in direction of warmer
region Direction varies with time of day
Afternoon Night
Figure 49.8Page 893
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Biogeographic Realms
Eight areas in which plants and
animals are somewhat similar
Maintain their identity because of
climate and physical barriers that tend
to maintain isolation between species
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Biogeographic Realms
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Biomes
Regions of land characterized by habitat conditions and community structure
Distinctive biomes prevail at certain latitudes and elevations
A biogeographic realm generally composed of many biomes
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Fig. 5.2
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Olympic NP
The most famous temperate rainforest is in the Olympic National Park of Washington state.
It is locates on the western slope of an Olympic mountain where it gets about 200 inches of rain per year.
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Temperate Rainforest Great Smoky Mountains NP
Each 1,000 feet of elevation gained is the equivalent of moving 250 miles north. This creates a temperature gradient combined with
additional precipitation (GT 100 inches per year) classifies small sections of the Park as a temperate rainforest. http://www.great.smoky.mountains.national-park.com/info.htm
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Forests in the Great Smoky Mountains Five forest types dominate the Great Smoky
Mountains. The spruce-fir forest caps the Park's highest
elevations. (4500 – 5500 ft) A northern hardwood forest dominates the
middle to upper elevations from 3,500- 5,000 feet. Drier ridges in and around the Park hold a pine-
oak forest. A hemlock forest often grows along stream
banks. The cove hardwood forest lines the valleys
throughout the Park.
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Fig. 5.3
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Hot Spots Portions of biomes that show the
greatest biodiversity
Conservationists are working to inventory and protect these regions
24 hot spots hold more than half of all terrestrial species
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Conservation International’s Definition
Conservation International defines hotspots as "regions that harbor a great diversity of endemic species and, at the same time, have been significantly impacted and altered by human activities."
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Hotspots Map
http://www.usaid.gov/locations/asia_near_east/sectors/env/biodiversity_eastasia.html
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Ecoregions
Large areas of globally important biomes or water provinces
Currently vulnerable to extinction
Targeted by World Wildlife Fund for special study and conservation efforts
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WWF global 2000 Project “WWF has ranked the terrestrial Global
200 ecoregions by their conservation status - classifying those ecoregions that are considered critical, endangered, or vulnerable as a result of direct human impacts, and those that are relatively stable or intact. Nearly half (47%) of the terrestrial ecoregions are considered critical or endangered; another quarter (29%) are vulnerable; and only a quarter (24%) are relatively stable of intact.”
http://www.panda.org/about_wwf/where_we_work/ecoregions/global200/pages/mapdownload.htm#map3
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Map of WWF’s Ecoregions
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Soil Characteristics
Amount of humus
pH
Degree of aeration
Ability to hold or drain
water
Mineral content
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Soil Profiles
Layer structure of soil Soil characteristics
determine what plants will grow and how well
Rainforest Desert Grassland
Figure 49.12Page 896
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Deserts
Less than 10 centimeters annual
rainfall, high level of evaporation
Tend to occur at 30 degrees north and
south and in rain shadows
One-third of land surface is arid or
semiarid
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Sonoran Desert
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Temperate Grasslands
Precipitation less than 60 centimeters per year and greater than 10 cm per year
Temperature range -5 to 20 C0 (usually)
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Grasslands
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Dry Shrublands and Woodlands
Semiarid regions with cooler, wet winters and hot, dry summers
Tend to occur in western or southern coastal regions between latitudes of 30 and 40 degrees
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Dry Scrubland
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Savannas “A savanna is a rolling grassland,
dotted with trees, which can be found between a tropical rainforest and desert biomes.”
“There are actually two very different seasons in a savanna; a very dry season (winter), and a very wet season (summer).”http://www.rain.org/global-garden/biomes/BIOME_SA.HTM
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Map of Savannas
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African Savanna
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Forest Biomes
Tall trees form a continuous canopy Evergreen broadleaves in tropical
latitudes
Deciduous broadleaves in most temperate
latitudes
Evergreen conifers at high temperate
elevations and at high latitudes
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Evergreen Broadleaf Tropical Forest
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Temperate Deciduous Forest
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Evergreen Forest, Pacific Coast
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Taiga
Biome that borders the artic tundra
Few trees Most common tree is the black
spruce Can be considered an ecotone Low bio - productivity and diversity
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Taiga
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Taiga
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Arctic Tundra
Occurs at high
latitudes
Permafrost lies
beneath surface
Nutrient cycling
is very slow
Do not post on Internet
Arctic tundra in Russia in summer
Figure 49.19 Page 903
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Alpine Tundra
Occurs at high elevations
No underlying permafrost
Plants are low cushions or mats as in Arctic tundra
Do not post on Internet
Figure 49.19 Page 903
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Lakes
Bodies of standing freshwater
Eutrophic: shallow, nutrient-rich,
has high primary productivity
Oligotrophic: deep, nutrient-poor,
has low primary productivity
LITTORALLIMNETIC
LITTORAL
PROFUNDAL Figure 49.21Page 904
Lake Zonation
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Thermal Layering
In temperate-zone lakes, water can form distinct layers during summer
THERMOCLINE
Figure 49.22Page 904
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Seasonal Overturn
In spring and fall, temperatures in
the lake become more uniform
Oxygen-rich surface waters mix
with deeper oxygen-poor layers
Nutrients that accumulated at
bottom are brought to the surface
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Eutrophication
Enrichment of a body of water with nutrients
Can occur naturally over long time span
Can be triggered by pollutants
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Streams
Begin as springs or seeps
Carry nutrients downstream
Solute concentrations influenced by streambed composition and human activities
Figure 49.23 Page 905
Do not post on Internet
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Ocean Provincesneritic zone
oceanic zone
intertidal zone
BENTHIC PROVINCE
PELAGIC PROVINCE
0200
1,000
2,000
4,000
11,0000 depth (meters)
continental shelf
bathyal shelf
abyssal zone
hadal zone
deep-sea trenches
sunlit water
"twilig
ht" water
sunless water
Figure 49.24Page 906
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Phytoplankton
Floating or weakly swimming
photoautotrophs; form the base
for most oceanic food webs
Ultraplankton are photosynthetic
bacteria
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Plankton Nets
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Diatoms and Dinoflagellates
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Primary Productivity
Primary producers are usually the phytoplankton
Productivity can vary seasonallynorth temperate
north polar
tropical
Figure 49.25Page 906
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Deep Ocean Food Webs
Regions too dark for photosynthesis Marine snow supports a detrital
food web Organic matter drifts down from
shallower water Diverse species migrate up and
down in water column daily
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Hydrothermal Vents Openings in ocean
floor that spew mineral-rich, superheated water
Primary producers are chemoautotrophic bacteria; use sulfides as energy source Tube worms at hydrothermal vent
Do not post on Internet
Figure 49.26 Page 907
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Mangrove Wetlands
Tropical saltwater ecosystem
Form in nutrient-rich tidal flats
Dominant plants are salt-tolerant
mangroves
Florida, Southeast Asia
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Estuary
Partially enclosed area where
saltwater and freshwater mix
Dominated by salt-tolerant plants
Examples are Chesapeake Bay, San
Francisco Bay, salt marshes of New
England
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Estuarine Food Webs
Primary producers are phytoplankton
and salt-tolerant plants
Much primary production enters
detrital food webs
Detritus feeds bacteria, nematodes,
snails, crabs, fish
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Intertidal Zones
Littoral zone is submerged only
during highest tides of the year
Midlittoral zone is regularly
submerged and exposed
Lower littoral is exposed only
during lowest tides of the year
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Rocky Intertidal
Grazing food webs
prevail
Vertical zonation is
readily apparent
Diversity is greatest
in lower littoral zone
Figure 49.29Page 909
Do not post on Internet
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Sandy Coastlines
Vertical zonation is less obvious
than along rocky shores
Detrital food webs predominate
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Beaches
http://www.infocom.cqu.edu.au/Units/aut98/00101/DONE/Assign02/Nfi/beaches.jpg
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Beach Processes
“Sandy beaches form by the accretion of sand particles, the product of erosion, which have been carried in and deposited by waves.
Once it forms, a beach changes continuously. Winds are constantly blowing the sand - often in the opposite direction of the waves.”
http://www.amyingalls.net/jekyll/pages/beach/sandy_b.html
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Accretion Accretion: the process of growth or
enlargement by gradual buildup. Barrier islands grow through the process of accretion. Currents wash the sand from the northern end
of the island and deposit it on the southern tip.
The growth of the islands in this manner causes the islands to migrate up and down the coast. Jekyll Island is migrating south toward Florida.
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Erosion
Erosion:Erosion: the process or state of being slowly worn away. Soil is eroded by wind and water .
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Biotic Factors Crabs and other
animals are moving sand from the bottom up as they emerge from their burrows. Crabs can move several tons of sand in one day
THE GHOST CRAB, Ocypode quadrata
http://www.amyingalls.net/jekyll/pages/beach/sandy_b.html
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Beach Dynamics
Through the seasons, the waves constantly rework the sand and reshape the beach.
During spring and summer, gentle waves deposit sand onto the beach platform forming a broad sandy slope called a berm.
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Summer Sand Accretion
During the summer, the gentle waves build up sand on the beach platform.
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Berm
A berm is a narrow shelf or ledge of sand and debris running parallel to the beach. It is made by the building up, or accretion, of sand.
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Winter Sand Removal
Through the seasons, the waves constantly rework the sand and reshape the beach.
During the Winter, storms often remove sand from the berm.
The Southerly long shore current tends to move the entire barrier island southward.
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Sand Dunes
Sand dunes are vital to the barrier island ecosystem. They provide shelter for shorebirds and sea turtles.
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Dune Sand Reservoirs
Dunes also provide the necessary sand supply for the constantly changing beach.
This supply of sand helps to control beach erosion - a problem many beaches experience.
Sand dunes provide the first line of defense from severe storms and hurricanes.
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Dune Zonation
There are three different zones in the sand dunes: primary dunes, secondary dunes, and the interdune meadow.
As the dunes get older, they migrate back toward the maritime forest.
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Interdune Meadows
Between the dunes in a interdune meadow, water will begin to collect. If there is enough soil to hold this water, a swamp will form.
These swamps are called sloughs (pronounced slews).
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Role of Freshwater
Because they are far enough back from the ocean, sloughs contain fresh, and not salt water.
Fresh water allows more animals and plants to live and grow.
If enough time passes, the slough will find itself in a maritime forest.
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Later, alligator - 9-footer comes ashore on St. Simons
Fri, Aug 23, 2002By KAREN SLOAN The Brunswick News
Tourists were not the only ones who wanted to enjoy the sun and surf on the beach near the old U.S. Coast Guard Station on St. Simons Island Thursday. A 9-foot alligator was found about 10 a.m. lingering in the waters about 20 feet from the beach….
http://www.thebrunswicknews.com/local/278347593804907.php
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Upwelling
Upward movement of water along a coast; replaces surface waters that move away from shore
Figure 49.31Page 910
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ENSO
El Nino Southern Oscillation
Climactic event that involves changes in
sea surface temperature and air circulation
patterns in the equatorial Pacific Ocean
(Western Pacific waters become warmer)
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Between ENSOs
Warm water and heavy rainfall
move west across the Pacific
Warm moist air rises in the
western Pacific causing storms
Upwelling of cool water along
western coasts
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During an ENSO
Trade winds weaken and warm water
flows east across the Pacific
Sea surface temperatures rise
Upwelling along western coasts ceases
Heavy rainfall occurs along coasts,
droughts elsewhere
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Cholera Connection
Cholera outbreaks correlate with rises in sea temperature
Copepod population increases when phytoplankton increase in warming seas
Copepod host of Vibrio choleraeharbors dormant stage
Do not post on Internet
Figure 49.34 Page 913