Download 03_Climate and Biomes

A CarranzaBio 12
Climate and Biomes
SRJC
The Biosphere
 Biosphere Subdivisions
 Aquatic
 Terrestrial
 Biogeographic regions and Biomes
 distinguished by species distributions (plants)
 Biogeographic Realms
 Six general regions of similar conditions and communities
Biomes
 Divisions of realms, characterized by habitat conditions and community structure
 A broad region characterized by vegetation types shaped by:
 Climate
 Average weather condition in a region
 Climate is affected by:
 amount of incoming solar radiation
 prevailing winds
 Topography- the elevation of land masses
 Rain Shadow
 Air rises on the windward side, loses moisture before passing over
the mountain
 As you travel higher in elevation, conditions resemble those at higher
latitudes (i.e. going up a mountain can seem like traveling toward the
poles)
 Composition of regional soils.
Terrestrial Biomes
 Deserts Annual rainfall < 10 centimeters; high level of evaporation
 Form between 30 degrees north and south and in rain shadows
 Dry Shrublands and Woodlands
 Semiarid regions with cooler, wet winters and hot, dry summers
 Occur in western or southern coastal regions between latitudes 30 and 40
 Plants adapted to dry conditions and fire (some rely on fire!)
 California Chaparral
 Dry Grasslands
 Shortgrass prarie
 Tallgrass prarie
 Desertification
 Conversion of large regions of natural grasslands to desert-like conditions
 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
 Tropical Rainforests- lots of moisture, greatest diversity if life
 Tall Trees- competition for light
A. Carranza
Page 1
8/15/2015
A CarranzaBio 12
Climate and Biomes
SRJC
 Vines grow on tree trunks
 Large, dark green leaves adapted to living in shade of taller plants
 Epiphytes- plants growing on tree trunks, some can be parasitic
 Tropical forest canopies are layered, space is limiting factor
 Temperate Deciduous Forests- broad-leaf trees, drop leaves in winter
 Coniferous Forests- needle-shaped leaves conserve heat, keep them all year round
 Tundra- plants grow low to conserve heat
 Arctic
 Permafrost lies beneath surface
 Alpine
 Occurs at high latitudes
 The Water Provinces: Freshwater Biomes (or Province
 Lakes- Bodies of standing freshwater
 Eutrophic: shallow, nutrient-rich; has high primary productivity (green
water)
 Oligotrophic: deep, nutrient-poor; has low primary productivity (clear
water)
 Thermal Layering
 In temperate-zone lakes, water can form distinct layers during summer
 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
 Eutrophication
 Enrichment of a body of water with nutrients
 Can occur naturally over long time span
 Can be triggered by pollutants
 Rivers and Streams
 Water moves continuously in one direction.
 Water may become polluted as it travels to the sea.
 Estuary
 Partially enclosed area where saltwater and freshwater mix
 Dominated by salt-tolerant plants
 Chesapeake Bay, San Francisco Bay, salt marshes of New England
 Salt Marsh
 Mangrove Wetlands
 Tropical saltwater ecosystem
 Form in nutrient-rich tidal flats
 Dominant plants are salt-tolerant mangroves
 Florida, Southeast Asia
 Estuarine Food Webs
 Primary producers are phytoplankton and salt-tolerant plants
 Much primary production enters detrital food webs
 Detritus (decomposing organic material) feeds bacteria, nematodes, snails,
crabs, fish
A. Carranza
Page 2
8/15/2015
A CarranzaBio 12
Climate and Biomes
SRJC
Ocean Provinces (biomes)
 Intertidal-(Littoral zone)- within the mean high and low tides
 Intertidal Zones
 Upper littoral
 submerged during highest tides of cycle (low diversity)
 Midlittoral zone
 regularly submerged and exposed (moderate diversity)
 Lower littoral
 exposed only during lowest tides
 Benthic- attached to or living at the bottom
 Pelagic- swimming or drifting in the water column (open water)
 Sandy Coastlines
 Loose sediments, continually rearranged
 Few grazing food webs
 Detrital food webs from organic debris
 Interstitial Meiofauna
 Communities of microscopic animals living between sand grains
 Coral Reef Biomes
 Reef-building corals have photosynthetic, dinoflagellate symbionts
 Oceanic Biome (or Province)
 Photic Zone (Euphotic zone) depth to which light can reach photosynthetic
organisms
 Marine Snow- form basis of food chain where light cannot reach
 Hydrothermal Vents
 Chemoautotrophic bacteria use mineral-rich hot water as energy source
 Upwelling
 Brings cold, nutrient-rich bottom waters to the surface
 Upwelling of cool water along
western coasts
 Wind driven phenomenon
 ENSO (El Niño Southern Oscillation)
 Climactic event that changes sea surface temperature and air circulation
patterns in the equatorial Pacific Ocean
 Between ENSO’s
 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
 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
A. Carranza
Page 3
8/15/2015