Major Ecosystems of the World

1
Chapter 7

• Major Ecosystems of the World

2
Lecture Outline

• Terrestrial Biomes
• Define Biome
• Representative terrestrial biomes
  (characteristics physical biological)
• Human impacts on biomes
• Impact of altitude latitude
• Aquatic Ecosystems
• Environmental factors that affect ecosystems
• Representative aquatic ecosystems
• Human impacts on aquatic ecosystems

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What is a biome?

• A broad, regional type of ecosystem that has
  distinct climate and soil conditions and a
  distinctive kind of biological community adapted
  to those conditions.

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Biomes

• Include
• Many interacting ecosystems
• Terrestrial ecology
• Community -gt ecosystems -gt landscape -gtbiome
• Temperature precipitation are very important in
  determining a biome
• Also influenced by landforms (especially
  mountains).

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Major Biomes of World
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Vertical Zonation

• Going up a mountain is like traveling to the
  poles
• As you go up a mountain the biomes change
• Important differences between latitude and
  elevation biomes

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Tundra(Arctic or Alpine Tundra)

• High mountains or northern/southern latitudes
• Treeless
• Short growing season
• Cold, harsh winters
• Frost in any month
• Water locked up in snow/ice (not available for
  plants)

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Arctic Tundra

• Low productivity, low diversity, low resilience
• Soil is frozen (permafrost) and only upper few
  centimeters thaws in summer.
• No deep root growth
• Heave/settlement due to freeze thaw
• Very little precipitation
• No drainage

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Alpine Tundra

• Due to altitude
• Different from Artic
• More solar radiation
• Very hot temperatures during day possible
• Lots of wind, gravelly or rocky
• Well draining

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Tundra Fauna

• Year round lemmings, voles, weasels, artic
  foxes
• Migratory musk ox caribou, alpine mountain
  goats, mountain sheep

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Tundra Flora

• Dwarf willows, dwarf birches, sedges, grasses,
  mosses, lichens
• Grow smaller

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Human effects on Tundra

• Oil and natural gas wells
• Mineral excavation

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Taiga(Boreal forests, Conifer forests)

• Taiga
• Found in northern hemisphere only
• On edge of artic tundra
• Low productivity low resilience
• Peat formed by cold temperatures, very wet soil
  in summer, acids from fallen needles
• Boreal Forests
• Found between 45 60 degrees north latitude
• Moist cool
• Many streams wetlands

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Taiga Flora Fauna

• Taiga Flora
• Black white spruce, balsam fir, eastern larch,
  aspen, birch
• Taiga Fauna
• Caribou, wolves, bears, moose, rodents, rabbits,
  lynx, sable, mink, migratory birds, insects

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Temperate Rain Forests(Conifer Forests)

• Northwest America, Southeastern Australia,
  Southern South America
• High precipitation
• Condensation from dense canopy is a major source
  of precipitation
• Mosses, lichens and ferns cover tree branches
• Olympic National Park

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Temperate Rain Forest Flora Fauna

• Flora
• Large evergreen trees including western hemlock,
  Douglas fir, western red cedar
• Epiphytes including mosses, lichens, ferns
• Fauna
• Squirrels, wood rats, mule deer, elk, birds,
  amphibians, reptiles

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Human Impact Taiga, Boreal Forests Temperate
Rainforest

• Logging
• Peat Mining

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Temperate Deciduous Forest(Broad-Leaved)

• Rainfall plentiful
• Key adaptation is ability to produce summer
  leaves, than shed for winter
• Rich topsoil with underlying clay

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Temperate Deciduous ForestFlora Fauna

• Flora Oak, maple, birch, beech, elm, ash,
  smaller shrubs, flowers, and herbaceous plants
• Fauna puma, wolves, bison, deer, bears and many
  small animals and birds

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Grasslands (Prairies Savannas)

• Dry continental climates of Great Plains, Russian
  Steppes, African veldt, South American pampas
• Richest soil in world
• Few trees
• Wildfires help maintain grasslands

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Grassland Flora Fauna

• Flora
• Grasses both short and tall grass
• Herbaceous flowering plants
• Savannas - acacia
• Fauna
• Prairies - Bison, wolves, deer, elk, antelopes,
  shorebirds, migratory birds.
• Savannas wildebeest, antelope, giraffe, zebra,
  elephants, lions and hyenas.

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Human Impact on Grasslands Savannas

• Agriculture
• 90 of North American grassland has vanished.
• Rarest biome in North America
• Rangeland
• Savannas being converted for cattle

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Chaparral(Mediterranean, Thorn Shrub)

• Warm, dry summers cool, moist winters
• California, Mediterranean Coast, Southwestern
  Australia, central Chile, South Africa
• Covers small area
• Highly desired for human population
• Drier areas African Sahel, northern Mexico,
  Great Basin

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Chaparral Flora Fauna

• Flora
• very different around world.
• Evergreen shrubs with small, leathery leaves
• Scrub oak, small trees,
• Fire resistant
• Fauna
• Mule deer, wood rates, chipmunks, lizards, many
  species of birds,
• Thorn shrub snakes, lizards, rodents,
  antelopes, gazelle, rhinos, giraffes.

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Human affects on Chaparral

• Preferred location of humans to live
• Crowding out the indigenous flora fauna

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Deserts

• Low moisture levels
• Precipitation infrequent and unpredictable
• Occur at 30 degrees north and south latitudes
• High in mineral content

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Desert Flora Fauna

• Flora Perennials annuals, cacti, yuccas,
  Joshua trees, sagebrushes
• Fauna amphibians, reptiles, rodents, mule deer,
  jack rabbits, kangaroos.

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Human impacts on Deserts

• War
• Development into agricultural areas
• Habitation

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Tropical Rainforests

• Temperatures warm all year and precipitation
  daily
• South Central America, Africa, Southeast Asia,
  Pacific Islands
• Soil is old, thin, acidic and nutrient poor
• 90 of all nutrients are contained in living
  organisms.
• Rapid decomposition and recycling of dead organic
  matter

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Rainforests Flora Fauna

• Flora
• Evergreen flowering plants
• Three distinct stories of plants
• Tall trees
• Middle story forms continuous canopy
• Lower story small plants, less dense
• Epiphytes, lianas
• One-half to one-third of all species of plants
  and insects
• Fauna
• Reptiles, amphibians, birds, sloth's, monkeys,
  elephants.

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Aquatic Ecosystems

• Freshwater
• Rivers, Streams, Lakes, Ponds, Marshes, Swamps
• Estuaries
• Marine
• Intertidal
• Benthic
• Neritic
• Oceanic

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Freshwater Ecosystems

• Vary significantly
• Influenced by
• Local climate
• Soil
• Surrounding ecosystems
• Affects from upstream or uphill

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Rivers and Streams

• Flowing ecosystem
• Changes greatly from source to mouth
• Groundwater can intersect
• Depend on land for energy - detritus

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Rivers and streams

• Features of a river

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Flora Fauna of Rivers Streams

• Greatly influenced by surrounding terrestrial
  ecosystem
• Varies widely depending on velocity of water,
  temperature, water quality

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Impact of Humans on Streams and Rivers

• Pollution
• Dams
• Development

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Lakes and Ponds

• Littoral zone most productive zone, where
  photosynthesis is greatest.
• Limnetic Zone open water beyond littoral zone.
  Extends down as far a sunlight penetrates. Main
  organisms are microscopic
• Profundal Zone Beneath limnetic zone, shallow
  lakes do not have. Food drifts from above.

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Lake Zones
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Thermal Stratification in Lakes

• Layering in lakes determined by how much light
  penetrates
• Thermal stratification
• Summer sunlight penetrates water -gt warms
  surface, less dense
• Cool water stays on bottom, more dense
• Line that marks change in density is called a
  thermocline
• In fall, surface water becomes colder than lower
  water and the warmer water below rises (fall
  turnover)
• In spring, reverse happens after ice melts
  (spring turnover)

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Marshes SwampsWetlands

• Areas covered by shallow water for part of year
  (plants can grow in water)
• Soil rich in nutrients
• Grasslike plants dominate
• Swamps wetlands with trees
• Marshes wetlands without trees
• Bogs Fens areas without trees that accumulate
  peat, low productivity

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Estuaries

• Bays or semi-enclosed bodies of brackish (salty
  but less than seawater)
• Contain rich sediment carried from upstream.

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Marine Ecosytems

• Divided into several zones
• Intertidal
• Benthic
• Pelagic
• Neritic
• oceanic

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Pelagic Environment

• Determined by depth of water
• Neritic province area from shoreline to depth
  of 200 meters
• Oceanic province area in open ocean with water
  depths greater than 200 meters.

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Intertidal Zone

• Shoreline area that is between low and high tides
• High levels of light and nutrients
• Abundant oxygen
• Highly productive but stressful environment

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Benthic Environment

• Ocean floor
• Mostly sand and mud
• Zones
• Abyssal benthic zone extends from 4000 to 6000
  m
• Hadal zone extends deeper than 6000 m.

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Flora of Marine Ecosystem

• Kelp
• Coral Reefs
• Sea Grasses

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Neritic Province

• Shallow water close to shore
• Upper reaches comprise the euphotic zone
• Extends to depth of 150 meters
• Enough light penetrates to support photosynthesis
• Phytoplankton are producers, zooplankton are
  primary consumers, nekton are secondary
  consumers, carnivorous nekton are tertiary
  consumers

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Oceanic Provinces

• Largest marine environment
• Deep water organisms feed on marine snow (organic
  debris that floats down from upper reaches)
• Organisms adapt to dark environment (called
  aphiotic)
• Many organisms can produces own light

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Human Impact on Marine Environments

• Damage to coral reefs
• High salinity
• Pollution
• Overfishing
• Tourism
• Global warming
• Oceans
• Pollution
• Development
• Mining
• Oil Drilling
• Overfishing