Chapter 52 - An Introduction to Ecology and the Biosphere

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• Chapter 52 - An Introduction to Ecology and
  the Biosphere

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Earth from the moon - A Humbling ViewDoes our
Environment Have Limits?What is Our Role?
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The Control of Nature is a phrase conceived in
arrogance, born of the Neanderthal age of biology
and philosophy, when it was supposed that nature
exists for the convenience of man.Rachel
Carson in her 1962 book Silent Spring.
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Ecology The scientific study of the
interactions between organisms and their
environments.(from the Greek Oikos home
-logos study) Ecology vs.
Environmental ConcernDistribution (Geographic
Range)Abundance ( of Particular Organism in
Range)Factors Affecting Distribution and
AbundanceAbiotic Factors (Non-Living Chemical
and Physical Factors like Temperature, water,
light and nutrients.)Biotic Factors (Living
Factors All of the organisms that are part of
an individuals environment. They may compete
with, prey on or change its physical or chemical
environment.)
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Distribution and Abundance of the red kangaroo in
Australia, based on aerial surveys
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Four Basic Levels of Ecology
Organismal Ecology Population
Ecology Community Ecology
Ecosystem Ecology
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• Ecological Time (Minutes, Months, Years)
• Evolutionary Time (Decades, Centuries, Millenia,
  or Longer!)
• Example Hawk Feeding on Field Mice
• Four Basic Levels of Ecology
• Organismal Ecology (Individual)
• Population Ecology (s)
• Community Ecology (Interaction)
• Ecosystem Ecology (Energy Flow)
• Other Types of Ecology
• Landscape Ecology (Arrays of ecosystems and
  how they are arranged in a geographic region)
• Biosphere Global Ecosystem Sum of all
  Planets Ecosystems includes atmosphere,
  sub-terranium, land, lakes, caves, oceans.

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Biogeographic realms
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Distribution of Organisms Flowchart of
factors limiting geographic distribution
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• Species Dispersal
• Dispersal The distribution of individuals
  within geographic boundaries.
• - Geographic isolation in evolution.
• - Broad patterns of current geographic
  distributions

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Species Transplant Set of transplant
experiments for a hypothetical species
Transplant Successful Distribution Limited
because the area is inaccessible, time has been
too short to reach the area, or the species fails
to recognize the area as suitable living
space Transplant Unsuccessful Distribution
limited either by other species or by physical
and chemical factors. Control A transplant done
within existing range provides a baseline on
handling and transporting. Rarely Done Most
observation done on natural and human caused
transplant. Example Zebra Mussels
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Spread of the African honeybee in the Americas
since 1956
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Biomes and Biosphere

• Biosphere - the sum of all the planets
  ecosystems
• Biome - areas of predominant flora and fauna
• Affect of Temperature and Precipitation on
  Defining Biomes

Ecotone biome grading areas
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Terrestrial biomes

• Tropical forests- equator most complex constant
  temperature and rainfall canopy
• Savanna- tropical grassland with scattered trees
  occasional fire and drought large herbivores
• Desert- sparse rainfall (lt30cm/yr)
• Chaparral- spiny evergreens at midlatitudes along
  coasts
• Temperate grassland- all grasses seasonal
  drought, occasional fires large mammals
• Temperate deciduous forest- midlatitude regions
  broad-leaf deciduous trees
• Coniferous forest- cone-bearing trees
• Tundra- permafrost very little precipitation

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Global climate

• Seasons

Precipitation Winds
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Lake stratification turnover

• Thermal stratification - vertical temperature
  layering
• Biannual mixing - spring and autumn
• Turnover - changing water temperature profiles
  brings oxygenated water from the surface to the
  bottom and nutrient rich water form the bottom to
  the surface

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Aquatic biomes

• Vertical stratification
• photic zone - photosynthetic light
• aphotic zone - little light
• Thermocline - narrow stratum of rapid temperature
  change
• benthic zone - bottom substrate
• Benthos - community of organisms
• Detritus - dead organic matter food for benthic
  organisms

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Freshwater biomes

• Littoral zone - shallow, well-lit waters close to
  shore
• Limnetic zone - well-lit, open water farther from
  shore
• Profundal zone - deep, aphotic waters
• Lake classification
• oligotrophic - deep, nutrient poor
• eutrophic - shallow, high nutrient
  content
• mesotrophic moderate productivity
• Wetland - area covered with water
• Estuary - area where freshwater merges with ocean

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Marine biomes

• Intertidal zone- area where land meets water
• Neritic zone- shallow regions over continental
  shelves
• Oceanic zone- very deep water past the
  continental shelves
• Pelagic zone- open water of any depth
• Benthic zone- seafloor bottom
• Abyssal zone- benthic region in deep oceans