Chapter 52 Hercules scarab beetle-Panama Descending dry air

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Ecology and the Biosphere

• Chapter 52

Hercules scarab beetle-Panama
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Definitions

• Ecology
• The study of interactions between organisms and
  the environment
• Ecosystem
• A community of organisms and its physical
  environment
• The biosphere
• The global ecosystem, the sum of all the planets
  ecosystems

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Organisms and the Environment

• The environment of any organism includes
• Abiotic, or nonliving components
• Biotic, or living components. (All the organisms
  living in the environment are the biota)

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Questions of organisms and the environment are
frequent in ecology

• What environmental components affect the
  distribution and abundance of organisms? Can you
  predict the distribution of Red Kangaroos by
  looking at environmental components?

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Subfields of Ecology
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Organismal ecology

• Studies how an organisms structure, physiology,
  and behavior meet the challenges posed by the
  environment

How do hammerhead sharks select a mate?
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Population ecology

• Concentrates mainly on factors that affect how
  many individuals of a particular species live in
  an area

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Community ecology

• Deals with the whole array of interacting species
  in a community

(c) Community ecology.What factors influencethe
diversity of speciesthat make up aparticular
forest?
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Ecosystem ecology

• Emphasizes energy flow and chemical cycling among
  the various biotic and abiotic components

(d) Ecosystem ecology. Whatfactors control
photosyntheticproductivity in a
temperategrassland ecosystem?
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Landscape ecology

• Deals with arrays of ecosystems and how they are
  arranged in a geographic region

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Global ecology

• The Big Picture

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Ecology and Environmental Issues
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Ecology and Environmental Issues

• Ecology provides the scientific understanding
  underlying environmental issues
• Rachel Carson
• Is credited with starting the modern
  environmental movement

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• Silent Spring 1962 warned that widespread
  pesticide use (DDT etc.) was causing widespread
  population declines in nontarget species
• Over increasingly large areas of the United
  States, spring now comes unheralded by the return
  of the birds, and the early mornings are
  strangely silent where once they were filled with
  the beauty of bird song.

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• Aldo Leopold A Sand County Almanac (1949)
• There are some who can live without wild things,
  and some who cannot. These essays are the
  delights and dilemmas of one who cannot.
• Land ethic
• That land is a community is the basic concept of
  ecology, but that land is to be loved and
  respected is an extension of ethics.
• A land ethic, then, reflects the existence of an
  ecological conscience, and this in turn reflects
  a conviction of individual responsibility for the
  health of land.

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Precautionary Principle

• Most ecologists follow the precautionary
  principle regarding environmental issues
• The precautionary principle
• Basically states that humans need to be concerned
  with how their actions affect the environment
• To keep every cog and wheel is the first
  precaution of intelligent tinkering.Aldo
  Leopold

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Distribution of organisms
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Climate and the distribution of organisms

• Interactions between organisms and the
  environment limit the distribution of species
• Ecologists recognize global and regional patterns
  of distribution of organisms within the biosphere
• Biogeography study of distribution of organisms

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Biographic realms

• Broad patterns of distribution

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Dispersal and Distribution

• Dispersal
• Is the movement of individuals away from centers
  of high population density or from their area of
  origin
• Contributes to the global distribution of
  organisms

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Natural Range Expansions

• Natural range expansion show the influence of
  dispersal on distribution

Spread of great-tailed grackle 1974-1996
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Natural Range Expansions
Cattle egretNative to the Old World. First
reported in South America in 1877
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Species Transplants

• Species transplants
• Include organisms that are intentionally or
  accidentally relocated from their original
  distribution
• Can often disrupt the communities or ecosystems
  to which they have been introduced

Purple loosestrife-Introduced from Europe
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Behavior and Habitat Selection

• Some organisms do not occupy all of their
  potential range
• Species distribution may be limited by habitat
  selection behavior

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Biotic Factors

• Biotic factors that affect the distribution of
  organisms may include
• Interactions with other species
• Predation
• Competition

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Abiotic Factors

• Abiotic factors that affect the distribution of
  organisms may include
• Temperature
• because of its effects on biological processes
• Water
• Sunlight
• Light intensity and quality can affect
  photosynthesis.
• Also important to the development and behavior of
  organisms sensitive to the photoperiod
• Wind
• Rocks and soil

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Wind

• Wind
• Amplifies the effects of temperature on organisms
  by increasing heat loss due to evaporation and
  convection
• Can change the morphology of plants

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Rocks and Soil

• Many characteristics of soil limit the
  distribution of plants and thus the animals that
  feed upon them
• Physical structure
• pH
• Mineral composition

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Climate
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Climate

• Climate is the prevailing weather conditions in a
  particular area
• Four major abiotic components make up climate
• Temperature, water, sunlight, and wind

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Climate scale

• Climate patterns can be described on two scales
• Macroclimate, patterns on the global, regional,
  and local level
• Microclimate, very fine patterns, such as those
  encountered by the community of organisms
  underneath a fallen log

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Sunlight Intensity

• Sunlight intensity plays a major part in
  determining the Earths climate patterns

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Sunlight Intensity
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Air circulation and wind patterns
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Landscape features contribute to local variations
in climate
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Bodies of Water

• Oceans and their currents, and large lakes
  moderate the climate of nearby terrestrial
  environments

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Mountains

• Mountains have a significant effect on
• The amount of sunlight reaching an area
• Local temperature
• Rainfall

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Microclimate

• Microclimate is determined by fine-scale
  differences in abiotic factors.
• Shade from a tree
• Wind blockage by a boulder
• Low-lying area that collects moisture

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Biomes

• Biomes Are the major types of ecological
  associations that occupy broad geographic regions
  of land or water

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Aquatic Biomes-distribution
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Aquatic Biomes

• Aquatic biomes
• Account for the largest part of the biosphere in
  terms of area
• Can contain fresh or salt water
• Oceans
• Cover about 75 of Earths surface
• Have an enormous impact on the biosphere

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Stratification of aquatic biomes

• Stratified into zones or layers defined by light
  penetration, temperature, and depth

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Lakes
Nutrient rich / oxygen poor
Nutrient poor / oxygen rich
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Wetlands
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Streams and Rivers
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Estuaries
A transition area between rivers and the ocean
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Intertidal Zones
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Oceanic pelagic biome
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Coral Reefs
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Marine benthic zone
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Terrestrial Biomes

• Climate
• largely determines the distribution and structure
  of terrestrial biomes
• important in determining why particular
  terrestrial biomes are found in certain areas

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Climate and Terrestrial Biomes

• climograph

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Terrestrial biomes-distribution
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Terrestrial Biomes

• Terrestrial biomes
• Are often named for major physical or climatic
  factors and for their predominant vegetation

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Tropical Forest
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Desert
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Savanna
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Chaparral
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Temperate grassland
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Coniferous forest
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Temperate broadleaf forest
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Tundra
TUNDRA
Denali National Park, Alaska, in autumn