Transcript Ecology & Biosphere

• Chapter 40 Population Ecology and
Distribution of Organisms
Earth from the moon - A “Humbling View”
Does our Environment Have Limits?
What is Our Role?
“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.”
Ecology – The scientific study of the interactions between organisms and their
environments.
(from the Greek “Oikos” home -“logos” study)
Ecology vs. Environmental Concern
Distribution (Geographic Range)
Abundance (# of Particular Organism in Range)
Factors Affecting Distribution and Abundance:
Abiotic 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
individual’s environment. They may compete with, prey on or change its physical
or chemical environment.)
Distribution and Abundance of the red kangaroo in Australia, based on
aerial surveys
Four Basic Levels of Ecology
Organismal Ecology
Population Ecology
Community Ecology
Ecosystem Ecology
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
(Arrays of ecosystems and how they
Landscape Ecology
are arranged
in a geographic region)
Biosphere “Global Ecosystem” – Sum of all Planet’s Ecosystems – includes
atmosphere, sub-terranium, land, lakes, caves, oceans.
Biogeographic realms
Distribution of Organisms
Flowchart of factors limiting geographic distribution
Species Dispersal
Dispersal: The distribution of individuals within geographic boundaries.
- Geographic isolation in evolution.
- Broad patterns of current geographic distributions
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
Spread of the African honeybee in the Americas since 1956
Biomes and Biosphere
• Biosphere - the sum of all the
planet’s 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 (<30cm/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
Global climate
• Seasons
• Precipitation & Winds
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
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
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
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