Chapter 52
1. Organismal Ecology
a. Subdisciplines of physiological, evolutionary, and behavioral ecology
b. Concerned with organisms structure, physiology and behavior
2. Population Ecology
a. Population - group of individuals with viable offspring
b. Analyzes factors that affect population size and why it changes through time
3. Community Ecology
a. Community - group of populations in an area
b. Examines how interactions between species (predation and competition) affect a
community structure and organization
4. Ecosystem Ecology
a. Ecosystem - community of organisms in an area and the physical factors with
which those organisms interact
b. Emphasizes energy flow and chemical cycling between organisms and the
environment
5. Landscape Ecology
a. Landscape - mosaic of connected ecosystems
b. Focuses on factors controlling exchanges of energy, materials, and organisms
across ecosystems
6. Global Ecology
a. Biosphere - sum of all the planet’s ecosystems and landscapes
b. Examines how regional exchange of materials and energy influence the functions
and distributions of organisms across the biosphere
Rachel Carson: “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 exsists for the
convenience of man.”
Factors that determine distribution of organisms:
1. biotic - living factors--all of the factors are part of the individuals environment
a.
2. abiotic - nonliving factors--all the chemical and physical factors (temperature, light, soil,
etc.)
a. Temperature: effect on biological processes. Few organisms can maintain an
active metabolism at extreme temperatures
b. Water: Distribution of terrestrial species reflects their ability to obtain and
conserve water
c. Salinity: Most aquatic organisms are confined to either freshwater or saltwater.
But many terrestrial organisms can excrete salts from glands or in feces. Still,
salt flats and high-salinity habitats have few plants or animals.
d. Sunlight: photosynthetic organisms drive most ecosystems--initial point of
energy. Quality and quantity are both factors.
e. Rocks & Soil: pH, mineral composition and physical structure of rocks and soil
limit distribution of plants and therefore animals.
●
Climate - long-term, prevailing weather conditions in a particular area.
○ Microclimate - patterns on the global, regional and local level
■ determined mostly by solar energy and the planet’s movement in space.
■ Bodies of water - oceans influence climate along the coasts by heating/
cooling overlying air masses.
■ Mountains - affect the amount of sunlight that reaches an area and
therefore the temperature and rainfall of an area.
■ Seasonality ○ Microclimate - fine patterns such as in a community of organisms under a log.
Dispersal - movement of individuals away from their area of origin or from centers of high
population density [Ex. cattle egret was found only in Africa and SW Europe, but in 1800s some
crossed the Atlantic and colonized NE South America]
1. Natural range expansions clearly show the influence of dispersal on distribution.
2. Transplant is successful if the organisms survive and are able to reproduce in the new
area. If it's successful then the potential range of the species is larger than the actual
range.