Chapter 50 Notes
An Introduction to
Ecology and the
Biosphere
The Scope of Ecology
The interactions between organisms and
their environments determine the
distribution and abundance of
organisms
- Why are there no malaria-carrying
mosquitoes in Minnesota?
- Why are there so many deer in Ohio?
The Scope of Ecology
What factors limit the geographic range,
or distribution, of a species?
What factors determine the abundance
of a species?
The environment of any organism will
include both biotic (living) and abiotic
(nonliving) components.
The Scope of Ecology
Ecology can be divided into four
increasingly comprehensive levels of
study
Organismal ecology: concerned with
the morphological, physiological, and
behavioral ways in which organisms
meet the challenges of biotic and
abiotic environments
The Scope of Ecology
Population ecology: concentrates on
factors that affect how many individuals
of a particular species live in an area
Community ecology: deals with
interacting species in a community
The Scope of Ecology
Ecosystem ecology: emphasis is on
energy flow and the cycling of
chemicals among biotic and abiotic
components
Biosphere: the global ecosystem; the
sum of all the earth’s ecosystem
Factors Affecting the
Distribution of Organisms
Darwin and Wallace began to recognize
broad patterns of geographic
distribution
Biogeography: the study of the past
and present distribution of individual
species
Factors Affecting the
Distribution of Organisms
Factors Affecting the
Distribution of Organisms
Species dispersal contributes to the
distribution of organisms
ex. Why are there no Kangaroos in North
America?
- one way to determine if dispersal is a
key factor limiting distribution is by
observing when humans have
transplanted a species
Factors Affecting the
Distribution of Organisms
- if a transplant is successful, then the
potential range is larger than its actual
range
- if a transplant is unsuccessful,
meaning it is unable to survive and
reproduce, then we need to determine
if biotic or abiotic factors exclude it
from this area
Factors Affecting the
Distribution of Organisms
Factors Affecting the
Distribution of Organisms
Problems with introduced Species
ex. African Honeybee
- the African honeybee was brought to
Brazil in 1956 to produce more honey in
the tropics.
- many escaped in 1957 and have been
traveling about 110 km per year ever
since.
Factors Affecting the
Distribution of Organisms
- beekeepers are worried that the
African bee will damage the established
honeybee industry
- will the colder Northern winters
prevent them from moving north?
Factors Affecting the
Distribution of Organisms
Factors Affecting the
Distribution of Organisms
Abiotic factors affect the distribution of
organisms
Temperature
- affects biological processes
- most organisms are not able to
regulate internal body temps.
Factors Affecting the
Distribution of Organisms
Water
- availability affects the location of
organisms
- aquatic life must balance water levels
Sunlight
- provides the energy that drive most
ecosystems
- distribution on land and in the water
Factors Affecting the
Distribution of Organisms
Wind
- amplifies the affects of environmental
temperatures on organisms
- contributes to water loss
Rocks and soil
- physical structures, pH, and mineral
composition of rocks limit the
distribution of plants and animals
Factors Affecting the
Distribution of Organisms
Temperature and water are the major
climatic factors determining the
distribution of organisms
Climate: the prevailing weather
conditions at a locality
Biomes: major types of ecosystems that
occupy broad geographic regions
Factors Affecting the
Distribution of Organisms
- rainfall and temperature are
reasonable means that correlate with
biomes
- climographs are used to measure
these factors
Factors Affecting the
Distribution of Organisms
Factors Affecting the
Distribution of Organisms
Global Climate Patterns
- the suns affect on the atmosphere,
land, and water establish temperature
variations
- the tilting of the earth on its axis
causes seasonal variation in the
intensity of solar radiation
Factors Affecting the
Distribution of Organisms
Tropics: regions between 23.5o north
latitude and 23.5o south latitude
- receive the least seasonal change
- intense solar radiation initiates global
circulation of air, which creates
precipitation and winds
Factors Affecting the
Distribution of Organisms
Factors Affecting the
Distribution of Organisms
Local and seasonal effects on climate
- the proximity to water and
topographic features such as mountain
ranges create climate patchiness
- ocean currents influence the climate
along the coasts of continents
- seasonal changes in wind patterns
produce variations in ocean currents
Factors Affecting the
Distribution of Organisms
- with seasonal changes, turnover will
occur in lakes and ponds
- turnover: brings oxygenated water
from the surface of lakes to the bottom
and nutrient-rich water from the bottom
of lakes to the surface
- microclimate: climate on a very fine
scale
Factors Affecting the
Distribution of Organisms