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 Speciesex. 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