Chapter 34 Lecture Notes

Chapter 34.1
The biosphere is the global ecosystem

Define the following key terms:

The study of Ecology

Ecologist: are scientists who conduct research in ecology.
Ecologists test their hypotheses outdoor in the field as well as in the lab.
They also use computer models to understand complex interactions between organism and their environment.

The study of Ecology

Ecologist: are scientists who conduct research in ecology.
Ecologist test their hypotheses outdoor in the field as well as in the lab.
They also use computer models to understand complex interactions between organism and their environment.
An organisms environment consists of other organisms as well as non living factors.
Ecologist study the relationships among biotic and abiotic factors.

List 3 abiotic factors.

An Individual organism is part of a

Population which makes up a

Community which is part of an

Ecosystem which is in the Biosphere

See figure 34-1

Patchiness of the Biosphere

The Biosphere is not spread out uniformly around the planet (see fig. 34-2)
Observe the uneven distribution of ecosystems (deserts, grassland, forest etc)
The environmental variations are due to differences in biotic & abiotic factors such as temperature, soil type, availability of water & light.
See figure 34-3

Key abiotic Factors

Abiotic factors include sunlight, water, temperature, soil and wind.
Sunlight: provides light & warmth
Water: essential for all life on Earth
Temperature: regulated by the amount of sunlight, most organisms survive between 0 and 50 °C. Some organisms are adapted to live in more extreme temperatures.
Soil: is a product of abiotic forces (such as ice, rain & wind) and living things (such as microorganisms, plants & earthworms)
Wind: affects the distribution & activities of organisms e.g. wind moves clouds (rain), disperses seeds, and stirs up rivers and lakes creating water currents.

Assessment