- Air: is composed of 78% nitrogen, 21% oxygen, 4% carbon dioxide and water vapour.
Look ahead to section on nutrient cycles to read more detail. Oxygen is used in
cellular respiration and combustion and is returned to the environment by the process
of photosynthesis. Carbon dioxide is a product of cellular respiration and decayed
organic matter. It is removed from the atmosphere by plants during the process of
photosynthesis. Nitrogen is needed by all living organisms for the synthesis of proteins.
The amount of water vapour found in the air remains constant on average, however, it
can vary greatly from one place to another. Some parts of the earth are prone to high
humidity levels, while other locations have very dry air. Much of what we consider
weather is caused by water vapour. The clouds in the sky are largely made up of it,
and it is the condensation of this vapour into droplets that creates rain and snow.
Project: Identifying abiotic, biotic and cultural characteristics of a natural environment
Aim:
Identify abiotic, biotic and cultural characteristics of a natural environment near you. To
make your profile, follow the instructions below:
Instructions:
- Select an area that is undeveloped (e.g. no buildings, no pavement, no bulldozing, no
spraying of pesticides, no farming, no grazing, etc.). Your area must be at least the size
of a soccer field. Make a map of your province and show, approximately, where your
area is located. - Identify at least 10 abiotic features of your area. Consider factors such as:
- Landforms (mesa, mountain, valley, etc.)
- Altitude
Identify at least 15 biotic features of the area. Consider things such as:
- Plants (trees, shrubs, grasses, flowers etc.)
- Insects (ants, bees, praying mantis etc.)
- Amphibians, reptiles, and/or fish
- Mammals
Identify at least 3 cultural components. Look for evidence of human influence. Consider
things such as:
- Recycling and conservation efforts
- Pollution
- Introduced species
Analysis:
Examine the data you collected when making your profile. Use your collected data to answer
the following questions. Discuss your answers afterwards in your group/with your partner.
Chapter 9. Biospheres to ecosystems 273