Although there are thousands of plants which are as different as people, they all share the same requirements in order to survive, grow and flourish. These are often referred to as abiotic factors. Abiotic factors are non-living elements found within an ecosystem. There are six abiotic factors that affect plant growth: air, water, space, temperature, light and soil (nutrients). These are the basic requirements that plants need to grow. Each of these factors, however, is subject to pollutants which affect plants growth. Some of the effects are quite visible and students can easily conclude pollution is detrimental to life through a simple experiment. The remainder of this unit will refer to results obtained from this experiment.
For simple, very brief student reading, see "Factors Affecting Plant Growth" . (www.urbanext.uiuc.edu/gpe/case1/c1facts3a.html) Read aloud the description of each growth factor. After discussing each factor, brainstorm how that variable might be affected by pollution. Students may be able to identify global warming as a result of pollution which affects temperature and may affect plants growth. This lesson, reading and brainstorming, is a great way to assess prior student knowledge and further introduce the unit.
As students read through these factors, ask students how they might change one element in an experiment. For example, water is important in the plant_s ability to make and move nutrients. Plants can die from too much water, not enough water or from polluted water as pollution interferes with the plant_s ability to move nutrients. How might students design an experiment that varies water?