Education

During the last decades, an increasing awareness has developed that humankind will have to make important decisions about the environment which will demand substantive knowledge of critical ecological phenomena such as the production and decomposition of biomass (World Commission on Environment and Development, 1987). As a biology teacher the researcher found that students at different levels have great difficulties expressing, in their own words, how biomass builds up and breaks down; also where matter comes from and where it goes. This can be true even of students who have studied photosynthesis and respiration. The researcher has also found very limited knowledge about issues concerning transformations of matter, such as decomposition and combustion, when people discuss general environmental issues. Could this lack of knowledge be due to the fact that teaching has not been based on students thinking about ecological phenomena? In order to create teaching situations in which students ' ideas about natura