Modelling Ecosystem Structure and Energy Flow in a First Year Environmental Biology Practical: Not a Complete Waste of Energy

Gerry Rayner


The modelling of energy flow through ecosystems is conceptually difficult, and has been shown to be complicated to teach, at both the secondary and tertiary levels. Endeavours to integrate such modelling into a first year environmental biology curriculum are thus likely to pose considerable challenges. This paper reports on efforts to quantitatively model energy flow through a simplified, paper-based ecosystem in a first year environmental biology unit. In addition to curriculum-related objectives, the broader aims of the initiative were to enable students to apply concepts and processes introduced in lectures and readings, enhance learning through collaboration and discussion about energy flow and ecosystem trophic structure, and develop student skills in oral or visual communication. Although some aspects of the project, such as collaborative learning and class presentations, were moderately successful, student deficiencies in quantitative skills, together with the simplistic nature of the ‘paper ecosystem’ meant that numerical analyses were complex and subjectively made. One misconception was that a complex ecosystem, conveniently divided into trophic categories, could be simplified in terms of energy flow from source to sink. Following revision and the inclusion of more structured guidelines, the project was reintroduced to the biology program. The revised project was more successful in terms of student consistency and accuracy in modelling energy flow and also with regard to their overall satisfaction with the project. Nevertheless, after considerable deliberation, it was decided that a hands-on, field-based project would provide a more true-to-life experience in the context of the first year environmental biology curriculum.

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