CTS Guide: Transfer of Energy in Ecosystems, pp 122-123- Section IV Research Summaries
Flow of Energy
A common middle and high school students’ biological idea of energy is that it is anything that enables life; thus, they often refer to “matter and energy cycles” with energy and matter both cycling through soil nutrients. During decomposition they typically see energy as being recycled in the form of nutrients that are released for plant growth, rather than energy that a decaying plant provides to decomposers. Energy during decomposition is sometimes confused with minerals and nutrients (Jin and Anderson 2012; Rice, Doherty, and Anderson 2014).
Various studies have shown that students have limited knowledge of how energy flows through a food web and that energy is a challenging concept for understanding fundamental ecological processes. Understanding representations is key to understanding how energy flows (Wernecke et al. 2018).
Beals et al. (2012): Both students and teachers have been found to believe that energy can be recycled (e.g., by decomposers) and reused (e.g., by plants) in an ecosystem. The confounding of energy flow and matter cycles was commonly found in their study.
Driver et al. (1994): Some students consider ‘stronger’ organisms such as predators as having more energy which they use to feed on ‘weaker’ organisms which they regard as having less energy. The researchers also found that students tend to use accumulation reasoning to explain what happens to energy as it flows through a foods chain. They believe the energy adds up so that a top predator would have all the energy from the organisms that came before it in the food chain.
Gaylord (1986): A study of 17- and 18-year- old biology students revealed that many students thought that energy flows from place to place and is stored like a material. They thought energy was either created or destroyed in biological processes rather than converted and conserved.
Research reveals three commonly held ideas about energy transfer: 1) some students think that the top predator gets all of the energy from the trophic levels beneath it, 2) energy is cumulative as you move up a food chain or food web., and 3) no energy is lost between trophic levels(Griffiths and Grant 1985).