CTS Guide: Ecosystems Stability, Disruption, and Change pp 114-115- Section IV Research Summaries
Changes in Populations
University of York Science Education Group (2021): A summary of research findings identified specific misunderstandings about changes in food webs that are commonly held by school children, including that: 1) a change in the size of a population will only affect another population if they are related as predator-prey; 2) a change in the size of a population will only affect other populations in the same food chain within a food web (and will not affect populations in other food chains within the food web); and 3) if the size of one population changes, all other populations in the food web will change in the same way (e.g. a decrease in one population means all other populations will also decrease).
Griffiths and Grant (1985): There is a distinction between students’ ability to recall that populations in a food web interact, and their ability to apply that principle to predict possible effects of a change in one population on others in the same food web.
Human Impact on Ecosystems
Caspar and Balgopal )2018): Some students do not consider humans to be part of an ecosystem, which may affect their understanding that humans have an impact on ecosystems. They must first appreciate that humans are part of an ecosystem. The researchers found many students used the word ‘natural’ when referring to ecosystems, and that those students who defined ecosystems as natural “usually excluded human society and/or the built environment from ecosystems”.
Ecosystem Terminology
Yücel and Özkan (2015): Student misunderstandings related to habitats are that habitats are only forests, or that habitats are places where only fish and other animals live. They also found that students confused the concept of ‘ecosystem’ with ‘habitat’. They also found that students aged 12-14 when presented with the word ‘environment’ failed to mention non-living things other than air.
Adeniyi (1985): Students at age 11 are likely to be more familiar with the everyday, rather than the ecological, use of terms such as ‘population’ and ‘community’. In one study, a quarter of children in a sample of secondary school students thought that a ‘community’ could only be formed by people living together, and another quarter of students could not distinguish between ‘population’ and ‘community’.
Ecosystems and Biotic and Abiotic Factors
Dove (2012): One of the common misunderstandings about rainforest ecosystems include the idea that there is dense vegetation on the floor of the rainforest. Also, many students do not fully understand why rainforest soils are not rich with nutrients.
Prokop (2007): Found that while students, ages 11-12, recognized living things to be major components in ecosystems, they considered the abiotic components to be less important than the living things.
Sander (2006): Observed the misunderstanding that the dependence of organisms on climate and other abiotic factors was one-directional; the researchers noted how students felt that organisms, except for humans, had no influence on ecosystem changes. It was also observed that some students thought ecosystems had to be large areas.