Science ObjectDigital resources are stored online in your NSTA Library.
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the fourth of four Science Objects in the Interdependence of Life SciPack. It explores agents of change in ecosystems.
Various influences (including human impact, natural disasters, climate change, and the appearance of new species) can force an ecosystem into a state of different equilibrium. Depending on both the severity of the disturbance and the diversity of populations, feedback mechanisms may be sufficient to restore a state of equilibrium similar to the original ecosystem. However, if the disruptive influences are so severe (in duration and/or degree) they can push an ecosystem beyond its capacity to maintain equilibrium, irreversibly altering the system. In this case, a new point of dynamic equilibrium is eventually established, thus defining a new ecosystem.
- Describe how populations might reach a new state of equilibrium following significant changes to the conditions (abiotic and biotic factors) defining their ecosystem.
- Sequence and provide the rationale for a series of ecological processes that could logically occur following a large-scale disruption.
Given a description of factors that influence and affect population sizes in an ecosystem, identify those factors that could most likely contribute to an ecosystem’s long-term inability to return to dynamic equilibrium.
- Explain how human activity (mining, dam construction, housing development) could affect the equilibrium of an ecosystem.