Interdependence of Life: Agents of Change in Ecosystems

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.

Learning Outcomes:

  • 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.

  • Elementary
  • Middle
  • High

Community ActivitySaved in 4180 Libraries

Reviews (6)
  • on Sun Jan 24, 2016 3:03 PM

Thank you all for your reviews. Living in Alaska we are seeing ecosystem change at a drastic pace over the past 50 years. I am really interested in finding ways to teach my students on ways they can adapt to these changes. If you have any other suggestions of articles you have seen on the learning center board, please let me know!

Maxine Dibert  (Fairbanks, AK)
Maxine Dibert (Fairbanks, AK)

  • on Sat Mar 14, 2015 7:12 AM

Great information to introduce students to both natural and man-made environmental problems, as well as the ways that human can avoid/improve negative environmental changes.

Robin Willig  (Rye Brook, NY)
Robin Willig (Rye Brook, NY)

  • on Tue Sep 02, 2014 7:31 AM

I really enjoy Science Objects. In 1-3 hours, the Interdependence of Life: Agents of Change in Ecosystems Science Object will help me re-learn, refresh, or learn for the first time some critical science concepts I will have to know to obtain my Science Educator credentials. I appreciate that I can complete them at my own pace, and that, if used as park of a SciPack, I have access to a content expert to go to for help. The NSTA Learning Center Science Objects are very beneficial!

Naomi Beverly  (Marietta, GA)
Naomi Beverly (Marietta, GA)

  • on Mon May 05, 2014 5:19 PM

There was so much I wanted to cover in my mini ecology unit. I would have used this to talk about invasive species and their effects on ecosystems. This sparked new ideas about invasive species brochures and other projects.

Hazel Robateau
Hazel Robateau

  • on Sat Mar 16, 2013 6:32 PM

This was an objective look at nature's and man's impact on a variety of ecosystems. Much of the information provided can and should be used at a variety of grade levels, from kindergarten to high school. I believe more emphasis could have been put on the urgency of environmental reparation, but nonetheless issues are addressed and resolutions are presented. The information has a universal theme that can lead into other conversations regarding cause and effect with man and nature. A very applicable topic that must be introduced and reintroduced to children at every grade level.


  • on Fri Feb 08, 2019 10:52 PM

This science object is a good resource for teachers to learn about what can change an ecosystem. The introduction clearly outlines what concepts will be explored and the expectations for what knowledge should be acquired by the end of the science object. It also goes into detail about natural disasters as well as human impacts on ecosystems. Moreover, the science object contains a glossary with definitions for all of the vocabulary terms involved within this topic. It also has visuals to go along with a lot of the information, which will help teachers learn about the content Lastly, it has an assessment at the end with multiple choice questions to test for learning. This science object receives a rating of 3 out of 5 stars from me because there is a lot of organized information and assessment questions about this topic. However, it is not that interactive nor does it come with links to interactive activities or websites to further reinforce learning. Thus, while teachers may find this resource to be useful, there may also be better science objects on the NSTA website.

Andy T
Andy T

Free - NSTA Members

$5.95 - Nonmembers

Login or Create a Free Account to add this resource to your library.