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Nature Net’s Pre- and Post-Visit Field Trip Materials

Subject: Ecosystem

Level: Middle School

 

Introduction: The ecosystem concept helps to define the order of the natural world. An ecosystem refers to its biotic organisms (plants, animals, fungi, etc.) and interactions among those organisms, as well as the abiotic physical processes of the system (climate, topography, geology, etc.). Ecosystems are chock-full of lessons in biology, physical sciences, history and other disciplines. So read on for examples of fun activities to do with your class!

 

Pre-trip and Post-trip Activities: Activities that begin in class, which you can build on during your field trip and continue when you’re back in class! Modify them for your class needs!

 

 Pre-trip: Pick an ecosystem - wetland, prairie, forest, etc! (Make it one you’ll visit on your field trip.) Let your class brainstorm about all the kinds of living creatures known to live there, and write them on the board. Don’t let them forget different insects, worms and other not-so-charismatic critters. Then, brainstorm about what the climate, rocks, soil and water availability are like. Write that on the board, too. Talk about where you’d find different plants and animals in an ecosystem (the niche concept). Go over the concepts of food webs, producers and consumers and ask the students to draw links among living and non-living components to create food webs. Then, bring it all together! Make a big picture or diagram that represents all these components and interactions in a clear way. Kids can cut pictures out of magazines and/or draw the different biotic and abiotic parts of their ecosystem, being true to niches. Interactions and/or energy flows can be represented by different-colored arrows and their directions: e.g. red for "eats," blue for "gets eaten by," black for "goes back to soil."

You can also incorporate predator/prey relationships, animal adaptations, keystone and indicator species, trophic levels, the hydrologic cycle, and other such topics into this activity.

Discuss the different ecosystems found in Wisconsin.

 

During the trip: In the real-life ecosystem on your field trip, have kids identify and record what they see by writing and/or drawing. Help kids to "read the landscape" by encouraging them to think about associations of plants, animals and abiotic elements. What things are found together? What visits the pond (or tree, log, etc.) versus what lives there permanently?

 

Post-trip: Do a comparison exercise between the class’ ecosystem picture made before the trip versus what they found on the trip. This would be a good time to discuss biodiversity and ecosystem health.

You can follow up by looking at the current and historical management of the ecosystem you visited, issues of environmental pollution, environmental policies, etc. One example: 1) have students write letters to experts and government officials to get information on protection and management of an ecosystem; 2) have students research the human system of organizations and individuals involved in the management and protection of the ecosystem; 3) have students research the "stakeholders:" people and organizations directly impacted by management (e.g. State DNR, recreationists, county agencies, nearby landowners). Then you might break students into groups and have them research and analyze the interests stakeholders have for the ecosystem, and their beliefs about it. Bring the class together to compare! How do beliefs and interests influence management of the ecosystem?

Ü Or, have students do research and report on a local ecosystem of their choice. What are the abiotic and biotic components? What are characteristic interactions within the system? Draw and describe examples of food webs found in the system. Include a picture of the system. What are current threats to that system? Write a poem about some aspect of the ecosystem. …Etc…

 

Pre-trip: This is a small group project in which you ask each group to create an illustrated story of a food web. Provide poster paper and drawing tools. Ask each group to pick an ecosystem they will work within. (note: make sure one is the system you will be visiting on the field trip.) Tell the groups they must include examples of carnivores, herbivores, insectivores, etc.; different symbiotic relationships (predation, mutualism, etc.); and predator-prey relationships. (you can really have fun with this by asking students to only draw evidence of the interactions, not the animals themselves. E.g.: if the story is a hawk eats a mouse, draw mouse tracks that stop abruptly, and feathers.) Ask them to also include interactions with soil, water and air (like nutrient and hydrologic cycles, etc.). Ask groups to number each interaction in the story, and describe it on the back of the paper. Tell them to keep their story confidential! When groups are done, each can present their story.. or have the rest of the class try to guess each group’s story.

 

Trip: Now that students have been thinking about interactions in ecosystems, and even signs of these interactions, they can look for them in the real world. In the field, you can break the students out into groups again and ask them to "read the landscape," look for and try to decipher stories from what they see. Have them record what they see, and what they think the stories may be. What might this insect be doing on this plant? Does that bird live in the tree? How do you know? Do you see any tracks? What made them? Where was it going and why? Students may come up with many plausible answers. The exercise will help them hone their skills in inference and inductive thinking. Back in a single group – in the field or back in the classroom - talk about the stories together. The students might benefit from field guides: Golden Guides and Peterson’s Field Guides are classics and relatively easy to use.

 

Post-trip: Adapted from Predator Prey (Project Learning Tree).

Given the following food chain info, ask students to solve the problems:

 

Info - One reproducing gray wolf eats ~2,000 pounds of venison/year (in addition to moose and beaver). One deer eats ~3,650 pounds of vegetation/year in the form of grasses, herbs, brush and tree leaves. One square mile of deer habitat produces 800 pounds of vegetation acceptable as deer food/year.

 

Problems - 1) What is the minimum number of square miles of habitat needed to support one deer? 2) If a deer averages 130 pounds, how many deer are needed to feed one wolf for a year? 3) How many square miles of deer-wolf habitat are needed for one wolf to survive? 4) Research: what is the minimum number of wolves necessary to support a viable population? 5) Use a map of northern WI and outline an area large enough to serve as habitat for one wolf. Ignore places which don’t produce food for deer (roads, developments, etc). Then, do the same thing but this time take into account the non-deer-food-producing areas. Compare the first and second areas. 6) Research: investigate population trends of wolves and deer in WI. What are the causes of those trends? How have they impacted other wildlife, plants, and the forest ecosystem? What are the views of different groups of people on the matter?

 

Check it out! … try these web sites for great in-class activities on ecosystems:

http://www.ceismc.gatech.edu/busyt/ -- resources and a wealth of quality information on environmental topics.

http://www.naturenet.com – resources and lesson plans, plus special free services for teachers to help integrate outdoor education into the classroom!

Nature Net’s

Ecosystem Crossword

 

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ACROSS

4. ____________ relationship: a pattern of interaction between two living organisms in an ecosystem

7. chain of connections among organisms based on the idea "eat or be eaten"

10. the number of species of organisms within an ecosystem

14. an animal that is killed for food

 15. management practices that attempt to return health and stability to an ecosystem

DOWN

1. cycle that moves and recycles water in its various forms through the biosphere

2. science of relationships among organisms, and between organisms and their environment

planning and practicing wise use of the resources of an ecosystem

4. refers to the size or level at which you study an organism or ecosystem.

5. a type of interaction in which one species feeds on another (its "host") by living on or in its host, usually without killing it.

8. cycle in which nutrients (carbon, nitrogen, etc.) move from the environment through organisms, and back to the environment

9. the non-living parts of an ecosystem

10. the living parts of an ecosystem

 11. an interaction between 2 species in which both benefit

12. refers to the principle of connectedness between all living things

13. Aldo __________, a famous scientist from Wisconsin who studied and wrote about ecosystems, wildlife and management

 

Ecosystem - Definitions

 The words in this list were underlined throughout the activity sheet.

abiotic - refers to the non-living components of a system.

biodiversity - the diversity of species of living organisms

in a given system or area.

biotic - refers to the living components of a system.

consumers - animals that obtain their energy/food from

producers (plants), or other consumers.

ecosystem health - refers to the ability of a system to sustain itself and thrive. Ecosystems are healthy when their components (species, diversity, populations) are intact, and their processes (nutrient cycles, symbiotic relationships, etc) are intact. The health of an ecosystem is also measured by its "resistance" to damage and change, and its "resilience," its ability to bounce back from damage. For instance, an unhealthy forest ecosystem may have too many deer which browse so heavily that their food trees cannot develop into adult trees, and the species composition of the forest changes which has other effects (and so on..). Restoration and management are ways in which people try to achieve and maintain the health of different ecosystems.

food web - the many possible feeding relationships found within a given ecosystem.

human system (human ecosystem) - a self-regulating community of human beings interacting with one another and with their environment.

niche - an organism’s function or ecological role within a community. Another way to say it is: the way an organism lives including the things it needs, and how it uses them - a lifestyle.

producers - organisms that obtain energy for food/living from a physical or chemical source. Plants are producers, they convert the sun’s energy into sugars and carbohydrates. Bacterial microorganisms called cyanobacteria, which live in the ocean depths, create their food from chemical compounds.

symbiotic relationship - a relationship in which two unlike organisms live closely together. Symbiotic relationships may be beneficial to both species (mutualism - ants/aphids, where ants tend and protect the aphids and aphids supply ants with food); beneficial to one species and neutral to the other (commensalism - orchid/tree trunk, where the orchid benefits by having the tree as a substrate to grow, and the tree is neither benefited nor harmed); one species benefits with food and the other is killed as food (predation - wolves/deer); one species benefits and the other is harmed but usually not killed (parasitism - fleas/animals).