Grades: 4, 5, & 6 POND INTERACTIONS Teacher Guide February 2011 Time: 3 hours A pond is an ever-changing environment. The pond ecosystem is made of countless interactions that link living things to one another and to their surroundings. Uncover connections in the pond that are reflections of larger ecosystems. Wisconsin Standards: Students show how organisms have adapted structures to match their functions and cite how different organisms adapt to their environment. They collect information, make predictions and offer explanations. They will use books, charts or adults to answer science related questions. Focus Concept: Pond ecosystems are made of countless interactions that link living things to one another and to their surroundings. Essential Understandings, Processes, and Skills: Understandings: 1. The pond is a unique freshwater ecosystem made up of living and non-living things and their interactions. 2. All living and nonliving things in a pond are interconnected. 3. Each plant and animal in the pond has a specific role to play. 4. Plants and animals have unique needs that must be met in their environment in order to survive. 5. Plants and animals develop special adaptations to help them survive. 6. Pond food chains/webs are an example of interactions within a pond ecosystem. 7. A pond ecosystem is more than things in it it is also the interactions among and between all things. 8. Interconnection is more than a static relationship between two things interconnections are constantly changing. 9. Humans are connected to life in a pond in many different ways. 10. A pond is one system embedded in many others. Processes and Skills: 1. Observe the living and nonliving things that are part of a pond system 2. Gather data and record information 3. Collect and observe living organisms 4. Identify pond organisms using a taxonomic key 5. Use a microscope 6. Make predictions and offer explanations about the interconnectedness within the pond Background: Organisms are constantly interacting with each other and their environment. Organisms change in response to conditions in the environment. These changes can be quite rapid or quite slow. Living things also cause change in their environment. A pond ecosystem consists of countless numbers of interaction and interconnections. The study of a pond ecosystem is a good way to quickly uncover that everything is connected to everything else. All abiotic (never living) and biotic (living or once living) things in an ecosystem are interconnected.
An ecosystem is an intricately delicate balance in which plants, animals, bacteria and non-living components like water, air, nutrients and solar energy each have an important and specific role to play. An ecosystem consists of all the living and non-living things in a given area that interact with one another. Ecosystems overlap and affect one another. The birds of a prairie ecosystem may feed on the macro invertebrates of a pond ecosystem. A pond ecosystem may include frogs, fish, aquatic plants, dragonflies, birds, algae and microscopic organisms. A clean and healthy pond ecosystem depends on the interactions, interrelationships and interconnections of all of these parts. Each part of a pond ecosystem is important to the survival of the whole pond. No matter how the size or complexity of an ecosystem is characterized, all ecosystems exhibit a constant exchange of matter and energy between the biotic and abiotic community. Ecosystem components are so interconnected that a change in any one component of an ecosystem will cause subsequent changes throughout the system. Life in the Pond: Benthic Macro-Invertebrates Benthic macro-invertebrates are invertebrates (or animals without a backbone) that live on the bottom of streams during all or part of their life cycle. "Benthic" means bottom dwelling, and "macro" indicates that benthic macroinvertebrates can be seen with the naked eye. Benthic macro-invertebrates are an extremely important part of pond ecosystems, and serve as a link in the food web between decomposing leaves and algae, and fish and other vertebrates. Many benthic macro-invertebrates are the larval forms of flying insects, such as mayflies, stoneflies and caddisflies. Others are small animals that spend their entire lives in the pond, such as water mites. Some can travel between water and moist terrestrial environments, such as fresh water snails. Most macro invertebrates go through several stages from egg to adult. The number of stages depends on the type of metamorphosis. Insects that undergo incomplete metamorphosis follow three stages. They begin as eggs the hatch into nymphs, which then grow into adults. (the immature period is called to nymphal stage.) Examples of insects that undergo incomplete metamorphosis are mayflies, dragonflies, stoneflies, and true bugs. Many of the insects that undergo incomplete metamorphsis are aquatic only during the egg and nymphal stage. True bugs, such as the backswimmers, spend their whole life in the water. Insects that undergo complete metamorphosis have four stages: egg, larva, pupa, and adult. Examples of insects that undergo complete metamorphosis are true flies, beetles, and caddisflies. Aquatic insect life cycles range from less than two weeks for some midges and mosquitoes to two years or longer for some dragonflies. There are four feeding groups of macroinvertebrates: shredders, filter-collectors, grazers, and predators. Shredders such as stoneflies (plecoptera) feed on plant material and some animal material, which is generally dead, and break it into smaller particles through their feeding and digestive process. Collectors, such as caddisflies (trichoptera) and blackflies (diptera), feed on this fine particle material which they filter from the water. Grazers, such as snails and beetles, feed on algae and other plant material living on rocks and on plant surfaces. Predators such as dragonflies (odonata) feed on other macroinvertebrates. Individual species may be generalists, and fit into more than one of these groups (as opposed to specialists). The presence or absence of certain species of macroinvertebrates in a particular stream or river is commonly used by aquatic biologists as an indicator of the level of pollution in that stream. A healthy stream has a mixture of certain classes of organisms. The class system is designed to effectively assess the pollution level of moving water (streams, rivers, and creeks) rather than still water systems (ponds and lakes). It is important to understand that monitoring macroinvertebrates in a pond ecosystem may not effectively assess pollution levels. Relative diversity of life is an excellent indicator of ecosystem health in still and moving water. Preparation Activities at School: Riveredge is a partner with you, the teacher, in creating a high-quality educational experience. We depend on you to prepare your students for their hands-on activities at Riveredge. Please do at least the starred activities before your field trip. This preparation is essential to meet curriculum goals. We are committed to excellence, so if you are unable to meet the minimum expectations in this guide, please contact a Riveredge educator for help at 262/675-6888 (local), or 262/375-2715 (metro). *Denotes important activities which should be done before the field trip.
1. *Help student become familiar with the vocabulary words at the end of the guide by as a class create a concept map of interrelationships of key words (ex: decomposer, producers, prey, abiotic, biotic, etc.) 2. *Acquaint the students with who lives in a pond habitat by allowing them to explore a copy of the "Key to Life in the Pond". Help students learn to use the key by allowing students to write pond critter riddles for each other. 3. *Discuss the term interaction. The definition is: a reciprocal action; the combined or reciprocal action of two or more things that have an effect on each other and work together. Discuss what types of interactions they have had so far today. What types of interactions would you expect to find in a pond ecosystem? 4. Discuss the term adaptation. Plants and animals are adapted to their environment, which is why they survive. They must be adapted to meet all of their needs (for food, water, air and space). Ask what special circumstances a pond presents to plants and animals for which they would need special tools or adaptations. (For example: How do they get their air, or how do they keep from floating away?) 5. Familiarize the students with the life cycles of insects by having each student select a bug from the pond key and create a map is its life cycle. 6. With the pond key in hand, visit a local pond. Make sure to discuss how the pond was formed (i.e. glacial feature, spring flow collection, human-made). The pond student will be exploring at Riveredge is a human-made farm pond. At Riveredge: Special Notes: Ask your students to wear boots or old tennis shoes for this visit. It is usually wet and muddy around the pond and there's always the possibility that someone will get wet feet. In many cases, telling students to bring extra clothes is an invitation to "accidentally" fall in. Use caution when suggesting this. You may wish to bring extra socks, sweat pants and a shirt in case of a mishap. 1. Please meet your Riveredge teacher/naturalists in the main parking lot. Please have your students wear name tags. The teacher will introduce the program and acquaint the students with the procedure they will follow and equipment they will use in investigating the pond. All the equipment needed will be provided by the Center. 2. Each teacher s class will be kept together as one whole group. Within this group, students will be working in 8 smaller groups. You may wish to divide them into 8 groups in advance. 3. In their small groups, students will map out one of the 8 sections of the pond specifically looking at the biotic and abiotic things that interact to make up a pond ecosystem. Students will also collect animal and plant life from the pond. They will each attempt to identify at least one animal or plant (using microscopes), draw it, and research how it interacts with another biotic organism and an abiotic factor from the pond ecosystem. Follow-up Activities at School: My Pond Connection Follow-up Activities at School: Community Connections Focus Concept: All living communities are made of countless interactions that link living things to one another and to their surroundings. Each part of the community can have a positive impact on that community. Essential Understandings: 1. All ecosystems are made up of living and non-living things and their interactions.
2. All living and nonliving things in an ecosystem are interconnected. 3. Each member of a community has a specific role to play. 4. Each member of a community develops special adaptations to help them survive. 5. Interconnection is more than a static relationship between two things interconnections are constantly changing. 6. Humans are connected to natural communities in many different ways. 7. An ecosystem and a community are systems embedded in many other systems. Essential Processes and Skills: 1. Observe the living and nonliving things that are part of an ecosystem. 2. Gather data and record information. 3. Make predictions and offer explanations about the interconnectedness within the ecosystem. Essential Questions: 1. What are some interactions that take place within a living community or ecosystem? 2. What would happen if what you found disappeared from this community or ecosystem? 3. Why is it equally as important to understand the way things in the in an ecosystem are interconnected and interact as it is to know what is in the ecosystem? 4. How are we connected to all life on Earth? Timeframe and Equipment: This activity can be done if 45 minutes or be extended over several weeks and class periods. You will need the following equipment: Class set of magnifying lens Field Guides for the Ecosystem/Community you are investigating Activity: 1. Make a large poster of the pond map you create while at Riveredge by taping together the 8 pond sections. Include the Pond Interactions Key. Give student more time to describe additional kinds of interactions happening at the pond and to discuss how they are connected to the pond even while they are sitting in class. 2. Option 1: Prepare a class aquarium to simulate the pond. The aquarium should contain pond sediment, pond water, a branch or stem extending above the surface, several large rocks (to serve both as protection for animals and as anchors for rooted plants) several aquatic plants (both floating and rooted) and various predators and prey. Have students make observations periodically about the interactions happening in the aquarium and record their findings on a new pond interactions map. Option 2: Take student to another ecosystem (i.e. a forest, wetland, prairie, etc.) are create the same type of interaction map they create for the pond. 3. Once they have had time to thoroughly investigate and document their ecosystem, have students do creative writing about life in the ecosystem. This may be in the form of a story or a play. All writings should highlight the interactions happening in the ecosystem. Encourage the student to include interactions with people in their story or play that are both positive and negative. 4. As a concluding activity ask students to create a We Can Interact Positively with Nature bumper sticker like campaign to share with their fellow students. Have students generate a list of ways that we all act in a way that creates a positive interaction with the ecosystems and communities in our world. (Example might be ways to protect a natural environment directly such as invasive species removal or indirectly such as water conservation practices.) Select the top ideas into bumper sticker style messages that can placed around the school. 5. Riveredge is very interested in learning about the students follow-up activities. Please send us copies of your new interaction maps and We Can Interact Positively with Nature ideas.
Vocabulary: abiotic A factor in an ecosystem that was never alive and which affects the organisms that live there. (i.e. water, air, sunlight, soil, temperature, ph, etc.) adaptation A form or structure that a plant or animal has which helps it survive in its environment. algae A group of chiefly aquatic nonvascular plants with chlorophyll often masked by a brown or red pigment. biotic The things in an ecosystem that are alive or were once alive. consumer An organism that cannot make its own food; it must find other living or non-living things to eat. decomposer An animal or fungus that gets its energy from dead plants or animals food chain The system in which living things eat or are eaten by other living things. food web A complex feeding system comprised of linked food chains in a particular ecosystem. insect A class of arthropods with well-defined head, thorax and abdomen, only three pairs of legs and typically one or two pairs of wings. interaction A reciprocal action; the combined or reciprocal action of two or more things that have an effect on each other and work together. invertebrate An animal without a backbone or internal bony skeleton. photosynthesis The process in which green plants use sunlight, carbon dioxide, and water to make sugar and oxygen. predator An animal that hunts and kills other animals for food. prey An animal that is killed and eaten by a predator. producer An organism that makes its food through the process of photosynthesis, usually a green plant. scavenger An animal that feeds on refuse or carrion. Resources: Books Angel, H. and Wolseley, P., "The Water Naturalist", Facts on File, Inc., New York, 1982. Ried, G.K., "Pond Life", Golden Press, 1967. Riveredge Nature Center, "Wonderful Wacky Water Critters" (available in the Riveredge bookstore.) Curriculum Western Regional Environmental Education Council: Project WILD Aquatic These curriculum guides are only available by attending a six-hour workshop. Call Riveredge for more information or for other curriculum resource suggestions. Web Sites Aquatic Critters http://mbgnet.mobot.org/fresh/slide/intro.htm A photo-filled site for teachers and students covering the organisms that live in ponds, rivers and wetlands. The Amazing Adaptable Frog http://www.exploratorium.com/frogs/mainstory/index.html All about frogs! Pond Dipping Explore ponds and the wildlife in them such as frogs, tadpoles, newts, and more 1) Virtual Pond Dip http://www.microscopy-uk.org.uk/ponddip/index.html 2) Overview of macroscopic life found in freshwater ponds: http://www.microscopyuk.org.uk/pond/index.html 3) Pond Dipping by Roy Winsby http://www.microscopy-uk.org.uk/mag/articles/dipping.html