Part A: Preparing for the Field Trip
-
Your goal is to observe and identify as many organisms as you can in the area you are visiting so you can construct an accurate picture of the food webs in that ecosystem. During the field trip itself, you will identify each organism or trace of an organism you observe by name or with a description and a picture.
-
Discuss with your teacher and classmates the type of area you will visit to help you plan for what you might observe.
-
Review classification at the kingdom level in Section 18-3 if necessary. Identifying the kingdom is a useful step in determining how an organism gets food.
-
Gather enough descriptive information about the organisms you expect to observe so you can identify them with a field guide. This will enable you to research which step in the food chain the organism occupies.
-
Just because you don't see an organism doesn't mean it leaves no traces of its existence and interactions with its surroundings. Spider webs, for example, mean there are spiders eating insects. This kind of indirect evidence enables you to identify a consumer and infer where it is in the food chain. Other indirect evidence can include nests, burrows, and paw prints. Plan to sketch or photograph these traces.
-
Familiarize yourself with the biomes and ecosystems described in Section 4-3. Different plants grow in different biomes. The types of plants in an area determine the type of community.
-
Physical characteristics of an area determine the kinds of producers and ultimately the type of ecosystem. Find out as much as you can about the biome and ecosystem you will be visiting.
-
Some of your observations will be made in the field, and some will be made in the classroom. Prepare a data table similar to the one below to record your observations.
-
Have your teacher check your written plan and review all safety considerations.
Part B: Working at the Site
-
On the day of your trip, bring along all the materials listed in your plan.
-
Describe the location in which you are making observations. Observe a sufficient number of plants to help determine the nature of the ecosystem. If it is a land ecosystem, examine the soil for moisture and texture.
-
If you are visiting an aquatic ecosystem, collect some water samples. The organisms at or near the bottom of the water food chains are often microscopic.
-
Describe, sketch, and photograph any organisms or traces of organisms (tracks, nests, burrows, for example) that you see.
-
The best way to get close to larger animals is to wait patiently and quietly, hiding where you will not be seen. While you are waiting you can observe the surrounding plants and the behavior of smaller animals. Use a magnifying glass. Watch the skies for birds as well.
-
When you see an animal, pay careful attention to the placement of the eyes. Predators often have their eyes in the front of their heads. Animals that are preyed upon often have eyes at the sides of their heads.
-
Watch for behavior. Observe what an animal eats and how it eats. This tells you something about where it is on the food chain. Describe any other animal behavior you observe, such as hiding, burrowing, or nesting.
-
Record any other observations that you think might help to identify the role of the organism in its community. As soon as possible after you are done, wash your hands with soap and warm water.
Part C: Following the Field Trip
-
If you collected any water samples, prepare wet mounts of samples from the top, middle, and bottom of the container. Examine the slides for the presence of organisms. Fill in the required observations on the data table. Note whether the organisms have chlorophyll or not. Watch for feeding behavior. Wash your hands with soap and warm water when you are done.
-
Try to identify the organisms you have observed and the organisms that produced the traces you have observed, using field guides or the Internet. It is not necessary to know the species of each organism. You only need to know enough to learn how the organism obtains nutrients and what its predators are. For example, identifying a bird as an owl, a hawk, or a pigeon is sufficient for finding out what it eats. Write your conclusion in your data table.
-
If necessary, after you identify the organisms you observed, research in the library or on the Internet how the organisms obtain nutrients and which other organisms interact with them.
-
Classifying What were some of the interactions you observed between organisms? Describe at least one example of predation.
-
Analyzing Data Based on your observations and research, draw one or more food chains from the organisms in the community you visited. Identify the trophic levels in each food chain (producer, primary consumer, secondary consumer, decomposer).
-
Analyzing Data Based on the food chains you drew, draw a food web for the community you visited.
-
Drawing Conclusions Give one or more examples of symbiosis that you observed. Explain whether each relationship is based on food-getting or other factors such as living space.
-
Drawing Conclusions Based on the climate and type of organisms found in the community you observed, in what biome is it found? Support your conclusion with evidence and reasoning.
-
SAFETY How did you demonstrate safe practices during this investigation?