To understand the underlying ecological properties of grassland communities and to distinguish between short- and long-term responses to climate change, which allows the prediction of changes in grassland reproductive mechanisms and community structure.
Since global climate change can vary local environmental conditions, organisms may need to adapt to new conditions. Will these new environmental conditions change the amounts of fruits and seeds produced by the plants? This is an important question to ask since the new environmental conditions may affect plant survival and reproductive output.
This lesson provides students with an opportunity to explore the climate change concept in greater depth. Many science topics can be explored in relation to climate change. However, here the focus is on plant competition, reproductive output, and how these concepts may vary based on climate change predictions. The emphasis in this lesson is the effect of increasing amounts of water, predicted by global climate change models for some parts of the United States, on the production of fruits and seeds (measures of reproductive output). Equally, some parts of the United States are predicted to get dryer; however, it is easier to simulate water additions rather than trying to simulate dryer conditions.
Organisms that live in ecosystems interact with each other and the environment in various ways. Ecosystems are shaped by the nonliving environment (e.g., land, topography, water, solar radiation, rainfall, mineral concentrations, and temperature). In ecosystems, organisms use vital earth resources, each seeking their share of resources for survival in specific ways that are limited by other organisms. (Science for All Americans, pp. 65-6.) Reproduction is also necessary for species survival. Limitations, such as competition, on resource acquisition can limit growth, survival, and affect reproductive output. Change in resource supply and acquisition, whether by competition or changing environmental conditions due to global climate change, can therefore affect species survival by limiting growth and/or changing reproductive output (production of fruits, seeds, cones, or other reproductive plant structures).
By the end of the fifth grade, students should have a basic understanding that for any particular environment, some kinds of plants and animals survive well, some survive less well, and some cannot survive at all; organisms interact with one another in various ways besides providing food; and changes in an organism's habitat are sometimes beneficial and sometimes harmful. (Benchmarks for Science Literacy, p. 116.)
Students often have misconceptions about climate change and its effects on ecosystems. Middle-school and high-school students may believe that organisms are able to affect changes in bodily structure to exploit particular habitats or that they respond to a changed environment by seeking a more favorable environment. It has been suggested that the language about adaptation used by teachers or textbooks to make biology more accessible to students may cause or reinforce these beliefs. (Benchmarks for Science Literacy, p. 342.) Therefore, it is important for teachers to query their students to discover these misconceptions.
Student permission slip from parent/guardian may be necessary for work on this project depending on your school policies.
Forms or additional paperwork may be required to use school grounds, forewarn maintenance, etc., depending on your school's policies and procedures.
Reading materials for you include Communicating and Learning about Global Climate Change, from AAAS, 2007. You also can refer to the Background Resources teacher sheet for materials that provide more information about global climate change.
Since climate change has been discussed widely in newspapers, magazines, science books, etc., you should begin with a brainstorming session to assess what your students know or misconceptions they might have about climate change. You can easily begin the brainstorming session by asking your students directly what they have heard about climate change. You may want to consider these prompts to keep the discussion going and write out their answers on a chart:
- Have you ever heard of global climate change? If so, what do you think the idea means?
- ("Global climate change" refers to differences in the change of conditions on the earth. Some places may warm but others cool. Some areas may see increases in precipitation where other areas have decreases. The term "global climate change" more accurately describes the changes occurring on earth and seems to be the preferred term rather than "global warming," which implies that warming will occur everywhere.)
- How do you think wild plants and animals would be affected by climate change? If plants were affected, do you think the animals that feed on them would be affected too?
- (Answers will vary but you should look for student understanding that if wild plants are affected, the animals that feed on them will certainly be affected.)
- How do you think crop or horticultural plants might be affected by global climate change? Do you think this would affect humans? Where could we find this information?
- (The answer to the first question varies by region. If our crops are affected, humans will certainly be affected. Here is the opportunity to show the connection between environmental conditions and how they affect human food resources. Currently, there is a great deal of agricultural research on crop plants and their drought and salt tolerance. Crops and horticultural plant growing zones for the United States can be found on the USDA National Arboretum Hardiness Zones, listed for individual states or use the ZIP Code USDA Zone Finder.)
- Is there anything we can do to address problems associated with global climate change?
- (You can discuss what it means to be "green" and how making changes in your lifestyle can help address the concerns of global climate change.)
Scientists are currently doing research related to global climate change in many places around the world. At the Angelo Costal Range Reserve in Northern California, scientists and university students are studying how future climate change may affect ecosystems in a grassland meadow. One specific National Science Foundation-funded (PI: M. Thomsen; NSF#0816834) research project at the Angelo Reserve explores how predicted increases in rainfall may affect the stability of grassland ecosystems. Students should use their Grasslands and Climate Change student esheet to go to and read a brief article about this grassland meadow research, More time tells a different story about plants and climate change, Part A and B and answer the corresponding questions. The answers to these questions can be found on the Plants and Climate Change teacher sheet. They can record their answers to these questions on the Plants and Climate Change student sheet.
After reading the article, students should use their esheet again to go to and watch Climate Change Research in California, Part A and Part B, and answer the corresponding questions. In these videos, students will see that scientists aren't just people in lab coats working indoors in a test-tube filled lab. Students will see people doing research outdoors "in the field," working collaboratively to answer scientific questions. Students also will learn how professional scientists and college students interested in science are involved in fieldwork on the Angelo Reserve.
After students finish answering the questions for the article and the video, discuss the article, the video, and responses to the questions. From the article and the video, they should understand the point of the research. Basically, precipitation increases are predicted for the Angelo Reserve. The researchers added extra water to model the precipitation change forecasts for the Northern California area. They then studied how the grassland reorganized itself after the water additions over a span of five years. This on-going, long-term experiment demonstrates the importance of interacting species in a grassland community.
To simulate a portion of the research, students will participate in an inquiry-based science activity. You should ask the students to explain what they think happened because of the water addition in the Angelo Reserve experiments, as read and seen in the article and videos. You should then have students predict what will happen in their own schoolyard and then test their predictions using the activity. Students can use the Grasslands and Climate Change student sheet to help them conduct the experiment.
The amount of guidance provided by you will dictate how the experiment is set up. You can use the Grasslands and Climate Change teacher sheet as one potential way to guide one class of about 30 students through this simulation.
After your experiment is set up and running, students should read How We Know What We Know about Our Changing Climate: Scientists and Kids Explore Global Warming, by Lynne Cherry and Gary Braasch. This book is a good introduction to the types of evidence collected by scientists to support the theory of climate change. You might want to have your students focus on climate change research in the tundra (pp. 26-27). After completing the book, return to the ideas generated in the brainstorming session regarding climate change. Discuss their previous ideas and any new ones they might have after reading the book. If preferred, you may use a more formalized reading strategy and K-W-L chart with the book.
Once students have completed the experiment, they should reread the short EurekAlert article and compare their experimental results with what the scientists observed in the grassland meadow. They also should reread pp. 26-27 in the Cherry & Braasch book and compare their experiment with what the students in Queens, New York did. Your students should have an idea of how the Queens, New York students' results turned out when they varied water in their experiments.
After students have the opportunity to act like a scientist, they can write like a scientist too. This simulation provides an opportunity for students to write up a simple lab report about their experiment and how it relates to their original prediction. Students should specifically include information about their observations in terms of how the water additions affected the amount of reproductive structures produced by the plants in their "ecosystem," and how their data compares to the research conducted at the Angelo Reserve. Basically, does adding water to an ecosystem cause changes in that ecosystem?
Climate models: Students can connect their experimental results to the larger region. In the student lab report, discuss connections between their experimental results and regional climate predictions. Discussion of future experiments based on regional predictions could be added to this section of the lab report. Students could discuss a watering regime in future experiments which would more closely simulate rainfall predictions for your region. What long-term impact(s) might an increase in precipitation over many years have on your region?
The Science NetLinks lesson, How We Know What We Know about Our Changing Climate introduces students to the scientific basis of climate change.
Collecting additional plant material: a natural extension of this lesson would be to include vegetative material (stems, leaves, roots) in addition to reproductive material (fruits and seeds). To look at vegetative growth, you would need four, brown paper lunch bags per transect line instead of two. Two bags would be used for collecting above-ground vegetative materials (stems and leaves of grass and non-grass plants) and two bags for reproductive materials as discussed above (fruits and seeds of grass and non-grass plants).
Longitudinal study: you can build a class-produced database of results by keeping graphs generated from each year's class. Over time, the variation in graphed annual results would be an interesting in-class discussion topic. Students would benefit from seeing the differences in results from similar experimental procedures.
Observing insects: the procedure in the suggested experimental layout did not involve looking at any organisms feeding on the plants (producer/consumer relationship). And since caribou probably do not roam in your school yard, an additional extension could include observation of insects feeding on plants in the control and experimental transects. While you may not be able to identify all of the insects, observing changes in population numbers of general groups of insects would provide an opportunity to see if there were different numbers and kinds of insects in your control versus experimental transects. A good quality field guide of the insects in your region will help with identification.
You should consider the potential this experiment has for getting students more involved with research. There are many good avenues for student research presentations available through venues such as school district, local, or state-wide science fairs.