Biodiversity and Habitat Loss: No Room at the Top

Transcription

1 Grade Level: 5th-10th grade Activity Time: 50 minutes Subject Area: Science Biodiversity Objectives: materials: (per group) Mountain Biome Sheet and Biome Table (last 2 pages) Scissors Colored pencils Tape Students will: Understand how climate change affects habitat distribution around the world. Understand how climate change affects the range of animals and plants within a region. Understand how climate determines where organisms live. Plant species have a tolerance range of temperature and rainfall, each species with its own requirements. Some species have a narrow range of tolerance; others are more tolerant and able to live in a wide range of climates. Animals that depend on specific plants for food tend to live in the climate region where these plants are found. Understand that ecosystems contain many biomes and habitats and are measured by the number of species that live there. Increased biodiversity creates higher productivity in the ecosystem and its ability to recover when disturbed. vocabulary: Biodiversity Biome Climate change Elevation Habitat Niche background: In this hands-on activity, learners create a model to show how biomes shift upward in elevation on a mountain as carbon dioxide (CO2) in our atmosphere increases and the climate warms. In this lesson, the mountain begins with six biomes, and as the climate heats up, the biomes at the highest elevations as well as the plants and animals that live there disappear. Biodiversity of the mountain is reduced. Although estimates vary, it is widely believed there are over 1.5 million organisms catalogued on the planet so far. There are perhaps 2 million species yet to be discovered. This extraordinary variety of life represents the biodiversity we enjoy here on earth. The variety of species, biodiversity, is not evenly distributed around the globe, or even within a region. The biodiversity of an area is influenced by abiotic factors including: temperature, precipitation, altitude, geography, topography, as well as the biotic factors, such as the presence of other species. Generally, biodiversity is greater in the warmer regions, near the tropics, and lower in colder regions near the poles. It is generally believed that the greater the biodiversity the greater the productivity of a region. This means that the presence of more species in a region produce more and different kinds of products 1

2 than regions of fewer species or low biodiversity. Change in a habitat reduces the number and kinds of organisms that can live in an area. For instance, when agriculture develops large areas of land in a region, the number of plant species, and therefore the number of animals that live there, is greatly reduced. This change decreases the biodiversity of the land. Extinction is a natural event in the history of Earth. However, now it is believed that many plant and animal species face extinction because of habitat disruption due to human s development of the land and changes in the Earth s climate patterns. When habitat is lost to urban expansion, agricultural development, or climate change, many plant and animal populations are reduced to smaller numbers, which are not sufficient to reproduce and therefore, cannot survive. When populations or organisms become isolated and habitat area becomes small, a species is vulnerable to extinction from a region or from the planet. When food plants can no longer grow in an area, the animals that depend on those plants must move or die out. Climate change on Earth is shrinking some habitats and expanding others. There are winners and losers in these changes. When habitats shrink, the number of individuals in the species may become so small they cannot sustain the population. Extinction may occur. When habitats expand, populations increase. Some plant species will expand their range and along with them the animals that depend on them for food. As climate factors change, some species will move out, while others will move in. Because climate factors change with altitude one can experience several natural biomes as you travel up a mountain. Generally, warmer at lower elevations and colder at higher elevations, many mountains support a wide range of plant and animal species and therefore a high diversity of plants and animals for the region. In this activity, students will observe a mountain with six biomes from lower elevation grasslands to higher elevation arctic tundra. As the CO2 levels in our atmosphere increase and the climate warms, the colder climate biomes near the top of the mountain begin to disappear. As the colder climate range disappears, the plants and animals in that region also disappear. introduction: In a mountain biome, as the elevation increases, temperature decreases. There is more rain and winters are longer. Sometimes snow remains all year long near the top. Each biome has a different range of average temperature, rainfall, and length of wither. Plant and animal species vary on the mountain based on these ranges of variables. Lower on the mountain, plants and animals that tolerate warmer temperatures, less rainfall and long summers thrive. Alpine animals, such as Pika, only live in the upper elevations of the mountains and have learned how to cope with colder temperatures, harsh winters, and short summers. As the average temperature of the earth increases, spring starts earlier in many places and higher elevations that were cool are now warm. On mountains, warmer temperatures mean habitats move higher. Organisms that once could only live at 4,000 feet now can live at 5,000 feet. Pika which live near the top of the mountains start to lose their habitat. As the temperature increases, their Alpine habitat will continue to decrease and eventually disappear. 2

3 Carbon dioxide, in addition to other atmospheric gases, traps the heat radiating from the surface of the earth, increasing the average temperature. The concentration of CO2 in our atmosphere is measured in parts per million (ppm) and it is increasing. In this activity, as the ppm of CO2 increases, the T (temperature) increases and the warmer habitats migrate, or move, up the mountain. The cooler habitats shrink and space for them is decreased. The number of habitats decreases (6 to 4) on the mountain. Species (both plant and animal) die out as habitats are decreased or lost. 4. Insert the Mountain Biome Sheet into the Biodiversity Model so it slides in and out. It should look like the picture below. It is estimated that for every 100 parts per million (ppm) increase in atmospheric CO2, global temperatures increase about 1 C. procedure: Prepare 1. Research the mountain biomes and fill in the Biome Table of plants and animals found in each habitat. 2. Using the information from the Biome Table, illustrate the appropriate trees, animals, and other vegetation of the different biomes on the Mountain Biome Sheet. Make it visually attractive with colored pencils. 3. Trim off the left margin of the Mountain Biome Sheet. Cut off the pieces from the right side of the Mountain Biome Sheet to assemble the pull-up tab. Glue the top of the Mountain Biome Sheet matching the marks carefully so that 380 ppm is spaced correctly in relation to 400 ppm. Cut off the center section along the dotted lines of the Biodiversity and Range Shift Model. Assemble the model by folding along the left and right solid lines and taping the folds around the plain 8 1/2 x 11 piece of paper. 5. At each climate transition, or new biome, there is a change in vegetation and types of animals that live there. Above or below their climate range, these plants and animals are less common or not found at all. A region such as this mountain, which supports multiple habitats, provides for a large biodiversity or organisms, all interacting to create a high producing ecosystem. Note the position of the biomes against the elevation scale on the left side of the model. Record the elevations limits of each biome and the concentration of CO2. What can you say about the biodiversity of this mountain region? 6. In the western US and Rocky Mountain areas, the average winter temperature has increased 1.4 C over the last 100 years reducing the amount of snow pack that accumulates. Pull the tab out until the concentration of CO2 reads 400 ppm. What happened to the biomes on the mountain? As the habitats shift up the mountain, what will happen to the space each organism has? 3

4 7. Pika, which lives in alpine regions, cannot tolerate above 27 C and rarely nest in areas where the temperature exceeds 25 C. In areas where the temperature has risen, the Pika has disappeared. Pull the tab up until the concentration of CO2 is 440 ppm. What has happened to the biomes on the mountain? Has the biodiversity on this mountain increased or decreased? Explain your answer. 8. What has happened to the amount of space in which the Pika population can live? (Animals and plants can only climb so high before they run out of real estate. ) 9. As the depth of mountain snow pack and glaciers change, the seasonal melting and runoff have an impact on the organisms that rely on a continual supply of fresh water. Reduced run-off affects the amphibians and fish that live in the streams with repercussions all the way up the food chain. Pull the tab up until the concentration of CO2 is 480 ppm. What is happening to the ecosystems on this mountain now? What do you expect to happen to the amount of water run-off available to organisms living on this mountain as the climate warms? 10. Mountain ecosystems are isolated and disconnected from other mountains. As the climate changes and the organisms move up the mountain, the ability to move to another mountain is reduced. As a species is driven up a mountain in search of sustainable habitat, what happens to the amount of space in which they live? How will this affect their population numbers and availability of food? 11. Pull the tab up one more level until the ppm of CO2 is 500. Describe what has happened to the snow level, the elevation of the biomes, and the biodiversity of this mountain now. Use the tables to show a loss of biomes means a loss of biodiversity. Ponder: You have seen that increased concentration of CO2 has altered the elevation of biomes on a mountain region as the temperature increases. Return your model to today s conditions. It is estimated that the habitat shifts up a mountain at 0.11 km per year. If the side of this mountain from 2,000 feet to 13,000 feet is 10.5 km, how many years will it take for the broadleaf forest to reach 10,000 feet? Show your calculations. Not all organisms lose in a climate change event. As winter temperatures increase, survival rate of the bark beetle also increases. The range of these wood eating insects has grown in North America, and more and more pine forests are being infected by them. How will the loss of large pine trees affect the population of other plants, birds, and animals in the forest? Practice: Get the Big Idea? As climate change alters habitat ranges, organisms must migrate to new areas, or die out. Our model shows how habitats change in elevation in response to climate change: the same phenomenon occurs with latitude. Insects that could not tolerate the cold winters above 44 N now flourish at 50 N in both cases, hardy species will survive and outcompete more fragile ones. Habitat loss will decrease biodiversity, reducing the organisms that are pushed out, or cannot move. In every climate change event, 4

5 there are winners and losers. As new species move into areas that in the past had not been suitable for them, other species must move on, or die out. Extension Activities: Develop a presentation to share with a public audience: Preparing to Present Create a statement or question to engage your students about biodiversity and habitat shift and how it affects them. Think about what might happen if we could no longer grow corn or wheat in Montana. Prepare a visual aid to show people that different habitats support different species based on climate factors and that more habitats create a higher biodiversity, which keeps an ecosystem strong. Explain how increases in temperature cause habitats on a mountain to shift upwards. Make sure you can show your students how organisms losing their habitat, on a mountain, run out of room at the top. Help them understand how many species are not able to move to a new habitat (Ex: large trees that are not mobile, or species that are too isolated from the next area) and with loss of habitats comes a reduction in biodiversity. Are there other animals in the Greater Yellowstone Ecosystem that are impacted by the increasing temperatures? Investigate the habitat needs of wolverines and include this information in your presentation. resources: Short video from BBC s Attenborough Explores Our Fragile World about Pikas. National Wildlife Federation Article: No Room at the Top.. Wildlife/Animals/Archives/2006/No-Room-at-the- Top.aspx Pika Monitoring by the Upper Colombian Basin Network (Oregon, Washington, Idaho, Montana) Correlations to Education Standards: NSES Life Science Standard C: A population consists of all individuals of a species that occur together, and the physical factors with which they interact, compose an ecosystem. Millions of species of plants and animals are alive today. The number of organisms an ecosystem can support depends on the resources available and biotic factors such as light, water, temperature, and soil. Extinction of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient to allow its survival. Present Engage your audience with your visual aid about how different organisms (plants and animals) need different habitats and how a mountain can supply many different habitats. Allow your students to work the habitat loss model and predict what will happen as the concentration of CO2 increases. Show them how, as the ecological biomes move up the mountain, the biodiversity of the mountain is reduced. 5

6 CLEP 3a: Individual organisms survive within specific ranges of temperature, precipitation, humidity, and sunlight. Organisms exposed to climate conditions outside their normal ranges must adapt or migrate, or they will perish. 3c: Changes in climate conditions can affect the health and function of the ecosystem and the survival of entire species. 4a: Climate descriptors can refer to areas that are local, regional or global in extent. 6d: Some changes resulting from human activities have decreased the capacity of the environment to support various species and have substantially reduced ecosystem biodiversity and ecological resistance. 6e: Scientists and economists predict that there will be both positive and negative impacts from global climate change. Adapted from the curriculum the Environmental Literacy Framework with an emphasis on Climate Change developed by ANDRILL, with funding from NOAA. Written by Jean Pennycook. The National Park Foundation is the national charitable partner of the National Park Service. 6

7

8