Living Environment
Life Science
ES 5-6
Changing Environments
Virtual Field
For both of these activities students can have their own computers at their own stations. If individual computer stations are not available, then students can be in pairs. If working in pairs consider having individual students record their answers to the questions in the data collection and the analysis sections in their science notebooks. This will allow them to access their data in the future.
There is no special set-up needed for these simulations. Make sure that you have run all the models and simulations so that you are familiar with how they work so that you can help students trouble shoot as they are working.
The Changing Environments activity should take approximately 45 min. to 1 hr.
The Virtual Field activity should take approximately 45 min. to 1 hr.
In Changing Environments, students consider the question "How does a natural or man-made change in the environment affect the different plants and animals living in that environment?" . In Virtual Field, students consider the question "What does variation mean when growing plants?". These questions are used to consider an organisms role and interactions in its habitat.
An animal’s habitat is defined as the total elements in an organism’s physical surroundings which have direct bearing on that organism's function and survival. Different animals have different habitats based on their physical and behavioral adaptations. Each adaptation has been produced by evolution. As the environment changes, animals that cannot adapt die out, and only the adapted ones survive to produce babies. Because baby animals learn from their parents,the whole species then soon adapts to the new environment. Behavioral adaptations occur in response to environmental changes, but physical changes do not. Most importantly, an animal’s habitat has the food, water, and shelter best acquainted for them allowing for survival. A habitat is an animal’s home.
Populations of animals interact with each other and their environment in a variety of ways. Populations of animals that feed on other organisms are called predators. The populations on which predators feed are called prey. Predator and prey relationships are interdependent. When there is a high population of prey, the predator population will increase until the prey population starts to decease. Once the prey population adjusts their behavior (finding refuge, changing feeding patterns, etc..) they will begin to increase.
Producers use water, air, and sunlight to make their own food and food energy. Green plants are producers. They are the only living things that can make their own food. They use the sun’s energy to produce food energy, which they store in their cells (photosynthesis). Some producers include trees and bushes (leaves, fruits, berries, flowers), grasses, ferns, and vegetables.
Students of all ages see food as substances (water, air, minerals, etc.) that organisms take directly in from their environment. They also think food is a requirement for growth, not a source of for growth. They have little knowledge about food being transformed and made part of a growing organism's body.
Some students also hold misconceptions about plant nutrition. They think plants get their food from the environment and not by manufacturing it internally, and that food for plants is taken in from the outside. Even after consistent instruction, students have difficulty accepting that plants make food from water and air, and that this is their only source of food. Understanding that food made by plants is very different from other nutrients such as water or minerals is a prerequisite for understanding the difference between plants as producers and animals as consumers.
Lower elementary-school students can understand simple food links involving two organisms. They often think of organisms as independent of each other but dependent on people to supply them with food and shelter. Upper elementary-school students may not believe food is a scarce resource in ecosystems, thinking that organisms can change their food at will according to the availability of particular sources. Students of all ages think that some populations of organisms are large enough to fulfill a demand for food by another population.
What are some natural events that can cause a change to environment?
Some examples are: climate change and natural disasters (floods, fires, etc..).
How does a natural change in the environment affect the different plants and animals living in that environment?
If the change is due to a gradual change over time then organisms will be able to adapt. If the change is sudden then some organisms will not be able to survive and will not be found in that particular area.
What are some man-made events that will causes changes to environment?
Some man-made events are: deforestation, damming of rivers/streams, pollution, etc...
How does a man-made change in the environment affect the different plants and animals living in that environment?
Students should recognize that man-made changes to our environment tend to happen quicker than natural changes. When these changes happen quickly organisms have a harder time adapting and tend to leave the area. Example might include a dam blocking salmon migrations, loss habitat for water fowl resulting from draining lakes, or deforestation of rain forests that are home for some primates (monkeys, apes, etc.).
What does variation mean when growing plants?
Variation is how plants changes, and become different versions of the same plant.)
How do plants change over time?
Plants change through cross-pollination, and when the seeds are produced they are a new form of the original plant. If this happens over and over the plant will continue to change. Those that are best adapted to the environment will be more successful and produce more offspring.
What happens to plants if they do not get their basic needs (water, sunlight, and nutrients)?
The plants will not survive.
How might mountain growth affect the amount of water available for plants to grow?
As mountain ranges grow there is likely to be differences in the amount of rain/snowfall on different sides of the mountains. In the Pacific Northwest the western sides of the mountains tend to get more rain/snow while the eastern sides get less.
What trends are you seeing between the simulation and the graph that is forming?
In the plant simulation they may notice that the number of individuals changes as the mountains grow. They may also begin to notice changes in the physical characteristics of the plants as seen by the color changes. In the rabbit simulation should see a direct relationship between the amount of resources(grass) available and the population of rabbits. When the dam is put in place the water resources are limited for the grass and the rabbit population. The students should see a decrease in rabbit population when the dam in in place. If the students are looking at the plant simulation they will see how plant change over time. In the hawks and foxes they may notice that changes in one species affects other species.
In the simulation the plants with smaller leaves seem to be more successful in full sun and larger leaves do better in low sun levels. Why might this happen in real life?
A plant with larger leaves will be able to collect the maximum amount of light which will allow for greater photosynthesis activity.
What changes are occurring in transition light zones?
The plants seem to be adapting taking some characteristics from both sides of the transition zones allowing them to spread into these zones.
How does a natural or man-made change in the environment affect the different plants and animals living in that environment?
Changes in the environments affect both plants and animals. These changes can be both positive and negative. They can cause populations of organisms to decrease or increase based on availability of resources.
In the simulation with the dam that environment seemed to move back to its original balance after the dam was removed. Explain why this might happen. Will the new ecosystem be exactly the same as it was before?
When a change in the environment is reversed organisms will begin to move back into an area. The ecosystem that results may be similar to what existed prior to the disruption but may have some significant differences.
What does variation mean when growing plants? Be prepared to share your answer with the class.
Variation is how plants change over time, different versions of the same plant.
Besides light level, what other environmental variations could affect species success?
Answers should include moisture levels, nutrient content, introduce species, etc.
A food chain shows how energy passes from one living thing to another living thing. It follows a single path as different creatures eat each other for energy. All food chains begin with energy. This energy comes from the sun. The greatest amount of energy in an ecosystem is found in its producers.
Producers use water, air, and sunlight to make their own food and food energy. Green plants are producers and are the only living things that can make their own food. They use the sun’s energy to produce food energy, which they store in their cells (photosynthesis). Some producers include trees and bushes (leaves, fruits, berries, flowers), grasses, ferns, and vegetables.
A consumer is a living thing that eats, or consumes other living things to get food energy. Consumers cannot make their own food. When an animal eats or consumes a plant, some of the food energy inside the plant is passed on to the animal. Animals need this energy to live. Some animals that eat plants include: deer, moose, whales, elephants, cows, horses, pigs, rabbits, and squirrels. Many living organisms have behavioral adaptations to help them get food and water. In desert climates, animals and insects hunt for food and water during the night and early morning hours. Some of these nocturnal animals include rattlesnakes, lizards, birds, foxes, and rodents. Desert animals get much of their food and water from the plant life in their environment. Most desert animals get their water from the leaves and stems of desert plants. Cactus is an excellent source of water.
Not all consumers eat plants, however. Animals like lions, tigers, cats, wolves, sharks, walruses, polar bears, seals, vultures, anteaters, and owls eat other animals to get energy. In cold climates, living things also adapt their behaviors to find food and water. Some animals, like squirrels, mice, and beavers, gather extra food in the fall and store it to eat during the cold winter months. Other animals get ready for winter by eating extra food and storing it as body fat. Animals that cannot adapt to changing temperatures often migrate. This means that they travel to other places where the weather is warmer so they can find food.
What an organism eats and what eats it is called its niche. No two organisms fill the exact same niche, or role, in a community. In the oak tree food web, each organism has a special but very different niche in the community. For example, the caterpillars, beetles, and squirrels have different niches in the community because they eat different parts of the tree. In turn, they are eaten by different animals in the community. During its lifetime, however, an organism’s niche, or role, may change. This means that what it eats and what eats it may change over time.
As the mountain height changed, the environment on both sides of the mountains changed. What does this mean for the plants that lived there?
The plants that had limited resource struggled to survive and the plants that had resources were able to flourish.
In Graph 2, how many types of plants are there?
There are 2 plant types, separated by leaf size.
Look at the above four graphs again. Tell a story to describe what happened to the plants when the mountains formed and the environment changed.
Answers will vary but may say something like: As the plants continue to grow the plants on each side of the mountain became different variations of the original. The plants changed in flower color and leaf size.
Think about the impact the dam had on the ecosystem with rabbits and grasses. Over time, what happened to the water level below the dam?
The water level below the dam decreased.
How did the population below the dam change after many years?
The population of rabbits decreased over time because there were not enough resources for them to survive.
When the dam was removed, the rabbit population below the dam recovered to its pre-dam status. How did this population change happen?
As the amount of water increased the number of plants increased. This increase led to an increase in the number of rabbits of all sizes.
What differences did offspring have from their parents?
The offspring have different color blooms and different size leaves.
Where in the field did Leaf Size 9 plants grow best?
Leaf Size 9 grew best in little light.
In this graph, how many types of plants have flowers?
The graph shows that all (10 total) the types of plants have flowers.
Do you think the graph above is taken after one season, two seasons, or after many seasons? Explain your answer.
Answers may vary but should talk about the fact that it probably took many season because there are many variations of the original plant. These variations would take time to occur.
Students need to continue to see the relationship of organisms to the amount of resources available. To achieve a better understanding students need to work through the simulation involving predators, prey, and producers. This shows another level of the relationships between these organisms. They can also research local changes to their environments and find out how these changes to their environments have affected the different populations of organisms.
Since creating a an experiment that will show students variation in plants is both time consuming and costly students would benefit from completing the additional simulation located at the end of the activity. As a teacher you can change that amount of water that they can use and amount of money that they can spend on seeds by giving them verbal rules to follow.