Adaptations Unit 6 Lesson 3

Adaptations Unit 6 Lesson 3

Objective

We can Explain how plants and animals respond to changes in the environment.

VOCABULARY

Migrate- To move from one place to another because the seasons have changed

Hibernate-To go into a deep sleep during winter months

Dormant- A state where a living thing slows its natural activity to survive during the winter.

Impact- To directly affect something

THINK ABOUT IT

Think about your favorite animal or plant. Suppose that the animal or plant was no longer anywhere on Earth. How would you feel? Human actions can affect the survival of plants and animals. For example, many turtles are accidentally trapped in fishing nets. The turtles can die if they are not freed from the nets fast enough. Engineers have designed a device that prevents turtles from being tangled in the nets. It is called a Turtle Excluder Device, or TED for short. Using technology, engineers discover new ways to help save plants and animals from situations like this.

PROBLEM SOLVE

What other solutions can you think of to save the turtles from being caught in dangerous fishing nets?

CHANGES IN THE ENVIRONMENT

Living things depend on the environment to give them the things they need to survive. When the environment changes, plants and animals are affected too. Some changes are fast, such as when a wildfire kills plants. Other changes are slow and take many years to happen. For example, changes in climate over time can cause glaciers to melt and increase sea levels.

Changes in the environment are caused by humans, other organisms, and natural events. For example, humans cut down trees to build new homes or highways. Beavers cut down trees to build dams. Weather and climate changes can result in more or less rainfall. All of these changes affect landscapes, waterways, and the plants and animals living in the area.

LET'S TALK ABOUT IT

How might an increase in rainfall affect the plants and animals that live in an environment?

CASE STUDY: DENALI NATIONAL PARK

Much of Denali National Park in Alaska is covered in glaciers. Earth’s climate has become warmer over the years. One result is that there are fewer northern goshawks in the park. These birds feed on animals that do best in cold weather.

Another result is that glaciers now begin to melt much earlier in spring. Mosquitoes lay eggs in the puddles of melting ice. So, there are more mosquitoes now. The mosquitoes feed on caribou blood. More mosquitoes cause greater stress on the caribou. This has resulted in fewer caribou in the national park.

The increase in mosquitoes has an impact, or strong effect, on other animals too. Yellow-rumped warblers feed on mosquitoes. Because the warblers have more food, there are more of them now.

GOSHAWK

YELLOW RUMP WARBLER

MOSQUITO

PLANTS RESPOND TO SEASONAL CHANGES

Like animals, plants have adaptations that help them survive seasonal changes in their environments.

The plant in the picture is a caladium. During the dry season, caladiums become dormant, or go into a state of rest. This adaptation helps protect the plant when less water is available in its environment. The roots of these caladiums store food and water to help the plant survive while it is dormant.

PLANTS RESPOND TO SEASONAL CHANGES(CONTINUED)

Plants also respond to differences in temperature as the seasons change. Some flowering plants, such as these camellia bushes, lose their leaves when temperatures become colder. First, the plants stop making the substance they need to make food. Then, the leaves change color. Finally, the leaves fall from the plant. The leaves grow back in spring. Some trees, such as firs and pine trees, keep their leaves when temperatures become colder.

CHANGES IN ENVIRONMENT CONDITIONS

Natural events and human activities can affect the environment. How do animals respond? Some animals move in and out of changing environments. For example, if a forest is cut down for new homes, resources that an animal needs may be lost. The animal may move to a similar environment where resources are available.

Plants cannot move like animals can. They may die if their environment changes too much. For example, if an area of land floods, the plants there may not survive.