Primary and Secondary Succession in America's Forests

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One of the basic concepts students learn in Ecology or Environmental Science is succession, which is the regular pattern of changes in the types of species in a community. While people tend to think of forests as static, they are constantly changing over time. These changes follow generally predictable patterns. Scientists study these patterns to learn how the forest grows and to understand more about how human interference is changing ecosystems. Because resources in an ecosystem are limited, organisms are constantly engaged in a battle to win the resources that they need for growth. Different organisms have adopted different techniques to take advantage of resources. Since the forest is constantly growing and changing, tactics that provided an advantage at one point may not be as advantageous later. For instance, some species of trees grow quickly with lots of sunlight. Once they have grown however, their own shade makes it difficult for their own offspring to survive. Other trees are better adapted to growing seedlings in shady conditions and eventually grow to crowd out the first group of trees. With an understanding of the usual pattern of succession in an area, foresters can determine how mature a forest is and they can predict what it will look like in the future.

Initial colonization of disturbed areas is also of interest to scientists. Particular plant species, known as opportunistic species, come first and pave the way for other plants. Primary Succession is the initial colonization of land that has never been colonized before. This might include areas after a volcanic eruption or after a glacier recedes. Secondary Succession is recolonization of areas after a disturbance such as a fire or when a large tree falls. Given the increasing disturbance of ecosystems by human activity, the concept of succession has dramatic implications for the future of the earth as we wait to see how it will recover.

In this activity, students will have an opportunity to experience video footage that will take them to several different North American Forests while learning about the concepts associated with succession in both natural and disturbed environments.

This lesson addresses the following National Content Standards found at: http://books.nap.edu/html/nses

Content Standard C: As a result of their activities in grades 9-12, all students should develop an understanding of:

Scientific Frontiers - Nordic Sagas: Island Life
The birth of a volcano provides virgin land to be colonized. Learn how organisms convert hostile ground into fertile land for an ecosystem to grow.

Journey to Amazonia - Levels of Life in the Rainforest
Learn more about the structure of the forest and how different organisms have evolved to take advantage of resources in different ways.

Newton's Apple - Balloon Safari
Adopt a plot of land to learn the complex interrelationships of the organisms that use it.

Scientific American Frontiers - Galapagos: Backyard Science
Learn techniques that help students and scientists learn more about ecosystems.

30 Miinutes

Images of forest plants and animals with safety pins or yarn so that they can be worn on the students back. Choose organisms from several different types of forests, for instance a Northwest Old Growth forest might include: Douglas fir, ferns, spotted owl, deer, grizzly bears, and banana slugs. Other forests to consider might include Eastern hardwood forests, a mangrove swamp, the Everglades or other ecosystems from your area. If you choose organisms from several different forest ecosystems, place all the organisms from one ecosystem on cards of a particular color. For instance, organisms from a Northwest Old Growth forest might be pasted onto a red background, those from a mangrove swamp on a blue background.

Kentucky's Blanton Forest - Part 1 Blanton Forest, the largest old-growth forest in Kentucky, provides a glimpse into a forest ecosystem that has remained untouched by humans.

Northwest Temperate Rain Forests - Part 1 Temperate rain forests are characterized by high annual rainfall and relatively mild winters, creating an environment with a rich diversity of species.

 

Northwest Temperate Rain Forests - Part 2 The diversity of the plants and animals in a temperate rain forest changes dramatically from the forest floor to the forest canopy.

Discussion Questions for Video Segment:

In what ways was the Temperate Rainforest similar to Kentucky's Blanton Forest? In what ways were the two forests different? What are examples of limiting factors in forests? Why is water not a limiting factor in the rainforest?

Additional Video Segments: Alternatively, choose additional segments from the AFG video selection on forests for a virtual tour of a forest in your neck of the woods.

Bulls Island, South Carolina - Maritime Forest Denali National Park - Tiga Forest and Moist Tundra Acadia National Park - Forest and Pond Mingo Wildlife Reguge - Oak Hickory Forest Washington's Hoh Rain Forest - Sitka Spruce Forest Hawaii Volcanoes National Park - Tropical Rain forest Adirondack Mountains - Forest Redwood National Park - Forest Siskiyou National Forest - River Cape Cod National Seashore - Beech Forest Glacier National Park - Forest White Mountain, New Hampshire - Forest

30 minutes

Access to the AFG video clips and projection capability

	Kentucky's Blanton Forest - Part 2 Blanton Forest, the largest old-growth forest in Kentucky, provides a glimpse into a forest ecosystem that has remained untouched by humans.
Note: Clip starts at "Hey what's this formation all about?" Stop after hearing "pretty neat huh, very".

Crater Lake National Park - Pine Forests The area leading up to the Crater Lake rim is characterized by ponderosa pine forests and volcanic pumice fields.

45 minutes or more (depending on set-up)

Paper and pencil
Tape
Cameras (optional, see teaching instructions)