325500 To develop an understanding of the interdependence of all organisms and the need for conserving natural resources

Ecological succession is a series of sequential changes caused by populations of a community producing conditions that are unfavorable for their own survival.

3255J1.00 To understand primary succession

1.01 recognize the stages of primary succession.
1.02 observe examples of primary succession on the school yard.
1.03 list factors that will affect the rate of primary succession.
1.04 identify conditions that result in certain environments never developing climax species.
1.05 discuss the role that climate plays in the process of succession.

Defining, identifying, investigating, classifying, identifying cause and effect, sequencing, drawing conclusions

Six 55 minute periods (More if several of the activities are used)

I.Stages of primary succession
A.Pioneer stage
1. Plants
2. Animals
B.Developmental stage
1. Plants
2. Animals
C.Climax stage
1. Plants
2. Animals
II. Primary succession on the school yard
Ill. Rate of primary succession
IV.Environments never developing climax stage
V.Role climate plays in succession process

Rocks covered with lichens, etc., pictures of succession, camera, pictures of timber harvesting, etc.

Algae, climax community, developmental stage, ecological succession, fungi, lichens, pioneer stage, primary succession, secondary succession

This lesson addresses Instructional Objective 1.01.

(Hold up a card with the word "SUCCESSION" written on it.) Who can tell me what this word means? (response) Today we will begin a study of succession.

During the development of an ecosystem, the ecosystem goes through a series of changes known as ecological succession. Who can tell me what this means? (response) The changes happen within the structure of the community and usually are caused by the community itself. During succession, organisms tend to change their environment in such a way as to make conditions less favorable for themselves and more favorable for other organisms. The new organisms take over and, in turn, eventually make conditions unfavorable for their own survival and favorable for the survival of other organisms. There are two kinds of succession, primary and secondary. We will begin our study with primary succession.

What is primary succession? (response) It is the development of a community. Where does primary succession take place? (response) Primary succession occurs when the terrain is initially lifeless or almost so--when a new island rises out of the sea, or when a glacier retreats or a Mountainside caves in, leaving a pile of rocks, or in an area that is covered with lava, on a sand dune. Primary succession is usually very slow because it starts without soil. Consider an area of barren rock created by a landslide. (Have a picture if possible.) Water seeping into cracks in the rock may freeze, expanding and breaking the rock into chunks. The surface of the rock is also weathered by the beating of wind and rain. Carbonic acid, formed when atmospheric CO2 dissolves in water, helps to dissolve minerals in the rock fragments, providing nutrients. Pioneer plants begin to grow. Who can tell me the name of a pioneer plant? (response) One pioneer plant is the lichen (LI Kuhnz). What makes up the lichen plant? (response) A lichen plant is an organism made up of an algae and a fungus. (Algae-simple form of plant life that includes "seaweeds" and "pond scums"; funguses plant-like organism that does not have chlorophyll and so must obtain food from other organisms.) (Have a large rock covered with lichens, mosses and other small plants to show students. Lichens adapted to exposed conditions may spread over the rock surface; they produce organic acids, which further dissolve the rock. (Peel back the lichen on the rock and show the students the "sand-like, particles under the lichen.) Dead lichens also contribute organic remains to the forming soil, and mosses break up the rock more and add their own dead bodies to the pile so that the seeds of small rooted plants can germinate and grow. (If possible, make sure the rock you select has all of these things growing on it.) Some of these short rooted plants are grasses, ferns, and flowers. At this stage the vegetation begins to attract insects, small animals such as mice, amphibians, and reptiles. As the kinds and numbers of plants increase, more species of animals can live in the area. The life span of a pioneer plant is short when compared to that of the plants that follow.

(Have a small rock covered with lichens, mosses and/or small plants for each student, or groups of no more than three students. Pass out the rocks and ask the students to list everything they find on the rock. The list might include, lichens, moss, small grasses, violets, unknown plants, "sand-like" particles, soil, insects, etc. When list is completed have the students report to the rest of the class what was found. Make a class list of the findings. Have students keep this list in their notebook. They will need to refer to it later in the study of succession.)

Today we began our study on succession. Write on a piece of notebook paper the two kinds of succession. (Primary and secondary) Circle the one we began studying about today.

(Primary) Put this in your notebook. You will need to use this same page again tomorrow. (pause, summarize)

This lesson addresses Instructional Objective 1.01

Yesterday we began our study of succession. Who can tell me what kind of succession we discussed? (response) That is correct. Today we will continue our study of primary succession. We will begin the discussion with the Developmental Stage and move on to the final stage, the Climax Stage or Climax community.

Developmental Stage: The pioneer stage has prepared the soil for other species to follow. The grasses hold the soil and prevent erosion. The cover maintains moisture, and as the plants grow and die their decomposing bodies add organic compounds to the soil. The life span of a pioneer plant is short when we compare it to that of the plants that follow. What plants come after the pioneer plants? (response) The next plants are taller than pioneers, such as tall grasses and woody shrubs. Because these new comers shade the ground and their long root systems monopolize the soil and water, it is difficult for pioneer species to survive. Grasses and woody plants usually exist for 10-30 years. (Have pictures of these plants.) But even as these species choke out the pioneers, they are in turn, shaded and deprived of water by seedlings of certain trees, such as the pin cherry, dogwood, sumac, birch, cedar, and pines, which become established, and command most of the resources once they reach a respectable size. This stage will last for 25-50 years. What do you think is happening to the animals while the plants are going through these changes? (response) These early stages of succession support animals of grasslands and old fields such as meadowlarks, meadow voles, and grasshoppers. When the woody plants invade, a new structural element is added. (Use the drawings in this lesson or use pictures to show these early stages.) Meadowlarks decline, and field sparrows and song sparrows appear. When woody vegetation, whether young trees or tall shrubs, claim the area, shrubland animals colonize the area. Field sparrows decline and thickets are claimed by towhees, catbirds, brown thrashers, and goldfinches. Meadow mice give way to white-footed mice. When woody growth exceeds six meters and the canopy closes, shrub species decline and are replaced by birds and insects of the forest canopy. Large animals such as deer, bear, and fox, will live here.

Climax Stage: The process continues along similar lines with progressively more rock broken up into soil and more organic compounds being added to the soil, but succession is still not complete, because the first trees that grow in an area are not usually members of the species that make up the final stage. Can anyone tell me what this stage is called? (response) This stage is the climax stage of succession, or the climax community. As the meadow gradually changes to open woods, the environment becomes too shady for the seedlings of the elm, cottonwoods, birch, dogwood, pin cherry and sumac. However, their fallen leaves decay, building up and preparing the way for the species that will replace them. After many centuries, the oak and ash seeds germinate on the shady forest floor and these trees gradually replace the elms, cottonwoods and the other trees of the developmental stage.

Finally, a dense forest is formed. The ground has become rich in organic matter. Beech and maple seedlings compete with the oak and ash or hickory for space. They eventually crowd out most of the other trees. Here in Tennessee, and most of the other southern states, the oak-hickory forest is the final stage of deciduous forest succession, but the climax vegetation will vary from region to region. (The biome will be taught in the next section .) This time line implies that shade-tolerant species replace shade-intolerant ones and that trees replace shrubs. This is not always the case. A dense growth of shrubs such as meadow sweet, mountain laurel, or Saint-John's-Wort may claim a site and maintain their positions for centuries. Yellow-poplar, white pine, and red pine, to mention a few species, can remain dominant for well over 100 years. Douglas-fir, a pioneer species in western North America, may claim a site for over 1,000 years. A climax community is the final stage of ecological succession, in w hich no major changes occur in the kinds of species or the structure of the community. What is happening to the animal population while the succession of plants is taking place? (response). The animal population depends on the plant population. Therefore, as plant succession proceeds, the types and numbers of animals in the area change. As the community matures and more structural elements are added, new species appear. What are some of these species? (response) The tree squirrels, woodpeckers, and birds of the forest understory, such as hooded warblers and wood thrushes appear. The animals that fly and climb will live in the forest during this stage. Animals such as the grouse, rattlesnake, chipmunk, fox and deer are also found in the climax stage of succession.

Today we have discussed the final two stages of primary succession. On the same page that you used yesterday, list these two stages. (pause, summarize)

(Give each student a copy of the activity, Stages of Succession. Have them complete the worksheets, then put the activity sheets in their science notebook to be checked.)

Additional activities that could be used are:
1. Life in a Rotting Log
2. Empty Lot Succession
3. Field Trip to Climax Forest
4. Succession Transact (Project Wild, pages 97 and 98)

If you were to look at an area where nothing is growing for several years you would discover that small lichens would begin to grow on the bare rock, as time passed you would see other small plants and grasses replace the lichens, these in turn would begin to grow only to be replaced by herbaceous plants and small woody shrubs. Later evergreen trees would grow with the shrubs, and finally other kinds of deciduous trees would begin to grow only to be replaced by still other hardwoods until the climax vegetation is reached. The animal populations would also be changing at the same time, until a climax is reached.

Study the table which follows to identify the kinds of communities in which certain animals live:

Animal white-footed mouse beetles cricket thrushes tiny insects deer rabbit woodpecker earthworm pheasant rattlesnake fox garter wren frog robin grouse grasshopper snail squirrel mouse hawk chipmunk voles

Community areas with tall shrubs and trees tree bark grass woody area lichens woody area grass and small shrubs trees soil small shrubs and grass woody area tall shrubs and trees snake grass and area with small shrubs trees grass and area with shrubs and trees, near water tall shrubs and trees tall shrubs and trees grass and areas with small shrubs soil trees grass grass, shrubs and trees under tree roots grass, soil

Questions:

1.List the animals that are found in all three stages of primary succession.

Why do you think these animals can live in the different communities?

_____________________________________________________________________

2.List the animals found living in communities with lichens, grasses and herbs.

Why do these animals live only in these communities?

_____________________________________________________________________

3.List the animals living in communities with shrubs, evergreens, and small trees.

Why do you think these animals live in these communities?

_____________________________________________________________________

4. List the animals found in the climax communities.

Why do these animals live in this community?

_____________________________________________________________________

5. Describe the changes you see in the plants between the different stages:

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________

If a fire occurred in a forest like the one of the climax stage many of the plants would be burned as a result. When new plants began to grow in the area, what do you think the first plants would be?

Why?

_____________________________________________________________________________________________________________________________________________________________________________________________________________________________

Vocabulary:

Write a paragraph below explaining primary succession. Use these words in the paragraph: primary succession, change, pioneer stage, developmental stage, and climax stage.

___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

This lesson addresses Instructional Objective 1.02.

Today we will be going out on the school yard to observe where succession has taken place. Has anyone found a place you think we should begin? (response) This activity will last the rest of the year.

Succession on the School Yard is an activity that we will be doing outside on the school yard. (Project Wild Activity) We will make one long trip outside (a class period or maybe two class periods) to select our site and to make and record our first observations. If you have a camera I hope you brought it with you today. You will then be able to record your data with pictures as well as in written form. (Two activities have been included. You may choose the one you like best or you may have one of your own that is even better. Pass out one of the activities and go over the directions, etc. You will need to talk about why they are going outside, especially if they have not been out much with the group.)

Activity 2--SUCCESSION ON THE SCHOOL YARD - Project Wild

Directions: Get permission to isolate two areas near the school. The first should be a playground (Not black-topped) area (Leave it alone) and the second a grassy or cultivated area near a building (Stop mowing, watering, or fertilizing).

(During a class term ask students to take pictures of these two areas on a regular basis, probably once a week. The camera should be in the same position each time a photo is taken. This accurate pictorial record should be displayed in the classroom as the pictures are ready.)

(In addition to the photographs, ask the students to compare the areas by recording their observations in a journal or notebook. Suggest that data like the following be included:

1.Which plants and how many go to seed?
2.Plant growth rate. (Measure and graph in centimeters per week).
3.Changes in plant density. (Number of stems/square meter.)
4.Changes in species composition. (Do some species become more abundant?)
5.New species.
6.Evidence of animal life or visits, including those of humans.)
(Ask the students to make a general statement about apparent relationships between diversity and stability in plant communities, based on the data they have acquired.)

(This can take place outside or inside.) Today we have been observing succession on the school yard. Turn and tell a classmate what the three stages of succession are and if you found all three on the school yard. (pause, summarize)

This lesson addresses Instructional Objective 1.03 and 1.05.

Today we are going to discuss the role climate plays in the process of succession and how it affects the rate of succession.

What do you think is the most important factor affecting succession? (response) Climate is the most important factor affecting sail formation. Climate is an abiotic part of the community. What does climate refer to? (response) Climate refers to the precipitation, temperature, wind speed, and other elements of weather that an area usually experiences. Climate is the most important factor that determines the make-up of an area. Once a soil has matured, the parent material no longer has much effect on soil types. The soil formed from granite in wet tropical climate is very different from the soil formed from granite in a desert. At the same time, mature soils in a wet tropical climate strongly resemble each other no matter what their parent materials.

Tropical Soil: Tropical soil forms in the areas that have constant high temperature and heavy rainfall. Warm, wet conditions speed up chemical weathering, and sail forms quickly, therefore, succession is faster. The soil profile that results may be more than three meters thick. Frequent heavy rains wash nutrients out of the sail. Tropical soils are relatively infertile. They must be fertilized heavily if they are used to grow crops.

Grassland Soil: Grassland sail forms in areas that receive enough rainfall for heavy grass, but not enough for trees. The soil profile is usually less than a meter thick. Grassland soils are very rich in organic matter and, as a result, are very fertile soils. Grassland soils are good for growing wheat and similar grains.

Forest Soil: Forest soil forms in humid regions that have cool seasons and forests of hardwood and evergreen trees. The soil profile in a forest is usually less than a meter in total thickness. Forest soils are not very fertile, and do not form very fast.

Desert Soil: Desert soil forms in very dry climates. Their profiles are seldom more than a few centimeters from top to bottom. Nutrients that would be washed from the soil in a wet climate stay in a desert soil. Such soils have a great deal of calcium. These soils can be very fertile when they are watered, but succession takes place very slowly.

Arctic Soil: Arctic soils form at high elevations and high latitudes. These soils are poorly drained and baggy. The bottom layers are constantly frozen (Permafrost). The soil profile is very shallow, often only a few centimeters thick.

The climate, along with soil types, determines what organisms (Plants and animals) live in a given area. As succession proceeds, both the number and type of species in an area change. The climax community is determined mainly by the climate of the region.

Today we have discussed the most important factor affecting succession. On a piece of paper write down what this one factor is, have a classmate check to see if you are correct. Put this in your science notebook. (pause, summarize)

This lesson addresses Instructional Objective 1.04.

Today we will discuss some conditions that result in a community never reaching a climax stage. Who can tell me what some of those might be? (response)

Repeated disturbance will prevent an area from returning to the climax state. What could be some disturbances? (response) Suburban homeowners spend considerable time, energy, and money creating a continuous series of disturbances that maintains a lawn of a few species of short grasses, constantly interrupting the old field succession of tall weeds, shrubs, and light-loving tree seedlings that will take over if vigilance is relaxed. Many areas in the Midwest were prevented from reverting to climax forest by native Americans who deliberately set fires after they found that herds of buffalo, which live on the prairie, could be hunted more efficiently than the lone white-tailed deer of the young forests. Why does succession take place? (response) Succession occurs because of progressive changes in the environment that makes the environment less favorable for the species that are present and more favorable for colonization by others. What causes some of those changes? (response) Many of the changes are caused by the organisms themselves. As succession proceeds, the supply of available nutrients in the soil declines as minerals become increasingly locked up in living organisms. The community's production of new organic matter, through photosynthesis, and the total weight of all the organisms in the community, both increase during succession, leaving off as the climax stage is approached.

Many areas do not contain the climax community expected from their resources and climate because they have been disturbed by natural processes such as floods, fire, or volcanic eruptions, to name a few, or by other human activities.

Fire: Fire sets back succession, influences species composition by favoring fire-resistant species and selecting against fire-sensitive ones, and shapes the character of the community.

Timber Harvesting: Removal of a forest, especially by clear-cutting, returns the land to an earlier stage of succession. Unless followed by fire or badly disturbed by erosion and logging activities, the cutover area rapidly fills in with herbs and shrubs--blackberries and dense thickets of sprout growth and tree seedlings. The area passes quickly through the shrub stage to canopy closure. (Have pictures to show how this happens.) Humans can modify the forest to meet their requirements. Early in the life of a new forest, trees economically undesirable and poor in form can be removed. This improves the growing stand economically, but not necessarily ecologically.

Grazing and Browsing: Grazing and browsing mammals also influence succession and development of ecological communities. (The effects of browsing can vary widely. Have pictures if possible.)

Wind: A strong element of disturbance in forested ecosystems is wind. Depending on the strength of the wind and its associated storms, disturbance can range from the toppling of a single tree in locally heavy thunderstorms to large-scale windfalls caused by hurricanes. Either one will cause the ecological community to change.

Today we discussed several reasons why some communities never reach climax stage. On a piece of paper list at least four of these reasons. Exchange with your neighbor and check, put this paper in your science notebook.