|Teaching Conservation in Developing Nations (Peace Corps)|
|Appendix B: Nature Trails|
(open field) In sun-filled areas like this, the plants have to deal with special problems: too much light, periods with too little water and, often, poor soil. Pick a blade of grass. Examine it. The size of the leaf is small so moisture will evaporate out slowly. The roots are a thick mass of fibers that can grip the hard soil, but they don't go very deep. They get their moisture mostly from rain and dew.
(beginning of forest) Bigger plants like trees will slowly invade a field of bushes. They grow taller and make shade. This means that plants which love sunlight must slowly die and new plants that like more shade move in.
(any place with good view of different layer in forest) Look around you and up in the air. Notice how the forest is made of several different layers. High above, the branches of the big trees weave together to form a canopy. Beneath these, we see a sparse layer of trees trying to grow up through the canopy. Lower down there is a layer of shrubs and small trees. Below that is a layer of small plants like ferns and seedlings.
(strangler fig thee) This is a fig tree. It grows around another tree. its leaves shade out the sun until finally the other tree dies. Sometimes the original tree will rot away and the "trunk" of the fig tree will then be hollow.
(rest stop) (Any pretty place about halfway through the trail, especially good on top of a hill where people will want to stop anyway. Provide a log or a bench to sit on.) This is a good place to rest a minute. Sit and be absolutely quiet. Can you hear nature around you? The birds singing? The insects buzzing? The wind blowing?
(a bent tree) As the tree grows, it twists and turns to reach as much light as possible. This tree may have started growing toward a hole in the forest canopy. At some point a new hole with more light opened up and the tree changed directions. Why might a hole in the canopy occur?
(a bump on a tree) The lump on this tree is called a burl. It is caused by a virus infection. It does not kill the tree but it results in a malformation. The growth rings of the tree take on interesting shapes and the wood is used in tables, bowls and pipes.
(treetops) High above your head, the branches of the tallest trees lace together to form another world. Trees bloom and fruit there, and animals live out their lives without touching the earth. Can you catch a glimpse of the happenings in that other world?
(thee stump) This tree stump is decaying. It is becoming soil again. This process returns the energy that it used as a growing tree. Mosses and fungi are breaking it down on the outside. Ants, beetles and other insects are doing the same thing on the inside.
(young trees in a clearing) As the old trees die, holes develop in the forest canopy and new spots of sunlight reach the forest floor. Here seeds sprout and new trees begin to take the old ones' places. The forest will regenerate itself, but if people destroy it, a tropical forest like this takes hundreds of years to grow again. The forestry department is protecting this land for your children.
(shady area with big-leaved plants) Plants are adapted to where they live. Usually big, thin or lacy leaves are for shady places because they allow the plant to catch as much sun as possible. They will not dry out because their environment is cool and moist. A fern is an example.
(patch of abandoned farmland) The soil was too thin for good farming here and the land was abandoned. The forest is returning in stages. First grasses, then thick brush, third low, thin jungle, and after many years, there will be tall, thick jungle.
(buttress roots) Wide roots like these help to balance the tree. The roots cannot go deeply into the ground because it is hard clay just under the surface and all the nutrients are in the top two inches. The wide flanges give the trunk a wider base of support. Otherwise the weight of the trunk would tip and the roots would be pulled out of the ground.
(cave) This cave may have been formed many years ago when water slowly dissolved away some of the limestone in the earth. Some time later the surface of the earth changed, causing the cave to dry out and be revealed. Now it is a home for bats, snakes and other creatures.
(a very tangled, dense area of vegetation) More kinds of plants and animals live in a tropical jungle than any place else in the world. Notice how dense the plant life is. A mixture of many things living together makes a stable environment, because of the natural control all the species have on one another.
(rattan palm) This rattan palm sends out long runners covered with thorns. They hook on to passing animals. They pull the runner to a new place where it can touch the earth and start another plant far away from the competition of the first.
(clump of pretty bushes) Good soil allows plants to grow plentifully. It is a thin layer, however, and easily destroyed. Plants like these would soon die in a hot dry soil without water.
(rotting log) As this tree trunk rots, it builds up a soft, spongy layer of soil, called humus. This holds rainwater and provides food for other plants and insects. How does the rotting log feel? How does the ground nearby feel?
(rock with lichens) What looks like drops of paint on this rock is actually a combination of plants called lichens. They can live under very severe conditions, like on bare rock. They help to make soil by dissolving some of the rock into fine sand. Feel the rock around the lichen. Car you feel a sandy texture?
(place with many leaves on the forest floor) Leaves collect and rot, making new soil, just as the tree trunk did. Animal droppings and dead animals also add to the soil.
(a water spring) Rain soaks into the ground until it reaches a layer of rock which holds it. That water slowly moves underground until it comes out at springs or into rivers. If the soft topsoil is missing, the rain is not soaked up, but runs off. The water table underground is not replenished if the rain doesn't soak through the soil. The springs will then dry up.
(erosion site on a trail or hillside) Water is a powerful force. Can you see what it has done to the soil here? Compare this place to a protected place with plants. In a place with forest cover, the grid of roots holds the soft topsoil while the leaves slow the speed of the raindrops' fall. Shade keeps the ground from getting dry and hard.
(deep cut into a hillside where a trail or road was built, where soil levels are visible) Soil is found in layers. The top one is rich with plant food, the others are not. In the tropics the hot, wet weather makes things decay quickly, but topsoil does not build up because the food is utilized again by plants almost immediately.
(very large tree) Trees are the oldest living things on earth. Some can be over 4000 years old. They give many good things besides lumber - like good soil, clean air, and homes for wildlife.
(a clearing oh break in the forest where the sky is visible) Look at the leaves of the trees above. Each one is helping you. Leaves produce oxygen which you breathe. They also take away carbon dioxide (which you breathe out) and other poisonous gases. Where does it smell the best -in the middle of the city or here? The leaves release moisture into the air, helping to form new clouds; they shade the ground and air, keeping them cool and comfortable. Think for a moment. Where is it cooler? Here or in the city?
(roots on a rock) Just as the roots of this tree have encircled this rock, so they are holding the soil below it. Small roots weave a mat that traps the soil in tiny pockets. This protects the topsoil which is light, from the force of rainwater. If the forest is cut or burned, the roots no longer hold the soil, and in a short time the rich topsoil is washed away by rain.
(tiny stream) Forests help with the water supply. The leaves release moisture into the air, helping to form new rain clouds, while water in the spongy ground moves downhill slowly to emerge in springs and streams.
(leaves on the ground) Leaves fall all the time, but especially in the dry season when the trees don't want to lose moisture through their leaves. These leaves rot quickly in the rainy season, and help make new soil.
(tree with hole in trunk) Trees provide a nesting place for animals to raise their young, to store their food, and to escape from their enemies.
(rock ledge with animal hole) Under the large rock in front of you is a former animal home. The occupant may have moved away because so many people looked into it. See what a dry place he chose.
(tangled mass of bushes on edge of large clearing) The edges of forests often produce as much or more food and shelter for wildlife as the deep forest itself.
(dead tree on ground) A dead tree is a home for a great variety of things as it decomposes. Under the bark there are beetles and termites. Millipedes eat the decaying wood; centipedes hunt for other insects to eat. inside, perhaps a mouse, a weasel or a porcupine has dug out a den. The home territory of a wild animal is usually a place where it can easily find food and shelter - perhaps a patch of grass, a whole pond, or a fallen tree like this.
(a salt lick) Just as you like salt on your food, so animals like and need certain minerals in their diet. Water deep in the ground rises to the surface carrying dissolved minerals which are deposited there. Look in the mud around you and see how many kinds of animal tracks you can identify.
(clear streamside) The water here is cool and clear. You may see some fish. Compare this to any of the streams outside the park. Is the color the same? Just as some animals need a forest where the canopy is complete, so certain fish, snails and insects need streams where the water is clean. The forest and its soil filter the water and keep it clean.
(large tree that has food for animals in month when most visitors come) In the month of _______ this tree has much fruit which is eaten by (name some animals, birds). This also attracts animals which eat the fruit-eaters. All these animals help the tree in return by spreading the seeds and fertilizing the soil.