Rainforests. Beautiful green habitats that have evolved over millions of years and contain our richest collections of life. From ant eaters to quetzals, begonias to rosewood trees, cicadas to slugs, tropical rainforests teem with intricate webs of life. These biodiversity warehouses constitute 7% of earth's land, yet they contain from 50 to 90% of its living species. Like the rainforests themselves, tropical rainforest education may seem like an unorganized jumble of recommendations, activities, and disconnected efforts. To help point the way through the terrain, this Digest offers four guideposts: (a) structure, (b) location and climate, (c) importance, and (d) Conservation of resources.
Structure
Layers of Life. One of the most important features of a rainforest is its vertical stratification. Different microclimates and microhabitats exist in the layers. This layering is a major factor in the rich biodiversity of rainforests.
Pranis and Cohen (1995) describe how children can depict the layers of the rainforest. For the canopy, stand on chairs; sub-canopy, stand on the floor; understory, kneel; and ground, lie down on the floor.
Crane (1987) presents a mural guide of the layers made of two 7.5 foot strips of butcher paper on the wall. Each of the five layers (emergent, canopy, middle, shrub, and herb) is 18 inches tall. Student groups illustrate different layers and explain their layer to the class. A similar activity that involves constructing a three-dimensional paper rainforest mural has been suggested by McKee (1991) .
Rosenbusch (1994) suggests that after students learn about the layers they hypothesize about differences in microclimate between the layers.
Adaptations of Life. Rainforest organisms are adapted for survival in the particular microclimates of rainforests. Comparing these organisms with more familiar organisms is one way to learn their structures and functions. Science supply companies now offer seeds and kits students can use to observe the growth of rainforest plants.
Pranis and Cohen (1995) suggest creating rainforest conditions with a grow light and timer for 12 hours of light, heater for warm temperatures, and plastic enclosure to retain moisture. Humidity is added with a spray bottle. Beyond observing plant growth, students can compare the growing conditions with local and cultivated plants, as well as leaf transpiration rates.
The National Wildlife Foundation (NWF, 1989) described an activity where students observe and draw leaves from local forests. Illustrations of rainforest leaves are provided for students to compare the leaves. Typically temperate leaves have more variety in shape. Tropical rainforest leaves are elongated with "drip tips."
Students become jaguars in an activity by Morris and Morris (1994). Using a paper bag they cut out eye holes, paste on paper ears and a nose, paint it yellow with black spots, and add pipe cleaner whiskers. A tail is created by filling a nylon stocking with paper and gluing on black felt dots. Students can pretend they are jaguars and explain the functions of their structures.
Location and Climate
Where in the World. Tropical rainforests are located in the warm regions south of the Tropic of Cancer and north of the Tropic of Capricorn. Tropical rainforests have the greatest biodiversity, but there are non-tropical or temperate rainforests as well (such as those on the northwest coast of the USA).
Several rainforest maps and related activities are available (Morris & Morris, 1994; NWF, 1989; & Crane, 1987). McKee (1991) had primary grade students look at a map of the world and then place a strip of green cellophane along the equator, visualizing the tropical rainforest belt.
Tropical Rainforest Climate. Tropical rainforests are warm areas that receive a great deal of rainfall. Average temperatures range from 70-90 F. Rainfall ranges from 60-200 inches per year. Relative humidity is typically 70% in the daytime, 95% at night. Thornton et al. (1995) had first grade students graph local rainfall and compare it to rainforests.
Going, Going, Gone? Despite the beauty and importance of rainforests, they are being rapidly destroyed or altered. Analogies can help people understand the rates of loss. Between 1981 and 1990, tropical forest loss was 40 million acres a year. This is the size of the state of Washington (Fortner, 1992). According to Schneider (1996),we are currentlylosing the area the size of Florida each year. Within 75 years, all the rainforests could be gone.
Analysis of data is another way for students to learn about rainforest loss and integrate mathematics into their science learning. Scientific papers can be a good source of data for analysis.
Importance
Habitat For Biodiversity. The number of species in tropical rainforests is astonishing. One pond in the Amazon can contain more species of fish than all the rivers in Europe. One 25 acre plot of land in Borneo has almost 700 types of trees. This is more species than in all the six billion acres of North America. One rainforest park in Costa Rica has more species of butterflies than all of North America.
A good introduction to the idea of habitat and diversity is suggested by Crane (1987). Bring children to a natural area and have them count the number of different living organisms. Next take the children to a parking lot or a dirt area and rope off the same size area. Explain that this area used to look like the other area.
People of the Rainforest. Indigenous people to the rainforests are dependent on the rainforest. The Mbuti or Pygmies in Central Africa, Kuna of Panama, and Arowaks of Suriname are examples of indigenous people living sustainably in tropical rainforests. NWF (1989) presents an activity where students read about the lives of a Mbuti family as they look at pictures. McKee (1991) had students create a Mbuti hut. Morris and Morris (1994) present information on building replica huts of the Dyack people of Borneo.
