A biome is a community of animals and plants spreading over an extensive area, sometimes thousands of miles in length or width, with relatively uniform climatic conditions. The presence of broad temperature and precipitation belts determine the boundaries of each biome.
If we look at a geophysical map of North America we will immediately notice some significant features; the mountain ranges of both the west and east coast, the extensive central lowland, plateaus, and the coastal plain.
The children should be given outline maps of North America to study and color in the important geophysical features. Atlases or their Social Studies text will be helpful for this exercise and will emphasis the interdisciplinary nature of environmental studies. Using the same type of outline map have the children also find the approximate boundaries and color in maps showing temperature ranges, precipitation, and vegetative types. These maps should be kept in a special Biomes folder. After all the maps are completed some time should be designated for comparison and discussion of relationships between these physical and biological factors. The eye-catching weather maps of U.S.A. Today newspapers are great resources and by saving seasonal examples the children can see the climates in the various biomes over time. Generalized maps of both climate and biomes can be found in the Appendix.
As the children focus in on the biomes map they will see large areas along the Arctic Ocean with little plant life and much snow cover. Moving southward will be broad expanses of deep green pine trees with even more southerly pointing fingers of pine in the mountains of the east and west. Between these fingers of pine are regions of vegetation determined largely by the level of precipitation; leafy deciduous forests in the east fading into the grasslands of the central states and finally the dry deserts of the west. The concepts of the prevailing westerly winds and the effect of the mountains should be briefly explained here. The southern most tip of Florida, parts of Hawaii, and Puerto Rico illustrate the concepts of tropical ecosystems, and the western coast of Washington state harbors a splendid temperate rainforest. The biomes we will focus on are the desert, grasslands, tundra, coniferous forest, deciduous forest, and the rainforest, both tropical and temperate.