Answer to Question 1
Many areas impacted by continental glaciation are characterized by thin, rocky soils, exposed bedrock, and lakes scraped out by glaciers. Other areas show evidence of glacial deposits in the form of parallel hills called drumlins or moraines.
Answer to Question 2
The specific biomes of North America can be seen in Figure 2.17 . Forest biomes originally covered most of eastern North America to the edge of the Great Plains. Forests also cover much of the Pacific Northwest, the Rocky Mountains, and large portions of northern Canada. Forest biomes are characterized by regular rainfall averaging more than 30 inches a year.
Tundra is found only in the highest latitudes in North America. This biome is covered with the type of vegetation that can tolerate an extremely short growing season, little sunlight, and intense winter cold.
Grasslands cover the Great Plains. These ecosystems have large seasonal temperature variation and irregular rainfall. Soils in the Great Plains are some of the most productive in the world for agriculture, so very little of the original prairie ecosystem is left.
Deserts and steppes are areas with extremely dry climates with annual rainfalls of less than 10 inches. Any vegetation in these biomes must be able to survive with very little water and tolerate occasional flash flooding.
The Mediterranean biome is one of the most unusual in North America, existing only in western California and southern Oregon. A Mediterranean climate is characterized by cool, wet winters and hot, dry summers. Chaparral vegetation in this zone includes many shrubs and small trees that are adapted to regular fire.
The subtropical wetland biome also exists only in a tiny region in and around the Everglades National Park in Florida.