Answers to Figure Legend Questions

FIGURE 3.4 Grasslands and shrublands might occur in areas with combinations of precipitation and temperature usually associated with forests or savannas due to disturbances such as fire or deforestation by humans or an outbreak of herbivory.

FIGURE 3.5 A comparison of Figures 3.5A and B shows that the greatest human impacts have occurred in grassland and deciduous forest biomes of North America and Eurasia (principally due to agricultural development). Note that in the Indian subcontinent and in South America, human impacts have occurred primarily in the tropical seasonal forest biome.

FIGURE 3.11 Both east- and west-facing slopes would have distinct biological zonation associated with gradients of temperature and precipitation, but precipitation would be lower on the east-facing slope due to the rain-shadow effect. As a result, a forest community on the west-facing slope might be replaced by a shrub or grassland community at the same elevation on the east-facing slope.

FIGURE 3.14 Oxygen levels would be highest where the stream velocity is the fastest, in the main channel. This is where organisms with the highest oxygen demands, typically fish, are found. The lowest oxygen levels are found in the benthic and hyporheic zones, where organisms must be able to

tolerate hypoxic conditions.