CHAPTER 8 Focus Points
8.1 Climates and Biomes
Biomes: Biomes are regions with a uniform vegetation structure. Their locations are determined mostly by climate.
Köppen climate classification system: The Köppen climate classification system is used to classify different climate types.
8.2 Low-
Three biomes: The three low-
Climate: Low-
Vegetation: Plant adaptations in low-
Human footprint: Roads, logging, farming, and livestock ranching have had the greatest impacts in low-
8.3 Midlatitude and High-
Five biomes: The five midlatitude and high-
Climate: Winters are mild in the Mediterrean and temperate rainforest biomes, and they are cold in the other biomes at mid-
Vegetation: Vegetation structure at midlatitudes varies widely, from the dry Mediterranean biome to temperate rainforest, with the world’s largest trees. Fire occurs in all midlatitude biomes.
Human footprint: Human impacts includes non-
8.4 Biomes Found at All Latitudes
Three biomes: Montane forest, tundra, and desert are found at all latitudes. Some montane forests support large trees. Alpine tundra occurs at high elevations, and northern tundra at high latitudes, where it is too cold for trees. Desert has low biomass and drought-
Climate: The climates of these biomes vary by latitude. The montane forest biome has sufficient moisture to support forests and is cool. Tundra is always cold. Deserts have perennial moisture deficits and may be hot or cold.
Vegetation: Vegetation in these three biomes ranges from thickly wooded montane forest to the shrubs and herbs of the treeless tundra to the sparsely vegetated open ground of desert.
Human footprint: Human impacts include logging in montane forest, mineral extraction in tundra, and water diversions from desert streams.
8.5 Geographic Perspectives: The Value of Nature
Habitat fragmentation: Habitat fragmentation is the most significant driver of species extinctions today.
International trade: International trade is a driving force in habitat fragmentation and degradation of natural biomes.
Value of natural biomes: Natural biomes provide humans with resources, services, aesthetic value, and climate stabilization.