Chapter 43 The Biosphere

43.3 What Are the Major Biomes? _________________ with similar climates and _______________ ____________________________ regions as a result of similar environmental factors Discontinuous region characterized by its climate and __________________ vegetation

What Are the Major Biomes? (cont’d.) Figure 43.7 Major biomes. Climate is the main factor determining the distribution of biomes.

What Are the Major Biomes? (cont’d.) Differences between biomes ___________________________ are the main __________________ of the type of biome in a given region _________________________________ Properties of soils vary depending on the ____________, _________________, and ___________________________________ amounts of humus Climate and soils affect _________________________, so primary production varies among biomes

What Are the Major Biomes? (cont’d.) Similarities between biomes Unrelated species in widely separated parts of a biome ___________________________ that arose by _________________________ Example: cactuses with __________________ stems live in North American deserts, and euphorbs with water-storing stems live in African deserts, but cactuses and euphorbs do not share a ____________________ with a water-storing stem

43.4 What is the Most Productive Biome? Tropical rainforests Form between latitudes 10° north and south in Africa, ______________, Asia, and South and Central America ________________ centimeters (50 to 80 inches) of rain falls throughout the year _______________ productive and species- rich biome in which year-round rains and warmth support ____________________ of evergreen broadleaf trees

What is the Most Productive Biome? (cont’d.) Tropical rainforests (cont’d.) Tropical rain forest is the ___________________, ______________ complex, and species-rich biome Photosynthesis occurs year-round, but trees often form a __________________ that blocks light from the forest floor ___________________ is an ongoing threat to tropical rain forests in developing countries with fast-growing human populations

What is the Most Productive Biome? (cont’d.) Tropical rainforests (cont’d.) Decomposition and __________________ happen fast in the warm, moist environment Soils are highly ___________, _______________________, and are very ________________________.

What is the Most Productive Biome? (cont’d.) O horizon: Sparse litter A–E horizons: Continually leached; iron, aluminum left behind impart red color to acidic soil Figure 43.8 Tropical rain forest. The graphic to the right shows the soil profiles. B horizon: Clays with silicates, other residues of weathering

43.5 What Types of Forests Occur in Cooler Climates? Temperate ______________ forests Northern Hemisphere biome in which the main plants are ____________ trees that lose their leaves in fall and become dormant during cold winters Deciduous plant sheds leaves annually, prior to a season when _________________ conditions would not favor growth

What Types of Forests Occur in Cooler Climates? (cont’d.) Temperate deciduous forests (cont’d.) Form _________________ centimeters (20– 60 inches) of _________________ falls throughout the year Winters are cool and summers are warm Leaves often turn color before dropping in autumn Trees remain dormant in winter; flower and put out new leaves in spring

What Types of Forests Occur in Cooler Climates? (cont’d.) Temperate deciduous forests (cont’d.) Rich soil and a somewhat open canopy lets sunlight through and allows ________________________________ Tree species (e.g., oak, __________, maple) characterize different _____________ of these forests Animals in North American deciduous forests include grazing deer, seed-eating squirrels and ______________, and omnivores (raccoons, opossums, black bears)

What Types of Forests Occur in Cooler Climates? (cont’d.) Coniferous forests Conifers _________________ conditions than broadleaf trees, so they grow farther north and at __________________ The _______________ forest that extends across northern Asia, Europe, and North America – known as the _________________________ – is the most extensive land biome

What Types of Forests Occur in Cooler Climates? (cont’d.) Coniferous forests (cont’d.) Conifers (____________________________) such as pine, fir, and spruce are the main plants in coniferous forests Conifers are adapted to conserve water during _____________ or times when the ground is frozen Winters are long, cold, and dry; and most rain falls in the cool summer Moose are the dominant grazers

What Types of Forests Occur in Cooler Climates? (cont’d.) Coniferous forests (cont’d.) New Jersey pine ____________ are a mixed forest of ___________________ that grow in sandy, acidic soil Southeastern pine forests hold fast-growing loblolly pines that survive periodic fires that kill most hardwood species – these pines are a major source of lumber and wood pulp

What Types of Forests Occur in Cooler Climates? (cont’d.) Coniferous forests extend southward through _________________________ Spruce and fir _____________ highest elevations Firs and pines occupy lower elevations Coniferous forests in temperate lowlands along the Pacific coast hold the world’s _________________ Sitka spruce to the north (Alaska) Coast redwoods to the south (northern CA)

What Types of Forests Occur in Cooler Climates? (cont’d.) Figure 43.9 Cool forest biomes A North American temperate deciduous forest in fall. B Boreal forest (taiga) in Siberia.