1. Introduction to Geography Chapter 4: Biogeochemical Cycles and the Biosphere

2. Biogeochemical Cycles • Recycling processes that supply essential substances to biosphere • Connect Earth’s subsystems • Atmosphere, hydrosphere, lithosphere • All life processes dependent on exchanges of energy & matter • Law of conservation of energy & matter • 2 important cycles • Hydrologic • Carbon

3. Hydrologic Cycle • Flows of water among land, sea & air • 3 states of water • Gas • Solid • Liquid • All living things are mostly water • Large amounts of energy involved in changes in state • Water an excellent solvent

4. Vegetation and Hydrologic Cycle • Trees and forests require large amounts of water • Deep roots • Trees play key role in returning rainwater to the atmosphere • Deforestation • Grasses • Shallow roots • Variable transpiration rates

5. The Carbon Cycle • Processes that cycle carbon & oxygen between the environment & living things • Photosynthesis • Respiration • Combustion • Coal, oil, natural gas • Industrial Revolution • Lithosphere stores carbon

6. Soil • Interface between lithosphere & biosphere/atmosphere • Uppermost part of lithosphere • Part of atmosphere and biosphere • Storage site for • Water • Carbon • Plant nutrients • Factors that affect soil properties • Climate • Parent material • Biological activity • Topography • Time

7. Soil Characteristics • 6 principal soil components • Rocks and rock particles • Humus • Dissolved substances • Organisms • Water from rainfall • Air • Soil horizons • Layers of substances found in soils • Formed via movement of • Water • Minerals • Organic matter

8. Climatic Soil Regions • Humid tropical & subtropical soils • Highly weathered • Arid region soils • High in soluble minerals • Low in organic matter • Productive if irrigated • Midlatitude humid soils • Moderately to heavily leached • Midlatitudesubhumid soils • Fertile • Associated with grain-producing regions

9. Ecosystem • Includes all living organisms and the physical area in which they exist • Fundamental elements • Producers • Consumers • Decomposers • Material/energy needed for production

10. Food Chains • Plant photosynthesis • Herbivores • Carnivores • Omnivores • Trophic level • Biomagnification

11. Community Succession • Sequence • Succession • Climax community

12. Biodiversity • Diversity of species • Stability of community • Increases variety of food available to organisms • Habitat destruction, especially for agriculture, main cause of species extinction • Biosphere reserves • Importance of size • Managed landscapes

13. Biomes • Ecosystems grouped by: • Plant types • Animal types • Named for dominant vegetation/ climate • Typically contain many ecosystems

14. Major Biomes • Forest • Tropical rainforest • Midlatitude broadleaf deciduous forest • Needleleaf or boreal forest • Temperate rainforest • Savannah, scrubland & open woodland • Midlatitude Grassland • Prairie • Steppe • Desert • Tundra

15. End of Chapter 4