Chapter 4 Biosphere 2014 Pearson Education Inc Soil Quality Ability of soils to support plants Difficult to measure Plant needs Sunlight Carbon dioxide Oxygen Water Nutrients Nitrogen phosphorus potassium calcium magnesium sulfur 2014 Pearson Education Inc Human Impacts on Soil Quality Fallow periods Replacement by inorganic fertilizer Short term supply of necessary nutrients Reduction in capacity of soil to store nutrients Erosion Desertification Carbon storage 2014 Pearson Education Inc Ecosystems Include all living organisms in an area and the physical environment with which they interact Fundamental elements Producers Consumers Decomposers Material energy needed for production 2014 Pearson Education Inc Ecosystem Processes Food Chains Energy from the Sun moves through an ecosystem through food chains Plant photosynthesis Herbivores Carnivores Omnivores 2014 Pearson Education Inc Biodiversity Diversity of species in any environment Increases variety of food available to organisms Benefits to society Nutrient processing Food medicine other materials Carbon sequestration Habitat destruction especially for agriculture main cause of species extinction 2014 Pearson Education Inc Biomes Ecosystems grouped into biomes by Plant types Animal types Named for dominant vegetation climate Closely mirror distribution of major climate types Ecoregions are another way of mapping the biosphere 2014 Pearson Education Inc Major Biomes Tropical forest Tall broadleaved trees Dominate humid equatorial environments Desert Sparse vegetation adapted to moisture stress Large areas of bare ground Grasslands savannas and shrublands Prairie tall grass and short grass Steppe 2014 Pearson Education Inc Major Biomes Mid latitude forests Broadleaf deciduous forest Boreal forest Tundra Short growing seasons Limited plant growth 2014 Pearson Education Inc Ecoregions of the World 2014 Pearson Education Inc Human Effects on Biosphere Thirty seven percent of world s land area is cropland or permanent pasture Changes in climates will impact ecological processes and soil vegetation linkages Reduced vegetation affects humidity Reduced vegetation affects carbon storage Soil erosion increases atmospheric dust Desertification 2014 Pearson Education Inc End of Chapter 4 2014 Pearson Education Inc