Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Ecosystems: What Are They and How Do They Work? Chapter 3 Sections 5-7 Importance of Soils Provides nutrients for plant growth (Base of life on land) Water Cleansing & Storage Helps decompose & recycle waste Potentially renewable resource (1 cm of soil requires 15yrs to several hundred years to form) Climate Control - CO2 storage Soil Horizons O Horizon = surface litter - Brown or Black Nondecomposed leaves, twigs, crop & animal waste, fungi , A Horizon = Topsoil - Dark & Loose porous mixture of partially decomposed humus, and inorganic minerals B Horizon = subsoil C Horizon = Parent Material Soil Formation and Horizons Oak tree Wood sorrel Lords and ladies Dog violet Earthworm Fern Millipede Honey fungus Mole Grasses and Organic debris small shrubs builds up Moss and Rock fragments lichen O horizon Leaf litter A horizon Topsoil Bedrock B horizon Subsoil Immature soil Regolith Young soil Pseudoscorpion Mite C horizon Parent material Nematode Root system Mature soil Red earth Springtail Fungus mite Bacteria Actinomycetes Fig. 3-21, p. 51 Soil Profiles from Different Ecosystems Gray, Gray, yellow & red topsoils are low in organic matter & need N to support crops Fig. 3-22, p. 52 Animation Soil profiles interaction pH Acidity or alkalinity of water or water-bearing samples Scale 0-14 Acidic: pH 0-6.9 Neutral pH 7.0 Alkaline (basic): pH 7.1-14 The pH Scale Fig. 3-23, p. 192 Matter Cycling in Ecosystems: Biogeochemical Cycles Nutrient (biogeochemical) cycles Hydrologic (water) cycle Carbon cycle Nitrogen cycle Phosphorus cycle Sulfur cycle Simplified Hydrologic (Water) Cycle Condensation Rain clouds Transpiration Precipitation Precipitation to land Transpiration from plants Rapid Surface runoff (rapid) Evaporation Evaporation From ocean Precipitation Evaporation From ocean Precipitation to ocean Surface runoff (rapid) Infiltration and percolation Groundwater movement (slow) Ocean storage Fig. 3-24, p. 54 Animation Water cycle interaction Human Interventions in the Hydrologic Cycle 1. Large withdraw of surface and ground waters 2. Clearing vegetation / wetland destruction - runoff, 3. Pollution - addition of nutrients infiltration, groundwater recharge, flood risk, soil erosion & landslides The Carbon Cycle (Marine) Diffusion between atmosphere and ocean Carbon dioxide dissolved in ocean water photosynthesis Combustion of fossil fuels aerobic respiration Marine food webs Producers, consumers, decomposers, detritivores incorporation death, into sediments sedimentation uplifting over geologic time sedimentation Marine sediments, including formations with fossil fuels Fig. 3-25a, p. 56 The Carbon Cycle (Terrestrial) Atmosphere (most carbon is in carbon dioxide) Combustion of fossil fuels volcanic action Terrestrial rocks weathering photosynthesis aerobic respiration Land food webs Producers, consumers, decomposers, detritivores combustion of wood (for clearing land; or fuel) deforestaion Soil water (dissolved carbon) death, burial, compaction over geologic time Peat, fossil fuels leaching, runoff Fig. 3-25b, p. 57 Animation Carbon cycle animation- LEARN THE CARBON CYCLE! Human Interferences in the Global Carbon Cycle 1. Clearing Vegetation 2. Burning Fossil Fuels potential consequences? High projection Low projection Fig. 3-26, p. 56 The Nitrogen Cycle Gaseous Nitrogen (N2) in Atmosphere Nitrogen Fixation by industry for agriculture Food Webs on Land Fertilizers uptake by autotroph s excretion, death, decomposition uptake by autotroph s Nitrogen Fixation bacteria convert N2 to ammonia (NH3); this dissolves to form ammonium (NH4+) NH3, NH4+ in Soil loss by leaching Nitrogenous Wastes, Remains in Soil Ammonification NO3– in Soil by bacteria 2. Nitrification bacteria, fungi convert the residues to NH3; this dissolves to form NH4+ bacteria convert NO2– to nitrate (NO3–) 1. Nitrification NO2– in Soil bacteria convert NH4+ to nitrite (NO2–) Denitrification loss by leaching Fig. 3-27, p. 58 Animation Nitrogen cycle interaction - LEARN THE NITROGEN CYCLE! (Animations on School Server) Human Interferences in the Global Nitrogen Cycle 1. Add nitric oxide (NO) to atmosphere - can form acid rain 2. Add nitrous oxide N2O to atmosphere via anaerobic decomposition & inorganic fertilizers - greenhouse gas 3. Nitrate in inorganic fertilizers can leach thru soil & contaminate groundwater 4. Release large quantities of N into troposphere via habitat destruction 5. Upset aquatic ecosystems from excess nitrates in ag. runoff & sewage- eutrophication The Phosphorus Cycle mining Fertilizer Guano excretion agriculture uptake by autotrophs Marine Food Webs uptake by autotrophs Dissolved in Ocean Water leaching, runoff Dissolved in Soil Water, Lakes, Rivers death, decomposition sedimentation Land Food Webs weathering weathering settling out uplifting over geologic time Marine Sediments Rocks Fig. 3-29, p. 59 Animation Phosphorus cycle animation Human Interventions in the Phosphorus Cycle 1. Mining of phosphate rock 2. Clearing tropical forests reduces available phosphate in tropical soils 3. Phosphates from runoff of animal wastes, sewage & fertilizers disrupts aquatic ecosystems - eutrophication “Since 1900, human activities have increased the natural rate of phosphorous release to environment by about 3.7 fold” The Sulfur Cycle Water Sulfur trioxide Ammonia Ammonium sulfate Oxygen Sulfur dioxide Acidic fog and precipitation Sulfuric acid Hydrogen sulfide Plants Volcano Dimethyl sulfide Animals Industries Ocean Sulfate salts Metallic Sulfide deposits Decaying matter Sulfur Hydrogen sulfide Fig. 3-30, p. 60 Animation Sulfur cycle animation How Do Ecologists Learn about Ecosystems? Field research Remote sensing Geographic information system (GIS) Laboratory research Systems analysis Geographic Information System (GIS) Critical nesting site locations Private owner 1 USDA Forest Service USDA Forest Service Private owner 2 Topography Forest Wetland Habitat type Lake Grassland Real world Fig. 3-31, p. 61