Ground Water and Aquifer DepletionAquifers are Underground reservoirs in which the groundwater is storedSaltwater intrusions: The movement of seawater into a freshwater aquifer near the coast. Saltwater intrusions occur along coastal areas when groundwater is depleted faster than it recharges,Ogallala aquifer: The largest groundwater deposit in the world, which lies under 8 Midwestern states (extensive portions in Kansa, Texas and Nebraska). Farmers in the High Plains rely on water from the Ogallala aquifer. Water in the O.A> takes hundreds or even thousands of years to renew after it is withdrawn to grow crops and raise cattle.--South to North Water Transfer ProjectChinaBig investmentChannelization and the EnvironmentDeepening, Widening, Clearing, Lining existing stream channelsPurposes: flood control improve drainage, control erosion, improve navigationChannelization is widespread in Urban Areasex. Los Angeles RiverNegative Impacts of Channelization?Habitat ChangesPools, Rapids, SedimentLoss of ShadingMore severe temperature fluctuationsLoss of WetlandsIncreased FloodingDuring PrecipitationsDownstream of channelizationCommon in LAAesthetic DegradationEffect of Urbanization on Stormflow TimingBiological Diversity, Biogeography and ConservationBiodiversity has become a measurement for the success/failure of conservation effortsGenetic Diversity the “Raw Material” needed for adaptation/evolution.Interconnected: The loss of one species in a community may affect other species and the working of that communityPatterns of BiodiversityGlobal Scale: Plant Biodiversity greatest in the Tropics/Low LatitudesWhy- Greater solar energy, which will create more biodiversity, greater primary productivity in the tropicsBiodiversity “Hot Spots”Global “Hot Spots”Across the globalTend to see them in the tropics because of greater primary productivityCA is higher in animal biodiversityFactors that tend to Promote BiodiversityA physically diverse habitatMany nichese.g. Multiple Canopies in Tropical RainforestsAltitudinal Diversitye.g. Southwest Chinahot spots: river areas b/c as you move from West to East there are mountain ranges and river basinsEach river basin has its own unique biodiversityModerate amounts of DisturbanceTemperature, Moisture, etcChanges in the ecosystem via human activity, etcDisturbances are bad for the ecosystemE.g. Fire EcologyCrown Fires vs. Ground FiresProblems with Fire SuppressionAdaptations to Moderate Fire Disturbancee.g. Serotinous ConesAfter a fire, the Seritinous cones have survivedFire is necessary for certain communities to reproduce (ex:High diversity at one Trophic Level can stimulate High Diversity in anotherhelps stimulate biodiversity in another levelFactors that tend to reduce biodiversityExtreme EnvironmentsPlaces may be aesthetically beautiful, but there biodiversity may not be greatLimitations of a Crucial ResourceIntroduction of Exotic SpeciesSouth East AsiaCaliforniaHabitat FragmentationSeveral impactsThe “Edge Effect”increase the amount of edge, and decrease amount of poor habitatsHelps reduce biodiversityExotic species can get in there and change the environmentEx: The Cowbird – thrives in agricultural regionsLed to a decline in native bird species as the Cowbirds multiplyBiodiversity and ExtinctionBackground (or Normal) Extinction Rates versus Catastrophic (or Mass) ExtinctionExtinction is happening all the time and it is a natural processHumans causing the 6th Catastrophic Extinction?Geography 5 Week 9 Lecture 15← Ground Water and Aquifer Depletion- Aquifers are Underground reservoirs in which the groundwater is stored- Saltwater intrusions: The movement of seawater into a freshwater aquifer near the coast. Saltwater intrusions occur along coastal areas when groundwater is depleted faster than it recharges,- Ogallala aquifer: The largest groundwater deposit in the world, which lies under 8 Midwestern states (extensive portions in Kansa, Texas and Nebraska). Farmers in the High Plains rely on water from the Ogallala aquifer. Water in the O.A> takes hundreds or even thousands of years to renew after it is withdrawn to grow crops and raise cattle.← -← -South to North Water Transfer Project- China- Big investmentChannelization and the Environment- Deepening, Widening, Clearing, Lining existing stream channels - Purposes: flood control improve drainage, control erosion, improve navigation- Channelization is widespread in Urban Areasoex. Los Angeles River- Negative Impacts of Channelization?oHabitat ChangesPools, Rapids, SedimentoLoss of ShadingMore severe temperature fluctuations- Loss of Wetlands- Increased FloodingoDuring PrecipitationsoDownstream of channelization oCommon in LA- Aesthetic Degradation←← Effect of Urbanization on Stormflow Timing←← Biological Diversity, Biogeography and Conservation- Biodiversity has become a measurement for the success/failure of conservation efforts- Genetic Diversity the “Raw Material” needed for adaptation/evolution.- Interconnected: The loss of one species in a community may affect other species and the working of that communityPatterns of Biodiversity- Global Scale: Plant Biodiversity greatest in the Tropics/Low LatitudesoWhy- Greater solar energy, which will create more biodiversity, greater primary productivity in the tropics←← Biodiversity “Hot Spots”- Global “Hot Spots”- Across the global- Tend to see them in the tropics because of greater primary productivity- CA is higher in animal biodiversity Factors that tend to Promote Biodiversity- A physically diverse habitatoMany nichese.g. Multiple Canopies in Tropical Rainforests- Altitudinal Diversity - e.g. Southwest Chinaohot spots: river areas b/c as you move from West to East thereare mountain ranges and river basins oEach river basin has its own unique biodiversity- Moderate amounts of DisturbanceoTemperature, Moisture, etcoChanges in the ecosystem via human activity, etc oDisturbances are bad for the ecosystem- E.g. Fire EcologyoCrown Fires vs. Ground FiresoProblems with Fire Suppression- Adaptations to Moderate Fire Disturbanceoe.g. Serotinous ConesoAfter a fire, the Seritinous cones have survived- Fire is necessary for certain communities to reproduce (ex: - High diversity at one Trophic Level can stimulate High Diversity in anotherohelps stimulate biodiversity in another level Factors that tend to reduce biodiversity- Extreme Environments -