Human-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件

Human Impact on Resources and Ecosystems Human Impact on Resources and 1 HIT Environmental Science Wang Xiuheng 2008What did we do?Human species exploit mineral resources and use natural ecosystemThey are altered We success because we have ability to change our surroundingsBut Human-Altered does not equate to“Better”What did we do?Human species e HIT Environmental Science Wang Xiuheng 2008Why does ecosystem matter?All life on earth,including human life,relies on Ecosystem services clean air,clean water renewable resources,etcFor the first time in history,human actions are influencing ecosystems at a global scale.The consequences for ecosystem services are poorly understoodWhy does ecosystem matter?All HIT Environmental Science Wang Xiuheng 2008Some“ecosystem services”purification of air and water mitigation of droughts and floods generation and preservation of soils and their fertility detoxification and decomposition of wastes pollination of crops and natural vegetation dispersal of seeds cycling and movement of nutrients.How much can we degrade an ecosystem,and still receive these services?Some“ecosystem services”pur HIT Environmental Science Wang Xiuheng 2008PollutionPollution-Anything released into the environment that affects an organisms survival and reproduction.Human people produce in large enough quantities that it interferes with our health or well-being.Old days:small pop.+simple manner=diluted natural waste,biodegradable Now:generated faster than it can be degraded.PollutionPollution-Anything Forms of pollution,from health concerns to annoyanceForms of pollution,from healt HIT Environmental Science Wang Xiuheng 2008Several factors determine the impact of a society on natural resources.Impact of a pop.=Pop.Size/Area occupied x Degree of technological developmentPopulation sizePopulation densityDegree of technological Development always underestimated,purchase from other part,effect in distant places.Several factors determine the HIT Environmental Science Wang Xiuheng 2008Throughout history,humans have sought technological solutions to combat ecosystem degradation.Short-term solutionsThroughout history,humans hav HIT Environmental Science Wang Xiuheng 2008Ecosystems Modified by Human UseAgriculturalRangelandsForests Aquatic Ecosystems Wilderness Species ExtinctionEcosystems Modified by Human U HIT Environmental Science Wang Xiuheng 2008Agriculture Ecosystem40%of the worlds land surface has been converted to cropland and permanent pasture.Remove original vegetation(what is it?),substituted by exotic domesticated crops and animals.Pop.Increase,more land or new tech?Agriculture Ecosystem40%of th HIT Environmental Science Wang Xiuheng 2008Forests EcosystemsForest serviceClimate modificationProtector of watershedDeforestationFor wood or land,lost of habitat or nicheExpose the soil to increase erosionTropical forest decrease 0.6%per year,temperate forest no significant change Forests EcosystemsForest servi HIT Environmental Science Wang Xiuheng 2008Human-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件 HIT Environmental Science Wang Xiuheng 2008Tropical deforestationThe loss of tropical rain forest creates local environmental problem of enormous magnitude,but for the worlds people the impacts,such as climate change,are long-term.Tropical deforestation HIT Environmental Science Wang Xiuheng 2008Forest managementClear cutting vs.patch-work clear cutting Reforestation Lumber company:fast growing hybrid trees plantation,only economic value.Exotic No diversityForest managementClear cutting HIT Environmental Science Wang Xiuheng 2008Rangeland EcosystemFrom arid and semiarid lands support grasses or shrubsDomesticated animals,exotic speciesSelective eating plant soeciesNative animals Overgrazing-desertification Rangeland EcosystemFrom arid a HIT Environmental Science Wang Xiuheng 2008Human-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件 HIT Environmental Science Wang Xiuheng 2008Desertification土壤荒漠化土壤荒漠化Overgrazing and miss-farming convert arid and semiarid area to deserts.The loss of vegetation increase erosion by wind and water.Desertification HIT Environmental Science Wang Xiuheng 2008Extinction500 million to 5-10 million,98%extinctionNatural selection,mostly to be extinct:Low pop.DensityFound in small areaSpecialized nicheLow reproductive rateExtinction500 million to 5-10 HIT Environmental Science Wang Xiuheng 2008Human Accelerated ExtinctionFood prey speciesOrnament animal skin,ivoryPest tiger,wolf Habitat alterationQuestion?Why worry?Human Accelerated ExtinctionFo HIT Environmental Science Wang Xiuheng 2008Human-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件 HIT Environmental Science Wang Xiuheng 2008Human Impacts on Marine Systems few systems can now be considered natural-all have been modified,even the deep oceans human activity has changed marine communities in 5 major waysglobal climate changeover-fishing of marine organismsinvasions of exotic specieschemical pollution and eutrophicationloss or alterations of physical habitatsHuman Impacts on Marine System HIT Environmental Science Wang Xiuheng 2008Over-Fishing fisheries exploitation changes marine ecosystems more rapidly and over large scales than most other effects leads to changes in:distribution and abundance of speciesbody size(size for reproduction)diversity of organisms in systemdynamics of food webs(loss of predators)Over-Fishing fisheries exploi HIT Environmental Science Wang Xiuheng 2008Human-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件 HIT Environmental Science Wang Xiuheng 2008Habitat Damage commercial fishing gears are often very destructive to habitats lost structure and features crucial for supporting fishery AND other components of the ecosystem in major regions of the world remote imagery shows every metre of seabed as being trawled multiple times now seeing declines in recruitment of many species that need habitat as nursery areaHabitat Damage commercial fisFig.p.95鱼类食物链污染鱼类食物链污染Lip cancer of bullhead,in some tributaries of the Great Lakes,may reach 84%Fig.p.95鱼类食物链污染Lip cancer of HIT Environmental Science Wang Xiuheng 2008Ecosystem Impacts fisheries often target top-level predatorshigh food and economic value(e.g.tuna)these species often have enormous impact on the rest of the ecosystemso-called KEYSTONE species historical removal from over-fishing now implicated in major ecosystem collapses including;coral reefstropical seagrass bedskelp forestsEcosystem Impacts fisheries o HIT Environmental Science Wang Xiuheng 2008aquaculture?Some Problems to be Solved clearing of coastal vegetation for fish farms(e.g.mangroves)pollution from fish farm runoffinput of diseases and nutrients introduction of new genetic stock intowild population strong dependency on wild-caught fish in order to provide food for aquacultureaquaculture?Some Problems to HIT Environmental Science Wang Xiuheng 2008Human-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件 HIT Environmental Science Wang Xiuheng 2008Cultural Eutrophication nutrients limiting to primary producers excessive loading of nutrients into waterbodies=cultural eutrophicationhuman and animal wasterunoff of fertilizersdeposition of nitrogen from industrial releases,car exhausts and direct industrial discharges most control attempts-point source non-point source releases important amountsCultural Eutrophication nutri HIT Environmental Science Wang Xiuheng 2008Nuisance Algal Blooms increased loading of nutrients to estuaries enhances frequency and intensity of nuisance algal blooms increased algal production does not translate to high secondary productionplants usually toxic or inedibleno fish,consume algaeNuisance Algal Blooms increas HIT Environmental Science Wang Xiuheng 2008Fig.5.19may involve toxic forms,release toxicant mortality of clams and fishanoxic in bottom waters,low DO-dead zones on bottom of estuariesFig.5.19may involve toxic for HIT Environmental Science Wang Xiuheng 2008 Natural ResourceStructures and processes that human can use for their own purposes but not create.Sunlight,metal,scenery,soil.Renewable resources:can be formed or regenerated by natural process.ie.Soil,forest;but not inexhaustibleNonrenewable resources:fossil fuel and mineral.Natural ResourceStructures an HIT Environmental Science Wang Xiuheng 2008Mineral ResourceFormed millions of years agoQuestion Break:What is it?Include and Characteristic in ChinaUneven distribution through out the worldinternational exchange Disproportionate shareN.A.5.1%world population,30%consumptionMineral ResourceFormed millio HIT Environmental Science Wang Xiuheng 2008Costs Associated With Resource ExploitationEconomic-monetary costs necessary to exploit the resourceEnergy-energy expended exploiting the resourceEnvironmental-environmental effect of resource exploitation(often deferred)Costs Associated With Resource HIT Environmental Science Wang Xiuheng 2008Question What kind of env.cost?Mine tailingVegetationErosionWater wastingUltimately converted to economic costs through buying energy and pollution controls.Question What kind of env.c HIT Environmental Science Wang Xiuheng 2008SummaryPollution is anything that interferes with health and well-being of living organisms.Grazing arid land for increased food production is short-sighted and destructive.We change natural ecosystems by replacing them with simplified ecosystems.As human population increases,we alter more ecosystems to feed ourselves.SummaryPollution is anything t HIT Environmental Science Wang Xiuheng 2008Summary cont.Most productive areas of the ocean are also the most influenced by humans.Extinction is a consequence of a changing environment-and humans are influencing/changing almost all the worlds ecosystems.Exotic species can cause environmental harm.Summary cont.Most productive a