Human ecology final week 10

Loss of biodiversity
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Terms in this set (42)
Loss of biodiversity
Most exceeded safe planetary operating space threshold; number 1 environmental problem; part of all ecosystems; part of all BGCs; part of all ecosystem free services
Extinction
All individuals of a group are dead; 3 levels - an entire species; a subspecies of a single species; a genetically unique population of a single species
Brunea hot spring snail biodiversity loss
Primary cause - overdraft of connected aquifer drying up streams; other causes - climate disruption; pollution of remaining habitat; genetic erosion due to inbreeding because of loss of so many individuals
Population
Group of organisms of the same species that live in an area
Community
All organisms of all species in an area (biotic part)
Ecosystem
Biotic + abiotic + processes parts
Genetic biodiversity
Genetic variation (differences) among individuals within a single species; 2 parts - within-population and among-population
Within-population genetic biodiversity
Genetic variation among individuals in the same population; process of natural selection; need many individuals within a population for natural selection; ensures species survival; adaptation to changing local conditions
Process of natural selection
Within-population genetic biodiversity; individuals with genes better adpated to current environmental conditions leave more offspring; increases fitness (survival and reproduction)
Among-population genetic biodiversity
Groups of populations of a species differ from one another genetically; geographic variation; if groups of populations are different enough, called subspecies; adaptation to different environmental conditions within the range; gives evolutionary and survival advantage to species
Geographic variationAmong-population genetic biodiversity; spatially oriented genetic variationSpecies biodiversityAll the species on Earth; most familiar level of biodiversity; we know less than 10% of life on this planetEcosystem biodiversityAll the ecosystems on earth; species are not randomly distributed; grasslands, forests, deserts, tundra, etc.; depends on biome, major natural processes, geologic history, specific biotic/abiotic/process componentsExtinction step 1Death of unnaturally high number of individuals in a population; need monitor numbers, not just presence; need monitor over time to detect trendsExtinction step 2Death of entire populations; if population or group of populations lost is genetically distinct, then its loss is an extinctionExtinction step 3Death of the species; if all populations lost, entire species is extinctExtinction cascadeSpecies interconnected; when one species goes extinct, other connected species in trouble; symbiotic relationships - mutualismBison grazingImportant natural disturbance process; keeps tallgrass prairie in different successional stages; loss of bison in Illinois (1830s); affected remaining tallgrass prairieExtinction trendsNaturally, extinction rate = speciation rate; human-caused extinction rate now 100-1,000 x normalExtinction globallyHow many species endangered or threatened; 13% of plants; 25% of mammals, including almost all species of felines, primates; 11% of birdsCauses of US extinctionAgriculture; land development; water development; common theme - conversion of natural ecosystems into human-made ecosystemsCauses of Illinois extinction#1 agriculture; human development; has some of the most endangered ecosystems in the world; tallgrass prairie, oak savanna woodland, wetlandsHabitat lossReasons for loss of Illinois biodiversity; prairie/wetlands replaced by corn, soybeans; also lost to developmentHabitat degradationReasons for loss of Illinois biodiversity; simplification (natural forest vs. tree farm); fragmentation (agriculture, development)Habitat fragmentationLarge, continuous area of habitat becomes habitat islands; decrease in area; increase in distanceBiotic impact of habitat fragmentationReduces number of species that can live there; exposed to edge effects - degrades quality of remaining habitatEnergy solutionsFracking, nuclear (fission or fusion) solar, shale oil, 'clean coal', wind, hydrogen gas, ethanol, natural gas, hydropower; technology might not be efficientDirect biodiversity benefitsFood; spices; dyes; wood; fibers; medicines; etc.; make life more comfortable; easier to measure economicallyBiotechnologyDepends on key natural resource - genes; genes are in genetically unique populations, subspecies, species; extinction removes genes foreverIndirect biodiversity benefitsEcosystem free services; biogeochemical cycles; oxygen production; climate habitability; soil formation; air-water purification; reduces severity of floods, fires; control disease; makes life and economics possible; harder to measure economically, so ignoredProvisioningEcosystem service; food; water; fiber; and fuelCulturalEcosystem service; spiritual; aesthetic; recreation; educationalRegulatingEcosystem service; climate control; flood control; soil retention; disease regulationSupportingEcosystem service; primary production and soil formationUS endangered species actVisionary law for protecting biodiversity; most under political attack; 'people vs. species'; 'jobs vs. environment'; really short-term profit vs. ecological sustainability; reason for any endangered species - issue that will affect humansConservation of biologyPreservation of biodiversity; maintenance of ecosystem function; two approaches - species and ecosystemSpecies approachConservation of biology; focus on preservation of each speciesSpecies approach limitationsConservation of biology; focus on the cute and cuddly instead of the small, the drab, and the 'ugly'; forces one to do species triage; tend to wait until species nearly terminalEcosystem approachConservation of biology; preserve entire ecosystem; means preserve many species at once; preserving abiotic, process components; size is criticalEcosystem approach limitationConservation of biology public has poor awareness of ecosystems; they focus better on speciesNumber of known native species in Illinois54,000Illinois rank in amount of native vegetation left49th