BIOL 1060 1st EditionExam # 3 Study Guide Rachel Carson- The author of Silent Spring- Heightened awareness of DDT and pesticidesGarrett Hardin - Tragedy of the commonsEnvironmental Ethics- field of ethics that considers the moral basis of environmental responsibility Intrinsic/extrinsic value•Environmental ethics differ–Intrinsic value•People, organisms, or objects are valued–Instrumental value•Things valued as a means to something elseAnthropocentric- Intrinsic value: humans only- Instrumental value: everything else that helps humansBiocentric- (centered on all living things)- Intrinsic value: all living thingsEcocentric- (value within them)- Intrinsic value: communities and ecosystems - Deep ecology movementPreservationist–Protect nature because all life deserves respect–John Muir (founded Sierra Club)•Fought for National Parks–Preservationist view•Parks/public land should preserve wild nature in pristine state–All hands off!Conservationist-Utilitarian/Conservationist- Value natural resources for their usefulness- Roosevelt-Conservationist view- Should be used and managed sustainably to provide the greatest benefit to the greatest number of people–Timber, water, etc. may be used sustainablyUtilitarian- greatest good for most peopleDeep ecology•Deep Ecology Worldview –All species have an equal worth to humansEnvironmental Justice- the right of every criticism regarding of age, race and gender, social class or other factor to adequate protection from environmental hazards Intrinsic value- People, organisms, or objects are valuedInstrumental value- Things valued as a means to something elseThe Tragedy of the Commons- Solving environmental problems is result of struggle between short term VS. long term- unregulated exploitation causes resources depletion China- One child policy- in 1970, china had 790 million people in starvation, so government made 1 child policy- limits families to having only one child per parentsCarrying capacity- as we near carrying capacity the birth rates drop and the death rates increaseReducing human population growth- Counseling- Educationo Family planningEX: One child policy in ChinaZero population growth- The fourth stage of the demographic transition, sometimes called the stability transition, is characterized by a low birth rate and a low death rate. During the stability transition, the birth rate is nearly equal to the death rate. This stage is characterized by zero population growth oreven a decline in population.Using the Rule of 70- Always take your number and 70 and divide by it- 70/R=DT- 70/DT=RGreen Revolution- improved plant breeding and techniques- use of modern fertilization and pesticides- agriculture productivity increase- uses technologies to dramatically increase crop output Commonly grown crops- Corn- Wheat Aquaculture- agriculture of fishLivestock/CAFOs- CAFO-hog farms. Hogs are kept to grow to eventually be slaughtered tosell- Livestock- Animals people keep to slaughter and eatPest control- Keeps away pest (positive)- Can harm people, and plants as well (negative)DDT•DDT was developed and was effective in controlling mosquitoes that vectored malaria•DDT affects wildlife–Reduced use, banned in some regionsIPM- Integrated Pest Control- The combination of all 3 pest controls, designed to manage pests and minimize environmental damageSoil Layers/erosionWater Erosion: Irrigation water flowing through the exposed soil of this cornfield has cut into the ground and carried away sediments and nutrients.Preventing Soil ErosionPlanting crops in rows that follow the contours of hills causes water to flow across the rows and minimizes erosion. Here, strips of perennial alfalfa (green) alternate with strips of annual corn (gold) to further limit erosion.Cover Crop (example):A wheat cover crop between the rows of immature watermelon plants (green) prevents erosion and protects the young plants from blowing sand.American Dust Bowl- Great plains has low precipitation and is subject to drought- Major drought from 1930 to 1937 causing no natural vegetation roots to hold soil in place- Wind blew soil as far east to NYC and DC- Farmers went bankrupt Desertification- degradation of once fertile rangeland, agricultural land, or tropical dry forest into nonproductive desertGreen Revolution –Benefits and drawbacks- Benefits: Reduce pressure to convert more natural land to cropland- Drawbacks: Pollution and reduced biodiversity, more likely crop diseasebioaccumulation •The buildup of a persistent toxic substance in an organism’s body, often in fatty tissues–Synthetic chemical do not metabolize well–They remain in the body for extended periods of timebiomagnification •The increased concentration of toxic chemicals in the tissues of organisms that are at higher levels in food webs•Diagram (right) is example of biomagnification of DDTbody burden •Toxin transport and fate•Impact of certain toxins depends on movement through environment–Persistence–Volatility–Solubility in water–Uptake and fate in other organisms•Bioaccumulation•Body burden–Persistent organic pollutants (POPs)endocrine disruption/atrazine •A chemical that mimics or interferes with the actions of the endocrine system in humans and wildlife•Examples include:–PCBs, Dioxins–Heavy metals - lead and mercury–DDT•Animals exposed to these chemicals have altered reproductive development and are often sterile•Theo Colburn wrote Our Stolen Future in 1996.–Synthetic chemicals may be altering hormones.–This book integrated scientific work from various fields.•Infertility and hormonally related cancers are increasing–Breast cancer and testicular cancer•Phthalates have been implicated as potential endocrine disrupters–Common ingredient in: cosmetics, fragrances, nail polish, medication, toys, food packaging Evidence for hormone disruption•Frogs also have gonadal abnormalities.–Male frogs exposed to very low levels of atrazine became feminized.–Levels were below EPA standards for human health.DDT •Major issues in Africa•20% of children under 5 years old died from malaria•DDT was developed and was effective in controlling mosquitoes that vectored malaria•DDT affects wildlife–Reduced use, banned in some regionsEffects of lead, mercury•A chemical that mimics or interferes with the actions of the endocrine system in humans and wildlife•Examples include:–PCBs, Dioxins–Heavy metals - lead