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Cheryl Maafoh

Cheryl Maafoh Scott Connelly Ecology 1000 1 February 2018 STUDY GUIDE EXAM #1 (40 MC questions) ***Bring a pencil and an eraser; scantron provided***

Introduction to Ecology ➢ What is ecology and why is it important? ○ Ecology - the scientific study of interactions between organisms and their environments (abiotic and biotic) that determine the distribution, abundance, and the impact of organisms ○ Environmental Science - the study of all aspects of the environment, including physical, chemical, and biological ■ Value-free - how ecological interactions are viewed ■ Environmental science can assign value to ecological problems; it includes economic value, politics, moral value, etc. ○ Ecology informs environmental science Population Growths and Limits ➢ Periods of Human Population Growth ○ Pre-Agricultural Period ■ Grew as humans expanded into new territories and developed new tools ■ People travelled/colonized on foot; population grew slowly ○ Agricultural Period ■ Stimulated human population growth ■ Population grew more rapidly; technological advances ■ Increase in life expectancy ○ Industrial Period ■ Increased food production and improved sanitation, nutrition,

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medical care ■ Population grew rapidly over 3yrs ➢ Changes in population ○ “N” - population size; ΔN = B + I - D - E ➢ Life-history Traits - characteristics between organisms ➢ Models ○ Exponential (Logistic) Growth ■ Used for populations with continuous reproduction and/or overlapping generations; ex. humans ○ Geometric Growth ■ Used for populations with reproductions occurring at discrete intervals; ex. birds, rabbits, animals with mating seasons ➢ Rate of Change in Populations

○

dN =rN dt

N T

dN =change∈ pop ¿ time dt r= per capita growthrate(exp)

rate of change in Population size (slope of the line)

=

contribution of each individual to x population growth

number of individuals in the population

○ What does this mean? ■ Pop growth is rapid (exponential) and independent of density ■ More resources used means less available and growth rate eventually slows to zero

➢ Birth Rate and Wealth

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○ Reasons for increased birth rates - necessity for labor (farm hands), high death rates, religion, contraception, healthcare ○ Wealth views - think about ways to distribute wealth ➢ Birth Rates ○ Higher birth rates among younger women shortens generation time leading to more children growing and reproducing leading to higher population growth rates ➢ Population & Age Structure ○ Projections and Trends ■ Baby boomers - medicare, social security, etc. ○ Life Tables - summarize age-specific schedules of survival fecundity (typically for females) in a convenient format including: ■ Age (x)

Probability of survival between

■ Number alive

mortality rate and fecundity (reprod. output)

➢ Cohort ○ A group of individuals of the same age-class Population Growths and Limits (2) ➢ Carrying Capacity ○ Population can exceed carrying capacity in short term; not in long term due to resource allocation ➢ Logistic Growth Curve ○ As time increases, population increases ■ Inflection point - point at which population begins to slow down ■ Exponential growth is not realistic in nature ➢ What types of factors control population growth ■ Density-dependent factors - influence population growth in accordance with population size; change births and deaths ● Resource availability, competition, disease, controllable ■ Density-independent factors - affect population growth regardless of population size

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● Temperature, precipitation, natural catastrophes ➢ Regulation - tendency of a population to decrease in size when above a certain level (ex. carrying capacity, or K) and increase in size below that level ○ Population regulation must be density-dependent

Ecosystem Services and Environmental Economics ➢ Ecological Footprint ○ Land needed to provide resources and assimilate waste ○ Ecological footprint of a population is determined by size and amount of resources used by each person ➢ Natural Capital ○ Range of natural resources provided by ecosystems ○ Ex. A tree is a natural capital that provides oxygen, timber, energy, fuel, food, etc. ➢ Interface Carpet Company Case Study ○ Methods of the company ■ Biomimicry - products can model nature; ex. geckos’ use of electric connection to “stick” on surfaces mimicked for glue ■ Natural sunlight through skylights ■ Heating and cooling of manufacturing facilities ➢ Welfare of humans depends on maintaining ecological system functions ○ Ecosystem Services - conditions and processes of natural ecosystems and species that provides some human value; ex. pollination by bees ○ Human goal is to live the most efficient life using an efficient and reasonable amount of resources

➢ Honeybee Decline ○ Colony Collapse Disorder (CCD) - detrimental for farmers and crop pollination

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○ Without pollination, numerous crops cannot grow and sustain a population ➢ Aral Sea Case Study ○ Decline in water resources due to damming of rivers that feed into lake ○ Left dry patch of land with huge salt deposits and toxins ○ Surrounding village area is essentially toxic for the residents ➢ Lake Victoria Case Study ○ Introduction of new fish species ■ Nile Perch Introduced in 1950s ■ Linked to extinction or near extinction of several hundred native fish species ■ Local fishermen pushed out by large commercial operations ■ Secondary consequences - forest loss due to tree clearing for firewood ○ Bycatch - non targeted species that get captured and discarded, often after they are dead ■ Ex. sea turtles caught in fishnets ■ Turtle Excluder Devices (TEDs) - trap door allows for turtles to escape nets, as well as other large miscatches ● Con - some of the acceptable catch escapes as well; prices of catch is in turn increased for the consumer ➢ Externalities - costs that companies do not directly pay and are not reflected in the price the consumer pays ○ Ex. associated diseases with the production of produce; environmental degradation

➢ Total Economic Value ○ Use Value ■ Direct Use Value - resources used directly; ex. tree for wood ■ Indirect Use Value - resources used indirectly; regulating

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services, food prevention, water purification ● Ex. mangrove trees planted in India unintentionally protected from tsunamis ○ Nonuse Value ■ Bequest Value - future generations’ possible use ● Ex. right of children to enjoy clean air ■ Existence Value - right to exist; ex. services that support endangered species; ex. just because you don’t buy from a particular seller doesn’t mean he has no right to exist ○ Use and Nonuse Value ■ Option Value ➢ Sustainable Development - meet present needs without preventing future generations from meeting their needs ○ Inefficient Transactions - unregulated exchange of goods or services that carry externalities generate prices that do not reflect the full social cost or benefit of their transactions ○ Market Failure - the result of marketplace inefficiency ○ Ecological Market Failure - can result from the overuse of renewable resources ➢ Green businesses can be profitable if consumers are willing to pay more Ecosystem Services: Water ➢ Global Water Statistics ○ 10% of Earth's people do not have enough water; nearly 40% must drink and bathe in contaminated water ○ Freshwater is a limited resource and we are using it faster than it can be replenished ○ Takes several gallons of water to make basic consumer products ○ ⅓, more than 2 billion, people lack access to clean water ○ In many developing nations, people use surface level, contaminated water

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○ Water falling back to earth is not readily available to most of the planet’s populations ➢ Hydrological Cycle ○ Linkage of all marine and freshwater aquatic environments; process of water travels from atmosphere → earth → atmosphere ○ Water is not lost from planet, just reallocated ○ Toxins may be transported, picked up, or eliminated ➢ Watershed - the land area surrounding a body of water over which water (such as rain) could flow and potentially enter that body of water ➢ Water Definitions ○ Aquifer - an underground region of soil or porous rock which is saturated with water ○ Infiltration - the process of water (rain or snow melting) soaking into the ground ○ Water table - top of the underground water; saturated region; where wells tap into; changes during seasons and due to rate of pumping ○ Cone of Depression - must search deeper to reach water table after diminishing water funds ○ Saltwater Intrusion - pulling out so much freshwater that saltwater begins to seep in; varies based on proximity to ocean and lower water tables ➢ Georgia Water Source ○ Athens receives water from the Oconee River ○ Population in Atlanta and surrounding areas is rapidly growing; not enough water to sustain this growth ○ Water shortage solution ■ Dam rivers and create reservoirs; ex. damming of Buford River to create the Lake Lanier reservoir ● Provides: ○ A source of freshwater

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○ Flood control ○ Electricity production ○ Boating, fishing, and other recreation ● Downsides to damming ○ Enormous potential for evaporation, especially during the summer when we need water the most ■ Using new water-efficient technologies ■ Buying less stuff and using less energy ➢ Tri-State Water Wars Case Study ○ The ACT and ACF Basins - water wars between GA, AL, and FL; whoever controls the source is in power

■ Metro Atlanta receives 99% of this supply ■ Groundwater cannot be major source instead because of bedrock, like Stone Mtn. granite ○ Tri-State War ■ Georgia - upstream user; need to support growing population ■ Alabama - downstream user; receives water with concentrated

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sewage because of GA waste ■ Florida - downstream user; water necessary for shellfish industry ➢ Three Gorges Dam Case Study ○ Massive dam across the Yangtze River in China; size changed the earth’s center of gravity which in turn slightly increased earth’s speed ○ Caused landslides and pollution, causing 1.2 million people to relocate ○ Freshwater fish were affected ○ Built on seismic fault, so there is earthquake potential ➢ What We Need to Do ○ Conservation ○ Realistic Pricing ➢ Balancing Georgia Water Budget ○ Increase reserves ■ Likely not applicable because of water wars ○ Reduce withdrawals ■ Recycling; greywater ■ Landscape architecture ○ Permeable surfaces ■ Allows water to seep into ground rather than flowing downhill; ex. can be implemented into parking lots, created from recycled materials such as tire rubber; walkway made from cement tiles with grassy grooves

➢ Stream Pollution ○ Source can be hard to pinpoint; some pollution is easier, such as that coming from sewage treatment plants ○ Point vs Nonpoint sources of pollution ■ Point sources - source is known ■ Nonpoint sources - exact cause of pollution is unknown; variety

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○ Mississippi Watershed ■ Largest watershed in US ■ Largely used for agriculture, with various pesticides and fertilizers used ● Pollutions leaks into rivers and flows down to the Gulf of Mexico ○ Cuyahoga River - caught on fire because of extreme pollution ➢ The Dead Zone Case Study ○ Low oxygen at lower levels is caused by the increase in nutrients (nitrogen phosphorus) in the water, leading to increase in phytoplankton. When phytoplankton run out of nutrients, they sink to the bottom and decompose. Decomposition process uses significant amounts of oxygen. ○ Lack of oxygen also causes shrimp and fish to die or move locations which in turn damages the fishing industry ○ This area is known as a hypoxic, or “dead”, zone; water is depleted of oxygen ➢ Riparian Area ○ Boundary between what is in the water and what is terrestrial ○ Need to be protected by planting vegetated buffer zones that slow runoff and give rainwater time to sink into the ground ○ Part purposes ■ Plants - nutrient sinks; store nutrients in their tissues ■ Plant roots - stabilize banks and prevent erosion ■ Ground vegetation - slows runoff and allows water to soak into the ground ■ Leaf litter - provides food as a main nutrient for nitrifying bacteria and other life ■ Shade - cooler water can hold more oxygen than warmer water ➢ Advances at the National Level

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○ Clean Water Act (1972) - established the pollution standards and set in motion guidelines for the best management practices to reduce aquatic pollution

Agriculture, Pesticides, and Energetics ➢ Agricultural Practices ○ With about 30,000 edible plants, 15 plant and 8 animal species provide 90% of food ○ 35% of arable land used for food production ○ Ways to produce food ■ Traditional - human labor and draft animals used to produce food for the family ● Shifting cultivation in tropical forests ● Nomadic livestock herding ● Swidden - cutting down trees or area of land and burning them in order to clear land for planting ○ Two purposes: remove debris and clear land for planting; Ash is high in minerals which promotes plant growth ○ If land is allowed to naturally regenerate, sustainable growth is possible. Otherwise, sufficient amount of time between harvests must pass in order for the resources to recover ■ Industrialized - large inputs of energy; fossil fuels, fertilizers, irrigation, and pesticides ● Primarily in developed countries ● Large expanses of land ● Most, if not all, organic material removed ● Tilling exposes the soil to wind, water, and erosion ● Lost nutrient cycling; large quantities of chemical

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fertilizers must be added to maintain productivity ● Monoculture is susceptible to pests and plant diseases ➢ The Green Revolution ○ Research and development if technology that greatly increased agricultural production worldwide, 1930s-1970s ○ Increases in crop yields due to ■ New, high-yielding varieties of cereals; ex. wheat, rice ■ Higher uses of chemical fertilizers and pesticides ■ Increased irrigation and mechanization ➢ Tradeoff Between Sustainability and Productivity ○ Production increase comes at a cost of energetic input ○ Ratio of energy output between Mexico and US corn production ■ Much higher for traditional methods than industrial ■ Energy output is 17 times as much in an industrialized country ■ Due to externalities, chemical uses, etc. ○ Produce greater crop yield, but at the cost of significant externalities ○ World grain harvested per capita has decreased as nitrogen fertilizer use has increased; reason why per capita has decreased

○ Patterns of risk for nitrate (fertilizers) and other contamination ■ Birth defects, cancer, blue baby syndrome (lack of oxygen) ➢ The Haber Process ○ How to get nitrogen in non usable form to a way that can be utilized by crops ○ Process - main industrial procedure for the production of ammonia (i.e. fertilizer) today ■ Converts atmospheric nitrogen (N2) to ammonia (NH3), using 3-5% of the world’s natural gas production in the process ■ In combination with pesticides, these nitrogen fertilizers have

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quadrupled the productivity of agricultural land ➢ Chesapeake Bay Case Study ○ Watershed is bringing down pollution ○ People are used to the damaged ecosystem because they grew up with it ○ People want government interference to promote change ➢ Managing Agricultural Pests ○ About 40% of all agriculture consumed by pests and disease ○ DDT - pesticide that kills mosquitoes, but did not work on all insect pests ■ Long-lived compound; not easily broken down ■ Attached to and retained in body fats ■ Bioaccumulation - product accumulates in microorganisms in water → small fish → large fish → DDT fish eating birds

The Tragedy of the Commons Reading ➢ Intro ○

Technical Solution - one that requires a change only in the techniques of the natural sciences, demanding little or nothing in the way of change in human values or ideas of morality ➢ What Shall We Maximize? ○ Malthus ■ Stated the natural growth of population is exponential ■ This means the per-capita share of the world's goods must decrease ○ Reality is space and resources are finite ○ A finite world can support only a finite population ■ Therefore, population growth must eventually equal zero ○ Two reasons why Bentham’s idea of “the greatest good for the greatest number” is impossible ■ von Neumann-Morgenstern (Theorem) - It is not mathematically possible to maximize for two (or more) variables at the same time

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■

To live, any organism must have a source of energy that is utilized for two purposes ● Maintenance ○ Human maintenance requires about 1600 kilocalories a day; more than that which is necessary to stay alive would lend to work calories ● Work ○ Work calories - excess energy used to perform actions or activities; ex. going on fancy dinners or vacations; sports; music ○ To maximize population, work calories must approach zero per person ○ The optimum population is less than the maximum ■ Because of the immense amount of analysis to determine the maximum, the optimum level is unknown ■ Incommensurable - comparing one good with another is impossible because goods are incommensurable; they cannot be compared ■ In real life incommensurables are commensurable ● Only a criterion of judgment and a system of weighting are needed ● In nature the criterion is survival; natural selection commensurates the incommensurables ○ A positive growth rate might be taken as evidence that a population is below its optimum ○ Adam Smith The Wealth of Nations (1776) - discusses the invisible hand, the unobservable market force that helps the demand and supply of goods in a free market to reach equilibrium automatically ■ Continues the present policy of laissez faire in reproduction; ➢ Tragedy of Freedom in a Commons ○ Adding one more animal to a herd ■ The positive component is a function of the increment of one animal. Since the herdsman receives all the proceeds from the sale of the additional animal, the positive utility is nearly + 1 ■ The negative component is a function of the additional overgrazing created by one more animal. Since, however, the effects of overgrazing are shared by all the herdsmen, the negative utility for any particular decision making herdsman is only a fraction of - 1 ○ Adding together the component partial utilities, the rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd ■ This is the conclusion reached by every rational herdsman sharing a commons ■ The tragedy - each man is locked into a system that compels him to increase his herd without limit in a world that is limited ○ Options of change - reallocation of space

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➢ Pollution ○...