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Terms: Environment, ecosystem, ecology, is an environmentalist the same thing as an ecologist? Ecologist - Scientist who impartially examines the interactions among living things and the environment. Environmentalist – advocate for the environment. Environment – entire package of external factors (living and nonliving) affecting an organism. Ecosystem – the environment in a specific geographic location. Ecology – the study of organisms and their role in the environment. Basic facts on the human population of the world (number of people, annual increases) and of the USA. World Populations: 6.7 billion US population: 305 million Rate of increase in world population: 80 million per year. Basic facts on extinction crisis: number of species on earth (known and estimated), number of extinctions estimated to occur annually. causes of population decline are: loss and alteration of habitat, over-exploitation, competition with exotic species Historical rate of extinction: 1 per million per year Current rate of extinction : 1 per thousand per year Scientific method: hypothesis and experiments. Science and “proof.” Why is it difficult to apply the scientific method to environmental issues? Scientific method: identify a question, propose an answer, form that answer into a hypothesis that is testable, predict the outcome, do the experiment, then reject or revise the hypothesis if the results if the prediction is not supported. No hypothesis is ever “proved.” Hypotheses are only disproved. This is because laboratories are not the real world, and another hypothesis could give the same results. Politics & the environment: know the meaning of these phrases: public perception makes political reality, fragmentation of responsibility, incremental decision making. Politics is actions taken by groups to address problems not solvable by individuals. Public perception makes public reality means that once the public grows concerned with an issue, the political side will step in and address the issue, therefore public perception of an issue will cause the politicians to make it reality. Fragmentation of responsibility is the departments and organizations that work beneath the president to handle different precautions. For example, the department of agriculture handles soil conservation and forestry, while the department of labor handles occupational health. Economics and the environment: ideal free markets and government regulation. Positive and negative externalities. Estimated value of ecosystem services worldwide. The “tragedy of the commons.” Free market – set by supply and demand, interactions between individuals. No free market exists because there are costs and benefits that are not reflected in the price. Internal costs – are expenses borne by those using a resource
External costs – expenses borne by someone other than the person using the resource. Environmental train wrecks – for each example, know where they are found, what biome and why they are a train wreck. Spotted Owl, Marbled Murrelet, Salmon, Red-cockaded Woodpecker, California Gnatcatcher, Stephen’s kangaroo rat. Environmental train wrecks - complex situations involving environmental problems where the scientific, political and economic issues involved are so controversial that the problem has been allowed to fester until a crisis has arisen.
1. Spotted owl - live in old growth forests in the pacific northwest. Problem is due to timber harvest. Marbled Murrelet - is a bird that is a relative of the puffin, and lives along the coastlines of Pacific Northwest. They nest on tree branches of very old trees. Salmon - are fish that need clear, cold water streams with clean gravel beds to lay their eggs. The healthiest fish populations are those that breed in streams that go through undisturbed old growth forest.
- Thus, both the murrelet and salmon need the same old-growth forests as do the Spotted Owls.
- Timber industry creates jobs, but so does fishing salmon, so now becomes an issue of jobs vs. jobs.
- Solution: “Forest Summit” with the timber industry, fishing industry, recreation groups, environmental groups, everyone with a stake attending. They hammered out a regional plan for how the forests would be used. The Forest Plan protected some forests for wildlife, while opening others for the timber industry and protected water quality for the fish. 2. Red-cockaded woodpecker - This woodpecker is found in pine forests across the South from North Carolina to Texas.
- The woodpecker is restricted to the oldest forests.
- Just like in the Pacific Northwest, the oldest pine trees in the SE are the most valuable to the timber industry.
- Solution: The U.S. Forest Service has established agreements with the timber industry in the southeast, using a concept called “ Habitat Conservation Plans .” Under a HCP, private industry voluntarily agrees to set aside some of their lands for conservation. The government, in turn, agrees to allow the industry to proceed with its own planning and needs on other parts of its property. 3. Stephen’s kangaroo rat and California Gnatcatcher - found only in California coastal scrub community - a shrubby habitat dominated by sage and other low plants found from Los Angeles south to San Diego. Train wreck concerns habitat loss. 95% of the coastal scrub has been turned into housing developments.
- Solution: The U.S. Department of the Interior is developing HCPs with each county. These plans set aside important areas of natural habitat, releasing other areas for development. Because the HCP is being developed on a county-wide basis, individual developers are not restricted as long as their plans conform to the overall county plan.
agricultural conversion. Site of many conflicts between farmers and ranchers. Now site of conflict between farmers/developers and conservationists. Especially important on federal land in west. Scrap areas (e.g. railroad right-ofways, cemetaries, power line right-ofways). Many rare and endangered species can be found in these patches – small nature areas. Chaparral – thick schrub lands subject to intense fires. Northern coast of mediterraneian southern California. Stable annual climate; so heavily settled. Southern California is always burning up or caught in a mudslide. Dry in summer, most rainfall falls in short winter wet season. Fires common, schrubs fire-adapted and must burn to reproduce. Development vs. wildlife (California gnatcatcher, stephen’s kangaroos rat) Tropical dry forest (scrub) – cover huge areas of tropics. They hold lots of plants and animals. Extensive dry season in which leaves drop. Trees flower during dry season so that they are not destroyed by the rain. Tree have huge thorns. Habitats are rapidly being converted to farming or urban use. May be more endangered than rain forests. Tropical rain forests – most diverse forest in the world. usually extremely wet, but also has dry season. Poor soil because nutrients are leached out by excessive rain. Agriculture fails just 1- years after clearing forest. Deserts – all are very dry, but there are two types, warm and cold. Drought resistant succulents (e.g. cacti). Mountain ranges often block flow of water from precipitation or rivers (rain shadow). Thus, evaporation exceeds precipitation. Plants and animals respond dynamically to different weather conditions (may skip breeding season if no rainfall). Fragile systems subject to large impacts by disturbance (like tundra). Subject to abuse by off-road vehicles. Native plants (cacti) often stolen for landscaping. Deserts are often used for dumps (often viewed as valueless land). Primary & secondary succession. Climax community, disturbance climax, natural catastrophes. Primary succession – when algae and other plants begin to normalize an area of soil and rock making it possible for plant life to grow. Secondary succession – occurs on rock and soil that previously supported the growth of plant life before a disturbance of some sort destroyed the plant life. Climax community – is a biological community of plants and animals, which through the process of ecological succession, and the development of vegetation in an area over time, has reached a steady state. Disturbance climax - Catastrophes : larger, rare environmental events can affect populations of any size (hurricanes, forest fires, disease outbreak, etc.) Population ecology: Population demography: BIDE factors, growth rates, dispersal. Population structure, age pyramid, cohort. Population growth: linear, exponential, logistic. r- and K-selected species.
Landscape ecology. Definition of landscape, metapopulation, sources and sinks. Conservation implications of metapopulations and source/sink. Multiple use, wise use. Arctic NWR – what does each side want in this controversy? Landscape – complex mosaic of habitat patches surrounding an area of interest. Metapopulation – a set of patches (each with subpopulations) linked by dispersal of individuals. Not every patch may be occupied every year, therefore, empty patches may still be important to protect. Sources – subpopulations (or habitat patches) where local production is enough to maintain local populations and produce dispersers.sources are most important to protect because they hold the best quality of habitat patches. Sinks – subpopulations (or habitat patches) where local production is not enough to maintain populations. Renewable versus sustainable resource use. Common forestry practices (clearcutting, selection cutting, even-aged vs. uneven-aged forestry, rotation length). Grazing on public versus private property. Effect on riparian zones. Grazing leases as private property and management of public grazing lands. Bureau of Land Management. Fire management. Prescribed burns, crown fire, ground fire. 10 o’clock fire policy versus currentPolicy. Ground fires – relatively cool. They burn litter and ground layer. Crown fire – relatively hot, can kill mature trees. Prescribed burns – fires set by managers to control possibility of uncontrolled burns. 10 o’clock fire policy – put out any fire by 10 am the next morning. Current policy – let fires in natural areas burn unless they threaten human life and property. Parks and wilderness. National parks, national monuments: how are they created. Examples of problems faced by park managers. Brucellosis. Wilderness definition. Mining terms: types of fossil fuels, surface versus subsurface mining. Tailings, overburden, ore. Land reclamation, acid mine drainage, ground subsidence. Fossil fuels – any naturally occurring fuel of an organic nature, such as coal, crude oil and natural gas. Surface mining – when coal lies near the surface and can be extracted by removing the covering layers of rock and soil. Subsurface mining – the extracting ore or minerals from beneath the Earth’s surface. Tailings – waste rock left over after a mineral has been extracted. Overburden – layers of soil and rock covering a coal seam. Overburden is removed prior to surface mining and replaced after the coal is taken from the seam. Ore – a mineral that contains metal that is valuable enough to be mined. Land reclamation – the process of stabilizing disturbed land surfaces. Surface mining of coal is responsible for ½ of the disturbed land in the US. Acid mine drainage – the outflow of acidic water from metal or coal mines.
Solar power: active vs. passive, benefits and costs. Solar panels and photovoltaic cells. Nuclear fission, nuclear fusion. How long must nuclear waste be stored? Halflife. Solar Energy – the amount of solar energy that reaches earth’s surface annually is 10,000 times greater than all commercial energy used. It is renewable and free of cost, no delivery necessary. Solar energy is intermittent though, because the amount changes with cloud cover, time of day, and season.
- Passive solar system – allows sunlight to pass into living space and provide heat - Active solar system – converts sun energy to heat or electricity. Solar panels: usually absorb sun light and convert to heat. Photovoltaic cells – absorb sun light and convert to electricity. Nuclear Power – has nuclear fission which is the releasing of energy by splitting large atoms into smaller atoms. Nuclear fusion is the releasing of energy by combining (fusing) smaller atoms into large ones. All of our nuclear power comes from fission. - Advantages: extremely powerful source of energy, no greenhouse gases produced, and no sulfur compounds, ozone, etc. - Problems: tailings left over after mining uranium are toxic. Famous accidents like Three Mile Island, Pennsylvania, or Chernobyl, Ukraine. Nuclear waste half lives measure as over ten thousand years. 6-30 years of supply is minable if production is increased. Conservation Biology. Definition of biodiversity & reasons for saving it. Definitions of aesthetic and intrinsic values. Taxol & teosinte as examples of products from biodiversity. Economic values other than product value. Ecosystem services. Conservation biology: the study of threatened organisms and the process of extinction. Biodiversity: is the number of species present in an area, the genetic variation they contain, and the roles they plan in the ecosystem. Aesthetic intrinsic values – biodiversity is valuable because natural places are unique and beautiful. Organisms have a right to live just because they exist. Taxol- a new drug developed from the Pacific yew tree is being used to treat ovarian cancer. Taxol is threatened by destruction of old growth forests. Teosinte - a wild relative of corn discovered in Mexico during the 1960s, is resistant to four of the eight major diseases that kill corn in the United States. This could be useful in genetic engineering.
Economic values other than product value: recreational fishing, hunting, bird watching, whale watching, camping, ecotourism, genetic diversity. Global versus local extinction. Current versus historical extinction rates. 4 general causes of extinction & population sizes associated with each problem. Dusky Seaside Sparrow – why did it go extinct? Global extinction – the loss of all members of a species worldwide. Local extinction – the loss of one population of a species in a certain area. Historical rates of extinction are one species per million per year. Current rates of extinction are one species per thousand per year. 4 causes of extinction are:
- The loss of genetic variation – caused by lack of suitable mates and other problems in small populations of 50 or less (inbreeding). - Demographic stochasticity – random changes in characteristics of small populations of 50 or less (sex ratio, survival rates, breeding success, etc.) - Environmental stochasticity: random changes in local environment affect small populations of 500 or less (late frost or wet spring). - Catastrophes: larger, rare environmental events can affect populations of any size (hurricanes, forest fires, disease outbreak, etc.) Passenger pigeons - The primary factor emerged when pigeon meat was commercialized as a cheap food. Dusky seaside pigeons – found only in Florida, lived in estuaries (salt marshes near coast). They went extinct in 1986 because of pollution and pesticides. Causes of populations to decline and go extinct: over-exploitation, competition with exotic species, loss of alternation of habitat. Habitat fragmentation is reduction of a dominant habitat in a land scale down to small patches. Creates smaller populations which can lead to local extinctions. Habitat fragmentation – what are the major negative effects. Edge effects: physical & biological (predation and nest parasitism). Area-sensitive species, forest-interior species. Habitat fragmentation is reduction of a dominant habitat in a land scale down to small patches. Creates smaller populations which can lead to local extinctions.
Population viability analysis. 50/500 rule. Minimum viable populations. “Managing for the minimum.” Grizzly bears, desert tortoise – what techniques were used in each case? What was learned? 50/500 rule – 50 pairs are probably safe from genetic and demographic problems. 500 pairs are probably safe from random environmental events. Minimum viable populations - “What is the smallest population of this species that would probably not go extinct in the near future?” Numbers seem too exact: Is there really a “magic number” — a population size that makes an endangered species safe? Managing for the minimum – problem is that this leaves no room for error. Population viability analysis – similar approach as MVP, but eliminates the emphasis on minimum population. What is the probability that a species will survive for a certain period of time? Problem is that there are no standards on how these models are put together. Desert tortoise example – can killing ravens help desert tortoises? Endangered Species Act. Definitions of endangered and threatened species. Recovery plan, “listing,” critical habitat. Basic facts on number of listed species, where located, number recovered. Facts associated with each of the 5 ESA complaints (which ones are valid, which ones are not, why). Laws (such as the ESA) vs. rules: what are they, and who makes them? Endangered species act:
- 1966 – Endangered species protection act (a list of endangered species is made, but little protection). - 1973 – Endangered species act (has all the teeth). Reauthorized every 5 years, but last done in 1992. Requires all federal agencies and departments to do all methods and procedures which are necessary to bring any endangered or threatened species to the point at which this act is no longer necessary. Endangered species –is any species which is in danger of extinction throughout all or a part of its range. Threatened species – is any species likely to become endangered within the foreseeable future throughout all or a portion of its range. Listing – the decision to place a species on the list. Final decision made my secretary of interior or commerce. Recovery team – a group of scientists and managers formed after a species is listed. Recovery plan – specific, detailed plan to recover the species (recover = get it off the list, also called delisting). Critical habitat – the most important pieces of habitat needed to protect the species.
Facts on listed species:
- There are currently 1262 species native to the USA on the list. 558 foreign species are also listed. About 1000 (79%) of listed species have a recovery plan. About 200 have a designated critical habitat. - Hawaii, California, Alabama, and Florida have the most listed species. - 20 species have been delisted. Common criticisms:
- Concentrates too much on population.
- Species really not so rare.
- Too inflexible.
- Decision to list “unbalanced.”
- Too expensive. Ecotoxicology. Heavy metals, pesticides, bioaccumulation. Measures of toxicity. Atrazine, endocrine distruptors. Ecotoxicology is the study of poisonous compounds in the environment. Heavy metals that are toxic substances include – mercury, cadmium, lead, arsenic, nickel, etc. These all are toxins that are of particular concern in ecotox studies. Measures of toxicity – LC50 (lethal concentration 50) is the smallest concentration in water that kills 50% of exposed individuals. LD50 (lethal dose 50) is the smallest dose that kills 50% of exposed individuals. NOEL (no observed effect level) is the highest dose that produces no toxic effect. Bioaccumulation – effects get bigger as toxin moves higher in the food chain. First evidence of problem may appear with top predators such as bald eagles or ospreys. - Bioaccumulation 1 – study in England monitored presence of heavy metals using road kills. - Bioaccumulation 2 – studied herons. Results show that most toxins decreased with time, except mercury in aquatic systems. Atrazine – common farm herbicide used to kill weeds. Studies in 2004 show atrazine affected from at very low doses. Multiple sex organs in single frog. Endocrine disruptors – class of compounds that interfere with reproductive hormones. Some pesticides make males more feminized (males cannot breed). Restoration ecology. Kissimmee River, FL. Problems with restoring ecosystems.
Malnutrition – diets with less than minimum requirements of a nutrient (protein, vitamins, etc.) iron deficiency is the most common dietary imbalance in the world; it leads to anemia. Some good sources of iron are red meat, eggs, legumes, and green vegetables. Famine – characterized by large scale food shortages, massive starvation, social disruption, and economic chaos. Environmental conditions are immediate trigger, but politics and economics are often underlying problems. Aid from rich countries often distributes surplus commodities and produces feeling of generosity. Food camps have serious drawback: stress and crowding, lack of sanitation, close contact to epidemic diseases. Ways of increasing good supply:
- Greater productivity. Better crops, better techniques, genetic engineering. - Climate change affects production of food. This may be caused by amounts of precipitation in areas. Ways to ensure your crops will grow: farmers can shift farm operations to areas with enough rain, use more irrigation, and develop drought resistant crops. Slash and burn agriculture – cultivate more land but the best land is already in use. Also, losing farmland in many areas. Plus need land for wildlife, human housing, etc. Green revolution – spread of new varieties around the world. Genetic engineering: gene splicing, cloning – know basics and differences between 2 techniques. Potential problems / benefits of each. Gene splicing – method of placing a gene from one organism into a different one, creating the desired trait in the second organism. Often used a bacteria or a virus as a vector. - Problems : crop species may hybridize with weedy species in same field to make a super weed. GM variety may escape, and outcompete the native species altogether. Gene cloning – removal of whole DNA of one organism, and replacing it with the DNA of another. The result is an exact copy of the original organism; “clones.” - Problems : not sure if cloned animals will have the same health and lifespan as normal animals, reduces, genetic variation, and will cloning animals lead to cloning humans? Purdue and the environment. Where do Purdue’s electricity and water come from? (Also, electricity for Indiana, U.S.) What opportunities are there in the future for reducing the environmental impact of the university?
Waste management. Love Canal – basic facts. Hazardous waste, biodegradable waste. Landfills, incinerators, resource recovery (recycling & source reduction). Superfund (CERCLA). Coastal issues. Patterns of human population growth in coastal areas. Estuaries, barrier islands. Effect of climate change. Important laws (know the general issue that the laws were meant to address, and what was authorized under each law): 1970 National Environmental Policy Act (land management – environmental impact analysis, viable population mandate), 1964 Wilderness Act & 1969 Wild and Scenic River Act (creation of National Wilderness System), 1872 General Mining Act (allows mineral rights to be gained cheaply from government), 1977 Surface Mining Control & Reclamation Act (requires land reclamation by coal mining), 1990 Clean Air Act amendments (cleaner fuels, cleaner vehicles, less sulfur dioxide pollution), 1972 Clean Water Act (cleans up rivers and lakes, regulate what can be dumped into nation’s waters), 1974 Safe Drinking Water Act (regulates levels of contaminants in water you drink), 1987 Montreal Protocol (bans CFCs to protect ozone layer in stratosphere), Kyoto Protocol (reduce greenhouse gas emissions to control climate change – USA pulled out of negotiations in 2001). 1973 Endangered Species Act (protects endangered & threatened species) 1980 Superfund (CERCLA – cleans up toxic waste dumps)
