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Announcements – Oct. 16, 2006  Exam 2 on Wednesday.

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Presentation on theme: "Announcements – Oct. 16, 2006  Exam 2 on Wednesday."— Presentation transcript:

1 Announcements – Oct. 16, 2006  Exam 2 on Wednesday

2 Lecture Objectives: Agriculture III 1. What alternatives to fertilizers & pesticides exist? 2. What are GMOs? 3. How do GMOs influence our lives? 4. What are the impacts of agriculture on soil?

3 Review  Chemical fertilizers pros: increase yields cons: reliance on oil, only replace nutrients, runoff to aquatic systems  Chemical pesticides pros: increase yields, human health, decrease labor cons: selects for resistance, toxic effects to non-target organisms, persistence in environment

4 Alternative Agriculture  Crop rotation  Organic agriculture  Integrated pest management

5 Crop rotation Plant different, specific crop in a field each year  Pros Reduce build-up of pests specific to one crop Retain or enhance soil nutrients  Cons Requires more equipment Insects developing 2-year diapause

6 Organic agriculture No chemical fertilizers or pesticides used  Animal manure as fertilizer  Crop rotation to enhance productivity & reduce pests  Biological predators and human labor to combat pests  Higher up-front costs, but healthier and less damaging to environment

7 Integrated Pest Management  Use a variety of methods, not just chemical pesticides, to control pests  Ecology and physiology of crop, pest researched at universities & government organizations Reproduction disruption  Release sterile males  Pheromone traps

8 Plant breeding and genetic modification  Originally, selective breeding of crops done to increase crop size, yield, growth, etc. Has been going on for thousands of years  With the advent of modern genetics, scientists can now selectively breed and modify crops on a whole new level.

9 Genetic Engineering  Genetically Modified Organisms (GMO’s) Contain DNA possessing genes borrowed from unrelated species.  Pest-resistance  Wider tolerance levels  Increased growth  Herbicide resistance  Dietary supplements or oral vaccines

10 Green Fluorescent Protein

11 Genetic Engineering 70% of all processed foods in NA contain transgenic products. 75% of soybeans, 33% of corn, 71% of cotton grown in US is transgenic

12 GMO Salmon GMO fish grow faster and need less food Concern over possible escape from aquaculture “Trojan gene affect” – Muir & Howard, 1999; Howard et al. 2004

13 Roundup Ready Crops Crops are modified to tolerate herbicides Large quantities of herbicides can be sprayed directly on fields Concerns over spread of resistance and herbicide residue on crops

14 Bt Corn Bacillus thuringiensis (Bt) is a bacterium that makes toxins that are lethal to beetles Bt corn allows for reduced use of chemical insecticides Concerns over human health effects In 2001, Starlink, a Bt variety not yet approved for human consumption was found in a variety of foods No toxin found, just the genes that code for it Probably not toxic to humans, but may be an allergen

15 Bt Corn (Bt) is also lethal to Lepidoptera (butterflies) Also concerns over environmental effects

16 Golden Rice Each year, more than a million children die and another 350,000 go blind from the effects of Vitamin A deficiency Golden rice has moved genes from daffodils into the rice to provide beta carotene Considerable opposition to the distribution of golden rice

17 Debate over GMOs  Supporters argue: Improved yield with fewer insecticides Reduced hunger Increased health and nutrition  Critics argue: Increased use of herbicides What we don’t know now can hurt us later  Future environmental problems  Future human health problems

18 Points to Know 1) What is alternative agriculture “alternative” to? Name 3 methods discussed in lecture. 2) How does reproduction disruption help control insect pests? 3) What does selective breeding of crops/livestock do? How long has it been going on? 4) In what way is genetic modification via transgenetics (GMOs) different than traditional selective breeding? 5) What is the “trojan gene affect” and why could this be a big problem for GMOs? 6) What do the supporters and critics of GMOs argue?

19 2nd exam Wed, Oct 18  Bring:#2 pencil Photo ID Student ID# NetID ( usually 1 st part of e-mail )  Arrive early  Sit every other seat.  Neighbors should have different exams (colored booklets)

20 Test Format  50 questions, multiple choice & T/F  3 extra credit questions  50 minutes

21 Test Material  Any thing from lecture or readings is fair game  “Points to know”  Mostly fact-based questions, some concept application

22 Chapters from Book: 5, 6, 7 Assigned Reading

23 Chapter 5 Biomes and Biodiversity Most of chapter already covered in class

24 Tools for the study of biodiversity GIS - geographic information system: computer program that allows for the analysis of environmental data, species distributions, land cover - uses layers. GAP - gap analysis program: looking for “gaps” in habitat protection, tries to identify areas for protection

25 BENEFITS OF BIODIVERSITY  Food As many as 80,000 edible wild plant species could be utilized by humans.  Drugs and Medicines More than half of all prescriptions contain some natural product. Pharmaceutical companies actively prospect tropical countries for products.

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27 Environmental Conservation: Forests, Grasslands, Parks, and Nature Preserves Chapter 6

28 Outline Tropical Forests Temperate Forests Harvest Methods and Fire Management Rangelands Overgrazing and Land Degradation Parks and Nature Preserves History - Problems - Size and Design Wilderness Areas Wildlife Refuges

29 WORLD FORESTS  Forests play vital ecological roles: Regulating climate, controlling water runoff, providing food and shelter for wildlife, and purifying air.  Provide valuable materials. Wood, paper-pulp.  Scenic, cultural, and historic value.

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31 Forest Distribution  Currently, forests (trees cover more than 10% of land) encompass 9.6 billion acres. Greatest concern is over protection of Old- Growth Forests.  Areas that have been undisturbed by human activities long enough that trees can live out a natural life cycle. Only 25% of forests still retain old-growth characteristics.

32 Forest Products  Wood plays a part in more activities of the modern economy than any other commodity. Total annual wood consumption is about 3.7 billion metric tons.  $100 Billion each year. Developed countries produce less than half of all industrial wood, but account for about 80% of consumption. Food and other resources.

33 Debt-for-Nature Swaps  Banks, governments, and lending institutions hold nearly $1 trillion in loans to developing countries. Conservation organizations buy debt obligations on the secondary market at a discount, and then offer to cancel the debt if the debtor country will agree to protect or restore an area of biological importance.

34 Old-Growth Forests  Today, less than 10% of the old-growth forest in the United States remains intact. 80% of what is left is scheduled to be cut down in the near future.  Environmentalists sued U.S. Forest Service over logging rates in WA and OR in 1989. Protection of northern spotted owls. Timber industry claimed 40,000 jobs would be lost.

35 Harvest Methods  Clear-Cutting - Every tree in a given area is cut regardless of size. Fast and efficient, but wastes small trees, increases erosion, and eliminates wildlife habitat.

36 Harvest Methods  Strip Cutting - Harvesting all trees in a narrow corridor.  Selective Cutting - A small percentage of mature trees are taken in 10-20 year rotation. Can retain many characteristics of mature, old- growth forests.

37 Loggings and Roads in National Forests  Increasing number of people in the U.S. are calling for an end to all logging on federal lands. $4 Billion annual harvest vs. estimated $224 Billion from recreation and ecological function.  USFS builds roads in order for timber companies to extract trees. Hidden subsidy to timber industry.

38 Fire Management  For more than 70 years, firefighting has been a high priority for forest managers. Many communities are fire-adapted. Accumulation of woody debris.  Forest Service says 40% of all federal forest lands are at risk of severe fires. 68,230 fires burned 2.7 million ha in 2002.  Firefighting costs of $1.6 Billion.  How to undo years of fuel build-up ?

39 RANGELANDS  Pasture and Open range occupy about 25% of the world’s land surface. More than 3 billion domestic livestock producing meat and milk.  Attractive and frequently converted to human-dominated landscapes.

40 North American Parks  US national park system has grown to 280,000 km 2 in 376 parks, monuments, historic sites and recreation areas. 300 million visitors annually.  Canada has 1,471 protected areas occupying about 150,000 km 2.

41 Parks as Ecosystems  One of the biggest problems with managing parks and nature preserves is that boundaries are often based on politics rather than ecological considerations. Airsheds, watersheds, and animal territories and migration routes often extend far beyond official boundaries.  Biogeographical area must be managed as a unit.

42 WILDERNESS AREAS  A belief that wilderness is a source of wealth and the origin of strength, self-reliance, wisdom, and character, is deeply embedded in our culture.  1964 - Wilderness Act defined wilderness: “An area of undeveloped land affected primarily by the forces of nature, where man is a visitor who does not remain…” Most areas meeting these standards are in the Western US and Alaska.

43 Food and Agriculture Chapter 7

44 Outline  Hunger, Famine, Distribution of food.  Major Food Sources (Rice, Wheat, Corn)  Soil  Agricultural Resources  Genetic Engineering  Sustainable Agriculture

45 SOIL: A RENEWABLE RESOURCE  Soil - A complex mixture of weathered minerals, partially decomposed organic materials, and a host of living organisms. At least 20,000 different soil types in the US.  Vary due to influences of parent material, time, topography, climate, and organisms. Can be replenished and renewed.

46 Good Luck!


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