LAND RESOURCES AND AGRICULTURE Tragedy of the Commons In 1968, ecologist Garrett Hardin described the “tragedy of the commons” the tendency of a shared, unregulated public resource to become depleted by people acting in self-interest for shortterm gain Externalities: a cost or benefit of a good or service not included in the purchase price of that product or service In environmental science we are concerned about negative externalities because of the environmental damage they cause, for which no one bears the cost Negative externalities cause the “tragedy of the commons Land management practices vary according to their classification and use Public Lands • National parks: managed for scientific, educational, and recreational use, and sometimes for their beauty or unique landforms • Managed resource protected areas: managed for the sustained use of biological, mineral, and recreational resources • Habitat/species management areas: actively managed to maintain biological communities • Strict nature reserves and wilderness areas: established to protect species and ecosystems • Protected landscapes and seascapes: permit nondestructive use of natural resources while allowing for tourism and recreation • National monuments: set aside to protect unique sites of special natural or cultural interests Federal Parks and Reserves in US 1872—Yellowstone National Park became the world’s first national park National park system includes ~400 sites and receives ~285 million visits in 2009; Managed by the National Park Service 1903—President Theodore Roosevelt began system of national wildlife refuges ~550 sites are managed by the Fish and Wildlife Service; Hunting, fishing, and other recreation are allowed; Policies vary from refuge to refuge 1964—Wilderness Act: Areas designated within existing federal lands Open to public recreation but not exploitative development; >55% in Alaska; <2% in contiguous US Congress passed landmark conservation bill in ’09; Set aside 2 million acres as new wilderness in 9 states Many protected areas have multiple uses Open to logging, grazing, oil and gas exploration and extraction, mining, military exercises BLM manages 265 million acres in West and Alaska; Only 7.7 million acres protected or <3% Nonfederal entities that protect land State and country park systems Land trusts: Local, regional, national, international Nature Conservancy, World Land Trust, Conservation International; ~1700 land trusts in US; ~10 million acres Federal Regulation of Land Use National Environmental Policy Act (NEPA): mandates an environmental assessment of all projects involving federal money or permits Environmental impact statement (EIS): outlines the scope and purpose of the project Environmental mitigation plan: outlines how the developer will address concerns raised by the project’s impact on the environment Endangered Species Act: protects species from extinction Forests: Areas dominated by trees and other woody plants 1

Approximately 73% of the forests used for commercial timber operations in the United States are privately owned World’s forests cover 31% of land area on the planet Mature Forests are Complex Ecosystems Teeming with Life Old growth (primary) forests have greater biodiversity and provide more ecosystem services Store >60% more carbon than plantation forests Barlow et al. evaluated biodiversity of primary growth Amazon rain-forest, second growth forest and Eucalyptus plantations using 3 metrics of biodiversity Comparisons highly variable and highly dependent upon choice of focal taxon and value metric surprisingly high numbers of primary forest species found in areas of native regeneration and exotic tree plantations with understory of native shrubs these habitats can provide important conservation services that are complementary to strictly protected areas but this is a best case scenario and should retain networks of primary growth forest Forest resources and services: Ecologically and economically valuable Provide humanity with wood for fuel, food, construction, paper, medicines, soil and water protection, etc… UN reports that >1.6 billion people depend on forest resources for their livelihood How healthy are the world’s forests? Fires: Longer, more intense fire seasons: early snowpack melt with spring arriving earlier, higher temperatures, fire suppression; Increase GHG emissions Natural regeneration more difficult and make up of forest changing Air pollution: Acid rain in US and Europe; Smog and Sierra Nevada pines Storms and other climatic factors: Tree mortality increasing globally due to warmer temperatures and water deficits Invasive species: White pine blister rust Pests: North American forests suffering infestations; 4/5 of British Columbia pine forest at risk as a result of pine beetles Spruce budworm Destruction leads to reversal from carbon sink to source Commercial logging companies are allowed to use U.S. national forests, usually in exchange for a percentage of their revenues The federal government typically spends more money on management and building and maintaining logging roads than it receives in logging revenue Deforestation in developing and emerging nations Leading cause is agriculture then logging Tropical forests under threat Brazil: lumber, livestock, soy for cattle and cars, oil and gas exploration Indonesia: lumber and palm oil production Congo: charcoal for firewood, lumber, mining, agriculture India and Sahelian region of Africa: firewood Madagascar: 90% of forests gone - rosewoods, lemurs Advanced technologies have enabled rapid exploitation Foreign companies often pay a concession to cut down trees No incentive to manage forests sustainably, Can displace indigenous people and impacts subsistence economy UN FAO estimates that 20% of deforestation is illegal; Africa, Amazon, Indonesia most impacted Palm oil: Vegetable oil that is a staple foodstuff in developing nations used in margarine, soups, ice cream, candies, and many, many other processed foods, shampoo, skin lotions, cosmetics, soap, laundry detergents, candles, and biofuels

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Nearly all remaining forests in US are second growth Resource Management • Practice of harvesting potentially renewable resources without depleting them • Guided by science, politics, economics • Managed renewable natural resources include • Timber, soils, freshwater, wildlife, fisheries, and rangeland • Managed nonrenewable: Oil and gas, Minerals
Extraction NOT managed so mining operations have no incentive to conserve Maximum Sustainable Yield: maximum amount of a renewable resource that can be harvested without compromising the future availability of that resource ; equals half of the carrying capacity But don’t always know what that amount is or the consequences for the ecosystem as a whole Trees are cut at intermediate ages; eliminates habitat for species that depend on mature trees Strategies of Resource Management Ecosystem-based management: Seeks to minimize impact on ecosystems and ecological processes Adaptive management: Involves testing and refining different management approaches In both cases, science intended to drive management Timber harvesting or logging in US: Traditionally used maximum sustainable yield approach ~56% on private land owned by timber companies Primarily tree plantations in South Pacific coast and northern states Timber harvesting on public land—national forests Established in late 1800s over fear of “timber famine” 191 million acres or ~8% of land area ~20% protected and ~80% managed for resource extraction Govt employees plan and manage timber sales and build roads to provide access Extraction increased in ‘50s as demand for larger homes and paper consumption rose and decreased in ‘80s and ‘90s from public outrage over clearcutting Timber Harvest Practices Clear-cutting: removing all, or almost all of the trees in an area Selective cutting: removing single trees or relatively small numbers of trees from a forest, creating many small openings Clear cutting • Least costly in short-term to timber industry • Most costly in terms of long term ecological impacts Habitat and species loss, Speeds runoff, Soil erosion, Siltation of waterways Salmon Ecological community change Succession may result in community different from original • Public outrage resulted in a decrease though still widely practiced ~2% US forests cut for timber/year and ~4/10 acres continue to be clearcut Selective cutting • Even-aged stands: Single-species stands cut after a certain number of years • Uneven-aged stands: Aims to maintain a mix of ages and tree species Plantation forestry • ~7% of worlds forests 3

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Consist of fast-growing species in monocultures Usually even-aged stands Considered agriculture not ecologically functioning forests Lack complexity of a healthy natural forest Vulnerable to infestations and disease outbreaks

Ecologically sustainable forestry: is a third approach, directed toward maintaining all species, plant and animal, in as natural a state as possible Managing forests for more than timber Pressure from public led to multi-use management: National Forest Management Act, 1976 Programs to manage recreation, wildlife and habitat, non-game animals, endangered species, habitat restoration Consider economic and environmental factors Emphasized ecosystem-based management goals: 1990s - adaptive management strategies Research and monitor practices Timber production still often primary use: Political and economic swings Management for forest fires • Fire is a phenomenon that can renew ecosystems - some plant seeds germinate in response to fire Increases animal diversity and abundance • Prohibiting fires can lead to catastrophic fires because of accumulation of combustibles • Prescribed or controlled burns or “let it burn” • Salvage logging - removal of dead trees, or snags, following a natural disturbance Snags valuable as food sources and habitat Can cause severe erosion and soil damage, Impacts nutrient transfer, Decreases number of plant seedlings, Debris leads to accumulation of combustibles Fire and climate change: conifer forests of western US: • Since 1970, increase in spring and summer temperatures of 1˚C • Now earlier snowmelt, and longer summers • Results in increased fire frequency by 400% and burned area by 650% between 1970 and 2003 (Westerling et al. 2006) Residential land use is expanding Suburban: lower population-density areas surrounding metropolitan centers Exurban: similar to suburban areas, but unconnected to any central city or densely populated area Since 1950, more than 90% of population growth in metropolitan areas occurred in suburbs Urban sprawl: the creation of urbanized areas that spread into rural areas Removes the clear boundaries between rural and urban areas Main causes of urban Sprawl 1. automobiles and highway construction 2. living costs (people can get more land and a larger house in the suburbs for the same amount of money) 3. urban blight (city revenue shrinks as people move to the suburbs) 4. government policies • Highway Trust Fund: since 1956, federal gasoline tax pays for construction and maintenance of roads and highways Highways encourage people to live further from where they work • Zoning: planning tool to create quieter and safer communities Separates businesses and industry from residential communities For example, zoning can prohibit the development of a factory or strip mall in a residential area • Multi-use zoning: allows retail and high-density residential development to coexist in the same area 4

Smart Growth Smart growth: focuses on strategies to encourage development of sustainable, healthy communities The EPA lists the basic principles of smart growth, including mixed land uses within one area, a range of housing opportunities and price ranges, and walkable neighborhoods, where car ownership is not necessary Agriculture today: Agriculture is the practice of cultivating soil, producing crops, and raising livestock We have converted 38% of Earth’s surface for agriculture, the practice of cultivating soil, producing crops, and raising livestock for human use and consumption Croplands (for growing plant crops) and rangelands (for grazing animal livestock) depend on healthy soil More rangeland than cropland: ~1/3 cropland - feed for animals Traditional agriculture: ...is agriculture by muscle power, animals, hand tools, and simple machines Origins >10,000 years ago; 5000 years ago we were all farmers now <2% of Americans are farmers Subsistence agriculture - family produces only enough for itself Intensive traditional agriculture - family uses animals, irrigation water, and fertilizer to produce enough to sell at market Industrialized agriculture: can produce huge amounts of food efficiently. When managed improperly, industrialized agriculture can cause extensive environmental damage, including the destruction of fertile soil Large scale mechanization; Intensified irrigation; Synthetic fertilizers; Pesticides; Monoculture Soil as a system: Soil, full of life, is a complex mixture of organic and inorganic components Soil degradation: deterioration of land that diminishes its • Productivity • Biodiversity • Ecosystem functioning and services • Affects ~1/3 world population Most of the world’s soil is not ideal for agriculture But population growth is pressing many unsuitable lands into farming, causing considerable soil damage We are losing 5 – 7 million hectares (12 – 17 million acres) of productive cropland per year This loss results from soil degradation, with erosion a key factor harming soil quality Conventional farming methods can lead to degradation: Soil erosion, Salinization, Waterlogging, Water scarcity, Changes in soil structure and pH, Chemical pollution, Nutrient depletion, Loss of organic matter Erosion and deposition Erosion - removal of material from one place and its transport elsewhere by wind or water Deposition - arrival of eroded material at a new location These processes are natural and can build up fertile soil but where artificially sped up and occurs more quickly than soil is formed, can cause a loss of topsoil Erosion commonly caused by: • Overcultivating: too much plowing, poor planning • Overgrazing rangeland with livestock, removing plant cover • Deforestation: clearing forests on steep slopes or large clearcuts Soil erosion is a global problem 5

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Coupled with rapid population growth, these two forces may spell crisis for the future of agriculture Humans are the primary cause of erosion People are over 10 times more influential at moving soil than are all other natural processes combined

Desertification: “…is land degradation in arid, semiarid and dry subhumid areas resulting from various factors, including climatic variations and human activities.” FAO: affects agricultural land in >165 countries ~52% moderately or severely affected, affects >1 billion people “Fertile Crescent” Iraq, Syria, Turkey, Lebanon and Israel Can occur in grasslands and converted forests A loss of more than 10% productivity due to: Erosion, Soil compaction, Forest removal, Overgrazing, Drought, Salinization, Climate change, Depletion of water resources When severe, desert areas may expand, or new ones may be created (e.g., the Middle East, formerly, “Fertile Crescent”) Present day drylands • ~40% of land surface • Account for 1/3 crops and 1/2 livestock • Home to ~1/3 global population Dust Bowl Homesteaders of 20th century settled during time of unusually wet summers Great plains were a grassland • 1930 - 1936 –period of severe drought combined with degraded farmland • Dust storms lasted ~10 years and brought dust from the U.S. Great Plains all the way to New York and Washington, and wrecked many lives Soil conservation service As a result of the Dust Bowl, the U.S. Soil Conservation Act of 1935 and the Soil Conservation Service (SCS) were created biologists, economists worked with farmers to disseminate scientific knowledge and help develop soil conservation plans results: Conservation tillage, tree shelterbelts, strip-cropping, grassland restoration Served as a global model to disseminate scientific knowledge Soil conservation around the world Many nations followed the lead of the United States: Today local soil conservation agents help farmers in many places in the world Brazil’s no-till effort is based on local associations Strategies to prevent soil degradation • Crop rotation: Alternating the crop planted (e.g., between corn and soybeans) can restore nutrients to soil and fight pests and disease • Contour farming: Planting along contour lines of slopes helps reduce erosion on hillsides • Intercropping: Mixing crops such as in strip cropping can provide nutrients and reduce erosion, similar to crop rotation • Terracing: Cutting stairsteps or terraces is the only way to farm extremely steep hillsides without causing massive erosion • labor-intensive to create but has been a mainstay for centuries in the Himalayas and the Andes • Shelterbelts: Rows of fast-growing trees around crop plantings provide windbreaks, reducing erosion by wind 6

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Conservation tillage (e.g., no-till): No-till and reduced-tillage farming leave old crop residue on the ground instead of plowing it into the soil • covers the soil, keeping it in place Crop residues left on the ground • Can reduce erosion by 90%, Reduces fossil fuel use by 40 to 70%, Reduces irrigation by 10-20% • Enhances water infiltration and retention • Conserves soil biodiversity and Increases productivity • Provides shelter and winter food for animals • Reduces release of carbon to the atmosphere and Residues act as carbon sink • Reduces less labor and saves time; <1/2 of US farmers use reduced till, most use no till in Brazil

No-till and reduced-tillage farming: Ending or reducing tillage has gained popularity but is not a panacea for all crops everywhere can require more chemical herbicides (weeds not plowed under) and can require more fertilizer (other plants compete for nutrients) Overgrazing and soil degradation: Occurs when the # of livestock exceeds rangeland’s carrying capacity • Leading cause of desertification Depending on how livestock are managed • FAO: State of rangelands 65% are lightly to moderately degraded and >5% are severely degraded • Mostly in semi-arid regions • US federal policies facilitate overgrazing: Few restrictions and low fees Overgrazing can cause positive feedback Irrigation: …is the artificial provision of water to support agriculture 70% of all freshwater used by people is used for irrigation Irrigated land globally covers more area than all of Mexico and Central America combined but nonirrigated agriculture still produces most of the world’s food • Boosted productivity • Made unproductive regions fertile Negative impact: Waterlogging and Salinization Over-irrigation can raise the water table high enough to suffocate plant roots with waterlogging Salinization (buildup of salts in surface soil layers): Evaporation in arid areas draws water up through the soil, bringing salts with it. Irrigation causes repeated evaporation, bringing more salts up Waterlogging: when the soil remains under water for prolonged periods; impairs root growth because the roots cannot get sufficient oxygen Raising water productivity: In conventional irrigation, only 43% of water reaches plants Evaporates, percolates downward, or runs off and is Influenced by soil type, temperature, and humidity Efficient drip irrigation targeted to plants conserves water Fertilizers supply nutrients to crops Inorganic fertilizers - mined or synthetically manufactured phosphorus and nitrogen supplements Organic fertilizers - animal manure, crop residues, compost, etc. Growth of inorganic fertilizers: The use of inorganic fertilizer grew enormously between 1960 and 1990, and we now apply 150 metric tons per year and has greatly boosted global food production, But overuse causes severe pollution problems, such as the Gulf of Mexico “dead zone” 7

Organic fertilizer: animal manure, crop residues, green manure (cover crop), compost Improve soil structure, number of beneficial soil organisms, nutrient and water retention, help prevent erosion Not available for absorption right away Uses and impacts of inorganic fertilizers • Overapplied - 50% to 80% taken up by crops • Causes eutrophication and hypoxia of waterways • Leaches into groundwater • Air pollution and GHG emissions • Overapplication can lead to salinization Pesticides: Pest is any organism that damages crops Weeds - plants that compete with crops Pesticide - synthetic chemical developed to kill pests Insecticides, herbicides, fungicides Use risen 3 fold since 1960 largely due to herbicides ~900 million lbs/year with >75% on agricultural land, ~13% govt and industry; ~11% homeowners, >$30 billion spent worldwide - 1/3 by US Problems with their use Pests evolve resistance to them: >8000 known cases of resistance (~550 species) to >300 insecticides as of ‘08 Herbicide resistance reported in >60 countries, most in US Glyphosate resistance widespread Kill nontarget species, Air and water pollution, Harm wildlife and public health especially farmworkers Bioaccumulation: how pesticides enter the food chain Biomagnification: some pesticides build up over time in the fatty tissues of consumers or predators In order for biomagnification, pesticide must be: 1. long-lived 2. mobile 3. soluble in fats 4. biologically active DDT • dichloro, diphenyl trichloroethane • has a half life of 15 years • has low toxicity to humans • discovered just before WWII, and used extensively to control malaria-carrying mosquitoes and human lice • by 1960’s, problems were apparent • from a study done in Long Island Sound in 1967: water to zooplankton: 800x zooplankton to fish #1:

31x

fish #1 to fish #2:

1.7x

fish #2 to gull:

4.8x

overall:

202,368x

Integrated Pest Management (IPM) Integration of multiple methods • Environmental controls - alter the environment of the pest Crop rotation, trap crops, biological controls 8

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Natural chemical controls Natural pesticides found in plants - pyrethrums, rotenone Insect hormones like juvenile hormone Can harm nontarget organisms Pheromones - species specific, nontoxic, biodegrade Genetic controls Genetic resistance through plant breeding or genetic engineering Sterile male technique - screwworm flies and medflies Cultural controls Scarecrows, noisemakers, electrocution devices, population monitoring, mechanical removal, agricultural inspections… • May involve some synthetic pesticide use but as last resort • Indonesia and IPM Adopted in response to elimination of natural enemies by pesticides, Increased rice production while decreasing pesticide use and Required eliminating pesticide subsidies

Biological control: Organismal control of pests • Parasitoid wasp and caterpillars • Cactus moth and prickly pear cactus in Australia • Bacillus thuringiensis (Bt) and caterpillars, flies, and beetles It is not risk free • Most biocontrol agents are introduced from foreign ecosystems • Have potential to become an invasive species Cactus moths brought to the Caribbean jumped to Florida, are eating native cacti, and are spreading • Removing biocontrol agent difficult Pollination • Pollination is the process of plant reproduction • Vital to agriculture Nongrain crops mostly by bees - 1/3 US diet European honeybees used commercially Colony collapse disorder, 2006: 1 in 3 bees dying Multiple stresses: disease (mites, viruses, fungi), pesticides, “monoculture” diet and fed corn syrup in winter, inbreeding, travel 70/170 pesticides found in pollen, bees, and beeswax Neonicotinoids - attacks nervous system of insects • Loss of wild pollinators serious threat to crop yields More so than honey bees (Garibaldi et al, Science 2013) • Farmers and homeowners can help pollinators Use less or no pesticides including buying organic and Grow native flowering plants that provide food and nesting areas Genetic modification of food • Genetic engineering (GE): direct manipulation of an organism’s genetic material in the lab by adding, deleting, or changing segments of its DNA • Genetically modified organisms (GMOs): created by recombinant DNA technology • Recombinant DNA: DNA patched together from DNA of multiple organisms • Transgenic organism: organism that contains DNA from another species Genes moved between organisms are transgenes, Code for desired traits Rapid growth, disease and pest resistance, herbicide resistance (Round-up Ready), better nutrition, frost or drought resistance, salinity or flooding tolerance

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Genetic engineering vs. traditional breeding How they are similar • We have been altering crop genes by artificial selection for 1000s of yrs • Both approaches modify organisms genetically How they are different • Mixes genes of very different species in the lab • Uses novel gene combinations that didn’t come together on their own recombinant DNA technology

Prevalence of GM foods • 2/3 of US soybeans, corn, and cotton are now GM strains; >90% canola • Global area planted has increased ~10%/yr since 1996 Worth >$10 billion and accounts for >10% arable land • Most GE food crops fed to animals not people • 70-80% of US processed foods contain genetically engineered ingredients, (Grocery Manufacturers of America) Scientific concerns about GM organisms • Are there health risks for people? • Can transgenes escape into wild plants, pollute ecosystems, or harm organisms? • Can pests evolve resistance to GM crops just as they can to pesticides? • Can transgenes jump from crops to weeds and make them into “superweeds”? • Can transgenes get into traditional native crop races and ruin their integrity? Debate over GM foods • It’s about more than science – also policy and culture • Who funds science? Who owns living organisms? Who owns genes? • How should we approach new technology? Europe vs. US Preserving crop diversity • Important to ensure against crop failure • Different species are often able to cope with different environmental conditions and disease resistance • Once relied on 10,000 different plant species, now ~150 80% plant calories come from wheat, rice, corn, and potatoes and 12 species provide almost all food 10

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Monocultures put our eggs in one basket Pressures to have uniformity in appearance of fruits and vegetables Variants down by >75% Regions where first domesticated are repositories of biodiversity Accidental inter-breeding can decrease biodiversity Seed banks or vaults act as botanical libraries

Seed banks preserve seeds, crop diversity: Seed banks are living museums of crop diversity, saving collections of seeds and growing them into plants every few years to renew the collection Rise of meat consumption and factory farming • Consumption of animal products increased as global commerce increased 1961-2010 ~7 billion to >25 billion animals Most increase from chickens; Per capita consumption doubled • CAFOs (concentrated animal feeding operations) AKA factory farms or feedlot agriculture Warehouses or pens that deliver “energy rich” foods to animals at extremely high densities • Over 1/2 world’s pork and most poultry on factory farms Much of beef finished at feedlots • Tyson, Cargill, JBS, and Smithfield process more than half of the beef, chicken, and pork consumed in US • Consolidation of processing Rangeland: Dry, open grasslands that are primarily used for cattle grazing Cattle and sheep can be raised on lands that are too dry to farm livestock can damage stream banks and pollute surface waters and overgrazing can quickly denude a region of vegetation Feedlot agriculture • May reduce livestock impact on land BUT • Waste generation - USDA estimates that manure is >40 times more than human waste Stored in pits or lagoons, later some is applied to fields and Spills and leaks are common • Pollution • Pathogens • 50-80% of the nation’s antibiotics added to feed/year • Arsenicals, hormones • Nitrate in drinking water Toxic to many organ systems, cancer, miscarriages • Air and greenhouse gas (GHG) pollution Many cases of impacts on workers and nearby residents Methane and oxides of nitrogen, Potent GHGs What do we feed our food production animals? Sapkota et al. 2007 in the journal Environmental Health Perspectives: Legal feed in the US includes: • Processed grain by-products including distillers products, brewers dried grains, peanut skins • Fruit and fruit by-products including dried citrus pulp • Almond hulls and ground shells • Rendered animal protein from the slaughter of food production animals and other animals including dried animal blood, blood meal, feather meal, egg-shell meal, hydrolyzed whole poultry, hydrolyzed hair, bone marrow, and animal digest from dead, dying, diseased, or disabled animals including deer and elk • Animal waste including dried ruminant waste, dried swine waste, dried poultry litter, and undried processed animal waste products • Edible food waste from restaurants, bakeries, and cafeterias 11

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Food adulterated with rodent, roach, or bird excreta that has been heat treated to destroy pathogenic organisms Copper compounds and metal amino acid complexes Urea Plastics including Polyethylene roughage replacement

Farm Animal Confinement • Dense populations of animals in cages, crates, or tight pens, Common in US, China and increasing in developing countries • >90% of >300 million hens live in windowless battery cages; As many as 90,000 per shed with cages stacked 8 tiers high, Usually debeaked and fed antibiotics ~70% of ~6 million sows spend 3/4 life in a crate, Fed antibiotics and laxatives • Veal crates - Fed milk substitute intentionally lacking in iron and other essential nutrients, hormones, antibiotics Livestock and greenhouse gases • FAO, 2006 concluded it is one of the most significant contributors as measured in CO2 equivalents • Examined impacts of animals, land use and change • 9% of CO2 emissions – land use changes • 65% of nitrous oxide (296 times GWP of CO2 ) - manure • 37% of methane (25 times GWP of CO2 ) • Digestive systems of ruminants • Reductions are urgently needed • Improved diets to reduce enteric fermentation • Soil conservation methods • Biogas plants to recycle manure • Improved efficiency of irrigation • Introduce full cost prices for water together with taxes to discourage large-scale livestock production Aquaculture • Raising aquatic organisms for food in controlled environments - marine or freshwater Natural or manmade wetlands of Land-based ponds or holding tanks or Open water in large, floating pens • Fastest growing sector of food production, Particularly developing nations Provides ~1/2% of fish and shellfish for human consumption China accounts for ~70% production • ~220 species are being farmed, 25 species account for 90% production Carp, tilapia, catfish, trout, salmon, Oysters, mussels, clams, Shrimp Benefits of aquaculture Provides a reliable protein source • 10 to 1000 more fish per unit area than in marine waters • Enhances food security Can be small-scale, local, and sustainable • Vegetarian species: tilapia, catfish, carp • Filter feeders: oysters, clams, mussels Feed supplemented with other forms of protein • Soybean and chicken • Manure used to fertilize ponds for herbivores Can reduce pressure on wild stocks and Can eliminate by-catch, also Uses less fossil fuels than fishing Negative impacts of aquaculture Fish usually farmed in high density which Increased incidence of disease Large amounts of waste which pollutes water which Can move to distant shores Pressure on wild stocks fed to carnivorous species 12

• Also fed poultry trimmings and soybean • 2.5-5 lbs of wild fish to produce 1 lb salmon Fish may escape into the wild and interbreed with, compete with, or spread disease to wild species • Sea lice and die offs of wild salmon; salmon virus Habitat alteration or destruction • Marine species raised in coastal areas near wild fish • Mangrove forests and shrimp farms in Thailand Challenges of feeding the world Ability to produce food has grown faster than the human population >1 billion people are chronically hungry, Historic low in 1996, 800 million 2/3 in US are overweight, 1/3 of which are obese ~1/2 of food produced worldwide is lost, Rots or wasted ~1/3 of global grain is fed to animals Propose using recycled food waste ~14% of grain and oils fed to cars and trucks USDA: ~40% US maize in becomes biofuel which is Enough to feed 350 million people for 1 year Industrial vs. Sustainable agriculture Monoculture • Few crop varieties • Separation of animal and plant agriculture • High "Input” • Large amounts of pesticides, fertilizers, water, growth hormones, antibiotics, fossil fuels • Consequences • Degrades soils • Pollution harms wildlife and public health • Accounts for up to 70% of water pollution • Contributes significantly to climate change Polyculture and use of multiple cropping methods • Many crop varieties • Animals and plants are together • Low “input” • Sustainable amounts of water, IPM, fertilizers, fossil fuels, no antibiotics or hormones • Consequences • Soils are not degraded Stores more carbon, nutrients, moisture, organisms in soils • Reduced pollution and GHGs • Genetic and biodiversity are maintained • Yields can be comparable

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