LAND MANAGEMENT

AGRICULTURE & FORESTRYManaging Agriculture and ForestryThe land must contain the nutrients needed to grow the foodHuman nutritional needs2,000-2,500 calories otherwise undernourishedHumans need 22 different amino acids to build proteins (body can synthesize all but 8 essential amino acids)Contained in meat & cheese, legumes & grainsFamines massive acute incidences of undernourishment catalyzed by political or economic upheaval, or environmental devastationOvernutrition Americans consume 1000-1500 more calories than necessary1.1 billion people are overweightMalnourishment inability to acquire adequate vitamins and nutrients can eventually lead to disease

Eating animal products has significant impactsAs wealth and commerce increase, so does consumption of meat, milk, and eggsGlobal meat production has increased fivefoldPer capita meat consumption has doubledDomestic animal production for food increased from 7.3 billion in 1961 to 20.6 billion in 2000

Feedlot agricultureFeedlots (factory farms) = also called Concentrated Animal Feeding Operations (CAFOs)Huge warehouses or pens designed to deliver energy-rich food to animals living at extremely high densitiesOver of the worlds pork and poultry come from feedlots

Debeaked chickens spend their lives in cages; U.S. farms can house hundreds of thousands of chickens in such conditionsThe benefits and drawbacks of feedlotsThe benefits of feedlots include:Greater production of foodUnavoidable in countries with high levels of meat consumption, like the U.S. They take livestock off the land and reduces the impact that they would have on itDrawbacks of feedlots include:Contributions to water and air pollutionPoor waste containment causes outbreaks in diseaseHeavy uses of antibiotics to control disease

Energy choices through food choices90% of energy is lost every time energy moves from one trophic level to the nextThe lower on the food chain from which we take our food sources, the more people the Earth can support.Some animals convert grain into meat more efficiently than othersEnvironmental ramifications of eating meat Land and water are needed to raise food for livestockProducing eggs and chicken meat requires the least space and waterProducing beef requires the most

When we choose what to eat, we also choose how we use resourcesManaging Agriculture and ForestryLand degradationDesertification the process of converting farmable grassland into nonarable desertLand is overfarmed, nutrients and organic material depletedErosion soil moved from its point of originWater and wind can remove topsoilChemical nutrient depletion or salinization (watering with brackish water)Physical compaction by machines or cattleExcessive water (overirrigation, poor drainage or ocean encroachment)Protecting soil: crop rotation and contour farmingCrop Rotation = alternating the crops grown field from one season or year to the next, Cover crops protect soil when main crops arent plantedReturns nutrients to soil, breaks disease cycles, reduces erosionWheat or corn and soybeansContour Farming = plowing furrows sideways across a hillside, perpendicular to its slope, to prevent rills and gullies

Protecting soil: terracing and intercroppingTerracing = level platforms are cut into steep hillsides, sometimes with raised edgesA staircase to contain waterIntercropping = planting different types of crops in alternating bands or other spatially mixed arrangementsIncreases ground coverReduces disease

Protecting soil: shelterbelts and reduced tillageShelterbelts or Windbreaks = rows of trees or other tall, perennial plants that are planted along the edges of fields to slow the windAlley cropping (agroforestry) = shelterbelts + intercropping + treesReduced Tillage = furrows are cut in the soil, a seed is dropped in and the furrow is closedNo-till farming disturbs the soil even lessCan improve soil quality

Managing Agriculture and ForestryLand degradationPesticide useToxicity to non target species bioaccumulation & biomagnificationPest resistance and resurgence a few hardy insects survive & bloom in a pest resurgenceTypes of pesticidesInorganic pesticides arsenic, copper, mercury, lead toxic & persistentChlorinated hydrocarbons DDT, aldrin, lindane, toxaphene block nerve transmission bioaccumulate & biomagnifyOrganophosphates parathion, malathion neurotoxin & not persistentCarbamates carbofuron and aldicarb behave like organophosphatesBotanical pesticides pyrethrum extracted from botanicalsManaging Agriculture and ForestryLand degradationPesticide useIntegrated Pest management (IPM) non-chemical solutions to pestsCombination of strategiesNonchemical use of natural predators, sex pheromones to attract, introduce sterile breeding partners, crop rotationChemical Greater deliberation & specific targetingPlanting trap crops that mature earlier & attract pests, spraying & destroying trap cropManaging Agriculture and ForestryLand degradationFertilizer useOveruse can cause nutrient pollutionAlternate crop rotation of nitrogen-demanding with nitrogen-producing (peas, alfalfa, clover)Energy useCurrent farming practices depend on fossil fuelsManaging Agriculture and ForestrySustainable Agriculture vs Industrial MonocultureSubsistence farming grow only what is needed to support needs of growerMore than 65% of global populationIndustrial monoculture planting large tracts of land with a similar crop, same maintenance techniques appliedHigher yieldsLarger accumulation of one type of pestSustainable farmingLow or no-till farming & contour farmingUses crop rotation & polycultureUses natural fertilizersMinimizes pesticide useMinimizes use of fossil fuelsMinimizes use of irrigationManaging Agriculture and ForestryFarming vs RanchingEcological aspects of Meat ProductionTotal energy input more energy to produce meatFeedlot pollutionGive antibiotics, growth hormonesRunoff contains antibiotics & hormones & nutrientsOvergrazing Public LandsUse of National Forests & BLM LandIn west 75% of land is available for grazingPermits cost 3-5% of the true cost of grazing land85% of government-owned rangeland is considered poor quality landManaging Agriculture and ForestryAgricultural RevolutionsGreen Revolution1950s scientists develop strains of crops the provide higher yieldsFewer genetics strains of crops (where once there were several)Single strains became vulnerable to diseases & insectsGreater dependence on expensive seeds, chemical fertilizers & pesticidesResistance to pesticidesSome individuals are genetically immune to a pesticideThey survive and pass these genes to their offspringPesticides stop being effective Evolutionary arms race: chemists increase chemical toxicity to compete with resistant pests

Biological controlBiological control (Biocontrol) = uses a pests natural predators to control the pestReduces pest populations without chemicalsCactus moths control prickly pearBacillus thuringiensis (Bt) = soil bacteria that kills many pests

Biocontrol agents may become pests themselvesNo one can predict the effects of an introduced speciesThe agent may have nontarget effects on the environment and surrounding economiesCactus moths are eating rare Florida cacti Removing a biocontrol agent is harder than halting pesticide useDue to potential problems, proposed biocontrol use must be carefully planned and regulated

Managing Agriculture and ForestryGMOs (Genetically Modified Organisms) or Transgenic SpeciesMoving genes from one species to anotherHoped to produce strains more resistant to pests & adverse environments, more durable in shipping, yield better nutrients, grow at different times of the yearRepresent 70% of food grown & sold in the US

Genetically modified organismsGenetic engineering = laboratory manipulation of genetic materialGenetically modified organisms = organisms that have been genetically engineered by Recombinant DNA = DNA created from multiple organisms

Genetic engineering has benefits and risksBenefits of genetic engineering:Increased nutritional contentIncreased agricultural efficiencyRapid growthDisease and pest resistanceNegatives of genetic engineering:Risks are not yet defined or well understoodProtests from environmental activists, small farmers, and consumer advocates

Biotechnology is impacting our livesBiotechnology = the material application of biological science to create products derived from organisms Transgenic organism = an organism that contains DNA from another species Transgenes = the genes that have moved between organismsBiotechnology has created medicines, cleaned up pollution, and dissolves blood clots

Some genetically modified foods

Genetic engineering versus agricultural breedingArtificial selection has influenced the genetic makeup of livestock and crops for thousands of yearsProponents of GM crops say GM foods are safeCritics of GM foods say:Traditional breeding uses genes from the same speciesSelective breeding deals with whole organisms, not just genesIn traditional breeding, genes come together on their ownTraditional breeding changes organisms through selection, while genetic engineering is more like the process of mutation

Biotechnology is changing our worldGM foods become big businessMost GM crops are herbicide resistantFarmers apply herbicides to kill weeds, and crops surviveMost U.S. soybeans, corn, cotton, and canola are genetically modifiedGlobally, more than 10 million farmers grew GM foods on 102 million ha of farmland, producing $6.15 billion worth of crops

What are the impacts of GM crops?As GM crops expanded, scientists and citizens became concernedDangerous to human healthEscaping transgenes could pollute ecosystems and damage nontarget organismsPests could evolve resistanceCould ruin the integrity of native ancestral racesInterbreed with closely related wild plantsSupporters maintain that GM crops are safeSupporters make the following points:GM crops pose no ill health effectsThey benefit the environment by using less herbicides Herbicide-resistant crops encourage no-till farmingGM crops reduce carbon emissions by needing fewer fuel-burning tractors and sequestering carbon in the soil by no-till farmingCritics argue that we should adopt the precautionary principle = dont do any new action until its understoodStudies on GM foods show mixed resultsBetween 2003 and 2005, the British government commissioned three large-scale studies, which showedGM crops could produce long-term financial benefitsLittle to no evidence was found of harm to human health, but effects on wildlife and ecosystems are not well knownBird and invertebrate populations in GM fields were mixed; some crops showed more diversity, some less, depending on the cropThe GM debate involves more than scienceEthical issues plays a large rolePeople dont like tinkering with natural foodsWith increasing use, people are forced to use GM products, or go to special effort to avoid themMultinational corporations threaten the small farmerResearch is funded by corporations that will profit if GM foods are approved for useCrops that benefit small, poor farmers are not widely commercializedThe GM industry is driven by market considerations of companies selling proprietary productsGMO producers are suing farmersMonsanto has launched 90 lawsuits against 147 farmers, winning an average $412,000 per case Monsanto charged farmer Percy Schmeiser of Canada with using its patented GM seeds without paying for themSchmeiser charged the seeds blew onto his field from the neighbors adjacent fieldThe courts sided with Monsanto, saying Schmeiser had violated Monsantos patentFarmers say that [they] are being sued for having GMOs on their property that they did not buy, do not want, will not use, and cannot sell

Nations differ in their acceptance of GM foodsEurope opposed GM foodsThe U.S. sued the European Union before the World Trade Organization, charging that the European Union was hindering free tradeBrazil, India, and China approve GM cropsZambia refused U.S. food aid, even though people were starving, because some seeds were genetically modifiedSustainable AgricultureIndustrial agriculture may seem necessary, but less-intensive agricultural methods may be better in the long runSustainable agriculture = does not deplete soil, pollute water, or decrease genetic diversityLow-input agriculture = uses smaller amounts of pesticide, fertilizers, growth hormones, water, and fossil fuel energy than industrial agricultureOrganic agriculture = Uses no synthetic fertilizers, insecticides, fungicides, or herbicidesRelies on biological approaches (composting and biocontrol)A standardized meaning for organicPeople debate the meaning of the word organicOrganic Food Production Act (1990) establishes national standards for organic productsThe USDA issued criteria in 2000 by which food could be labeled organicSome states pass even stricter guidelines for labeling

The market for organic food is increasingSales increased 20%/year in Canada and the U.S. from 1989-2005Expanded by a factor of 40 in EuropeAmount of land for organic farming is increasing10-35%/year in the U.S. and CanadaIn 2005 the U.S. had 1.7 million acres of organic cropland and 2.3 million acres of organic pasturelandThe benefits of organic farmingFor farmers:Lower input costs, enhanced income from higher-value products, reduced chemical costs and pollutionObstacles include the risks and costs of switching to new farming methods and less market infrastructureFor consumers:Concern about pesticides health risksA desire to improve environmental qualityObstacles include the added expense and less aesthetically appealing appearance of the productThe U.S. doesnt financially support organic farmersIn 1993, the European Union adopted a policy to support farmers financially during conversion to organic farmingThe U.S. offers no such supportOrganic production lags in the U.S.Farmers cant switch, because they cant afford the temporary loss of incomeIn the long run, organic farming is more profitableOrganic agriculture succeeds in citiesCommunity gardens = areas where residents can grow their own foodIn Cuba, over 30,000 people work in Havanas gardens, which cover 30% of the citys landRecord yields for 10 crops in 1996-1997

Locally supported agriculture is growingIn developed nations, farmers and consumers are supporting local small-scale agricultureFresh, local produce in season Community-supported agriculture = consumers pay farmers in advance for a share of their yieldConsumers get fresh foodFarmers get a guaranteed income

U.S. programs promote soil conservationFood Security Act of 1985: Farmers that adopt soil conservation plan receive price supports and other benefitsConservation Reserve Program (1985)Farmers are paid to stop cultivating and place highly erodible land into conservation reservesTrees and grasses are planted instead of cropsSaves 771 million tons of topsoil per yearGenerates income for farmers Provides habitat for native wildlifeFederal Agricultural Improvement and Reform Act (1996)Known as the Freedom to Farm ActAimed to reduce subsidies and government influence over farm productsCreated the Environmental Quality Incentive Program and Natural Resource Conservation FoundationPromotes and pays for conservation practices in agricultureLow-Input Sustainable Agriculture Program (USDA, 1998)Provides funding for sustainable agricultural practices for individual farmersInternational soil conservation programsFood and Agriculture Organization (FAO) = the United Nations main agricultural program The FAOs Farmer-Centered Agricultural Resource Management Program (FAR)Helps farmers duplicate agricultural success storiesUses local communities to educate and encourage farmers to conserve soils and secure the food supplySupports innovative approaches to resource management and sustainable agriculture in around the worldChina, Thailand, Vietnam, Indonesia, Sri Lanka, Nepal, the Philippines and IndiaManaging Agriculture and ForestryUse of forests30% of worlds land areaAbsorbs precipitationControls climateProvides oxygenPurifies airProduces usable resourcesCreates habitatEcological value of forestsOne of the richest ecosystems for biodiversityStructural complexity houses great biodiversityA forest provides many ecosystem servicesStabilizes soil and prevents erosionSlows runoff, lessens flooding, purifies waterStores carbon, releases oxygen, moderates climate

Loggers moved westward, searching for large treesPrimary forest = natural forest uncut by people Little remained by the 20th century Second-growth trees = grown to partial maturity after old-growth timber has been cut

Managing Agriculture and ForestryCurrent Forest Harvesting PracticesClear-cutting cutting every tree regardless of species or sizeLarge trees dragged to access roadsSmaller trees wastedSoil exposed to erosionHabitat disruptedSelective cutting harvesting a portion of mature treesBetter growthMore stable habitatProtects from erosionManaging Agriculture and ForestryCurrent Forest Harvesting PracticesSwidden or milpa agriculture used by indigenous people of tropical rainforestsFarmer clears small plot by cutting or burningAshes provide nutrientsCrops are planted or harvested during natural succession of forestSustainable as long as density of farmers does not exceed forests ability to regenerateRainforest Deforestation to grow hardwood and commercial food crops (sugar & coffee)Rainforests contain 2/3 of global biomass & of global biodiversityThreatens biodiversity, climate stabilization, flood control & O2 productionManaging Agriculture and ForestryCurrent Forest Harvesting PracticesForestry as AgricultureMonoculture forestryDense single species standsIncreases yield & ease of harvestingEncourages disease & pest infestationManaging Agriculture and ForestryCurrent Forest Harvesting PracticesFire ManagementPast practice was to eliminate all firesThis allowed undergrowth to grow unabatedFires then became more damagingEliminated benefits from fires (open seed cones, meadows for wildlife)Current policy is let burn use fire-fighting resources only when lives or property are threatenedBurned forests are essential part of natural and healthy cycleThe National Forest Management Act (1976)Mandated that plans for renewable resource management had to be drawn up for every national forestGuidelines included:Consideration of both economic and environmental factorsProvision for species diversityEnsuring research and monitoringPermitting only sustainable harvestsProtection of soils and wetlandsAssessing all impacts before logging to protect resourcesMaximum sustainable yield Maximum sustainable yield = aims to achieve the maximum amount of resource extraction Without depleting the resource from one harvest to the next Populations grow most rapidly at an intermediate sizePopulation size is about half its carrying capacityManaged populations are well below what they would naturally be

Reducing populations so drastically affects other species and can change the entire ecosystemLivestock graze one-fourth of Earths landGrazing can be sustainable if done carefully and at low intensityBureau of Land Management (BLM) = owns and manages most U.S. rangelandNations single largest landowner: 106 million ha (261 million acres) across 12 western statesRanchers can graze cattle on BLM lands for low feesLow fees encourage overgrazingRanchers and environmentalists have joined to preserve ranchland against development and urban sprawlAquacultureWorld fish populations are plummetingTechnology and increased demandAquaculture = raising aquatic organisms for food in a controlled environmentAquatic species are raised in open-water pens or land-based ponds

Aquaculture is growing rapidlyThe fastest-growing type of food productionProvides a third of the worlds fish for human consumptionMost widespread in Asia

The benefits and drawbacks of aquacultureBenefits:A reliable protein sourceSustainable Reduces fishing pressure on overharvested wild fish stocksEnergy efficient

Drawbacks:Diseases can occur, requiring expensive antibioticsReduces food securityLarge amounts of wasteFarmed fish may escape and introduce disease into the wild