land use: terrestrial biodiversity and public lands chapters 10
TRANSCRIPT
Land use: terrestrial biodiversity and Public Lands
Chapters 10
Forests
• Old-growth/primary (36%)– Uncut/undisturbed by human activities or natural
disasters for 200+ years• Second growth (60%)
– Result of secondary ecological succession– Post: clear-cutting, farming, fire, hurricanes, volcanoes
• Tree plantation/tree farm/commercial forest (4%)– Managed forest – usually monoculture –clear-cut as
soon as commercially viable then replanted• Leads to poor soil and ↓ biodiversity• Can possibly produce all of our wood needs – good for old
growth forests
Economic & ecological services
• Economic– Medical applications– ¼ of the world population lives off forests– Jobs– Fuelwood/lumber/paper products
• Ecological– Removal of CO2
– Production of O2
– Prevent runoff, thereby aiding aquifer recharging and flood control
– Prevent erosion– Stabilization of climate– Wildlife habitat
Harvesting methods
• Selective cutting– Removal of individual trees or small groups of trees that
are mature or economically viable• Expensive, best for ecosystem
• Clear-cutting– Removal of all of the trees from a large area
• Most economical, most negative impacts on ecosystem
• Strip cutting– Removal of all of the trees in a narrow strip of land
• More economically profitable, with fewer negative impacts on the ecosystem
• The next strip will not be cut until regeneration of the first strip has occurred.
(a) Selective cutting
(c) Strip cutting
Clear stream
(b) Clear-cutting
Muddy stream
UncutCut 1 year ago
Dirt road
Cut 3–10 years ago
Uncut
Clear stream
Deforestation• Almost 50% of the world’s forests have been lost – most in
the last 60 years• Rate of .3% to .8% per year – 40% of remaining forests
could be gone in as little as 20 years• Primarily in LDCs• Tropical rain forests• Boreal forests of Canada, Alaska, Russia, Scandinavia• Economic benefits in the short term; long-term
environmental effects.• U.S. has more forest land than it did in 1920. Each year
more wood is grown than is cut, and the total area planted with trees increases
• Haiti – Country in Crisis
Tropical Deforestation
• If deforestation continues at its current rate – most of the world’s rainforests could disappear in the next 20 to 40 years.
• Underlying causes of deforestation– Population growth– Poverty– Government subsidies for industry such as
logging, ranching, mining,
Tropical deforestation
• Amazon and South American– Forests cleared for cattle grazing and soy bean
plantations as well hardwood lumber• Indonesia and SE Asia
– Forests cleared for oil palm plantations• Africa
– Individuals clearing plots for small scale farming and harvesting wood for cooking and heating
• Abandoned cleared and degraded forests are then converted into less diverse ecosystems
Climate change and deforestation
• Forest fires (natural and slash and burn) contribute 17% of global greenhouse gas emissions each year, which is twice as much as motorized vehicles
• Brazil is the 4th largest emitter of greenhouse gases due to destruction of the Amazon rain forest
• The decrease in CO2 absorption will result in atmospheric warming
Wangari MaathaiKenya Greenbelt Movement• Wangari Maathai Tribute Film
Sustainable Forest Management
• Sustainable harvest– Selective cutting– Strip cutting– Canopy vine separation– Certification of sustainably grown timber
• FSC = Forest Stewardship Council
Solutions
• Decrease demand for paper and wood products– Illegally harvested tropical hardwoods– Bamboo– Kenaf
• Government Actions– Protection of large tracts of forest land– Debt for nature swaps– Conservation concessions– Carbon markets
Forest Fires
• Surface fires– Burn undergrowth and leaf litter– Allow animals to escape and do not harm mature trees
• Crown fires– Burn entire tree and spreads by way of the crown (top) of
the tree – Very intense, hot fire – kills most wildlife and many mature
trees• Prescribed burns• Causes
– Human activities – sparks, unattended fires, cigarette butts, arson
– Lightning
Benefits of regular forest fires
• Remove fuel from forest floor• Kill insects and invasive species• Release valuable mineral nutrients from
decomposing or dead trees which enriches the soil • Release seeds from some cone-bearing trees
(lodgepole pine)• Stimulate germination of some seeds – giant
sequoia and jack pine• Fire adapted species – long leaf pine (endangered)
Okeefenokee Swamp Fires of 2011
• Started on April 28th, 2011 by a lightning strike
• Officially announced “out” on April 17th, 2012
• Burned 318,000 acres (only 20,000 outside of park)
• 42 million (value) in timber losses – from timber that would have been harvested outside the refuge
• Large swamp fires every 20-40 years• Okeefenokee Fire
Management of Forest fires
• Smokey the Bear aka “The Devil”• Preventing all forest fires leads to crown fires• Forest uses (logging, ranching) may lead to
increased severe fire risk• Methods to manage fires
– Prescribed burns– Goats– Allow fires to burn– Tree thinning in areas b/w people and wildlands– Forest thinning– Forest thinning with slash burning
Public Lands• International categories of public lands• 2003 United Nations List of Protected Areas (6)
– National Parks• Managed for scientific, educational, and recreational use• In most cases are NOT used for mining, logging etc
– Managed Resource Protected Areas• Multi-use. Sustained use of biological, mineral, and recreational
resources
– Habitat/Species Management Areas• Managed to maintain species (fire prevention/predator control)
– Strict Nature Reserves and Wilderness Areas– Protected Landscapes and Seascapes
• Tourism and recreational use only
– National Monuments• Protect unique sites of special natural or cultural interest
Public Lands in the United States
• Rangelands• National Forests• National Parks• National Wildlife Refuges• Wilderness Areas
Federal management of land use
• Bureau of Land Management (BLM)– Grazing, mining, timber harvesting, and recreation
• United States Forest Service (USFS)– Timber harvesting, grazing, and recreation
• National Park Service (NPS)– Recreation and conservation
• United States Fish and Wildlife Service (FWS)– Wildlife conservation, hunting, and recreation
Resource conservation ethic
• States that people should maximize resource use based on the greatest good for everyone
• In public land use this means that areas are preserved and managed for economic, scientific, recreational, and aesthetic purposes
Multiple Use lands
• Allows public lands to be used for multiple uses– Recreation– Grazing– Timber harvesting– Mineral extraction
Rangelands
• Public Land managed by the BLM• Dry open grasslands that are semiarid, making them
susceptible to fires and other environmental disturbances
• Primary use – cattle grazing– Positives
• Can raise cattle on land too dry to farm• Uses less fossil fuels to raise cattle than in feedlots
– Negatives• Can damage stream banks and pollute surface waters • Overgrazing leads to loss of vegetation which in turn leads to
erosion by wind and rain
• Maintained by occasional wildfire
RANGELANDS vs. pastures
• Rangelands Unfenced grasslands in temperate and tropical areas that supply
wild vegetation (forage) for grazing• Pastures
– Fenced and managed by humans– Usually planted with domesticated grasses or
forage crops (alfalfa, clover)
Rangeland management
• Number of grazing animals• Length of time area is grazed• Rotational grazing• Protect riparian areas• Routine prescribed burns
Environmental impacts of grazing
Benefits Uses less fossil fuels than feed lots Beneficial to the grasslands when in moderation
Disadvantages Damage to the grasses and their roots Decreases grass cover Erosion by water and wind Compaction of soil make regeneration difficult due to
inability to hold water Invasive species Damage to riparian areas river and stream banks Water pollution
Taylor grazing act of 1934
• Passed to stop overgrazing• Converted federal rangelands from a
commons to a permit based system to limit the number of animals grazing in a particular area
• Low costs of permits continues to encourage overgrazing
• Grazing is subsidized with federal funds because the government spends more on management than it receives for permits
National park lands
• Yellowstone National Park was established in 1872
• US National park system was established in 1912
• 58 major national parks • 333 monuments and historic sites• Management was based on preservation
of resources rather than ecology prior to 1960
Environmental challenges for National parks
• Too many visitors• Traffic congestion • Noise Pollution• Eroded trails• Invasive species• Illegal hunting • Air pollution• Acid rain
*Controversy – dirt bikes, dune buggies, jet skis, snowmobiles, off road vehicles (Yes or no)
National parks – islands of biodiversity
Wilderness
• Highest level of protection from human impacts• 5% of the land on earth is protected as
wilderness• Nature Conservancy• Land trust groups• Buffer zone concept• Habitat corridors• Wilderness Act of 1964• 2009 Obama added 2 million acres of public land
to our wilderness areas (9 states)
Federal regulation of land use
• National Environmental Policy Act (NEPA) 1969– Mandates an environmental assessment of all
projects involving federal money or permits– In conjunction with CAA, CWS, ESA, creates a
regulatory process designed to ensure protection of the nation’s resources
– Environmental impact statement (EIS)– Environmental mitigation plan– Presence of Endangered Species
Biodiversity hotspots
Ecological restoration
• The process of repairing damage caused by humans to the biodiversity and dynamics of natural ecosystems– Replanting forests– Restoring grasslands– Restoring coral reefs– Restoring wetlands and and stream banks– Reintroducing native species– Invasive species removal– Removal of dams to restore river flow
4 types of rehabilitation
• Restoration– Return an ecosystem to its natural state (or as close as
possible)• Rehabilitiation
– Turning a degraded ecosystem into a useful ecosystem without trying to restore it to its original condition (remove pollutants, plant to reduce erosion)
• Replacement– Replacing a degraded ecosystem with a different type of
ecosystem (degraded forest to grassland)• Creating artificial ecosystems
– Changing ecosystems to provide important ecosystem services (flood control)
Land Use: Food, Soil, & Integrated Pest ManagementChapter 12
Food Security
• What is food security?• Food Security• Interactive Food Security Map US• Causes of food insecurity
– Poverty– Land and Gender– Conflict and Governance– Environmental Degradation
Terms• Hunger
– Not consuming enough calories to be healthy• Malnutrition
– A diet lacking the correct balance of proteins, carbohydrates, vitamins, and minerals
• Famine– A condition in which food insecurity is so extreme
that large numbers of deaths occur in a given area over a relatively short period of time
• Overnutrition– The ingestion of too many calories and improper
foods causing a person to become overweight
Nutritional Deficiencies
• Macronutrients– Proteins– Carbohydrates– Lipids
• Micronutrients– Minerals
• Iron• Iodine
• Vitamins • A• C
Hungry Planet
• For each slide - jot down your impressions about the food available for each country as represented in each picture
• After you have viewed all slides, rank each country (1 having the highest number or percentage) in the following categories– Meat consumption in pounds– Sugar Consumption in pounds– % Overweight– % undernourished– Cost in US dollars– Fertility rate– Life expectancy
World Hunger
• What is the solution?• Can we increase crop production and
solve the issue of food insecurity?• Should we develop more cropland?• Should we create new and improved
strains of plants that can increase our yield?
• Should we invest in industrialized agriculture in LDC’s?
Traditional Agriculture
• Subsistence– Produce enough food for their family, but little is left
over to sell– Input of human and animal labor– Slash and burn agriculture
• Intensive • Produce enough food for their family with extra left
over to make a profit• Large inputs of human and animal labor• Large inputs of water, fertilizer, pesticides
Industrialized Agriculture & the Green Revolution
• 3 systems produce our food– Croplands
• 77% of the worlds food• Rice, wheat, corn = 48% of world’s food calories • 2/3rds of population survive primarily on these grains
– Rangelands, pastures, feedlots (CAFOs)– Fisheries and Aquaculture
Industrialized Agriculture AKA Agribusiness
• Major goal: To increase yield (amount of food produced per unit area)
• Applies the techniques of the industrial revolution – mechanization and standardization
• High Input Agriculture– Financial capital– Fossil fuels – Water– Inorganic fertilizers and pesticides
• Energy Subsidy – takes more E to produce meat than the consumer (people) get out of the meat
• Food produced in the US generally has a net E loss due to transport and processing
Table 1: List of Foods By Energy Required to Produce One Pound
Food Energy (kWh) to Produce 1 Lb
Corn [1] 0.43
Milk [2] 0.75
Apples [3] 1.67
Eggs [4] 4
Chicken [5] 4.4
Cheese [2] 6.75
Pork [6] 12.6
Beef [7] 31.5
The data above indicate the huge difference in energy required from one end of the food spectrum to the other. Roughly twenty-five times more energy is required to produce one calorie of beef than to produce one calorie of corn for human consumption. Dairy products are actually fairly energy efficient, as they are very dense in calories. Vegans may indeed be able to boast that their diets use 90% less energy than the average American’s, and even those who eat only eggs and dairy can lay claim to significant energy efficiency.
Food Calories / Lb Energy Efficiency
Corn 390 102%
Milk 291 45%
Cheese 1824 31%
Eggs 650 19%
Apples 216 15%
Chicken 573 15%
Pork 480 8.5%
Beef 1176 4.3%
Table 2: Energy Efficiency of Various Foods (Measured as Food Calories / Energy Used in Production) [8]
The Green Revolution• Norman Borlaug (Nobel Peace Prize Winner) developed
new strains of wheat that produced higher yields and were disease resistant
• Use of fertilizers and irrigation improved yields• Spread to LDCs such as Mexico and the Philippines• Result:
– Decrease of family farms using human labor and small quantities of fossil fuels
– Massive increase in fossil fuel consumption – Heavy reliance on fertilization, irrigation, and improved crop
varieties– Massive increase in grain production worldwide– Serious negative environmental impacts– Persistent world hunger
Green Revolution cont.
• 3 steps of the green revolution– Select or genetically engineer plant monocultures with high
yield– Input large quantities of water, fossil fuels, fertilizers and
pesticides– Increase the number of crops grown on each unit of lend
per year
• 2nd green revolution– Creation of fast-growing dwarf varieties for tropical and
sub-tropical climates
• Have we reached the maximum production point? Can we still food yields?
Crossbreeding and Genetic Selection
• Crossbreeding • Artificial Selection• Gene Revolution
– Genetic engineering– Gene splicing– GMOs
• 12% of cropland (worldwide- ½ of that in US)• Soybeans, corn, cotton and canola• 80% of corn, soybeans and cotton in US • 70% of foods on grocery store shelves contain GMOs• Most frequently modified for resistance to something: heat or cold,
herbicides, insects, parasites, viruses, drought, poor soil conditions
GMOs• Possible way to solve
world hunger• Do we have enough
knowledge – should we leave well enough alone?
• What about loss of genetic diversity?
• GM crops and organic crops – how do farmers prevent cross pollination and contamination?
The Dust Bowl
Dust Bowl
• One dust storm reached the Atlantic in 1934 – NY city and DC were engulfed in dust for over 5 hours
• Plagues of grasshoppers and jackrabbits• Both man-made and natural disaster• Dust storms contained large amounts of
lightning• Name came from a newspaper reporter• The Grapes of Wrath
Dust Bowl cont.
• Inhaled dust caused silicosis - a condition similar to coal miners lung
• Federal government paid farmers to slaughter their cattle and plow under their crops
• Most farm families did not flee the dust bowl
• Soil Conservation Service was created to help farmers maintain their farmland to prevent future damage
Environmental Impacts
Natural Capital Degradation
Topsoil Erosion
Environmental Impacts
• Topsoil Erosion– Loss of soil fertility– Water pollution
• Desertification– Overgrazing, deforestation, drought = loss of crops
• Salinization and waterlogging– Irrigation contains dissolved salts which cause soil to
become salty = ↓ crop production– Soil becomes waterlogged and deprives plants of
oxygen, killing them– Excessive irrigation depletes groundwater supplies
Environmental Impacts
• Air Pollution/Climate Change– Greenhouse gas emissions– Livestock and methane (18% of worlds greenhouse
gases)– Nitrous oxide is released from inorganic fertilizers,
manure, clearing of land for crop production
• Loss of Biodiversity– Agriculture = loss of native biodiversity– Loss of agricultural biodiversity – commercially
produced crops are generally the one type that has the best productivity and shelf life – not the best tasting etc.
Meat Production
• Production of beef, pork, and poultry is • Population
– population = greater demand for meat– middle class = greater demand for meat
• Free range vs. Feedlot (CAFOs)– ½ are free range or pasture fed– Free Range Chickens– ½ are Feedlot
• Antibiotics, hormones, grains and meat byproducts rather than grass
Environmental Impacts of CAFOs
• Fossil fuel use• Water• Animal wastes – pollution of surface and
ground water– The Gulf of Mexico Dead Zone
• Odors• Overgrazing and soil degradation• Antibiotic resistance
Fisheries and Aquaculture
• Fishery – Concentration of particular aquatic species
suitable for commercial harvesting• Aquaculture (aka blue revolution)
– The practice of raising marine and freshwater fish in freshwater ponds or underwater cages in coastal or open ocean waters
– Carp, catfish, tilapia, shrimp, salmon– Meat eating species eat wild catch fish as food
Aquaculture Environmental Impacts & Human Health concerns
• Bioaccumulation of toxins• Large quantities of waste• Captive fish escape and become invasive
species
Pest Management
• Pest – Any species that interferes with human
welfare by competing with us for food, invading lawns or gardens, destroying building materials, spreading disease, invading ecosystems, or simply being a nuisance
– Weeds, insects, fungi, and microbes– Human activities increase the problems
associated with pests – usually natural predators keep the pests in balance
Pesticides
• Pesticides– Herbicides– Insecticides– Fungicides– rodenticides
• First generation pesticides– Mainly natural chemicals (plant based)
• Second generation pesticides– Produced in the lab, complex chemical
composition
Pesticides
• Biopesticides• Synthetic pesticides• Broad spectrum• Narrow spectrum• Persistence
– The length of time they remain deadly in the environment
– Long persistence can lead to biomagnification
Pesticide Use
Advantages• Save lives (malaria,
plague, typhus)• Increased food supplies• Increase profit for farmers• Fast working• Proper use has very low
risks relative to benefits• Newer pest control
methods are safer and more effective than older ones
Disadvantages• Genetic resistance• Financial burden for
farmers• Kill natural predators and
parasites that help control the pest population
• Pollute the environment due to runoff and overspray
• Negative impacts on wildlife (bees)
• Human health hazard
Rachel Carson
• 1962 Silent Spring– DDT– Bird deaths gave rise to the title of her book– Controversy associated with her book– Led to the ban of DDT
Safety and Food Protection
• Organizations– EPA– USDA– FDA
• Legislation– FIFRA
• (Federal Insecticide, Fungicide, and Rodenticide Act of 1947/amended in 1972)
• Regulates the sale and use of these products– Food Quality Act
• Called for decreased levels of pesticide residue
Alternative Pest Management
• Rotate crops to make it more difficult for pests• Provide habitat for natural predators of pests• Genetically modify plants• Import natural enemies (law of unintended
consequences)• Spray with insect pheromones• Use hormones to slow down reproduction• Decrease use of synthetic herbicides
Integrated Pest Management (IPM)
• Aim is to decrease crop damage• Uses a combination of
– Cultivation practices crop rotation, altering planting time, remove bugs by
vacuumning
– Biological controls • natural predators, parasites, disease organisms
– Chemical controls• Apply small amounts of insecticides or herbicides
preferably biopesticides rather than synthetic
IPM
Advantages• Increased crop production• Decreased resistance from
organisms (plants & animals)
• Decreased pollution• Decreased cost associated
with fertilizer• Prevents pollution (air and
water)
Disadvantages• Requires expert
knowledge about each type of pest
• Takes more time than applying conventional pesticides
• Initial cost can be higher• Methods differ for each
crop and planting area
Sustainable Ideas
• Decreasing Soil Erosion– Soil conservation– Terracing– Contour planting– Strip cropping– Alley cropping/agroforestry– Windbreaks/shelter belts– Conservation tilling/no-till/low till farming
Sustainable Ideas
• Restoring Soil Fertility – Decreasing irrigation– Inorganic fertilizers– Organic fertilizers
• Animal manure• Green manure• Compost• Crop rotation
Organic Farming
• 2% of the food consumed is certified as organically grown
• Can increase yield• Uses less energy• More labor intensive• Cost the consumer more than food from
industrialized crops• Less transport and processing• Locavore
Soil• Mixture of eroded rock, mineral nutrients, decaying
organic matter (humus), water, air, microorganisms• Horizons
– O: at the surface; layer of organic detritus (leaves, needles, twigs, animal bodies) in various stages of decomposition; O for organic
– A: top layer of soil; organic material and minerals mixed together
– B: subsoil; composed primarily of minerals, very little organic matter, nutrients are here
– C: always beneath B; least weathered, most similar to parent material aka bedrock
– *E: in some soils a zone of leaching eluviation; always above B
Soil Composition
Soil Properties
• Texture – the % of sand, silt, and clay– Sand: largest, loosely packed– Silt: intermediate– Clay: smallest, most tightly packed
• Porosity– How quickly soil drains
Soil Triangle
Bonus Information
• After the Harvest - Fighting Hunger in the Coffee Lands