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
(b) Clear-cutting
Clear stream
Muddy
stream
(c) Strip cutting
Uncut
Cut 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 Maathai
Kenya 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 Management
Chapter 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.
Table 2: Energy Efficiency of Various
Foods (Measured as Food Calories / Energy
Used in Production) [8]
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%
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
Farms of the future
Hydroponic Cilantro
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