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AP Exam
Part III
Marine Ecosystems
• Coastal- occur near shore where tides and
currents are always changing, causing a mixture
of nutrients.
• Zone is from the high tide mark of shorelines to
the continental shelf.
• Organisms include: coral (in tropical regions),
zooplankton, phytoplankton, crustaceans,
echinoderms, dolphins, sharks, etc..
Marine Ecosystems
• Esturaries- Animals in these areas must
be able to adapt to a rapid and constant
change in salinity.
• Rich in nutrients
• Excellent spawning and breeding grounds
for fish, crustaceans and birds.
Inland Wetlands
• Water levels vary from standing water in
the wet season to none during the dry
season or during droughts. Include
marshes, swamps and bogs.
• Differentiate between a marsh, swamp
and bog
Marine Ecosystems
• Open Ocean- These areas occur beyond
the continental shelf .
• Deep water up to 11,000 meters
• Zones below 200 m are dark, cold, and
poor in nutrients.
Legislation Regarding Aquatic
Environments
• Alaska National Interest Lands Conservation Act, 1980
• Designated certain public lands in Alaska as units of the
National Park, National Wildlife Refuge, Wild and Scenic
Rivers, National Wilderness Preservation, and National
Forest Systems, resulting in general expansions of all
systems.
• Created 79.54 million acres of refuge land in Alaska.
• 27.47 million acres were designated as wilderness.
• Anadromous Fish Conservation Act, 1965
• Conservation, development and enhancement of
anadromous fish, including those in the Great
Lakes
• Anadromous fish are those that are born in fresh
water, migrate to salt water to grow into adults
and return to fresh water to spawn.
• Examples: salmon, smelt, striped bass,
sturgeon
• Catadromous fish- live in fresh water and enter
salt water to spawn.
Additional Legislation
• Convention for the Conservation of Antarctic
Marine Living Resources (CCAMLR), 1980• Management of all southern ocean fisheries.
• Fish & Wildlife Act, 1956
• Emphasis on the commercial fishing industry,
but also adheres to every citizen’s right to fish
for pleasure and enjoyment.
• Fish and Wildlife Coordination Act, 1980
• Authorized financial and technical assistance to
the states for the development, revision, and
implementation of conservation plans and
programs for non-game fish and wildlife
• Great Lakes Fish and Wildlife Restoration Act,
1998
• Marine Mammal Protection Act, 1972
• Conservation of marine mammals with
management vested in the Department of
Commerce for cetaceans (whales, dolphins, and
porpoises) and pinnipeds (seals, sea lions,
walrus) other than the walrus.
• A sterile male technique of pest control:
• A. relies on the use of phermones, chemicals
that attract fertile males away from
reproductively capable females.
• B. Is often effective because females of many
insect species breed only once during their
lifetime.
• C. Relies upon genetic engineering techniques
to produce infertile males.
• D. Uses male animals that are sterilized by
treatment with Bacillus thuringiensis bacterium.
• E. Can cause eggshell thinning in some bird
species.
Aquatic Review
• A mixture of fresh and saltwater is known
as
• A. brackish
• B. Gray water
• C. Black water
• D. Connate water
• E. Lentic water
International Acts
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Antarctic Treaty – signed Dec. 1, 1959/ enforced
June 23 1961
Antarctica is the only continent with no
nations. While seven nations (not including the
United States) have made claims to Antarctica, no
single nation controls any part of the continent.
The Antarctic Treaty governs the actions of people
in Antarctica. 12 nations listed in the preamble
signed the Antarctic Treaty on 1 December 1959 at
Washington, D.C. The Treaty entered into force on
23 June 1961.
• Cairo Conference on Population &
Development- Sept. 1994
• The United Nations International Conference
on Population and Development (ICPD) was
held from 5-13 September 1994 in Cairo,
Egypt. During this two week period world
leaders, high ranking officials,
representatives of non-governmental
organizations and United Nations agencies
gathered to agree on a Programme of Action.
Main Point- Population Control
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Kyoto Conference-1997
Sponsored by the United Nations
Held in Kyoto, Japan
Result:
1)Agreement among 10 nations requiring
greenhouse gas emissions reduction,
especially carbon dioxide, to 5% below 1990
emissions by 2010. Developing nations’
reductions are voluntary.
• 2) Long term objective was to prevent
emissions from human sources from
interfering with the natural climate system.
• Montreal Protocol- 1987 (Amended in
1990, 92)
• Agreement to reduce air pollutants that
destroy stratospheric ozone. CFCs,
halons, carbon tetrachloride, and
methyl chloroform--are to be phased
out by 2000 (2005 for methyl
chloroform).
• Rio Earth Summit- 1992
• Held in Rio de Janeiro, Brazil.
• Attendees: world’s leaders, politicians,
diplomats, etc.
• Result of Summit:
• 1)Attempts will be made to reduce
greenhouse gas emissions by the year
2000 to the 1990 levels
• 2) Developing countries will be given
more and easier access to technology
that minimizes environmental damage.
• UN Conference on the Human
Environment, Stockholm (Capital of
Sweden)- 1972
• The United Nations Conference on the
Human Environment, having met at
Stockholm from 5 to 16 June
1972,having considered the need for a
common outlook and for common
principles to inspire and guide the
peoples of the world in the preservation
and enhancement of the human
environment
• Cities Treaty- 1976
• Adopted by Congress in 1976, in an effort to
maintain and protect endangered
populations in ancestral habitats, prohibits
the removal of Asian elephants and other
endangered species from the wild and their
importation into the United States. The
stresses on habitat and space, poaching and
unregulated hunting have severely limited
the ability of native populations to maintain
enough genetic diversity to survive.
• Hadley cell model
• Resides over the equator to the subtropics. It
causes dry are to absorb moisture as it
descends
• The major environmental result of creating
power through nuclear fuel is
• Storing its waste
• Nuclear breeder reactors convert
• Nonfissable U238 into plutonium
• Integrated pest management is the concept that
• All insects can be controlled by using a natural
biological or other natural controls
Pesticides
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Biocide - Kills wide range of organisms.
Herbicide - Kills plants.
Insecticide - Kills insects.
Fungicide - Kills fungi.
Acaricide - Kills mites, ticks, and spiders.
Nematicide - Kills nematodes (round worms)
Rodenticide - Kills rodents.
Avicide - Kills birds.
Algicides: Kills algae
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Chemical Classes
Inorganic Pesticides - Broad-spectrum, generally highly
toxic, and essentially indestructible. (arsenic - copper)
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Generally neurotoxins
Natural Organic Pesticides (Botanicals) - Generally plant
extracts. (nicotene - phenols)
Fumigants - Small molecules that gasify easily and penetrate
materials rapidly. (carbon tetrachloride - ethylene dibromide)
Chlorinated Hydrocarbons - Fast acting and highly toxic to
sensitive organisms. (DDT - mothballs)
Inhibit nerve membrane ion transport and block nerve signal
transmission.
Persistent - Tend to biomagnify.
Organophosphates - Extremely toxic to mammals, birds and
fish. (Malathion)
• 1939- DDTdichlorodiphenyltrichloroethane
created by Mueller. He received a
Nobel Prize in 1948.
– Advantage of DDT: Cheap, stable, soluble
in oil, and easily spread over a large area.
• Highly toxic to insects, but relatively nontoxic
to mammals.
The Ecological Niche
• The role as species plays in an ecosystem
• Habitat – the actual physical location where a
species lives
• N-dimensional hypervolume- many conditions and
resources influence the maintenance, growth, and
reproduction of an organism
• Fundamental Niche – full potential range of
conditions and resources it could theoretically use if
no competition
• Realized Niche – part of a fundamental niche an
organism occupies
Generalists vs Specialists
• Generalists
– Have broad niches
– Live in many different places, eat variety of foods,
wide range of environmental conditions.
• Specialists
– Narrow niches
– One type of habitat, only one or two types of food
– More prone to extinction
– Advantage in constant environmental conditions
Types of Species
• Native species, exotic/alien species
• Indicator Species – species that serve as early
warnings that a community or ecosystem is
being damaged (Birds)
• Keystone – role in ecosystem is more important
than abundance, play pivotal roles in structure,
function, and integrity of ecosystem b/c critically
linked to large number of other species
Competition and Predation
• Interspecific competition – two or more species
compete for limited resource, can harm competing
species
• Predation – one species feeds directly on all or part of
living organisms. Predator benefits, prey is harmed
• Symbiosis – long-lasting relationships, species live in
intimate association
– Parasitism – parasite feeds on host
– Mutualism – both benefit
– Commensalism – one benefits, other is neither
harmed nor helped
How do species compete?
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Interspecific competition results when niches
overlap. One species must:
– Migrate to another area
– Shift its feeding habits
– Suffer a sharp population decline
– Become extinct in that area
Species compete in two ways
• Interference – one species limits another's access
to resource, member establish a territory
• Exploitation – competing species have = access
Principle of Competitive Exclusion
• Two species require the same resource cannot
coexist indefinitely in ecosystem where there is
not enough of that resource to meet the needs of
both species.
Species have reduced competition by:
• Resource partitioning – the dividing up of
available resources
• Character displacement – species develop
physical or behavioral characteristics or
adaptations allowing them to use diff resources
Predator and Prey Interaction
• Predators feed on prey, do not live in or on prey. (+)
feedback system for predator limited by (-) feedback when
prey populations fall below certain minimum.
• benefits prey: eliminates sick, weak, aged
Predators increase chances of getting meal:
• Pursuit – run fast to catch prey, keen eyesight, hunt in
packs
• Ambush – camouflage
Prey defend themselves against predators by:
• Run, swim, fly fast, keen sight or sense of smell
• Chemical warfare – chemicals that are poisonous
• Warning coloration – predators know animal is bad tasting
• Mimicry – species take on appearcnce of poisonous animal
Symbiotic species Interactions
• Parasitism:
– Parasitoids – parasites that kill hosts as part of life
cycle (used by farmers for pests)
– Endoparasites – live inside host
– Ectoparasites – live outside host
• Mutualism:
– Nutritional Mutualism – lichens: photosynthetic algae
and chlorophyll- lacking fungi. They cannot live apart,
aka obligatory mutualism.
– More common when resources are scarce
• Commensalism:
– Redwood sorrel benefits from growing in the shade of
tall redwood trees
Ecosystem Structure
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Physical appearance
Niche structure
Species diversity
Species abundance
An ecosystems respond to change
• Ecological succession – gradual change in species
composition of given area.
• Primary – gradual establishment of biotic communities
(lifeless, soil-less area)
– Pioneer species – lichens and mosses
– Early successional plants – close to ground, break up rock and
make soil
– Midsuccessional- herbs, grasses, low shrubs
– Late successional - trees
• Secondary – reestablishment of biotic community.
Begins where natural community has been disturbed, but
soil sediment remains. Ex. Abandoned farmlands,
burned forests etc.
How do species replace each other?
• Facilitation – species behave in such a way that
facilitates growing of other species. Ex – legumes
convert nitrogen to nitrates making soil more suitable
• Inhibition – early species hinder establishment and
growth of other species
• Tolerance – ate successional plants are unaffected by
plants at earlier stages of succession
What is the role of Disturbance in succession?
• A disturbance is a discrete event in time that disrupts an
ecosystem
• Natural disturbance – fires, hurricanes, floods
• Intermediate disturbance hypothesis – communities that
experience frequent disturbance have greatest diversity
of species
Ecological Stability and Sustainability
• Stability is maintained only by constant dynamic change in response
to changing environmental conditions
• Inertia – ability of living system to resist disturbance
• Constancy – ability of system to maintain certain size within limits
imposed by available resources
• Resilience – ability of system to bounce back after external
disturbance
The signs of ill health in a stressed ecosystem:
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Drop in primary productivity
Increased nutrient loss
Decline of indicator species
Increased populations of insect pests
Decline in species diversity
Present of contaminants
General Information
• Pests: any species that competes with us or
food, invades lawns and gardens, destroys
wood in houses, spreads disease, or is a
nuisance
• Pesticides: Chemicals developed to kill
organisms that we consider undesirable
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Insecticides: insect-killers
Herbicides: weed-killers
Fungicides: fungus-killers
Nematocides: roundworm-killers
Rodenticides: rat- and mouse-killers
Co-evolution
• Plants have been producing chemicals to
ward off herbivorous predators for ~225
million years. As herbivores adapt, so thy
don’t starve, plants adapt so that they
survive. This is an example of coevolution.
First Generation Pesticides
• Sulfur: used as an insecticide since 500
BC
• Arsenic (As), lead (Pb), and mercury (Hg)
by the 1400’s
• Nicotine sulfate: extracted from tobacco
leaves in the 1600’s
• Pyrethrum: obtained from the heads of
chrysanthemum flowers
• Rotenone: from the root of the derris plant
Second Generation Pesticides
• About 2.5 million tons of pesticides are used yearly worldwide. In
the US, about 630 different biologically active (pest-killing)
ingredients and 1,820 inert (inactive) ingredients are mixed to make
25,000 different pesticides products.
• DDT: 1939, entomologist Paul Mueller discovered that DDT was a
potent insecticide. It soon became the world’s most-used pesticide.
• Broad-spectrum agents: toxic to many species
• Selective-spectrum agents: effective against a narrowly defined
group of organisms
• Persistence: length of time in which pesticides remain deadly in the
environment
• Biomagnification:
• Spoil
– Unwanted rock and other waste materials produced
when a material is removed from the earth's surface
or subsurface by mining, dredging, quarrying, and
excavation
• Overburden
– Layer of soil and rock overlying a mineral deposit.
Surface mining removes this layer
• Open-pit mining
– Removing minerals such as gravel, sand, and metal
ores by digging them out of the earth's surface and
leaving an open pit.
• Area strip mining
– Type of surface mining used where the terrain is flat
• Dredging
– Type of surface mining in which chain buckets
and draglines scrape up sand, gravel, and
other surface deposits covered with water
• Contour strip mining
– Form of surface mining used on hilly or
mountainous terrain
• Depletion time
– The time it takes to use a certain fraction,
usually 80%, of the known or estimated
supply of a nonrenewable resource at an
assumed rate of use
• Petrochemicals
– Chemicals obtained by refining (distilling) crude oil.
They are used as raw materials in manufacturing
most industrial chemicals, fertilizers, pesticides,
plastics, synthetic fibers, paints, medicines, and many
other products
• Tar sand
– Deposit of a mixture of clay, sand, water, and varying
amounts of a tarlike heavy oil known as bitumen.
Bitumen can be extracted from tar sand by heating. It
is then purified and upgraded to synthetic crude oil
• Ore
– Part of a metal-yielding material that can be
economically and legally extracted at a given time
• Shale oil
– Slow-flowing, dark brown, heavy oil obtained when
kerogen in oil shale is vaporized at high temperatures
and then condensed. Shale oil can be refined to yield
gasoline, heating oil, and other petroleum products
• Breeder nuclear fission reactor
– Nuclear fission reactor that produces more nuclear
fuel than it consumes by converting nonfissionable
uranium-238 into fissionable plutonium-239
• Kerogen
– Solid, waxy mixture of hydrocarbons found in oil
shale rock. Heating the rock to high temperatures
causes the kerogen to vaporize. The vapor is
condensed, purified, and then sent to a refinery to
produce gasoline, heating oil, and other products
• Net energy
– Total amount of useful energy available from an
energy resource or energy system over its lifetime,
minus the amount of energy used (the first energy
law), automatically wasted (the second energy
law), and unnecessarily wasted in finding,
processing, concentrating, and transporting it to
users
How do minerals form?
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Magma crystallizes
Sedimentary process
1. Sedimentary sorting
2. Precipitation
3. Groundwater evaporates, leaving salts
that precipitate
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Weathering process
1. Water dissolves and removes soluble
ions
2. Residual deposits form
What are the environmental
impacts of using mineral
resources?
• Scarring of land
• Collapse of land over underground
mines
• Erosion of toxic mineral wastes
• Acid mine drainage
How is oil extracted and
processed?
1. Primary oil recovery
– Drill well, pump out lighter crude oil that
flows out through pores
2. Secondary oil recovery
– Pump high-pressure water into well to
force out heavier crude oil
3. Tertiary oil recovery
– Superheated steam forces out oil
– Detergent dissolves heaviest oil, which
can then be pumped out
What are components of a nuclear
fission reactor?
• Core: contains fuel rods
• Uranium oxide fuel: uranium-238
• Control rods: move in and out of reactor
to absorb neutrons
• Moderator: slows neutrons so that chain
reaction keeps going
• Coolant: circulates to remove heat and
produce steam for electricity
What types of energy do we use?
Global and in U.S.
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Oil: 30% (40% in US)
Coal: 22% (22% in US)
Natural gas: 23% (22% in US)
Nuclear power: 6% (7% in US)
Hydropower, geothermal, solar, wind: 6%
(5% in US)
• Biomass: 12% (4% in US)
Chapter 15
1. CAFE: (Corporate Average Fuel Economy) requires
new cars to meet certain average fuel efficiency
standards, averaged over all cars produced. Between
1973 and 1985, the average fuel efficiency doubled for
new American cars and rose 37% for all passenger cars
on the road because of CAFE.
Chapter 17
1. NAPAP: (National Acid Precipitation Assessment Program)
established in 1980 to 1. coordinate government acid deposition
research, 2. assess the costs, benefits, and effectiveness of the
country’s acid deposition legislation and control program, and 3.
report its findings to Congress.
2. Clean Air Act: passed in London in 1952, then by Congress in
1963, but did not have much effect until a stronger version of the
law enacted in 1970. The Clean Air Act of 1970empowered the
federal government to set air pollution emission standards for
automobiles and industries that each state was required to
enforce. Stricter emissions standards were imposed by
amendments to the Act in 1977 and 1990. Emissions of the six
most common outdoor air pollutants decreased by 31% between
1970 and 1998
The Case for Pesticides
• Pesticides save human lives: Since 1945, DDT and other
insecticides have probably prevented the premature deaths of at
least 7 million people from insect-transmitted diseases.
• Pesticides increase food supplies and lower food costs: About 55%
of the world’s potential human food supply is lost to pests before or
after harvest. Without pesticides, these losses would be worse, and
could cause the prices of food in the US to rise nearly 50%.
• Pesticides increase profits for farmers: Overall, for every dollar spent
on pesticides, there is an increase in US crop yields worth
approximately two dollars.
• Pesticides work faster and better than alternatives: Pesticides
control most pests quickly and at a reasonable cost.
• The benefits overpower the health risks: Safer and more effective
pesticides are being developed.
The Case Against Pesticides
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Genetic resistance: Insects can develop immunities to pesticides in just a few years.
Broad-spectrum insecticides kill good organisms: This includes killing natural
predators and parasites that may have been maintaining the population of a pest
species at a reasonable level.
Unexpected outcome: wiping out natural predators can also unleash new pests
whose populations the predators had previously held in chick, causing other
unexpected effects
The pesticide treadmill: A situation where farmers are forced to pay more for a pest
control program that often becomes less effective as a genetic resistance develops
Although the use of synthetic pesticides has increased 33-fold since 1942, it is
estimated that more of the US food supply is lost to pests today than in the 1940’s.
The estimated environmental, health, and social costs of pesticide use in the US
range from $4 billion to $10 billion per year
Alternative pest control practices could halve the use of chemical pesticides on 40
major US crops without reducing crop yields.
A 50% cut in US pesticide use would cause retail prices to rise by only about .2% but
would raise average income for farmers about 9%.
Environmental Effects
• Less than 2% of the insecticides applied to crops by
aerial spraying or by ground spraying actually reach the
target pests
• Some pesticides can harm wildlife: DDT had harmful
effects in the environment when it biologically magnifies
in food webs. This resulted in certain birds being listed
on the endangered species list in the US because of
fatal effects.
• Each year 20% of honeybee colonies in the US are
wiped out by pesticides, while another 15% are
damaged, costing farmers over $200 million annually.
Human Health Effects
• An estimated 25 million agricultural workers in
developing countries are seriously poisoned by
pesticides each year. 220,000 deaths result.
• In developed countries an estimated 300,000 farm
workers suffer from pesticide-related illnesses yearly.
250,000 Americans get sick each year from home
misuse of pesticides.
• Approximately 13% of vegetable and fruits consumed in
the US may contain illegal pesticides and levels of
approved pesticides above their legally allowed limits.
• At least 75% of the active ingredients approved for use
in US pesticide products cause cancer in test animals.
Pesticide Regulation in the US
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All commercial pesticides must be approved by the EPA for general or restricted use
When a pesticide is legally approved for use on fruits or vegetables, the EPA sets a
tolerance level, which specifies the amount of toxic pesticide residue that can legally
remain on the crop when the consumer eats it.
According to a National Academy of Sciences study, federal laws regulating the use
of pesticides in the US are inadequate and poorly enforced by the EPA, FDA, and
USDA
Exposure to pesticide residues in food causes 4,000-20,000 cases of cancer per year
in the US
A 1993 study of pesticide safety by the US National Academy of Sciences urged the
government to do the following things:
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Make human health the primary consideration for setting limits of pesticide levels allowed in
food
Collect more an better data on exposure to pesticides for different groups, including farm
workers, adults, and children
Develop new and better test procedures for evaluating the toxicity of pesticides, especially
for children
Consider cumulative exposures of all pesticides in food and water, especially for children,
instead of basing regulations on exposure to a single pesticide
Progress Made with the Passage of
the 1996 Food Quality Protection
Act
• Requires new standards for pesticide tolerance levels in
foods, based on a reasonable certainty of no harm to
human health
• Requires manufacturers to demonstrate that the active
ingredients in their pesticide products are safe for infants
and children
• Allows EPA to apply an additional 10-fold safety factor to
pesticide tolerance levels to protect infants and children
• Requires the EPA to consider exposure to more than one
pesticide when setting pesticide tolerance levels
• Requires the EPA to develop rules for a program to
screen all active and inactive ingredients for their
estrogenic and endocrine effects by 1999.
Solutions
• Cultivation practices
– Crop rotation
– Planting rows of hedges or trees around fields
to hinder insect invasions
– Adjusting planting times so that major insect
pests either starve or get eaten by their
natural predators
– Planting trap crops to lure pests away from
the main crop
Solutions cont.
• Genetically resistant plants
– Plants and animals that are genetically resistant to
certain pests insects, fungi, and diseases can be
developed
– Genetic engineering can be used to build pest
resistance into crops and thus reduce the need for
pesticides
• Using natural enemies to help control pests
– Biological control using predators, parasites, and
pathogens to regulate pest populations
• Using biopesticides to control pests
Solutions cont.
• Insect birth control, sex attractants, and
hormones
– Males of some insect pest species can be raised in
the laboratory, sterilized by radiation or chemicals,
and then released into an infested area to mate
unsuccessfully with fertile wild animals
– Hot water: the ‘Aqua Heat’ machine sprays boiling
water on crops to kill weeds and insects
– Radiation: exposing certain foods after harvest to
gamma rays emitted by radioactive isotopes will
extend food shelf life and kill harmful insects, parasitic
worms, and bacteria
Integrated Pest Management
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Integrated pest management (IPM): in this approach, each crop and its
pests are evaluated as parts of an ecological system. Then a control
program is developed that includes a mix of cultivation and biological
chemical methods applied in proper sequence with the proper timing.
– The overall goal is not to eliminate pest populations but to reduce crop damage
to an economically tolerable level.
– IPM requires expert knowledge about each pest situation, and is much slower
acting than conventional pesticides.
– Although long-term costs are typically lower than the costs of using conventional
pesticides, initial costs may be higher.
– Scientists urge the USDA to promote IPM by the US by:
• Adding a 2% sales tax on pesticides and using revenue to fund IPM research and
education
• Setting up a federally supported IPM demonstration project on at least one farm in
every county
• Training USDA field personnel and county farm agents in IPM so that they can help
farmers use this alternative
• Providing federal and state subsidies to farmer who use IPM
• Gradually phasing out subsidies to farmers who depend almost entirely on pesticides,
once effective IPM methods have been developed for major pest species