APES UNIT 5 - Land and Water Use
Which of the following is a typical change in genetically modified organisms?
(a) increased reliance on pesticides (b) increased resistance to extreme weather (c) decreased crop yield (d) increased genetic diversity
Which of the following describes bycatch?
(a)It is a common problem with increased pesticide use (b)It is a management technique in CAFOs (c)It is a cause of fishery collapse. (d)It is common in large-scale fishing
Which of the following is an environmental impact caused by synthetic, inorganic nitrogen fertilizer?
(a)Production relies on fossil fuel energy. (b)It reduces global concentrations of carbon dioxide. (c)It contains small concentrations of nutrients. (d)(d) It is difficult for plants to absorb the nutrients contained within.
When deep wells are heavily pumped, one result can be
(a)decreased groundwater recharge (b)spring formation (c)a cone of depression (d)increased groundwater recharge
the green revolution
(a)discouraged the mechanization of agriculture. (b)decreased the energy subsidy of most food. (c)encouraged the use of monocropping. (d)pertained to leafy green plants only.
4. Groundwater recharge
(a)is the result of precipitation. (b)sometimes occurs as a spring. (c)occurs rapidly in confined aquifers (d)occurs after heavy irrigation
ultimately, slash and burn agriculture leads to a net loss of nutrients due to
(a)leaching from rainfall in tropical areas. (b)drought evaporating essential nutrients (c)salinization from fertilizers (d)reduction of soil horizons.
negatives of CAFOs
- ethical concerns of confinement of animals - animals fed grains, instead of natural grasses - crowded for cows which is not comfortable - easier to spread diseases in confined spaces AND antibiotic resistance (anytime u are given an antibiotic it kills 98-99% percent but 1-2% it doesnt bc body is resistant but if ur very close in environment, then they become resistant and the cows will mate and then the next generate is antibiotic resistant) negative bc bacteria doesnt get cured by the antibiotic anymore - high use of antibiotics and nutrient supplements - hormone treatments provided to increase body mass - manure lagoons used
benefits of CAFOs
- minimized land costs - improved feeding efficiency - increased food energy through higher animal body mass
Important distinctions to make when referring to the tragedy of the commons.
1.The land must be common — that is a public or shared resource. 2.And in order for the tragedy of the commons to occur, the land must be degraded. 3.If there is a public apple orchard in a town, and people in the town harvest apples without damaging the trees or the soil, that would not be a tragedy of the commons. The trees and the land will produce more apples the following year. 4.The actions of the townspeople are sustainable, meaning that they are able to do something now without jeopardizing the ability of future generations to engage in similar activities.
if US farmland is being converted to residential uses at a rate of 405000 ha (1 million acres) per year, how much land will be converted in 10 years?
405000 ha / yr times 10 yr = 4050000
based on your answer, if there is roughly 369 million ha (911 million acres) of farmland in the US, what percentage is lost each decade?
4050000 ha divided by 369 million ha = 0.011 times 100% = 1.1%
The causes and consequences of overfishing
After a peak harvest in 1940, overfishing led to a decline in the number of fish caught. In 1973, fishery managers introduced a system of individual transferable quotas. By 1980, the fishery had rebounded.
benefits and consequences of different meat production
Agriculture in the United States (and other developed nations) trends towards higher demand for meat Meat production is less efficient than crop production due to higher demands of water and land space to grow food to feed the meat The high demand for meat and highly mechanized methods of farming have led to over 167 million cows, pigs and lambs slayed in 2020. Billions of chickens, turkeys, and ducks were also slayed. animal products take up more space than vegetables and require more work and cost to the environment and to the economy is significantly more than plants
bycatch
An effect of attempting to catch as much fish as possible leads to unintentional catch of nontarget species when fish get caught too that youre not using for production or anything and killing a species that didnt need to be killed dolphins, seaturtles can be affected by commercial bycatch commerical fishers are considerate of not bycatching because if they respect the environment and keep it in good conditions, they can come back again to fish. if they disrupt the environment then there are consequences
ecologically sustainable forestry
Another approach has gained popularity: Ecologically sustainable forestry. This removes trees in ways that do not unduly affect the viability of other noncommercial tree species. This can be achieved by using animals to pull horses, to avoid soil compaction, and other methods to keep forests in their natural state. Economically, it is difficult to complete with more mechanized logging practices.
Additional benefits and consequences of different meat production methods
Another concern about a high meat diet is the diversion of corn and soy crops to feed livestock instead of people Much more caloric energy is available at lower trophic levels, but only 10-15% of this energy is available from cattle. Not all meat comes from CAFOs.
overgrazing
Another result of allowing cattle to graze in one location for too long grass gets grazed too much
Causes and consequences of overfishing
Another source of protein consumed by more than 3 billion people is fish. Wild caught fish are harvested from fisheries, which are considered a commercially harvestable population of fish within a particular ecological region. Overharvesting of these fisheries can lead to a fishery collapse, where 90% or more of the fish population declines.
fertilizers
Because output has had to increase, an increase in fertilizers has occurred as well. Growing crops and transporting them from the farm system to humans for consumption removes organic matter and nutrients from soil. If these materials are not replenished, they can be quickly depleted. Industrial agriculture, because it keeps soil in constant production, requires large amounts of fertilizers to replace lost organic matter and nutrients. Fertilizers contain essential nutrients for plants — primarily nitrogen, phosphorus, and potassium — and they foster plant growth where one or more of these nutrients is lacking.
Increasing meat production on land and harvesting fish from the oceans
Both meat production and fishing yield a more concentrated food product — more protein and energy per kg of food than vegetables — but also require greater land area and fossil fuel energy expenditure per kg of food obtained. Advances in recent decades that have allowed increased productivity and faster time to slaughter for meat and increased catch for fish have also led to greater environmental impact.
42% is publicly held, with most being held by:
Bureau of Land Management (BLM) - grazing, mining, timber, recreation United States Forest Service (USFS) - timber, grazing, recreation National Park Service (NPS) - recreation, conservation Fish and Wildlife Service (FWS) - wildlife conservation, hunting, recreation
shifting agriculture
Farmers then need to practice shifting agriculture - moving on to another area because of the nutrient-depleted soil. a way to make up for nutrient depleted soil
fertilizer runoff and soils affected by synthetic fertilizers - not on TEST but on EXAM
Fertilizers don't stay where they are applied, and can runoff into water and lead to algal blooms and low-oxygen environments. Soils can also be affected by synthetic fertilizers because they don't also add organic matter, so the CEC and water retention ability doesn't increase at the same time.
humans use land for:
Food Shelter Resources Intrinsic beauty Use of land by humans creates problems that can be controlled by regulations
further groups of pesticides include:
Fungicide - meant to target fungi Rodenticide - specifically meant to target rodents Persistent pesticides - pesticides that remain in the environment for years to decades Nonpersistent pesticides - pesticides the are meant to break down rapidly (weeks to months), but may have to be applied more often
global fish production from fisheries and aquaculture
Global fish production has increased by more than 100 percent since 1980, primarily as a result of the large increase in aquaculture. The graph shows data for capture (wild caught) fisheries-marine (orange), capture (wild caught) fisheries-inland (red), aquaculture-raised fish-marine (light blue), and aquaculture-raised fish-inland waters (dark blue).
examples of commons can inclue:
Global fisheries Public land The atmosphere (pollution and greenhouse gases) Oceans (pollution)
negative effects of plowing and tilling
Higher rates of wind erosion Increased sediments in water Increased decomposition, leading to higher greenhouse gases Long-term soil compaction
benefits and consequences of genetically modified organisms (GMOs)
Humans first began modifying organisms through artificial selection - choosing which animals or plants should reproduce rather than allowing reproduction to naturally occur. Modern genetic engineering has made many new options available to genetically modify crops into a genetically modified organism (GMO). Some benefits of this include: Increased crop yields Increased profits Some areas of concern in using GMOS: Possible allergies to GMOS Effects on biodiversity Regulation of GMOs
cone of depression
If multiple users of an aquifer do not regulate use, a cone of depression expands, lowering the water source for all. (a) When a deep well is not heavily pumped, the recharge of the water table keeps up with the pumping. (b) In contrast, when a deep well pumps water from an aquifer more rapidly than it can be recharged, it can form a cone of depression in the water table and cause nearby shallow wells to go dry.
Irrigation can cause waterlogging, salinization and aquifer depletion
Large amounts of water evaporate and leave behind salts, which can be toxic and impede plant growth. Aquifers can become depleted due to overuse from different sources.
benefits and consequences of green revolution innovations
Many crops are grown in climates that are not ideal Water can become depleted from overuse, causing salinization - the small amounts of salts in irrigation water become highly concentrated on the soil surface through evaporation. These salts can eventually reach toxic concentrations and impede plant growth. If too much water is used, soil can be degraded through waterlogging - a form of soil degradation that occurs when soil remains under water for prolonged periods, impairs root growth because roots cannot obtain oxygen Over time, irrigation can degrade soil by leaving a layer of highly concentrated salts (such as sodium and calcium) at the soil surface and waterlogged soil below
resulting efficiency and fossil fuel impacts of mechanization
Mechanization results in the energy subsidy of agriculture - more energy from humans and fossil fuels is put into, than is received by, the food output. The further food travels, the more energy subsidy is needed. Additional energy (beyond that provided by the Sun) input per calorie of food obtained is greater for modern agricultural practices than for traditional agriculture. Energy inputs for hunting and gathering and for small-scale food production are mostly in the form of human energy, whereas fossil fuel energy is the primary energy subsidy for large-scale modern food production. EXAMPLE •If it takes 20 kg (44 pounds) of grain to feed cattle to produce 1 kg (2.2 pounds) of beef, the energy subsidy is 20. •If it takes 2.8 kg (6 pounds) of grain to feed chickens to produce 1 kg (2.2 pounds) of chicken meat, the energy subsidy is 2.8, which is considerably smaller than the energy subsidy for beef.
effects of fertilizer use
Modern day fertilizers introduce nitrogen (N), phosphorus (P), and potassium (K) to soils. Fertilizers can be used in personal gardens as well as in large scale agriculture. Synthetic fertilizers provide rapid fertilization due to high concentrations of N-P-K
externality
Not often taken into account are externalities - costs that result from, but are not directly included in, the purchase price of the good or service. The degradation of a public resource is a cost not accounted for. The cost or benefit of a good or service that is not included in the purchase price of that good or service, or otherwise accounted for.
forest management
One other approach to forest management can be after-the-fact, meaning areas can be reforested, planting more forest that was previously clear or selectively cut. Another can also be through use of tree plantations, areas that are planted with a single, fast-growing species for the purpose of logging. Land use is regulated through the National Environmental Policy Act (NEPA), which mandates an environmental assessment before use of federal money or federal lands. endangered species act -A 1973 U.S. law designed to protect plant and animal species that are threatened with extinction, and the habitats that support those species.
forest management - endangered species act
One regulation that needs to be considered is the Endangered Species Act, which protects plant an animal species. If a species is found on land and is considered endangered or may become endangered, then the land can't be used commercially.
Pesticide resistance and the impacts of genetic engineering on crops
One way to reduce use of pesticides is increased use of genetically modified organisms (GMOs). Strains of crops can be modified to release toxins to pests so they can't eat the crop. Other methods could include making crops herbicide tolerant, so that crops can continue to be sprayed without being affected by the herbicide. This won't reduce use of pesticides, but can save more crops.
There are 2 main types of fertilizers used:
Organic fertilizers: composed of organic matter from plants and animals Synthetic fertilizers: produced commercially with the use of fossil fuels
Advantages and consequences of pest control methods
Pesticides are meant to reduce pests, but may cause adverse consequences. An alternative to pesticides is integrated pest management, to minimize pesticide inputs Overuse of pesticides can lead to pesticide resistance, a trait that certain individual pests develop when they are exposed to a pesticide and survive, passing on traits aiding in surviving the pesticide. This leads to application of more and stronger pesticides - known as the pesticide treadmill.
pesticides
Pesticides are often needed to remove pests from crops, and can be classified in different ways according to the pest targeted: Insecticides - those that affect insects and invertebrates that eat crops Herbicides - those that target weed plants that compete with crops for nutrients Or can be classified by their range of pests affected: Broad-spectrum pesticides - those that kill many species, quickly Selective pesticides/ Narrow-spectrum pesticides - those that target a narrow range of organisms
aquifer
Pore spaces found within permeable layers of rock and sediment underneath the soil that store groundwater.
unconfined aquifer
Porous rock covered by soil.
changes in agricultural practices throughout human civilization
Progressive innovations have changed agriculture over time. 11,000-12,000 years ago, during the First Agricultural Revolution, species of plants and animals were separated from wild populations and became domesticated. The Second Agricultural Revolution occurred from the 1600s to the 1930s, beginning the mechanization of farming for plowing, planting, and harvesting. During that second period, the US and western Europe moved away from Subsistence farming - farming for feeding primarily family. As the industrial revolution occurred, machines were made to aid in farming. The Third Agricultural Revolution occurred in the 1920s, and is also called the Green Revolution Industrial agriculture (agribusiness) has become the modern form of growing food, using mechanization and standardization of food production
the tragedy of the commons - Public Lands
Public lands are classified according to their uses. About 14% of terrestrial areas and 3.4% of marine areas are protected globally. In the US, public land can be owned at the federal, state, or local level.
current methods of commercial fishing include:
Purse-seine nets Bottom trawl nets Midwater trawl nets Gill nets Longlines Each of these methods is designed to capture large amounts of fish very quickly.
rangeland and forest land management
Rangelands are dry, open grasslands primarily used for grazing cattle, and the most common use of land in the US. When overused due to grazing, biodiversity is lost and erosion can occur. Forests are land areas dominated by trees and other woody vegetation, and can be used for commercial logging. National forests were established as a steady source of timber, so commercial companies pay a fee to use the land through royalties of sales.
Types of irrigation
Several techniques are used for irrigating agricultural crops, each with its own set of costs and benefits furrow irrigation flood irrigation spray irrigation drip irrigation - most efficient
benefits and consequences of Green Revolution innovations
Some of the innovations during the Green Revolution include: Mechanization Fertilizers Irrigation Pesticides Monocropping Farming has moved away from human farming and towards mechanization - meaning that there are now fewer workers, who can be paid higher wages. This has moved farming to an economies of scale model, where average costs decrease, as output increases.
confined aquifer
Surrounded by a layer of impermeable rock or clay, which impedes water flow to or from the aquifer.
ogallala aquifer - depletion
The largest aquifer in the United States is the massive Ogallala aquifer in the Great Plains, which is located under portions of eight western states from Texas to South Dakota. Large amounts of water have been withdrawn from this aquifer for household, agricultural, and industrial uses. Unfortunately, the slow rate of recharge is not keeping pace with the fast rate of water withdrawal. As a result, the depth of the water has declined by about 5 m (16 feet) from 1950 to 2015 and the Great Plains region could run out of water during this century. The Ogallala aquifer is the largest in the United States, with a surface area of about 450,000 km2 (175,000 miles2). The aquifer has declined by about 5 m (16 feet) from 1950 to 2015, mostly due to withdrawals for irrigation that have exceeded the aquifer's rate of recharge.
monocropping
The process of monocropping, or using one species of crop, can exacerbate the : One type of crop may attract more pests, increasing necessary use of pesticides If the crop needs too much water, waterlogging and salinization may occur The crop may deplete soils, increasing necessary use of fertilizers The benefits include: Large expanses of land can be planted at the same time and later harvested at the same time. With the use of large machinery, the harvest can be done easily and efficiently.
total per capita water use per day around the world
The total water use per person per day for agriculture, industry, and households varies tremendously by country.
desertification
The transformation of arable, productive, low-precipitation land to desert or unproductive land due to climate change or destructive land use such as overgrazing and logging Certain regions of the world are much more vulnerable to desertification than others.
environmental impacts of clear-cutting
The two most common ways to harvest trees are clear-cutting and selective cutting.
water table
The uppermost level at which the groundwater in a given area fully saturates the rock or soil
CAFOs
These numbers have led to concentrated animal feeding operations (CAFOs), or large indoor and outdoor structures to create maximum occupancy of animals for maximum output of meat. These are also known as "factory farms."
aquifers are sources of usable groundwater
Unconfined aquifers are rapidly recharged by water that percolates downward from the land surface. Confined aquifers are surrounded by an impermeable layer of rock or clay, which can cause water pressure to build up underground. Artesian wells are formed when a well is drilled into a confined aquifer and the natural pressure causes water to rise toward the ground surface
slash and burn farming
Warm climate areas with nutrient-poor soils have their nutrients contained by plants (e.g., rainforests). Slash-and-burn agriculture clears the land by burning the existing vegetation to release nutrients into the soil. This method is only effective for a few years before the soil becomes completely depleted of nutrients. Long-term, the soil nutrients tend to get washed away, and continued pressure to use land for agricultural production doesn't allow time for nutrients to recover
water as a resource and in wells as used for irrigation
Water in wells can take 10,000-20,000 years to recharge. Water is a resource that is limited, but does cycle through. Overuse prevents water from recycling fast enough to replenish. Efforts are focused on water conservation.
Irrigation can cause waterlogging, salinization and aquifer depletion
Waterlogging can have long term impacts. Plant roots extend into the A and B horizons, and when there is high amounts of irrigation, those roots are flooded. When crops become waterlogged, another problem that occurs is salinization.
manure lagoon
a large, human-made pond lined with rubber to prevent the manure from leaking into the groundwater. After bacteria has broken down the manure — the same process that occurs in sewage treatment plants — the manure can be spread onto farm fields to serve as a fertilizer.
how plowing and tilling interfere with the natural progression of ecosystems
a regular disturbance of soils that occurs in order to turn soil over and aerate, bringing nutrients from the horizon and removing weeds. Plowing is a form of tilling, which includes other activities such as stirring, digging, and cultivation. Both plowing and tilling 1.Turn over the top horizons of soil 2.Aerate soil 3.Expose nutrients to the surface Increase the cation exchange capacity (CEC) of the soil
Concentrated animal feeding operations (CAFOs) can best be described as
a) facilities where a large number of animals are housed and fed in a confined space. (b) a method of producing more meat at a higher cost. (c) a means of producing great quantities of manure to fertilize fields organically. (d) the storing and compacting of grain for use as a nutrient supplement for cattle.
the major commercial fishing methods
a)Purse seine nets surround a school of fish. b)Bottom trawl nets run along the ocean bottom c)Midwater trawl nets are pulled through the water above the ocean bottom d)Gill nets have larger holes in them and are set up like a wall and fish swim into the holes, become caught, and can't escape. e)Longlines can be more than a mile long and have baited hooks every meter (3.28 feet) or so.
in the US, most water is used for:
a)agriculture b)Households c)Industry d)hydroelectric plants
Which irrigation method is the most efficient?
a)furrow irrigation b)spray irrigation c)flood irrigation d)drip irrigation
The energy subsidy in modern agriculture
a)reduces financial cost for food. b)identifies the additional energy beyond the sun added to food. c)provides economic benefits for farmers and consumers. d)can appear to be a violation of the Second Law of Thermodynamics.
Which of the following processes is known to reverse succession?
a.slash-and-burn agriculture b.pesticide use c.the use of GMOs d.fertilization
free-range grazing
allowing animals to graze outdoors on grass for most or all of their lifecycle
Some confined aquifers can be drilled into to gather water at an
artesian well
causes and consequences of overfishing
bycatch Species such as sea turtles, dolphins, whales and sharks' numbers continue to be affected as bycatch of commercial fishing. Ways to address these issues is to practice sustainable fishing. Laws have been enacted to protect fisheries by setting maximum catch limits and shortening harvesting seasons. Movements by individuals to reduce consumption of fish, or to consume only farmed fish, can also reduce these issues.
Other nurtients such as calcium, magnesium, and more potassium
can be provided through crushed rock. The formation of synthetic fertilizers leads to more carbon dioxide released by the fossil fuels used in the process Nitrogen compounds also produce nitrous oxide, another greenhouse gas.
about module 25
examine agricultural methods that utilize the commons to produce a large amount of food at the lowest economic price, but not necessarily resulting in the least environmental impact. It is important to understand modern large-scale agricultural methods, their benefits, and their costs before examining alternatives.
what are externalities?
externalities are costs or benefits not included in the price of a good or service, and the tragedy of the commons can be the result of negative externalities. ex: someone decides to build a dam but what they dont realize is the damage they took down to amke the dam is 4 mil dollars and that is the exrternality things that have to be accounted for
what are the environmental impacts of clear-cutting?
forests may be clear-cut or selectively cut clear cutting may have greater environmental consequences than selective cutting tree plantations are sometimes established as replacement forest after clear cutting
Other methods of producing meat include:
free range grazing nomadic grazing
sources and locations of water used for irrigation
fully formed clay is impermeable to water Ground water and surface waters are used for irrigation. Agriculture is the largest use of water worldwide, with 70% of water use for irrigation. takes aquifer 10 to 20 thousand years Groundwater is stored in pore spaces within permeable layers of rock and sediment, similar to a sponge, known as an aquifer. Aquifers that allow water to easily flow are called unconfined aquifers. Aquifers that are surrounded by impermeable rock or clay are called confined aquifers. The uppermost levels of aquifers are known as the water table.
what does the graph represent?
global grain production has increased from 1950 through the present
As water from precipitation percolates through soil, it passes into the groundwater known as
groundwater recharge
clear cutting
involves removing all or almost all the trees in an area. easiest harvesting method and in most cases most economical It is beneficial economically, but causes environmental disturbance and erosion. Because often one species of tree is planted in the newly cleared area, and other species may not be so successful in these conditions, there can be an overall reduction in biodiversity
what are rangeland and forest land management?
rangeland and forest land are two land types that are sometimes public lands and have the potential to be misused understanding these land types helps environmental scientists reduce environmental harm from their use
selective cutting
removes single trees or a relatively small percentage of trees at a time. This only creates small openings in the forest. It still has the same effects as clear cutting, but in a smaller area. Selective cutting is not as beneficial economically, due to need for repeated trips back to the forest and smaller amounts harvested at a time. The environmental impact of selective cutting is less extensive than that of clear-cutting. However, many of the negative environmental impacts associated with logging remain the same
drip irrigation
slowly dripping water through hoses directly near a plants roots. Useful for perennial crops because the hoses do not have to be moved for plowing, and it has a water-use efficiency of over 95 percent.
increased use of machinery can also cause
soil compaction Carbon monoxide (CO) and carbon dioxide(CO2) are released through this method - leading to local air pollution and a net rise in CO2 When rainforests that process carbon dioxide are removed, more is released into the atmosphere and less can be stored in the forest short-term and long-term.
Water can percolate up to the ground surface, known as
springs
flood irrigation
the entire field is flooded with water. Easy and inexpensive, with 70 to 80 percent water-use efficiency significantly cheaper
nomadic grazing
the feeding of herds of animals by moving them to seasonally productive feeding grounds, often over long distances
tragedy of the commons
the tendency of a shared, limited resource to become depleted or degraded because people act from self-interest for short-term gain becomes depleted if it is not regulated in some way When the farmers make decisions that benefit only their own short-term gain and do not consider the common good, eventually, everybody loses. That is why it is called a "tragedy" — there are no winners. Note that this example describes a situation where the land is public (no individual owns it) and sustainability is not achieved (the land is degraded) When a resource belongs to everyone, it is therefore regulated by no one, which commonly results in the resource being overused. the use of global fisheries as commons has led to the overexploitation and rapid decline of many commercially harvested fish species and has upset the balance of entire marine ecosystems The release of carbon dioxide to the atmosphere or sewage to an estuary are other examples of the tragedy of the commons
What is the tragedy of the commons?
the tragedy of the commons describes the tendency of shared, common resources to be over-exploited
furrow irrigation
trenches or furrows filled with water next to crops. Easy and inexpensive, but has a low water-use efficiency; only 67 percent of the water is accessible by the plants.
The total daily per capita use of fresh water for a country or the world is known as the
water footprint
spray irrigation
water is pumped and sprayed over crops through nozzles. More expensive, but water-use efficiency is 75 to 95 percent.
