- Explanations
- Food miles and 100-mile diet
A 100-mile diet refers to a diet that consists of foods raised and grown within 100 miles of a dinner table (Tancock). Usually, food travels some 1,500 miles before reaching the dinner table in North America (Tancock). The traveling miles are called “food miles” and affect the environment, quality of food and farming practices. Food miles increase carbon emissions through the numerous planes, boats, and trucks involved in the transport of food materials. In addition, food miles promote unsafe agricultural practices because the consumers are unlikely to visit the farms that produce their foods. Consequently, food miles may encourage the use of banned pesticides and child labor in the food-producing countries (Tancock). Chemicals are also added to food substances to reduce the rate of spoilage; hence, the foods are of low quality.
- Organic and genetically-modified foods
Organic foods refer to foods obtained through organic farming, a technique that utilizes natural processes to produce food. Hence, artificial pesticides and fertilizers are not incorporated into the production process. However, organically certified insecticides may be used in limited quantities. The farmers use natural fertilizers and manage weeds through crop rotation. In Canada, organic agriculture has expanded since the 1980s.
In contrast, genetically modified foods have not gained wide popularity due to their perceived health impacts. Genetically modified (GM) food materials are obtained from organisms whose genes have been altered (EatRight Ontario). For example, a genetically modified soybean has a gene from soil bacteria. The gene allows the soybean to grow even when sprayed on using an herbicide. In a related case, the genetically modified corn contains a gene that produces a toxin. The poison kills the corn borer and helps the plant to grow without damage. Since 1994, over eighty-one GM foods have been sanctioned for human consumption in Canada (EatRight Ontario). Such foods include corn, lentils, rice, and soybeans (EatRight Ontario). However, various consumers have raised concern over the possibility of adverse environmental and health effects that may arise from the consumption of GM foods (Anderson et al.).
In Canada, domesticated animals and plants have shown responsiveness to genetic manipulation. For almost all species grown in the country, plant breeders have produced new varieties that mature faster and are more tolerant to drought, cold, pests, and spoilage.
- Pesticide resistance and pest resurgence
Researchers have observed that pests sometimes develop resistance to chemicals; hence, chemical pesticides lose effectiveness with time. For example, potato farmers in New Brunswick controlled Colorado potato beetle with only a single spraying of pesticide in the 1980s. In the 1990s, however, farmers used up to six sprayings but the beetles still attacked the potatoes. Therefore, the pesticide had lost its effectiveness because the beetles gained resistance. The insects’ immunity is acquired through genetic mutations.
Synthetic organic pesticides also cause pest resurgence. The problem usually occurs after an insecticide eliminates a pest outbreak, but the population recovers and increases to more severe levels. Such recovery is often followed by secondary pest outbreaks that increase the population of previously less abundant insects. Secondary outbreaks, as well as resurgences, occur because more insects than the targeted pest species are involved in food webs. For example, insecticides affect more predaceous pests than the herbivorous insects. Consequently, the lack of predation increases the population of herbivorous insects resulting in secondary outbreaks and pest resurgences.
- The “three sisters” in Joseph Boyden’s book
The three sisters referred to in the book represent squash, corns, and beans. The novel explores grief, loss, and love. In the story, there are moments of travel and peace, as well as the planting and harvesting of the crops referred to as the “three sisters.”
- Canada’s apple growing regions and the importance of pollinators
The apple trees grown in Canada have been introduced from Eurasia’s cooler regions (Appleman). They are deciduous and woody perennials. Moreover, the trees have flower and vegetative buds that do not grow in the autumn. Consequently, the buds require a significant amount of the winter cold before resuming growth in the next spring. The apple is the most popular of the species grown in the fruit tree regions. The Central agricultural region that includes Quebec and Ontario is Canada’s most productive region. In the country, the main fruit-growing area is the Niagara Peninsula, which lies on the southwestern section of Lake Ontario (Gardner). The area is called the Niagara Fruit Belt and extends from the Niagara River to Hamilton, along Lake Ontario’s shore. However, about 17% of the total apple orchards in Canada occur in Quebec. Most of the orchards are near Deux-Montagues, Missisquoi, and Huntington. In the Atlantic Region, the Annapolis Valley is the principal apple producing area (Statistics Canada). The Valley stretches for nearly 130 km between Kentville and Bridgetown. Each year, the area produces nearly 50, 000 tons of apples.
Cross-pollination is the primary fertilization mode among apples (Jackson 286). Therefore, growers maintain pollination trees in every orchard, where they keep honeybees to spread the pollen. The apple development then commences after pollination and fertilization. Hence, honeybees are significant in the development of apples.
- Impacts of weeds and their control in Canada
Weeds are a serious hindrance to high-yielding agroecosystems. Each year, the losses to Canadian agroecosystems are estimated at 750 million dollars. In Saskatchewan, for example, farms spend nearly $311 million annually in an attempt to control weeds. Weeds reduce crop yields by using up the available soil nutrients, moisture, and light. Some of the weeds taint the flavor of milk while others are poisonous to livestock. Moreover, they contaminate commercial seeds and increase the costs involved in farming through tillage and spraying of herbicides. Weeds also reduce the urban ecosystems’ esthetic value while some weed species such as ragweed produce pollen that causes allergic reactions. The most serious Canadian weeds include Canada thistle, wild oats, leafy spurge, St. John’s wort, tansy ragwort, and diffuse knapweed. The weeds are native to Europe and were introduced accidentally into Canada.
Weeds are controlled primarily through herbicides or tillage. Herbicides contain toxic substances that directly poison weeds or accelerate their rates of growth and, hence, result in their death. In the use of herbicides, the objective is to minimize weed abundance and maximize the profit derived from the farming operation. About 20% of all cultivated land in Canada was sprayed with herbicides in 1970 with the aim of controlling brush and weeds. However, the figure doubled to nearly 51% by 1985, with the greatest spraying intensity occurring in southern Manitoba and southern Ontario. The most effective herbicides use the hormone or growth-regulating chemical compounds called phenoxyacetic acids. An example of such compounds is the 2, 4-dichlorophenoxyacetic acid (2, 4-D), which is widely used in herbicides. The use of 2, 4-D, as well as the related chemical compound 2, 4, 5-T has improved agricultural productivity in Canada significantly. The compounds are useful because only small amounts of the herbicides are required to kill weeds. Yield increases of between 10 and 50 percent, usually, result from the removal of weeds from corn, wheat, barley, and other crops. In addition, the use of herbicides saves operational costs and increases the ease of harvest. 2, 4, -D is a selective herbicide, which selectively kills weeds without harming crops. The selection occurs because crops such as cereals do not absorb the chemical as readily as broad-leaved plants such as Canada thistle. In addition to their use in agriculture, herbicides are used in forestry to reduce the competition from hardwoods and, hence, allow the efficient growth of conifers.
Unfortunately, the use of some herbicides is associated with environmental damage, as well as the development of weed’s resistance. For example, the herbicide metolachlor is transported into streams through soil erosion. Consequently, it affects aquatic macrophytes and disrupts aquatic ecosystems. Attempts, therefore, have been made to control weeds biologically. The biocontrol of weeds involves introducing organisms that consume the weed and, thus, reduce its vigor or density. The method uses the principle that natural enemies are significant in limiting the abundance and distribution of plants. The ideal biocontrol agent exerts stress on the target weed and depresses it below an economic threshold. In Saskatchewan, for example, the nodding thistle has been controlled using the seedhead weevil.
- Loss of productivity due to salinization and compaction
Presently, Ontario produces about three-quarters of Canada’s corn. Apart from perennial forages, corn is planted on more farmland than other crops. In addition, the change from mixed farming to the use of specialized systems has increased the efficiency and productivity of agricultural practices. However, the specialized practices have caused adverse effects on the environment. For example, the growing of corn has been linked to an increase in soil degradation. Hence, it leads to soil compaction and loss of soil’s organic matter.
The removal of harvested crops and their residues from farms also leads to the loss of organic matter. Consequently, it reduces water penetration and the growing capacity of soils. The reduced water infiltration causes the retention of water on land surfaces. The water then evaporates resulting in the accumulation of salts on soil surfaces. Annually, the process of salinization results in cumulative economic impacts of more than $100 million.
Soil compaction is another form of soil degradation that is common across Canada. It occurs when heavy farm implements are frequently used on farmlands. Compaction reduces soil aeration and restricts the movement of water and air in the soil. Therefore, the dense soil structure hinders water infiltration and increases the risk of water erosion and salinization. Moreover, the degradation impedes the penetration of roots through the soil and, hence, plants experience nutrient and moisture stress. As a result, severely compacted soils reduce the crop yield by almost 60%.
- Peregrine falcons, the science of ecology, and DDT in relation to the environmental movement
Organochlorines such as DDT accumulate in animals’ fat tissues and do not break down readily in the environment. Consequently, DDT was banned in the USA and Canada in 1973. Unfortunately, organochlorines are still in use in parts of Central and South America. As a result, the pesticides have been linked to various environmental problems. In 1982, for example, a male peregrine falcon found dead at the Rankin Inlet on Hudson Bay was tested for toxic chemicals. The test result showed that the falcon’s brain had 2 ppm of dieldrin, 1.1 ppm oxychlordane, 60 ppm PCBs, and 14 ppm DDE. The conclusion was that the bird had died from chemical poisoning in a region far from the location where the chemicals were in use. Researchers suspect that falcons experience pesticide exposure when they prey on the native birds of Central and South America where DDT is still in use.
The chemical by-products of human activities have contaminated birds in all parts of the world. In the 1960s, it was observed that peregrines were declining rapidly due to the use of organochlorines. As a result, the birds became a symbol of a continuing environmental movement that seeks the proper utilization of pesticides. The DDT in the contaminated birds that were fed on by the falcons inhibited the development of eggshells. Therefore, the falcons’ eggs were broken easily during a brooding adult’s movements on the nest. The result was a decrease in the numerical abundance of falcons. After DDT had been banned in the North America, there was a decline in the environmental levels of DDT. The reduction in the environmental level of the chemical has led wildlife officials to attempt reintroducing falcons in the areas of Canada where they were exterminated. In 1990, organizations such as the Falconbridge Ltd., World Wildlife Fund, and Laurentian University initiated “Project Peregrine –Sudbury” that helped in bringing back the falcons to central Ontario.
The concern over the misuse and the adverse long-term impacts of insecticides such as DDT has led to the application of ecological science. Ecological pest management manipulates natural factors to protect forests and crops without jeopardizing environmental health or upsetting the ecosystem. The method is called biological control because it utilizes natural factors in pest management instead of synthetic pesticides. Biological control includes genetic control, control by natural enemies, natural chemical control, and cultural control.
- Ecological History and Damage caused by:
- Emerald ash borer
Argrilus planipennis has killed numerous Ash trees in the Great Lakes States and the southwestern areas of Ontario (Invading Species). Its significant environmental and economic threat has led the Food Inspection Agency to restrict the movement of firewood from Ash trees forests (Invading Species). The pest attacks both stressed and healthy trees when its larva tunnels through the trees’ vascular systems. The insect is dispersed to long distances as infested Ash wood materials such as firewood are moved from the forest.
- Spruce budworm
Spruce budworm is the most common pest in Canadian forests. In Quebec, for example, the recent outbreak of the pest led to a loss of over 200 million cubic meters of lumber. The moth’s caterpillar feeds on balsam fir, as well as the white, black, and red spruce. The defoliation caused by the pest leads to tree mortality, growth loss, top-kill, economic losses, and stand mortality. For example, mature fir stands experience mortality rates of between 70 to 100% in the event of an outbreak while immature stands suffer a mortality rate of 30 to 70%. The stands that comprise of over 50% balsam fir or have an over-maturity of over 50 years are the most vulnerable to spruce budworm damage. In the last 200 years, seven principal outbreaks have been reported in Canada. However, the major outbreaks were separated by about 30 to 60 years of low populations, which were kept in check by predators and adverse weather conditions. In the past, the moths were not considered as pests until the 1930s when the paper and pulp industry established an economic demand for spruce fiber and fir. By 1950, New Brunswick’s economy relied heavily on six paper and pulp mills. Thus, significant social and economic considerations led to the use of insecticides to protect foliage and, hence, control the outbreak of budworm.
- Gypsy moth
The moth, Lymantria dispar, is native to the temperate regions of southern Asia and Europe. In 1869, a French naturalist introduced the moth from Europe into North America. At Medford, Massachusetts, the biologist attempted to cross the gypsy moth with the silkworm moth. However, some of the gypsy moths escaped and colonized nearby trees. Unlike the native species, the introduced moth was difficult to control. Initially, the dispersal of its larva followed the prevailing winds and, thus, spread the moth to the east and north of the country. At present, the moth has established on trees from Virginia to Quebec and southern Ontario. The pest reached Sudbury’s oak trees in 1991.
Several factors are attributed to gypsy moths’ success in North America. For example, they can feed on a wide variety of available food substances, have a high potential for reproduction, and their egg masses or pupae are spread into new areas by automobiles. In addition, their favorite host plants have a wide distribution, and their instar larvae are dispersed easily over short ranges. The moths are also successful because they lack natural enemies in the areas they infest. Consequently, a combination of factors has led to devastating infestations in various sections of eastern North America, with a population of about 12, 500, 000 moths per hectare defoliating forests.
- Mountain pine beetle
The pine beetle, Dendroctonus ponderosae, has destroyed huge quantities of spruces and pines in western Canada (Natural Resources Canada). Their impacts are noticeable especially in Waterton Lakes National Park. The species colonizes a living tree and must kill it for the brood to grow. The colonization leaves fine boring dust at the base of the tree. Subsequently, the crown of the tree shifts from green to a light brown color, and the leaves begin falling. The outbreak of Dendroctonus ponderosae is caused by the adult’s preference for injured and weakened trees, as well as trees with a diameter of over 20 cm and age of above 80 years.
- Energy Utilization in a Modern Canadian Agroecosystem
An agroecosystem is a site of agricultural production that is viewed as an ecosystem (Gliessman). The essential components of an ecosystem are the biotic factors, which interact with abiotic factors. The biotic factors or the species in a community have nutritive needs. The meeting of such needs forms a trophic structure (Gliessman). Plants are the foundations of every terrestrial trophic structure because they capture solar energy and store it as chemical energy in their biomass. The stored energy is then utilized by other species as they feed on the biomass. Hence, plants are autotrophs because they obtain their energy needs without preying on other species. Consumers, which utilize plant biomass, include the herbivores that feed on the plants and the predators that feed on the herbivores. Each organism in an ecosystem uses energy for physiological processes. The energy brought by plants into the system is measured by determining the biomass of the plants.
The conversion rate of solar energy into biomass is estimated by determining the gross primary productivity (Gliessman). However, the net primary productivity is obtained by subtracting the energy utilized by plants from the total primary production. Nevertheless, only a small proportion of the biomass at a particular trophic level is converted into biomass at the next level because a large energy portion is lost as heat. Heat losses occur through respiration. Moreover, a significant percentage of the biomass at each level is either not consumed or is not digested. Thus, detritivores and decomposers break down the biomass in the fecal waste. During decomposition, much of the energy used to produce biomass is lost as heat.
In an agroecosystem, however, human manipulation alters the energy flow. Inputs are derived mainly from human sources and are usually not self-sustaining. Inputs include pesticides and fertilizers. Therefore, agroecosystems are open systems where significant amount of energy is directed out of the system during harvesting (Gliessman). In natural ecosystems, however, the energy stored in biomass is recycled back into the system.
The human manipulation in agroecosystems includes the use of machinery, which consume energy in the form of gasoline and electricity. Part of the energy is used to run the machines while a significant proportion is lost as heat energy.
- Source of Gasoline for Automobiles and Electricity for Home lighting
The gasoline used to run automobiles is the result of a process, which begins back in time. Millions of years ago, autotrophs converted solar energy into biomass through photosynthesis. Some of the biomass was consumed by herbivores and became incorporated in their bodies. Similarly, the predators fed on some of the herbivores. However, the remaining plants, herbivores, and predators eventually died and were covered with layers of earth through geomorphologic processes. Consequently, the biomass was subjected to immense pressure as the ground layers piled up. Subsequently, the biomass converted into crude oil over millions of years. Presently, crude oil is extracted continuously and transported to refineries where it is purified into gasoline. The gasoline is then used to drive vehicles.
The electricity used to light homes is mainly generated from wind-powered turbines, nuclear power plants, and hydroelectric plants. The electric power from the different sources is fed into the national grid and distributed through a network of wires until it reaches individual homes. The electricity in the national grid is in the form of alternating current. However, most of the appliances used at home have resistor-capacitor circuits that convert the alternating current into direct current, which is then used to run the devices.
Works Cited
Anderson, Jon C., Cheryl J. Wachenheim, and William C. Lesch. “Perceptions of Genetically Modified and Organic Foods and Processes.” AgBioForum 9.3 (2006): 180-194. Web. 17 Nov. 2014.
Appleman. History of Apple Growing in the Maritimes. Appleman, n. d. Web. 17 Nov. 2014.
EatRight Ontario. Understanding Genetically Modified Foods. Dietitians of Canada, n. d. Web. 18 Nov. 2014.
Gardner, John. What You Should Know about Fruit Production in Ontario. Ministry of Agriculture and Food, n. d. Web. 17 Nov. 2014.
Gliessman, Stephen R. Agroecology: The Ecology of Sustainable Food Systems. 2nd ed. New York: CRC Press, 2007. Web. 17 Nov. 2014.
Invading Species. Emerald Ash Borer. Invading Species Awareness Program, n. d. Web. 17 Nov. 2014.
Jackson, John E. The Biology of Apples and Pears. Cambridge: Cambridge University Press, 2005.
Natural Resources Canada. The threat of mountain pine beetle to Canada’s boreal forest. 6 Oct. 2014. Web. 18 Nov. 2014
Statistics Canada. Sharp decline in number of farms in Atlantic Canada. Statistics Canada, n. d. Web. 17 Nov. 2014
Tancock, Kat. Interview: The 100-Mile Diet. Canadian Living, n. d. Web. 18 Nov. 2014
