Assignment 4: Mid-Term Exam
Question 1
- Permafrost
Permafrost is a thick sub-layer of ground comprising of soil, rocks, ice, or organic materials, which remains frozen for at least two sequential years. It forms the sub-surface soil layer of Polar Regions such as the arctic region.
- Great Lakes-St. Lawrence Hardwood Forest Ecotone
An ecotone describes an area of transition that occurs between biomes. An example of such an area occurs in northern Ontario between the Great Lakes- St. Lawrence and the boreal forests (Liu). The Boreal forest changed into the St. Lawrence wood nearly 7,400 years ago (Liu) when hemlock, white pine, and beech immigrated to the Nina Lake. The population of white pine advanced northward, hence, causing the ecotone to shift about 140 kilometers north of its current position (Liu). The ecotone, however, was encumbered by the physiographic boundary occurring between the Canadian Shield upland and the Clay Belt. Later, neoglacial cooling led to a population decimation of the white cedar in the Clay Belt and the regions’ white pine (Liu). Eventually, the ecotone retreated until it reached Jack Lake at around 2600 BP. It then stabilized to its present position (Liu).
- Water pollutants
Water pollutants are the physical, radioactive, chemical, and pathogenic microbial substances that contaminate natural water bodies. Adverse water quality alteration presently results in large-scale deaths and illness. It also accounts for nearly fifty million annual deaths worldwide, particularly in Asian, as well as African countries (Hogan).
- Luvisolic vs. podzolic soils
Podzolic soils are low-pH soils and have a B-horizon comprising of amorphous material accumulations. Usually, the soils form in sandy materials covered by vegetation in cold and humid areas. Water percolating through the porous substances leaches elements such as calcium and causes the development of acidic conditions. In contrast, Luvisolic soils possess eluvial horizons that have leached out clay after heavy rains or snowmelt, and illuvial horizons containing clay deposits. Luvisolic soils occur primarily in forested areas whose climate ranges from sub-humid to humid. In addition, the parent materials must include an appreciable clay amount in order for Luvisolic soils to form. In Canada, the soils cover nearly nine percent of the land area.
- Stratification
Stratification is the formation of layers that prevent the mixture of different strata. In water bodies, stratification causes the formation of layers that hinder mixing, hence, may cause euxinia or anoxia. The process occurs due to the presence of water masses that have different properties such as temperature, oxygen content, density, and salinity. For example, stratification due to density describes the vertical water density distribution in bodies of saline or fresh water. The stratification occurs owing to the formation of a vertical density gradient referred to as the pycnocline. The stratification stability depends on water depth, density, and vertical gradient. Therefore, an increase in vertical gradient and density, with increasing depth increases the stratification stability. Similarly, a decrease in density gradient, water density, and depth result in unstable stratification. Stable stratification reduces the vertical exchange of momentum, heat, and mass while unstable stratification causes intense vertical exchange to occur in a water body.
- Attributes of communities that cannot be studied by examining individuals
Community attributes that cannot be studied by examining individuals include competition and mutualism. Different species enter into a competitive interaction in order to obtain a finite resource. It limits community biomass and species richness. In mutualism, the involved species derive different benefits from each other.
- Evidence of glaciation near the community
Glaciation refers to the recession, formation, and movement of glaciers. Glaciers molded much of the Canadian landscape for thousands of years. The processes widened valleys, sculptured moraines, and smoothened bedrocks. In addition, glaciation left behind vast amounts of sediments, such as gravel, which are significant in the Canadian export economy. Large gravel deposits occur in glacier-derived braided streams, such as Yukon’s Donjek River. The Donjek Glacier in the mountain of Saint Elias fed the river. Moreover, the deposition of gravel and sand by glacial streams has caused the formation of eskers and kames. Lakes created from glacial deposits are found across Canada. Their formation occurred when glaciers dammed existing lakes or left nonporous deposits that prevented draining. Glacially dammed lakes include Lake Agassiz, which covers large parts of Ontario, Manitoba, and Saskatchewan. Beach ridges, comprising of sand and gravel, form along the margins of quondam glacial lakes.
- Secondary succession following fires in the forests of Banff National Park
Secondary succession involves a series of community alterations that occur in a formerly colonized, but damaged or disturbed habitat. Parks Canada utilizes a prescribed burns’ method in the Banff National Park’s forest, which imitates the effect of natural fire. The fire destroys different types of plant life. However, the roots, seeds, and other parts of plants remain either inside or above the soil. Gradually, the plant materials allow the regeneration of the previous forest. The process is important because it destroys various pests and disease agents.
- Differences between a living hawk and a non-living object such as a rock
The term hawk describes a category of medium-sized or small predatory and diurnal birds. In contrast, a rock is a stable aggregate comprising of minerals that occur naturally. Unlike rocks, living hawks carry out biological processes such as feeding, reproduction, and excretion. In addition, hawks fly from one location to another while rocks remain stationary until external forces cause their movements. Hawks have a limited lifespan while rocks can exist continuously unless external forces cause their disintegration. Therefore, rocks are suitable for construction purposes while hawks are kept as pets. Biologically, hawks are significant because they control the numerical abundance of relatively small animals such as mice. In contrast, rocks have geological significance because they determine the characteristics of the earth’s lithosphere.
- Biotic potential
Biotic potential describes the highest reproductive capacity of the organisms kept under optimal environmental conditions. Usually, the potential is expressed as a percentage increase per year or the time that the population takes to double in size. In disease-related studies, however, biotic potential refers to the number of susceptible organisms that contract the disease from infected individuals. Environmental resistance and other factors that inhibit the numerical increase in abundance restrict the complete expression of an organism’s biotic potential. Such factors include a lack of light, space, and suitable substrate. In addition, unfavorable climatic conditions, deficiencies of essential chemical compounds and adverse genetic changes limit the biotic potential’s expression. Other defining aspects include the inhibitory effects of parasites, predators, and disease organisms.
Question 2
a) Status of the Lambton power plant near Sarnia, Ontario
The Lambton power station began electricity generation, using coal fuel, in 1969. Its total generating capacity was 1,976 megawatts before some of the generating units were permanently shut down in 2010. In 2013, the power-generating plant stopped utilizing coal as fuel. The plant is no longer in operation; nevertheless, two of its generating units are being preserved for future conversion into units that can utilize alternative fuels.
c) Loss of honeybees and other pollinators
Honeybees, as well as other insect pollinators, are facing a sharp annual decline worldwide. The decline, which is referred to as the Colony Collapse Disorder has begun reducing food supplies. In addition, it continues to reduce the variety and number of herbs, as well as tree crops and flowers. Presently, the introduction of new pesticides, insecticides, and genetically engineered plants has reduced the abundance of the pollinators significantly. Further, expanses of the pollinator habitats have been lost to resource extraction, agriculture, and urban growth. Although such land uses can supply floral resources and bring benefit to some pollinators, many butterflies and bees are habitat-specific. Therefore, the loss of habitat, which forms the site for nesting, overwintering, and foraging for nectar, can affect the pollinators adversely.
e) Cattle manure
Cattle manure is a waste product generated by domesticated bovines such as cows. The gradual decomposition of cow-dung forms cattle manure. It is then used to increase the yield of various crops. The decomposing cow-dung is valuable because it contributes to soil fertility by adding nutrients.
f) Use of genetically modified foods in the Canadian agroecosystems
Genetically modified (GM) foods are obtained from organisms that have undergone genetic modifications. Since 1994, Canada has approved the use of more than eighty-one GM foods, which include wheat, canola, soybeans, and corn. The foods are used for both human and animal consumption.
g) Fracking
Fracking is the procedure of taking out natural gas from sedimentary rock layers within the earth. The process allows the extraction of natural gas from shale plays that were formerly unreachable through conventional technologies. The technique is also referred to as hydraulic fracturing.
Question 3
Energy flow and cycling of nutrients in a typical deciduous forest in Ontario and a typical central Ontario Lake of about 5 ha2 in size and depth of averaging 3 m
A typical deciduous forest experiences a dry cold season in which trees lose leaves. Fire is an essential aspect of the nutrient cycle that occurs in such forests. It burns the plants growing on the forest floor and returns their nutrients to wildflowers and trees. The bacterial decomposition of the leaf litter enriches the soil with nutrients, which are then taken up by various plants. Major plants in such forests include maple, oaks, hickories, and sycamore trees. Typical animals include mice, white-tailed deer, raccoon, and predatory birds. The energy source in the ecosystem is the sun. The plants use the energy to build biomass through photosynthesis. The deer and other herbivores graze on the plants while predatory animals feed on the herbivores. The energy, therefore, flows from the primary producers to the secondary producers and finally to the tertiary consumers.
In a typical shallow lake, the aquatic macrophytes and algae build biomass through photosynthesis. Various herbivorous fish feed on the algae and are then fed on by the piscivorous fish. Thus, in a typical lake, the sun’s energy is stored in the primary producers’ biomass. It then moves to the secondary and tertiary consumers through their feeding habits. Fish wastes undergo decomposition and release nutrients into the water. The primary producers then take up the nutrients and use them for growth.
Question 4
Alberta has impressive Rockies whose foothills tower to the west. The province has five national parks and five significant sites that UNESCO has designated as World Heritage Sites. Therefore, Alberta has taken measures to preserve the sites. The province has raised the bar for the rest of Canada by returning acres of farmland to their natural habitat. It has also increased water conservation by pipelining recycled wastewater to an oil refinery. Recently, government officials have observed that the province’s tourism has focused primarily on environmental conservation and, hence, minimizing degradation (Banff).
Saskatchewan occurs in western Canada and between the provinces of Manitoba and Alberta. It is located north of the U.S. states of Montana and North Dakota. Saskatchewan encompasses nearly 100,000 lakes, five million acres of parklands, and eighty million woodland acres (Barber). The vast natural resources form a quality stage for ecotourism. As a result, eco-tourists can enjoy nature-based recreation activities that enhance the appreciation and conservation of heritage sites. Along with an ample mix of culture and history, Saskatchewan provides visitors with abundant wildlife, endless freshwater fishing, and uncrowded parks. In addition, it offers water-based recreation opportunities, outdoor adventures such as horseback riding and canoeing, farm vacations, and accessible golf courses.
Conservation efforts have allowed tourists to view animals of historical significance such as the bison. The reintroduction of the bison to the prairies of Canada has been hailed as a significant conservation success story (Canadian Bison). Millions of bison once ranged on the North American plains, before the European settlement. On the Canadian prairies, the bison numerical abundance was as high as ten million animals (Canadian Bison). Nevertheless, as the 19th century closed, the Canadian prairies had virtually no plains bison. Primarily, the mass extermination resulted from unrestricted hunting, as well as weak and un-enforced conservation legislation (Canadian Bison). Consequently, the Canadian herds failed to withstand the combined pressures arising from subsistence hunting by the natives, as well as the thriving fur trade that demanded pemmican and buffalo hides.
Outstandingly, some wood bison, whose range included the forests of northwest Saskatchewan and northern Alberta, survived the slaughter. Eventually, the Canadian government carried out significant conservation of the wood bison. In 1922, for example, the government established a massive ecological preserve, the Wood Buffalo National Park, which spans the Alberta –Northwest Territories border (Canadian Bison). Presently, the conservation efforts have allowed more than 250,000 bison to roam on Canadian farms, public lands, and ranches (Canadian Bison).
Question 5
Physical and ecological attributes of the Arctic Biome and its susceptibility to damage by human activities
The arctic tundra occurs in the northern hemisphere. It encircles the North Pole and extends southward towards the taiga’s coniferous forests (University of California Museum of Paleontology (UCMP)). The arctic biome has cold and desert-like conditions, with a growing season that ranges from fifty to sixty days. The biome experiences an average winter temperature of nearly - 34° C and a mean summer temperature of 3-12° C (UCMP). Rainfall, however, varies in different parts of the arctic region. Annually, the region has a precipitation, including the melting snow, of between 15 to 25 cm. Soil formation occurs slowly creating permafrost, which consists primarily of gravel and fine materials (UCMP). The saturation of the ground surface with water results in the formation of ponds and bogs that provide plants with moisture. The arctic and subarctic have nearly 1,700 kinds of plants, which include reindeer mosses, small shrubs, grasses, sedges, liverworts, as well as foliose and crustose lichen (UCMP). The plants are adapted to soil disturbances and sweeping winds.
In the arctic, faunal species are also diverse. There are herbivorous mammals such as the caribou and lemmings, as well as carnivores that include the arctic foxes, polar bears, and wolves. Migratory birds in the region include ravens, falcons, snow buntings, loons, sandpipers, and snowbirds. There are also insects such as mosquitoes, moths, flies, grasshoppers, and arctic bumblebees. Cod, trout, salmon, and flatfish are some of the fishes found in the region. The animals are well adapted to resist the long and cold winters. Further, they breed quickly during the summer.
Despite the harsh and remote conditions of the arctic, humans have had a long history in the region. For example, the first settlers who arrived in North America from Asia over 20,000 years ago journeyed through the immense tundra settings on the two continents. Consequently, human activities in the tundra ecosystems have increased, primarily through the building of settlements and procurement of food. Humans have altered the landscape significantly through various construction activities, as well as the development of roads, mines, and ski resorts. Moreover, activities such as oil drilling and hunting have polluted the surroundings and threatened wildlife abundance in the arctic ecosystems. Scientists are concerned that the expansion of such activities, along with the air pollution that depletes the ozone layer, ultimately hastens climate change (Porter).
Works Cited
Banff, Aurum Lodge. Alberta ecotourism industry pushes for go-slow approach to popular trend. Calgary Herald, 16 Aug. 2010. Web. 30 Nov. 2014.
Barber, Sally. Ecotourism of Saskatchewan. Travel Tips, n. d. Web. 30 Nov. 2014
Canadian Bison. Bison - Canadian Conservation Success. Canadian Bison, n. d. Web. 30 Nov. 2014.
Hogan, C. Michael. Water pollution. EoE, 17 Nov. 2014. Web. 30 Nov. 2014
Liu, Kam-Biu. “Holocene Paleoecology of the Boreal Forest and Great Lakes-St. Lawrence Forest in Northern Ontario.” Ecological Monographs, 60, (1990):179–212. Web 1 Dec. 2014
Porter, Stephen. Climate Change and Arctic Impacts. Center for International Environmental Law, n. d. Web. 30 Nov. 2014.
