CIV220 Exam Notes.doc

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University of Toronto St. George
Civil Engineering
Robert Andrews

CIV220 Urban Engineering Ecology Exam Notes Bagley L3: Fundamentals of Ecosystems – Mass: • Ecosystem A self-sustaining biological system that consists of individual organisms, populations of organisms and communities of populations living together and interacting with each other and the surrounding environment. • Mass and energy are conserved in ecosystems Bagley L4: Fundamentals of Ecosystems – Energy: nd • 2 Law of Thermodynamics The amount of useful energy in a system decreases with every energy transfer, OR for every spontaneous reaction that occurs, entropy increases. • Energy flows through ecosystems and it is the flow of energy that drives the cycling of mass in ecosystems. Bagley L6: Energy Flow through Ecosystems: • Photoautotroph Organisms that can convert light energy to chemical bond energy and convert carbon dioxide and other inorganic nutrients to organic molecules. • Heterotroph Organisms that can only obtain energy for life from chemical bond energy. Bagley L5: Food Chains & Bioaccumulation: • Food Chain Movement of energy from one trophic level to another. • Detrivores Organisms that eat detritus (waste material), e.g.; vultures, fungi, bacteria, etc. • Toxicity The effect of toxic compounds. There are two types of toxicity. o Acute Toxicity Toxicity is manifested rapidly, or acutely. Responses include disease, loss of reproductive capability and sever mutations. It is caused by exposure to highly toxic compounds and large doses of less toxic compounds over a short period of time. o Chronic Toxicity Toxicity is manifested slowly, or chronically. It is caused by long-term exposure to small concentrations of toxicants. An example is the toxicity caused by carcinogens. • Bioaccumulation The concentrating of chemicals in species higher up in the food chains. Materials that bioaccumulate are pesticides, heavy metals, PCBs, and fat-soluble chemicals. • Global Distillation The spreading of harmful chemicals through a cycle of evaporation, atmospheric circulation and, eventually, condensation in sub-zero temperatures. This processes has resulted in colder areas like the poles becoming “sinks” for these compounds. Bagley L12: Cells and Metabolism: • Organism Self-contained biological unit that is capable of metabolism and reproduction. Organisms are made up of cells, and can even be single- celled. • Cell Self-contained biological package of molecules capable of metabolism. Three main components: o Cell Membrane o Genetic Material (inside nucleus) o Cytoplasm • Metabolism The sum of all chemical reactions occurring in living cell. • Cell Membrane It is the boundary between the cell and the rest of the universe. It is the cell’s system boundary. It is made up of a double layer of phospholipids, which are large molecules that have hydrophilic and hydrophobic ends. This double layer lines up in a manner so that the hydrophilic ends are towards the outsides so as to allow for the movement of particles in and out of the cell. Membrane proteins also help facilitate the movement of constituents across the membrane. • Genetic Material The chemical compounds that store information required by the cell. It is deoxyribonucleic acid (DNA). It is a polymer made of nucleotides. • Cytoplasm Everything else inside the cell that is not genetic material or any other organelle • Proteins Polymers made of amino acids. Proteins perform several functions: o Structural Form the principle components of hair, horns and spider webs. o Energy and material storage For example, egg components. o Transport For example, haemoglobin carries oxygen. o Cell Movement For example, contractile proteins in muscle. o Chemical Catalysts For example, enzymes. Catalysts are substances that increase the rate of reactions under a given set of conditions, but are not consumed the by the reaction. • There are two types of metabolism: o Anabolism The chemical reactions conducted to build cell components (synthesis). For example, plants take carbon dioxide and water and produce sugar, cellulose and many other plant products. o Catabolism The chemical reactions conducted to generate energy and electrons. Catabolic reactions  Provide energy to maintain cell activities such as movement and cell repair.  Provide energy to be used to synthesize new compounds and cells.  Provide electrons to be used for synthesis. A cell stores the energy form catabolism to use in anabolism. D&M Ch.6: Functional Ecology and Succession: • Plant CSR Theory Three primary threats to the survival of primary producers: o Stress Anything adversely affecting the ability to accumulate carbon through photosynthesis, e.g.; shade reduces productivity; cold climate. o Disturbance Anything that damages or destroys the biomass of plants and bacteria, either directly (e.g.; forest fire) or indirectly (e.g.; unstable substrate scree slope). o Competition Effects of other plants or bacteria in competitive foraging for resources such as water, light, nutrients and space. The overview of the CSR theory shows that: o Low stress, low disturbance  Competitors (C-strategists) o Low stress, high disturbance  Disturbance Tolerators (R- strategists) o High stress, low disturbance  Stress Tolerators (S-strategists) o High stress, high disturbance  Uninhabitable • r-K Model (Opportunist- Equilibrium) According to this model, there are two types of survival strategies: o r-strategists who are opportunists. Often small and rapidly dispersed, and are adapted towards rapid reproduction. o K-strategists are equilibrium species. Lower rate of reproduction larger and better at competing for resources and tend to live longer. • Succession The shifting of one ecosystem to another over time. Primary succession refers to the development of an ecosystem in an environment that previously had no life, e.g. lava fields. Colonization  small number of highly stress-tolerant plants, total biomass is low, soil lacking organic matter and nutrients. Development  Colonizing organisms modify the environment, making it favourable for other organisms. Pioneer organisms are eventually replaced by more competitive species. Climax  A diverse ecosystem is achieved that does not succeed to another ecosystem. Bagley L11: Ecosystem Types: • 4 major groups: o non-forest  temperate grasslands  tropical savanna  shrublands  deserts  tundra o forest  coniferous  temperate broadleaf  tropical o freshwater  lentic (standing water)  lotic (running water)  wetlands o saltwater  oceans  coral reefs  estuaries (mouth of a river where stream meets tide)  upwelling regions – upwelling occurs when deep, cool waters are brought against a continental barrier and forced to the surface, e.g.; coast of Peru in South America. Saltwater ecosystems are affected by temperature, salinity, pressure, winds and tides. Bagley L23: Diversity and Stability: • Ecological Diversity Also known as species richness, it is the number of species in an ecosystem or region. It is found by counting the number of species, and increases as the area, length of time spent counting and total number of organisms counted increases. • Diversity Indices There are two types of indices: o Dominance Indices – gives more weight to common, or dominant, species, e.g.; Simpson Dominance Index o Information Statistics Indices, e.g.; Shannon-Weaver Index • Keystone Species A species that ensures the diversity of an ecosystem because of its predation on and/or other interaction with a number of species. Bagley L14: Defining systems: • Population Group of organisms of the same species in a specific system. • System A specified group of processes with clearly defined boundaries. • Habitat The physical, geographic place where organisms live. Bagley L15: Population Growth and Death: • Steady-State The condition when things do not change with time. • Equilibrium The condition when a system is at minimum free energy. • Carrying Capacity The maximum possible population for a given level of resources. Bagley L17: Competition and Coexistence: • Competition Organisms compete for limited resources in an environment. There are two types: o Intraspecific Competition for resources between organisms of the same species. o Interspecific Competition for resources between organisms of different species. • Gause’s Principle At equilibrium, two species with identical resource requirements cannot occupy the same habitat. Bagley L18: Mutualism: • Mutualism Relationship between two species that benefits both. • Commensalism Relationship between two species that benefits one but does not affect the other. • Obligate Mutualism Mutualistic organisms are dependent on each other for survival. There are two types: o Non-symbiotic Mutualism Mutualistic organisms live physically different lives. o Symbiotic Mutualism Mutualistic organisms live together in close physical association. Bagley L19: Predator-Prey Dynamics I: • There are 4 general predator-prey relationships: o Herbivory animals eating plants. o Carnivory animals eating other animals. o Parasitism organisms sustaining themselves at the expense of other organisms not necessarily in the form of eating. o Cannibalism subset of carnivory where animals eat other animals of the same species. Bagley L21: Habitat Fragmentation: • Habitat Fragmentation The breaking up of a larger continuous habitat into smaller, discontinuous pieces or fragments. • Metapopulation A collection of smaller, physically separated populations of the same species. There are 4 types: o Classic  Individual populations are far enough to actually become extinct.  Individual populations are close enough to allow recolonization.  Direction of recolonization between individual populations is arbitrary. o Core/Satellite  Large core population is extinction resistant.  Satellite populations are smaller and may become extinct.  Colonization or recolonization occurs from core to satellite. o Patchy  Version of classic type.  Recolonization is so rapid that no individual population becomes extinct.  Is considered a metapopulation. o Nonequilibrium  Another version of classic type.  Individual populations are not recolonized after they become extinct because • physical barriers between colonies cannot be breached due to distance or other obstacles like human activity. • Other colony populations are not productive enough to allow migration out. Bagley L7: Photosynthesis: • Photosynthesis The process of converting light energy into chemical bond energy. • Reduction Reaction Atoms receive electrons. Occurs during the dark phase of photosynthesis and does not require light. • Oxidation Reaction Atoms lose electrons. Occurs during light phase of photosynthesis and requires light. Bagley L8: Oxygen and Carbon Cycles: • Oxygen Cycle o Photosynthesis – separates oxygen from water. o Respiration – biochemical oxidation of compounds to produce energy. Converts oxygen back to water. o Combustion • Carbon Cycle o Methanogenesis formation of methane, facilitated by methanogenic bacteria. Bagley L9: Sulphur, Acid Rain and Global Warming: • Acid Mine Drainage When sulphide found in mine tailings is exposed to air, it is oxidized to sulphuric acid, and can cause acid mine drainage. • Sewer Crown Corrosion The same phenomenon as acid mine drainage except found in sewers as a result of sulphide in sewer gas. Bagley L24: Concepts of Industrial Ecology: • Industrial Ecology An approach to the design of products and processes that evaluates such activities through the dual perspective of product competitiveness and environmental interactions. • Life Cycle Analysis (LCA) Examination of an entire life cycle of a product from raw material to disposal. Consists of three stages: o Inventory Analysis o Impact Analysis o Improvement Analysis • Inventory Analysis This stage consists of conducting mass and energy balances for the product over its entire life cycle. It is conducted as follows: o Clearly identify the final product of interest. o Identify all of the processes involved in producing this product and the mass and energy requirements of production. o Identify the mass and energy requirements of the product throughout its life. o Identify the ultimate fate of the product. • Impact Analysis Two questions: o How can the environmental impact of a product be determined? o How can different enviro
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