Man and his Environment Notes Essay Example

Man and his Environment Notes Paper Hence, energy flow through an ecosystem is non-cyclic and energy must be continuously supplied to the ecosystem. Suggested and excreted materials (e. G. Faces, urine) and dead organisms contain trapped chemical energy, which is released through the action of decomposer. Approximately 10% of net energy production at one tropic level is passed on to the next level. Not all the energy produced or consumed at each level is passed on. Energy transfer in ecosystems in inefficient. Here are some reasons why: . 3. 4. Energy is needed to carry out life processes. Heat is lost to the surroundings during respiration. Not every part of the organism gets eaten. Not everything consumed is digested by the consumer (e. G. Cellulose from plants cannot be digested by humans) Biology ; Man and His Environment Energy is transferred between tropic levels Organisms in any ecosystem can be classified as producers, consumers and decomposer. The transfer of energy and nutrients is dependent on the feeding relationships of an ecosystem. A food chain shows the sequence of food transfer from one organism to another. Each stage in a food chain is known as a tropic level. Producers: Producers are organisms that are able to produce their own organic matter (e. G. Carbohydrates) from inorganic nutrients (e. G. Water, carbon dioxide) through photosynthesis. We will write a custom essay sample on Man and his Environment Notes specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Man and his Environment Notes specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Man and his Environment Notes specifically for you FOR ONLY $16.38 $13.9/page Hire Writer They are also known as atrophic organisms or authors (auto-self, troop=nutrition). Other than green plants, algae and certain types of bacteria and unicellular organisms can produce their own food. Consumers: Organisms in the tropic levels above the producers. Herbivores are primary consumers which feed directly on producers. Carnivores are consumers which feed on other consumers. Consumers, which do not make their own food, are also known as heterodox (hetero=other). Decomposer: Decomposer (e. G. Bacteria and fungi) are a group of consumers that obtains their energy from detritus (dead material and waste of organisms from all tropic levels). Organic material from the tissues of organisms (e. G. Reverberates) will be broken down into simpler inorganic substances (e. G. Carbon, nitrogen). These substances can be recycled in the ecosystem. A food web shows the inter-relationships between different food chains. A food web is a more realistic representation of feeding relationships in an ecosystem as consumers usually have more than one source of food and some organisms are a source of food for multiple consumers. Ecological pyramids: Pyramid of numbers and Pyramid of biomass Ecological pyramids are a visual representation of how different populations interact within a community. They are used to compare the different tropic levels in a food chain. They are horizontal bar diagrams, with the producers placed at the base of the pyramid, followed by the primary consumers and so on. Pyramid of numbers Pyramid of biomass A pyramid of biomass compares the *mass A pyramid of numbers compares the of organisms present at each tropic level number of organisms present at each in an area at a particular time. Tropic level in an area at a particular time. *the average dry mass of each species in each tropic level must be obtained, and then multiplied by the estimated total number of individuals in the food chain. Example 1 Example 2. 2 Example 2. 1 Why do the two pyramids in Example 2. 1 and 2. 2 have different shapes? Why do the two pyramids in Example 1 and 2. 1 have different shapes? Most ecological pyramids are pyramid-shaped, but there are some exceptions, as seen in Example 2. In the table above. A pyramid of numbers may appear to be inverted if: Organisms on one tropic level are parasitic on organisms on another tropic level (e. G. Aphids feeding on the sap of an elder tree) Many small organisms on one tropic level feed on a large organism Of another tropic level A pyramid of biomass may appear to be inverted if it includes organisms which reproduce rapidly (e. G. Phytoplankton). (2) Nutrient cycling Inorganic nutrients like carbon and nitrogen can be recycled They are obtained from the biotic environment (e. G. Air, soil) Nutrients are continuously recycled in a balanced ecosystem The Carbon Cycle Carbon is constantly being removed from and released into the environment in the form of carbon dioxide. Thus, the concentration of carbon dioxide in the environment remains relatively constant. The processes involved in the removal of carbon dioxide and its release into the environment make up the carbon cycle. Photosynthesis: Photosynthetic organisms convert carbon, from carbon dioxide in the atmosphere, into carbohydrates. Carbohydrates can also be converted to proteins and fats. Feeding: Animals obtain carbon compounds (e. G. Carbohydrates, proteins and fats) by feeding on plants and other animals. Respiration: Some of the carbon compounds are converted back to carbon dioxide through respiration, which releases energy for cell activities. Decomposition: Decomposer like fungi and bacteria break down the carbon compounds in dead tissue into carbon dioxide, which is returned to the atmosphere Combustion: Some of the remains of dead organisms are locked up as carbon-based fossil fuels like coal and oil. The burning of such fossil fuels releases the stored carbon into the atmosphere as carbon dioxide. Ecological field techniques: Quadrate and Transect sampling Within an ecosystem, the Organisms are rarely distributed evenly and Hereford it can be very difficult to count their numbers accurately. Scientists therefore need to adopt appropriate sampling techniques to achieve a realistic estimate of population numbers. Why are such field techniques important? What can we do with the data obtained from these sampling techniques? Quadrate sampling A quadrate is a sampling unit of known area. They are usually taken using square frames of size 1 urn. Quadrate can vary in size, depending on the particular habitat and type of organisms likely to be encountered. Quadrate should be placed randomly so that a representative sample is taken. Transect sampling A transect is simply a line that is stretched over an area that we want to study. Compared to quadrate sampling the transect sample points are arranged in linear fashion. This approach is useful when recording changes in the species composition or population numbers where some sort of transition or environmental gradient exists (e. G. N intertribal area like a sea shore or mangrove, or an area next to where a pollutant is known to be spreading). Impact of Man on the Environment Our ecosystem consists of regularly interacting and interdependent components forming a unified whole, and it is meant to be functioning at a teddy state. However, due to the exponential increase in human population over the years, the impact of man on the environment is increasingly noticeable. Additional information Ecological and carbon footprints An ecological footprint measures the total amount of land and resources used to produce the resources that the population consumes and assimilate the wastes that the population produces. A carbon footprint is a measure of the impact our activities have on the environment, and in particular climate change. It relates to the amount of greenhouse gases produced in our day-to-day lives through burning fossil eels for electricity, heating and transportation and so on. Calculate your carbon footprint! Http://www. Onus. Du. So/goes/resources/carbonization_calculator. HTML pollution Pollution is the release of substances, which cause harm to living organisms, into the environment. Substances that cause pollution are called pollutants. Water pollution and fasciculation The use of insecticides to kill insects has its impact on other organisms. If insecticides are carried by rainwater into water bodies like rivers and lakes, they can accumulate in high concentrations in the bodies of aquatic organisms. For instance, EDT (dichlorodiphenyltrichloroethane) is an insecticide that is nonprogrammable, which means that it cannot be broken down by microorganisms. It is insoluble in water and is thus stored in the fatty tissues of organisms that consume it. If consumers keep consuming food that contains EDT, the concentration of EDT will further increase in their bodies. This is called fasciculation. The insecticide is then passed along food chains, increasing the concentration of EDT in the bodies of organisms along the tropic levels. This process is called pontification or pontification. Water pollution by sewage and inorganic waste Water-borne diseases and poisoning Sewage contains waste matter from homes and industries, which contains a lot of disseminating organisms like bacteria if left untreated. If such organisms get into drinking water, water-borne diseases like cholera and typhoid may spread. Inorganic waste from industries, like mercury, lead and zinc can be absorbed by aquatic organisms and cause poisoning (e. G. Intimate mercury poisoning in 1 sass Japan, where many who ate fish from the polluted water were blinded or paralyses). Triplication Triplication is the process where water receives excess nutrients like hostages and nitrates, which causes excessive growth of algae and water plants. Untreated sewage and inorganic fertilizers contains phosphates and nitrates. Inorganic fertilizers that are not absorbed by plants may dissolve in ground water, or get washed by rainwater into water bodies like rivers and lakes. Phosphates and nitrates are nutrients for algae and water plants. As a result, their growth is enhanced. The overgrowth of algae and floating water plants prevent sunlight from reaching the submerged plants. The submerged algae and plants die and are decomposed by bacteria and fungi. As the bacteria multiply rapidly, they use up oxygen in the water. Other organisms such as fish die due to the lack Of oxygen. Environmental biotechnology Sewage treatment Environmental biotechnology is the use of biological science to provide environmentally friendly solutions to red cue pollution. Sewage treatment helps to minimize the effects of water pollution on the environment. Decomposer like bacteria are naturally found in sewage. However, decomposition takes time and occurs at different rates. Sewage treatment in water reclamation plants is a controlled process which ensures that sewage is ropey treated in one location before being released into the environment. The sewage treatment process 1) Sewage from households is channeled into the water reclamation plant. 2) The used water is passed through bar screens to remove large, coarse materials. Primary treatment: 3) The screened liquid is sent to the primary settlement tank. Here, the liquid flow is very slow. This allows solids to settle at the bottom Of the tank as primary sludge. The primary sludge is removed and fed into an anaerobic digester (anaerobic-not requiring oxygen). The top liquid from this tank flows into an aeration tank. Secondary treatment: 4) Activated sludge process in the aeration tank: In the aeration tank, the liquid is mixed with aerobic microorganisms like bacteria. Bubbles of air are pumped into the liquid. The oxygen in the air is used by the microorganisms for aerobic respiration (aerobic-requiring oxygen). The microorganisms absorb and break down organic pollutants in the water into harmless substances and carbon dioxide. ) Final settlement tank: The treated water, together with the microorganisms, is channeled into the final settlement tank. The microorganisms settle to the bottom of the tank as sludge. A portion of this sludge is returned to the aeration tank to be reused. The excess sludge is sent to the anaerobic digester. 6) Clean water at the top of the t ank is collected and may be discharged as effluent into nearby rivers, streams or lakes. The effluent may also be treated further using reverse osmosis technologies (I. E. Neater). Anaerobic digester: The anaerobic digester is a closed tank with no oxygen supply. Anaerobic bacteria decomposes the sludge. Biogas, mainly methane, is produced through the breakdown of the organic matter. The biogas is used as fuel to generate electricity for the reclamation plant. The remaining solid material is removed from the tank, and can be incinerated or used as fertilizer. Think: How is sewage treatment a sustainable practice? Sustainability and Conservation Sustainable development involves meeting the needs of the present without compromising on the ability of future generations to meet their own needs. Thus, we wish to maintain, or improve the environmental, economic and social characteristics of the world we live in, in a manner that can be continued into the future. In ecology, sustainability refers to the capacity for biological systems to remain diverse and productive over time. The principles of sustainable development Conservation, which is part and parcel of ensuring sustainable development, is the protection and preservation of natural resources in the environment. Reasons for conservation Maintaining Biodiversity It is important to maintain a large gene pool as many wild plants and animals contain favorable genes. By cross-breeding organisms with favorable genes, we can improve agricultural produce (e. G. Disease-resistant plants) Economic purposes: Plants and animals are major sources of food and raw material. Many tropical plants are sources of medicinal drugs (e. G. Nine which is an anti-malarial drug) It is important to maintain a stable and balanced ecosystem to prevent disruption of nutrient cycles like the carbon cycle (which may lead to global warming), and to alter feeding relationships in ecosystems. Scientific research on wildlife provides useful information to humans Management fisheries Fish are important sources of protein Overfeeding or indiscriminate fishing must be prevented in order to ensure that there is a sustainable yield for each species. The harvest each year should not cause a decline in the population. Sustainability can be ensured through