Presentation on ecosystem

Presentation on ecosystem

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  PRESENTATION ON ECOSYSTEM Varsity-Southern University Bangladesh Name-Tasfia Rahman Course-Environmental Science
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  ECOSYSTEM An ecosystem isa geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life. Ecosystems contain biotic or living, parts, as well as abiotic factors, or nonliving parts. Biotic factors include plants, animals, and other organisms. Abiotic factors include rocks, temperature, and humidity. All the ecosystems in the world fall into two categories. Ecosystems found on land are considered terrestrial ecosystems and all the ecosystems found in water are considered aquatic ecosystems.
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  THREE BROAD CATEGORIESOF BIOTIC COMPONENTS Producers are the plants in the ecosystem, which can generate their own energy requirement through photosynthesis, in the presence of sunlight and chlorophyll. All other living beings are dependent on plants for their energy requirement of food as well as oxygen. Consumers include herbivores, carnivores, and omnivores. The herbivores are the living organisms that feed on plants. Carnivores eat other living organisms. Omnivores are animals that can eat both plant and animal tissue. Decomposers are the fungi and bacteria, which are the saprophytes. They feed on the decaying organic matter and convert this matter into nitrogen and carbon dioxide. The saprophytes play a vital role in recycling the nutrients so that the producers i.e. plants can use them once again.
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  PHOTOSYNTHESIS Photosynthesis occurs whenplants use light energy to convert carbon dioxide and water into glucose and oxygen. During the process of photosynthesis, carbon dioxide enters through the stomata, water is absorbed by the root hairs from the soil and is carried to the leaves through the xylem vessels. Chlorophyll absorbs the light energy from the sun to split water molecules into hydrogen and oxygen. The hydrogen from water molecules and carbon dioxide absorbed from the air are used in the production of glucose. Furthermore, oxygen is liberated out into the atmosphere through the leaves as a by product.
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  CELLULAR RESPIRATION Cellular respirationis a biochemical process of breaking down food, usually glucose, into simpler substances. The energy released in this process is tapped by the cell to drive various energy-requiring processes. During aerobic cellular respiration, glucose reacts with oxygen, forming carbon dioxide and water.
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  ENERGY TRANSFER The energyflow is the amount of energy that moves along the food chain. This energy flow is also known as calorific flow. A chronological pathway or an order that shows the flow of energy from one organism to the other is food chain. In a community which has producers, consumers, and decomposers, the energy flows in a specific pathway. Energy is not created or destroyed. But it flows from one level to the other, through different organisms. A food chain shows a single pathway from the producers to the consumers and how the energy flows in this pathway. In the animal kingdom, food travels around different levels. Many interconnected food chains make the food web.
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  CARBON CYCLE: Carbon isin a constant state of movement from place to place. It is stored in what are known as reservoirs, and it moves between these reservoirs through a variety of processes, including photosynthesis, burning fossil fuels, and simply releasing breath from the lungs. The movement of carbon from reservoir to reservoir is known as the carbon cycle. Carbon can be stored in a variety of reservoirs, including plants and animals, which is why they are considered carbon life forms. Carbon is used by plants to build leaves and stems, which are then digested by animals and used for cellular growth.
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  The air webreathe contains 78% nitrogen, 21% oxygen and remaining are other trace gases. The nitrogen component of air is inert. So this means plants and animals cannot use it directly. To be able to use nitrogen, nitrogen fixing bacteria convert atmospheric nitrogen to molecules by a process called the nitrogen cycle. Animals derive their nitrogen requirements from plants or eating other animals. NITROGEN CYCLE There is a laundry list of elements that animals need for survival. One such element is Nitrogen. But we can’t just get nitrogen from the air. It needs to be converted to nitrates, via a process called nitrogen cycle. Nitrogen fixing bacterium
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  PHOSPHORUS CYCLE Phosphorus isan important element for all living organisms. It forms a significant part of the structural framework of DNA and RNA. They are also an important component of ATP. Humans contain 80% of phosphorus in teeth and bones. Phosphorus cycle is a very slow process. Various weather processes help to wash the phosphorus present in the rocks into the soil. Phosphorus is absorbed by the organic matter in the soil which is used for various biological processes. The aquatic plants absorb inorganic phosphorus from lower layers of water bodies. The animals absorb phosphorus from the plants or by consuming plant- eating animals. When plants and animals die, decomposition results in the return of phosphorus back to the environment via the water or soil.
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  ECOLOGICAL SUCCESSION Ecological succession isthe steady and gradual change in a species of a given area with respect to the changing environment. It is a predictable change and is an inevitable process of nature as all the biotic components have to keep up with the changes in the environment.
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  PRIMARY SUCCESSION Primary successionis the succession that starts in lifeless areas such as the regions devoid of soil or the areas where the soil is unable to sustain life. SECONDARY SUCCESSION type of ecological succession in which plants and animals recolonize a habitat after a major disturbance—such as a devastating flood, wildfire, landslide, lava flow, or human activity (e.g., farming or road or building construction)—significantly alters an area but has not rendered it completely lifeless. Secondary succession takes place where a disturbance did not eliminate all life and nutrients from the environment
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  Primary Succession SecondarySuccession Occurs In areas which are lifeless or barren In areas which were previously inhabited or recently denuded Time to complete Around 1000 years or more Around 50 – 200 years Soil The absence of soil in the initial process Presence of soil along with organisms DIFFERENCE BETWEEN PRIMARYAND SECONDARY SUCCESSION