Energy Flow Through Ecosystems PDF

ENERGY FLOW THROUGH ECOSYSTEM Prepared by: Arlouie Jane E. Beltran,LPT Energy Flow in Ecosystem The energy flow in the ecosystem is one of the major factors that support the survival of such a great number of organisms. For almost all organisms on earth, the primary source of energy is solar e...

ENERGY FLOW THROUGH ECOSYSTEM Prepared by: Arlouie Jane E. Beltran,LPT Energy Flow in Ecosystem The energy flow in the ecosystem is one of the major factors that support the survival of such a great number of organisms. For almost all organisms on earth, the primary source of energy is solar energy. Cellular Respiration- a process during which some of the energy stored in the nutrient molecules is released for use by the cells. Energy flow- the passage of energy in a one-way direction in an ecosystem. Food chain- the sequence of transfers of matter and energy in the form of food from organism to organism. Food chains intertwine locally into a food web because most organisms consume more than one type of animal or plant. Food web- a complex network of interconnecting and overlapping food chains showing feeding relationships within a community. Food webs are divided into trophic levels( from Greek word tropho which means nourishment). Food chains and Poisons in the Environment Certain toxic substances, including some pesticides, radioactive isotopes, heavy metals, and industrial chemicals enter food chains. The effects of the pesticide DDT on some bird species first drew attention to the problem. In 1962 U.S biologist Rachel Carson publish “Silent Spring” which heightened public awareness about that dangers of DDT and other pesticide. Ecological Pyramid- show the relative amounts of various parameters (such as number of organisms, energy, and biomass) across trophic levels. Ecological pyramids can also be called trophic pyramids or energy pyramids. Pyramid of numbers- shows the total number of individual organisms at each level in the food chain of an ecosystem. Pyramid of Biomass- the representation of total living biomass or organic matter present at different trophic levels in an ecosystem. Biomass is calculated as the mass of living organisms present at each trophic level in a given sample size. Pyramid of Energy- represents how much energy, initially from the sun, is retained or stored in the form of new biomass at each trophic level in an ecosystem. BIOGEOCHEMICAL CYCLES Matter moves in numerous cycles from one part of an ecosystem to another that is, from one organism to another and from living organisms to the abiotic environment. There are four cycles of matter namely: carbon, nitrogen, phosphorus, and water as representative of all biogeochemical cycles. Carbon Cycles- the process that moves carbon between plants, animals, and microbes; minerals in the earth; and the atmosphere. Carbon is the fourth most abundant element in the universe. With its ability to form complex molecules such as DNA and proteins, carbon makes life on Earth possible. Nitrogen Cycle- a biogeochemical process through which nitrogen is converted into many forms, consecutively passing from the atmosphere to the soil to organism and back into the atmosphere. It involves several processes such as nitrogen fixation, nitrification, Assimilation, denitrification, decay and putrefaction. STEP 1 Nitrogen fixation- is a process that implies the transformation of the relatively non-reactive atmospheric N2 into its more reactive compounds (nitrates, nitrites, or ammonia). STEP 2 Nitrification- is a microbial process by which reduced nitrogen compounds (primarily ammonia) are sequentially oxidized to nitrite and nitrate. STEP 3 Assimilation- is the process by which plants and animals incorporate the NO3- and ammonia formed through nitrogen fixation and nitrification. STEP 4 Ammonification- when an organism excretes waste or dies, the nitrogen in its tissues is in the form of organic nitrogen (e.g. amino acids, DNA). STEP 5 Denitrification- is the process of converting nitrogen compounds, such as nitrate, into gaseous forms like nitrogen oxides and nitrogen gas. Phosphorus Cycle- the biogeochemical cycle that describes the transformation and translocation of phosphorus in soil, water, and living and dead organic material. Hydrologic Cycle-refers to the continuous circulation of water through the earth's land, ocean, and atmosphere, involving the exchange of mass, matter, and energy. It plays a crucial role in the earth's ecosystem, climate, and energy budget. Estuaries- fresh water meets the ocean Runoff – movement of surface from land to ocean Watershed- area of land drained by runoff. Aquifers- underground caverns and porous layer of rock in which groundwater is stored. Aquifer depletion- removal of human of more groundwater than precipitation or melting snow recharges.