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Ecosystems and Energy Flow. Section 2.2 Summary – pages 46 - 57. The energy and trophic levels of an ecosystem are often depicted as ecological pyramids. Although all information could be shown on one pyramid, three are often used. Section 2.2 Summary – pages 46 - 57. Pyramid of Energy.
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Section 2.2 Summary – pages 46 - 57 The energy and trophic levels of an ecosystem are often depicted as ecological pyramids. Although all information could be shown on one pyramid, three are often used.
Section 2.2 Summary – pages 46 - 57 Pyramid of Energy Pyramid of Energy Heat 0.1% Consumers • The pyramid of energy shows the amount of available energy (represented as heat ) decreases at each succeeding trophic level. Note the conservation of energy. 1% Consumers Heat 10% Consumers Heat 100% Producers Heat Parasites, scavengers, and decomposers feed at each level.
Section 2.2 Summary – pages 46 - 57 Pyramid of Energy explanation : Energy Transfer • The total energy transfer from one trophic level to the next is only about 10 percent because cellular respiration “burns” food to release its energy, and in doing so, produces ATP, which carries some of the energy as well as heat, which carries the rest back into the environment.
Pyramid of Energy explanation : Energy Transfer • Organisms do not store the total amount of energy due to this process and also do not eat all the energy available at the lower trophic level. • Therefore, although a lot of energy may be taken in at any level, the energy that ends up being stored there – food energy for the next level — is much less.
Section 2.2 Summary – pages 46 - 57 Pyramid of Biomass Pyramid of Biomass • Biomass is the total weight of living matter at each trophic level. A pyramid of biomass represents the total weight of living material available at each trophic level. 1 kilogram of human tissue 10 kilograms of beef 100 kilograms of grain
Section 2.2 Summary – pages 46 - 57 Pyramid of Numbers • A pyramid of numbers shows that populations decrease at each higher trophic level. Population sizes decrease in relation to biomass, energy and sustainability . Nature is balanced! Pyramid of Numbers Fox (1) Birds (25) Grasshoppers (250) Grasses (3000)
The carbon cycle • Carbon is the building block of the molecules of life. • Linked carbon atoms form the frame for molecules produced by plants and other living things. The formula of photosynthesis is = • 6CO2 +12 H2O + Light energy → C6H12O6 + 6 O-- + __H2Ocarbon dioxide + water +sunlight= glucose+ ________+______
The nitrogen cycle Nitrogen in the atmosphere Some excess nitrogen evaporates from soil. Dead plant matter Urine from animals Decomposing organisms Assimilated by plants Decomposers—bacteria and fungi—break down tissues and wastes and nitrogen-containing compounds are released. Nitrogen-fixing bacteria in the nodules on roots of leguminous plants fix atmospheric nitrogen. Released to the atmosphere Nitrogen compounds released into soils and acted upon by soil bacteria Converted to other nitrogen compounds by soil bacteria Nitrogen-fixing soil bacteria
The phosphorus cycle • In the phosphorus cycle, phosphorus moves between the living and nonliving parts of the environment. • Phosphate is a nutrient that’s vital to all living things and is found naturally in our food, our water and our bodies. • Cellular respiration uses phosphates to convert glucose into a more usable form of energy called ATP. The formula of cellular respiration is = • P + ADP + C6H12O6 + 6 O2→ 6 CO2+ 6H2O + ATP
Section 2.1 Summary – pages 35 - 45 Biotic relationships- Symbiosis • symbiosis - a close and permanent association between biotic factors organisms of different species is called. • Symbiosis means living together. Three kinds of symbiosis are recognized: mutualism, commensalism, and parasitism. • Other abiotic and biotic relationships include : predator/prey, and competition and succession (Lesson 9)
Section 2.1 Summary – pages 35 - 45 Mutualism- + + - good for both • A symbiotic relationship in which both species benefit is called mutualism.
Section 2.1 Summary – pages 35 - 45 Commensalism - + 0 good for one, neutral for other • Commensalism is a symbiotic relationship in which one species benefits and the other species is neither harmed nor benefited.
Section 2.1 Summary – pages 35 - 45 Parasitism - +- Good for one , Bad for other • A symbiotic relationship in which a member of one species derives benefit at the expense of another species (the host) is called parasitism.
Section 2.1 Summary – pages 35 - 45 Parasitism • Parasites have evolved in such a way that they harm, but usually do not kill the host species. Why don’t the parasites want to kill their host?
Section 2.1 Summary – pages 35 - 45 Predation- + - predator/prey relationship • Predation is found in all ecosystems and includes organisms that eat plants and animals. • A predator is a type of consumer. Predators seek out and eat other organisms (prey). Clearly good for one, not so good for the other