Ecology II - Cycles of Matter Photo Credit: ©Bruce Coleman, LTD/Natural Selection Copyright Pearson Prentice Hall

Recycling in the Biosphere Recycling in the Biosphere Energy and matter move through the biosphere very differently. Unlike the one-way flow of energy, matter is recycled within and between ecosystems. The biosphere, speaking generically, is all the living things -- plants and animals -- in the world. The biosphere is the global ecosystem, the sum of all the planet's ecosystems. This includes the atmosphere (several kilometers), and the land (at least 3000 meters below ground to the depth of several kilometers). It is often referred to as the "zone of life", where all of earths organisms live. http://wiki.answers.com/Q/What_is_the_biosphere Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall The Water Cycle Water moves between the ocean, atmosphere, and land. This diagram shows the main processes involved in the water cycle. Scientists estimate that it can take a single water molecule as long as 4000 years to complete one cycle. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Nutrient Cycles The Carbon Cycle Carbon is a key ingredient of living tissue. Biological processes, such as photosynthesis, respiration, and decomposition, take up and release carbon and oxygen. Geochemical processes, such as erosion and volcanic activity, release carbon dioxide to the atmosphere and oceans. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Nutrient Cycles CO2 in Atmosphere Photosynthesis Volcanic activity feeding Respiration Erosion Human activity Respiration Decomposition CO2 in Ocean Uplift Carbon is found in several large reservoirs in the biosphere. In the atmosphere, it is found as carbon dioxide gas; in the oceans as dissolved carbon dioxide; on land in organisms, rocks, and soil; and underground as coal, petroleum, and calcium carbonate rock.  Deposition Photosynthesis feeding Fossil fuel Deposition Carbonate Rocks Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Nutrient Cycles The Nitrogen Cycle All organisms require nitrogen to make proteins. Although nitrogen gas (N2) is the most abundant form of nitrogen on Earth, only certain types of bacteria can use this form directly. Such bacteria live in the soil and on the roots of plants called legumes. They convert nitrogen gas into ammonia in a process known as nitrogen fixation. Other bacteria in the soil convert ammonia into nitrates and nitrites. Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen (N2) in the atmosphere is converted into ammonia. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Nutrient Cycles Once these products are available, producers can use them to make proteins. Consumers then eat the producers and reuse the nitrogen to make their own proteins. FYI: Ammonia is a compound of nitrogen and hydrogen with the formula NH3. (It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. ) The nitrate ion is a polyatomic ion with the molecular formula NO−3 and a molecular mass Copyright Pearson Prentice Hall

NH3 N2 in Atmosphere NO3 and NO2 Nutrient Cycles Synthetic fertilizer manufacturer Atmospheric nitrogen fixation Decomposition Uptake by producers Reuse by consumers Uptake by producers Reuse by consumers The atmosphere is the main reservoir of nitrogen in the biosphere. Nitrogen also cycles through the soil and through the tissues of living organisms.  Decomposition excretion Decomposition excretion Bacterial nitrogen fixation NO3 and NO2 NH3 Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Nutrient Cycles When organisms die, decomposers return nitrogen to the soil as ammonia. The ammonia may be taken up again by producers. Other soil bacteria convert nitrates into nitrogen gas in a process called denitrification. This process releases nitrogen into the atmosphere once again. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Nutrient Cycles The Phosphorus Cycle Phosphorus is essential to organisms because it helps forms important molecules like DNA and RNA. Most phosphorus exists in the form of inorganic phosphate, a salt. Inorganic phosphate is released into the soil and water as sediments wear down. Eventually the phosphates will enter the ocean, where it is used by marine organisms. Copyright Pearson Prentice Hall 10

Copyright Pearson Prentice Hall Why it phosphorus is a concern: In water, phosphorus behaves as a fertilizer, accelerating plant and algae growth. When plants and algae die, bacteria consume oxygen that is dissolved in the water. When this happens, less oxygen is available for fish and aquatic life that need oxygen to survive. Excess phosphorus in drinking water is difficult to remove, and also can require an increase in treatment chemicals which adds cost. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Nutrient Cycles Organic phosphate moves through the food web and to the rest of the ecosystem. Organisms Phosphorus in the biosphere cycles among the land, ocean sediments, and living organisms. Land Ocean Sediments Copyright Pearson Prentice Hall 12

Copyright Pearson Prentice Hall Nutrient Limitation Nutrient Limitation The primary productivity of an ecosystem is the rate at which organic matter is created by producers. One factor that controls the primary productivity of an ecosystem is the amount of available nutrients. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Nutrient Limitation If a nutrient is in short supply, it will limit an organism's growth. When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly, this substance is called a limiting nutrient. When an aquatic ecosystem receives a large input of a limiting nutrient—such as runoff from heavily fertilized fields—the result is often an immediate increase in the amount of algae and other producers. Why? Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Nutrient Limitation When an aquatic ecosystem receives a large input of a limiting nutrient—such as runoff from heavily fertilized fields—the result is often an immediate increase in the amount of algae and other producers. This result is called an algal bloom. Algal blooms can disrupt the equilibrium of an ecosystem. Why is that? See, Article Sabah, Malaysia (Red Algae bloom; where is?) http://www.pressherald.com/news/weeding-out-trouble_2010-07-15.html http://www.youtube.com/watch?v=1XlBGdX1r1g http://www.youtube.com/watch?v=IeQ5DCCfjpE http://www.google.com/search?q=sabah+malaysia&sourceid=ie7&rls=com.microsoft:en-us:IE-SearchBox&ie=&oe= Copyright Pearson Prentice Hall 15

Copyright Pearson Prentice Hall 3–3 Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3–3 Transpiration is part of the water cycle. carbon cycle. nitrogen cycle. phosphorus cycle. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3–3 Carbon is found in the atmosphere in the form of carbohydrates. carbon dioxide. calcium carbonate. ammonia. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3–3 Biologists describe nutrients as moving through cycles because the substances start as simple organic forms that plants need. provide “building blocks” and energy that organisms need. are passed between organisms and the environment and then back to organisms. are needed by organisms to carry out life processes. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3–3 The only organisms that can convert nitrogen in the atmosphere into a form useful to living things are nitrogen-fixing plants. bacteria. detritivores. animals. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3–3 When an aquatic ecosystem receives a large input of a limiting nutrient, the result is runoff. algal death. algal bloom. less primary productivity. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Resources: Pearson Prentice Hall DVD Holt Modern Biology http://www.pressherald.com/news/weeding-out-trouble_2010-07-15.html http://www.youtube.com/watch?v=1XlBGdX1r1g dtd 10/15/2010 http://www.youtube.com/watch?v=IeQ5DCCfjpE dtd 10/15/2010 http://www.google.com/search?q=sabah+malaysia&sourceid=ie7&rls=com.microsoft:en-us:IE-SearchBox&ie=&oe= dtd 10/15/2010 Copyright Pearson Prentice Hall

END OF SECTION References: Pearson Prentice Hall DVD Text Book: Holt, Biology 1999