Nutrient Cycles

Nutrient Cycles How are nutrients recycled through ecosystems? Why? We have learned the importance of recycling our trash. It allows us to use something again for another purpose and prevents the loss of natural resources. But what happens to the waste in nature? Why aren’t we up to our necks in natural refuse? Why is there always a supply of water? Why is there oxygen to breathe and carbon dioxide for photosynthesis? Organic compounds in nature are also recycled. This recycling process converts the complex organic compounds to simple, inorganic compounds, which then can be returned to nature to be used again and again. Model 1 – The Water Cycle water 1. Model 1 illustrates how nature recycles what natural resource? 2. Model 1 illustrates four major areas of water storage on Earth. Complete the list of these storage areas below. living things Atmosphere, surface water, groundwater ____________________, and ____________________. 3. Where is groundwater stored? in aquifers Nutrient Cycles 1 4. Name two processes in Model 1 in which water is converted to vapor.evaporation, transpiration 5. Describe two methods by which water on land (in lakes and rivers) returns to the oceans. water runoff, percolaton 6. Rain, sleet, and snow are examples of what? preciptaton 7. If the air contains high levels of pollutants, what effect might this have on water quality? it will lower the water quality, making ti usless to lving things 8. Which process(es) of the water cycle—precipitation, evaporation, condensation, runoff, percolation or transpiration—might contribute to the addition of pollutants to rivers, lakes, and oceans? Why? the concetrate chemicals long their path 9. Which of the processes associated with the water cycle might be responsible for helping to clean or filter the water?percolation, water gets filtered by soil 10. The water cycle is a closed system, meaning no water enters from beyond the system nor leaves the system. What does that say about the importance of keeping the water on Earth free from pollution? the water we have is all the water we have if we dont clean it the water we have will stay polluted polluted water is useless to living things 2 Model 2 – The Carbon Cycle D Atmospheric CO2 C B Re sp ir Respiration Combustion ati on Respiration A Auto and factory emissions Feedi Wastes ng Death Decay (by decomposing fungi, bacteria, and worms) il ss ati Fu el on rm Fo Fo Carbon Sink (coal, oil, peat, natural gas) 11. Model 2 illustrates how nature recycles what natural resource? carbon 12. Name two ways that carbon (usually in the form of CO2) enters the atmosphere. aniaml plant respiration 13. Process D on the diagram uses CO2 from the atmosphere. a. Label D on the diagram in Model 2 with the name of this process. photosynthesis b. What organisms carry out the process identified in part a?decomposeres 14. Wastes and dead organisms must be broken down in order for their components to be used again. a. What organisms in the cycle carry out this process? decomposers b. What would happen if decomposition did not occur? disease and infesttion would spread Nutrient Cycles 3 15. Not all dead organisms are acted on by decomposers. Instead of being immediately recycled, the carbon from some organisms is kept in a type of long-term storage, or carbon sink. Using Model 2, answer the questions below about this long-term storage. a. List four materials that contain this stored carbon. oil, peaqt, coal, natural gas b. What is the collective term for these four materials? fossil fuels c. How do humans use the materials in the carbon sink? for combustion to generate energy and move mavhines d. What is the scientific name for the process listed in part c? callular respiration 16. List five examples of combustion in your everyday life. car ignition , forest fires, bonfie, turning on natural gas in stove to cook, lighting a match 17. How is the majority of electricity generated in the area where you live? Does the process involve the combustion of coal? Check with your teacher if you are not sure. hydroelectric powe from lakes and dams from alabama and geogia 18. Many of the carbon-based fuels are categorized as fossil fuels because they formed from decayed organisms over millions of years. List as many examples of fossil fuels as you can. coal natural gas gasoline diesel machine lubricant oils peat petroleum derivatives 19. How does our use of these carbon stores affect the amount of CO2 in the atmosphere? the combustion of fossil fuels Read This! Carbon dioxide (CO2) is one of the so-called greenhouse gases. These gases hold heat energy in the atmosphere, which raises the overall temperature of the Earth. This helps maintain the Earth’s biosphere, but also has led to environmental concerns. The more CO2 in the atmosphere, the higher the Earth’s average temperature will be. 20. What is another way in which human activity is increasing the amount of atmospheric CO2, and what are potential global effects of these changes in CO2 levels? deforestation 4 Model 3 – The Nitrogen Cycle Absorption by roots of nonlegume plants Feeding Death Lightning De ath tes Was Nitrification by nitrifying baceria Atmospheric Nitrogen (N2) Nitrates in soil Nitrates n tio ina Decomposition m a De (by fungi, bacteria, and worms) N-fixing bacteria (Found in root nodules of legumes) Ammonia and other N-containing compounds in soil Nitrogen fixation Nitrites Nitrogen fixation Further nitrification by nitrifying baceria Denitrification by denitrifying baceria N-fixing bacteria 21. Model 3 illustrates how nature recycles what natural resource? lightning and bacteria 22. Name three types of bacteria involved in the nitrogen cycle. decombustion Read This! Nitrification is a process by which specific bacteria convert different forms of N-containing compounds (like ammonia, NH3) in the soil to nitrites (NO2) and nitrates (NO3). This process is important since the only forms of nitrogen that are usable by plants to build their proteins are the nitrates. 23. In what ways is N2 gas removed from the atmosphere? nirates in soil 24. By what process are animal wastes and dead organisms converted to other nitrogen-containing compounds? decompisation Nutrient Cycles 5 25. What is the only form of nitrogen that nonlegume plants can take in and use? nirates in soil 26. What do the denitrifying bacteria do during the denitrifying process? they comment nirates in soil into atmospereic nitrogen 27. If the number of nitrifying bacteria decreased, what effect would this have on the nitrogen cycle and what type of compounds would accumulate as a result? amonia would accumilate on the soil which woulf have low levels of nitration available 6 Extension Questions 28. Plants and animals are part of all of the nutrient cycles through the foods they eat and what eats them (food chains and food webs). Name the four classes of organic compounds (containing carbon) and explain how the carbon cycle and nitrogen cycle contribute to the usable supplies of these macromolecules. oganic compounds poteins and nucleic acids both contain nitrogen in their molecula composition if we are not able to consume nitrated in food well be difficent in those organic compound 29. In order to continually use the same area of land for agriculture, some farmers apply fertilizers to improve the level of nitrates in the soil. An alternative to this intensive use of fertilizer is to plow the roots of the leguminous plants back into the soil and leave the area unplanted for a season. Why would a farmer use this alternative method and what would be the benefit of turning over the soil and leaving the old plant roots? because the oots of leguminous plants such as bean soybeans and peanuts contain nitifying bacteria which fix atomspheric nitrgoen into the soil and makes it available for plants to grow consumers to eat. Nutrient Cycles 7