IntroductionThe Amazon Rainforest EcosystemNutrient CyclesJennings, S.B., Brown, N.D., Boshier, D.H., Whitmore, T.C., Lopes, J.C.A., 2000. Ecology provides a pragmatic solution to the maintenance of genetic diversity in sustainbly managed tropical rain forests. Forest Ecology and Management, 154, 1-10.Sample of Important SpeciesAlso see monitoringa) Redundant species hypothesis - With a decrease of biodiversity, ecosystem functions are unaffected until the point where only a few key species remain. If one of these species is lost, the system collapses. b) Rivet hypothesis - With a decrease of biodiversity, ecosystem function will decrease proportionally. This represents a direct correlation between the two. c) Idiosyncratic hypothesis - There is no relationship between biodiversity and ecosystem functions. There is some evidence for the redundant species hypothesis. For example, Nordgren et al studied the effects of heavy metal contamination on soil respiration. Species of fungi were killed in a gradient surrounding the source of the metals. However, respiration was only affected with a high level of metal (and therefore a high loss of species) near the source. In fact, there is a "general feeling...that functional redundancy indeed plays a role...". Nevertheless, despite great efforts arising from the Rio convention, there is very little empirical evidence to support any of Lawton's hypotheses. Still, as Naeem and Li put it, biodiversity is "ecological insurance." (Naeem). Rather than looking at the number of species to show health, bio-indicators can show continuation of attributes.Sources:(1) http://www.pbs.org/journeyintoamazonia/enter.html(2) http://www.txdirect.net/sitc/sci-rain.htm(3) Costanza, R. Norton BG and Haskell BD (eds) (1992) Ecosystem Health. IslandPress, Washington, D.C.(4) Doran JW and Safley, M. (1997) Defining and assessing soil health andsustainable productivity. In: Pankhurst CE, Doube BM and Bupta VVSR (eds)Biological Indicators of Soil Health (pp 1-28). CAB International, Wallingford.(5) Lawton, JH (1994) What do species do in ecosystems? Oikos 71: 367-374.(6) Naeem S, and Li S (1997) Biodiversity enhances ecosystemreliability. Nature390: 507-509.(7) Nordgren A, Baath E and Soderstrom B (1983) Microfungi andmicrobial activityalong a heavy metal gradient. Applied and Environmental Microbiology. 45:1829-1837.(8) The Oxford Dictionary of Natural History. Oxford University Press, Oxford,1985.(9) van Straalen, Nico M (2002) Assessment of soil contamination - a functionalperspective. Bio-degeneration. 13: 41-52.Aquatic BiotaA. Fish4. Land Use4.1 Agriculture and RanchingA. IntroductionB. Power ProductionC. EffectsD. ComparisonA. Acidification and pHCharacterizationTable of Contents1. Introduction………………………………………………22. Abiotic…………………………………….under construction3. Biotic……………………………………………………..64. Human Impacts- Deforestation………………………………………16- Logging…………………………………………….20- Mining……………………………………………..24- Agriculture and Cattle……………………………..26- Energy……………………………………………..35- Infrastructure………………………………………42- Nutrient cycles……………………………………..45- Pollution…………………………………………....525. Brazilian Government…………………………………….626. Education…………………………………………………657. Economics………………………………………………...718. Indigenous People………………………………………...82Appendix A: Brazilian States……………………………………87Appendix A: Laws……………………………………………….881IntroductionThe Amazon Rainforest is an incredibly complex ecosystem. The unique conditions of an almost constant temperature and a high, regular precipitation rate are what allow the incredible amount of biodiversity to occur there. Because of its size and high rate of productivity, the Amazon Rainforest ecosystem plays a substantial role in many of the biogeochemical cycles of the world. Definition of an Ecosystem - An ecosystem is defined as an open thermodynamic system composed by the living community or communities and their abiotic surroundings in which movements of matter (nutrients) and energy take place. Living matter and organisms cannot exist without the following abiotic factors:- Atmosphere (air) - Hidrosphere (water) - Litosphere (soil and rocks) All the components of an ecosystem maintain the open exchange of matter and energy on which the system is based. There are several attributes inherent to ecosystem that are based in this exchange:- Primary productivity - Energy fixation rate by primary producers, of which 99.99% are photosynthetic organisms, although chimiosynthetic organisms are considered primary producers as well. - Secondary productivity - Energy and matter fixation rate by consumers. - Decomposition rate - Velocity at which organic matter is degraded into chemicallyand physically simpler elements. - Use of energy efficiency: o Ratio of the rate of the matter and energy that is fixed in a trophic level of the ecosystem to that of a previous level. o Inefficiency: Food that is excreted and/or not used, that is the matter and energy used in metabolism. o Efficiency: Ingested and assimilated food, as well as matter and energy used in the production of new tissues. - Standing biomass: All the matter of the ecosystem (dry weight of the organisms.) - Velocity and pattern of circulation of nutrients: Velocity and places by which the nutrients (matter) travel. - Velocity and pattern of circulation of energy: Velocity and places by which each particle of energy that enters the ecosystem travels.Ecosystems share some attributes with communities as well:- Trophic structure - Trophic and connecting levels in regard to nutrient and energy circulation. 2- Key species - These species are crucial because their activities determine the pattern of circulation of matter and energy and help maintain the ecosystem's equilibrium. EnergyAs we can see, the movement of energy is open and in only one direction. This means that the energy goes through each trophic level one time. As it goes from one level to another, it
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