Characterization Table of Contents 1 Introduction 2 2 Abiotic under construction 3 Biotic 6 4 Human Impacts Deforestation 16 Logging 20 Mining 24 Agriculture and Cattle 26 Energy 35 Infrastructure 42 Nutrient cycles 45 Pollution 52 5 Brazilian Government 62 6 Education 65 7 Economics 71 8 Indigenous People 82 Appendix A Brazilian States 87 Appendix A Laws 88 1 Introduction The 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 chemically and 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 Energy As 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 is lost with metabolism and in the form of heat This means that for example the energy ingested by producers does not pass completely to consumers After the energy is lost as heat it cannot be used for work anymore Matter Matter on the other hand has a closed cycle and can follow several paths Matter can t be lost from the ecosystem because all nutrients are degraded and restored to the cycle Matter is distributed in air parts of plants above the ground soil chemical elements organic matter and dead matter and roots parts of plants under the ground This distribution varies from ecosystem to ecosystem BIOLOGY The Amazon Rainforest Ecosystem The two factors which enable a rainforest to exist are an almost constant temperature and a high regular precipitation rate These two characteristics are the basis for all functions which occur 3 The actual forest begins with a thick nearly impenetrable wall of trees vines and shrubs Once inside this wall the forest is actually very open with relatively little underbrush The forest is comprised of several canopy levels each with its unique group of flora and fauna The physical structure of the forest is very efficient capturing most of the sunlight before it reaches the ground story This is the reason for relatively little vegetation on the floor of the forest Most of the nutrients in the forest is locked up in the vegetation Unlike what one would assume the soil is not very rich or thick It is estimated that there is only about 1 of leaf litter and 1 2 of topsoil However the conditions in the rainforest high moisture and warm temperature allow for a very quick decomposition rate so nutrients are recycled very quickly One major problem is that when trees are logged nutrients are taken away from the system with no way for them to be returned Newman Growth Cycle The growth cycle in the Amazon begins with an opening in the canopy known as a gap The gap can be caused by trees naturally dying or by being removed by deforestation This is followed by the building phase a state of re growth the mature phase and then back in some cases to the degenerative phase When gaps are too large such as what can happen with deforestation the climax present species gives way to other pioneer species Once this happens it is very difficult for the forest to return back to its initial composition and diversity Whitmore Nutrient Cycles The most important biogeochemical cycles in the Amazon Rainforest are the Carbon Nitrogen Oxygen and Hydrogen cycles It is important to look at these cycles because even minor disruptions in flow with either inputs or outputs can greatly alter the transfer of the element and therefore the ecosystem This can cause either an accumulation of a certain element in a form that might be harmful such as C in the atmosphere or a lack of necessary elements such as nutrients being removed from the cycle by logging BIOLOGY 4 One important tool to help understand nutrient cycles and to predict possible future problems is computer modeling 5 2 Biotic Aspects of the Amazon Brazil has between 10 and 20 of the world s biodiversity with approximately 500 species of mammals1 1600 species of birds2 and 1 million species of insects3 and 50 0004 species of plants in a 2 5 million square mile area5 Many of the products that are important in the world economy are native to Brazil including ground nuts Carnauba wax palm rubber trees guarana pineapple cashew nuts as well as many species necessary for medicinal purposes 6 The dense population of tall trees creates a canopy that creates a constant warm humid and dimly lit environment to the lower layers In these
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