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Unformatted text preview: Exam 3 Notes compilation: Good luck yall Student 1 Exam 3 Ecosystems: group of plants and animals that are connected by energy and mineral flow there are no species that are not connected the ultimate source is the sun photosynthesis involves turning solar energy to chemical energy model of food chain sun plants (producers) herbivores carnivores top carnivores most of the energy is lost as respiratory heat if there is no sun there is no energy most of the energy flowing through the chain is degraded to heat energy and is noncyclic: cant recycle energy. Chains rarely have more than 4 trophic levels Energy on Earth (deciduous forest) 1% of the energy is captured by photosynthesis highest capture can be around 2% the energy transfer to the preceeding trophic level gets small, total amount declines to the next. Energy in Agriculture in a field of crops 1.5% of energy is captured by photosynthesis the processing of corn fed to cattle produces less food than corn to human, it feeds 20x more people with corn than the beef produced out of it Productivity of Products Net Productivity Primary = Gross Product Primary Plant Respiration the net productivity primary is the left over energy for plant growth per are per unit time ( what energy is available for plant growth) Energy Capture Ecosystem It is influenced by temperature and rainfall. Important availability are nutrients and soil high end on ecosystem: swamps marshes estutaries they are shallow fresh water why is this on the high on because of high nutrients and high productivity? nexthighet: tropical rain forest: not so good in nutrients because it has long growing seasons, meaning more photosynthetic temperate deciduous: limited in photosynthesis because of the shorter growing season meaning less productivity grassland: less leaves per unit area low productivity: Desert because it has very little water and precipitation. The soil is bad and low on nutrients 1. the increased precipitation the increased productivity 2. the increased temperature the increased productivity Nutrient levels: depending on biomass(weight of dry plant material) more weigh there is per square meter the more productivity more phosphorus in lakes the greater the algal mass, means greater amount of solar energy captured nutrial elements are correlated with mass Body Weight and Metabolism in Birds smaller birds have high metabolic rates seed the type of see effects how much calorie intake each birds gets depending on seed size the oil content of seeds and the handling time: some birds can crack seeds faster than other birds they choose ones that offer more calories/unit time Pumas and there Preys as the puma weight increases, prey weights increase as well optimal forging: most economic forging, max number of calories per number of calories expended amount of effort coming in is better that the energy expended out...
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