Eutrophication Stages 0.0 / 5 ? BiologyEcology and biodiversityA2/A-levelAQA Created by: emilyowlCreated on: 13-07-16 09:44 Stage 1 Lakes and rivers: naturally very low concentration of nitrate, nitrate ions are a limiting factor for plant and algal growth. 1 of 11 Stage 2 Nitrate ion concentration increases - leaching, is no longer limiting factor so populations grow. 2 of 11 Stage 3 Upper layers of water become densely populated with algae: 'algal bloom'. 3 of 11 Stage 4 Dense surface layer of algae absorbs light, preventing it from getting lower. 4 of 11 Stage 5 Light becomes limiting factor for the growth of plants, so they eventually die 5 of 11 Stage 6 Lack of dead plants and algae isn't limiting factor saprobiontic bacteria feeding and growth, populations of saprobionts grow. 6 of 11 Stage 7 Increased demand for oxygen, saprobionts require oxygen for respiration. 7 of 11 Stage 8 Concentration of oxygen in water is reduced, nitrates are released from decaying organisms. 8 of 11 Stage 9 Oxygen becomes limiting factor for population of aerobic organisms (e.g. fish), so they die. 9 of 11 Stage 10 Without aerobic organisms, less competition for anaerobic organisms whose populations rise. 10 of 11 Stage 11 Anaerobic organisms decompose dead material, releasing more nitrates and toxic wastes, which makes water putrid. 11 of 11
Energy transfers AQA A2 Biology PART 4 of 4 TOPICS: Nutrient Cycles 5.0 / 5 based on 1 rating Teacher recommended
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