CGS NS 202 Lecture 7: Nutrients, Cycles, and Hypoxia
Document Summary
High net primary productivity: ecosystems whose plants rapidly convert solar energy to biomass. A global map of npp: npp increases with temperature and precipitation on land, and with light and nutrients in aquatic ecosystems. Physical matter is circulated continually in an ecosystem. Nutrients: elements and compounds that organisms consume and require for survival: stimulate plant production, lack of nutrients can limit production, the water cycle can affect how nutrients move in ecosystems. Oceanic primary productivity is highest in water near shore: this is where rivers empty, providing nutrients. Aquatic dead zones result from nutrient pollution from farms, cities, and industry: most dead zones are located near europe and the eastern u. s. Scientists are investigating innovative and economical ways to reduce nutrient runoff. Phosphorus cycle: describes the routes that phosphorus atoms take through the environment: no significant atmospheric component, most phosphorus is within rocks and is released by weathering.