ENVI 201 Lecture Notes - Lecture 7: Nitrogen Fixation, Nitrogen Cycle, Phosphorus Cycle
Document Summary
Nutrients may remain in a reservoir for a period of time. Properties of water due to hydrogen bonds between water molecules. Some carbon takes a long time to recycle. Humans altering carbon cycle by burning fossil fuels. Excess carbon dioxide in the atmosphere has contributed to global warming. Nitrogen is recycled through the earth"s systems by different types of bacteria. The nitrogen cycle converts nitrogen into compounds that are useful nutrients for plants and animals. Combine gaseous nitrogen w hydrogen to make ammonia and ammonium ions. Soil bacteria change ammonia and ammonium ions into nitrate ions. Humans are adding nitrogen from the atmosphere faster than it can be removed. Humans are removing nitrogen from the soil faster than it can be replaced. We destroy forests, grasslands, and wetlands, releasing large amounts of nitrogen into the atmosphere. We pollute aquatic ecosystems with agricultural runoff. We remove nitrogen from topsoil from land-clearing and harvesting processes.