AP Enviornmental Science

Ionizing radiation
: enough energy to knock electrons from atoms forming ions, capable of causing cancer (ex gamma-X-rays-UV) 
First Law of Thermodynamics
1.       energy is neither created nor destroyed, but may be converted from one form to another
Second Law of Thermodynamics
1.       : when energy is changed from one form to another, some useful energy is always degraded into lower quality energy (usually heat) 
Humus
organic, dark material remaining after decomposition by microorganisms 
Leaching
1.       removal of dissolved materials from soil by water moving downwards 
Illuviation
1.       deposit of leached material in lower soil layers (B) 
Loam
perfect agricultural soil with equal portions of sand, silt, clay 
Solutions to soil problems
conservation tillage, crop rotation, contour plowing, organic fertilizers 
Parts of the hydrologic cycle
1.       evaporation, transpiration, runoff, condensation, precipitation, infiltration 
Aquifer:
1.       : any water bearing layer in the ground 
Salt water intrusion
near the coast, overpumping of groundwater causes saltwater to move into the aquifer
During an El Nino year
1.       : trade winds weaken & warm water sloshed back to SA  During a Non El Nino year: Easterly trade winds and ocean currents pool warm water in the western Pacific, allowing upwelling of nutrient rich water off the West coast of South America 
Effects of El Nino
1.       : upwelling decreases disrupting food chains, N US has mild winters, SW US has increased rainfall, less Atlantic Hurricanes 
Nitrogen fixing
1.       because atmospheric N cannot be used directly by plants it must first be converted into ammonia by bacteria
Ammonification
 1.       decomposers covert organic waste into ammonia   
Nitrification
1.       : ammonia is converted to nitrate ions (NO-3) 
Denitrification
1.       bacteria convert ammonia back into N 
Phosphorus does not circulate as easily as N because
1.       it does not exist as a gas, but is released by weathering of phosphate rocks 
 Because soils contain very little phosphorus
a major limiting factor for plant growth 
Excess phosphorus is added to aquatic ecosystems by
1.       runoff of animal wastes, fertilizer discharge of sewage