Biogeochemical Cycles (Water, Carbon, Nitrogen and Phosphorus Cycles)

Biogeochemical cycles

pathways by which chemicals cycle through ecosystems, involving both biotic and abiotic components

Reservoirs

areas of biogeochemical cycles where collections of certain elements are pooled and become available on a limited basis

Another name for the water cycle

Hydrologic cycle

The water cycle

the sun's rays cause fresh water to evaporate from the oceans, leaving salts behind; meanwhile, vaporized fresh water rises into the atmosphere, cools, and falls as precipitation over oceans and land

Eventually, all water returns to ______

the oceans

The carbon cycle

a gaseous cycle in which organisms exchange carbon dioxide with the atmosphere

Reservoirs for carbon

shells in ocean sediments, organic compounds in living and dead organisms, fossil fuels

Greenhouse gases

CO2, nitrous oxide, methane

How do greenhouse gases work?

they allow the sun's rays to pass through but traps the infrared (heat) wavelengths

Effects of global warming (potential)

rise in sea level, change in global climate patterns

Nitrogen makes up ___ of the atmosphere

78%

Plants need a constant supply of ____ or _____ (forms of nitrogen)

ammonium, nitrate

The nitrogen cycle

a gaseous cycle that depends upon a number of bacteria who initiate nitrogen fixation to convert atmospheric nitrogen to nitrogen-containing organic compounds available to a host plant

Cyanobacteria

an aquatic nitrogen-fixing bacteria

Nitrogen fixation

Process of converting nitrogen gas into ammonia

Denitrification

the conversion of nitrates into nitrogen gas

What happens to man-made fertilizer when broken down?

soil bacteria break it down, adding nitrogen oxides to the atmosphere at three times the normal rate

What are the two ways that human activities impact nitrogen levels and air pollution?

using fertilizer and burning fossil fuels

How do fossil fuels negatively impact air quality?

nitrogen oxides and sulfur dioxide that are released into the atmosphere when fossil fuels are burned react with water vapor to form acids that contribute to acid deposition

Nitrogen oxides and hydrocarbons react to form

photochemical smog

The phosphorous cycle

a sedimentary cycle in which only a small amount is available to plants by the weathering of the rocks; the biotic community recycles phosphorus back to the producers, temporarily incorporating it into ATP, nucleotides, teeth, bone and shells, and then returning it to the ecosystem via decomposition

Eutrophication

the polluting of water supplies by phosphates and nitrates

Algal blooms

Massive growths of algae and other phytoplankton that results form large amounts of a limiting nutrient, like phosphates.

Primary Productivity

Rate at which organic matter is created by producers in an ecosystem

Nutrients

All the chemical substances that an organisms needs to sustain life