All of the organisms on Earth and the nonliving environment with which they interact make up this.
describes the flow of matter through an ecosystem
are the parts of an ecosystem in which matter may reside, such as the atmosphere or soil.
are the rate at which matter moves from one pool to another
By knowing the mass of an element in each pool in an ecosystem and the fluxes of the element through that ecosystem, scientists can account for changes in the abundance of that element within an ecosystem.
of a particular pool is the total amount (mass) of an element or molecule that it contains.
If the net flux of an element is zero, then the capital of the element in that pool remains constant; such a pool is said to be in this.
is the average time that an atom of an element or molecule of a compound spends in a pool.
is the average time that it takes an element or molecule to make its way through an entire biogeochemical cycle.
Elements that organisms require in comparatively large amounts, such as carbon, oxygen, hydrogen, nitrogen, phosphorus, and sulfur, are this.
Organisms also require this, such as molybdenum, manganese, and boron, but only in very small amounts.
describes the distribution and flux of water through Earth’s biogeochemical system. Over 98% of Earth’s water is found in the ocean, and 99% of the remaining water occurs in saturated rocks out of reach of plant roots. At any moment, less than 0.001% of Earth’s water is in the atmosphere.
Evaporation from leaves is called this.
Rainwater that falls on land may flow across the surface as this, eventually entering lakes and streams.
Gravity causes some water to percolate through the soil and into the rock below as this.
A layer of soil or rock that is saturated with groundwater is called an this.
gross primary production (GPP).
The total amount of CO2 that photosynthetic organisms convert to organic carbon each year is called this.
net primary production (NPP).
NPP is the amount of organic carbon available to all the nonphotosynthetic organisms, or consumers, in an ecosystem.
Net ecosystem production (NEP)
This is the amount of organic carbon left each year after subtracting the respiration of nonphotosynthetic organisms from NPP. In other words, NEP is the net flux of carbon into an ecosystem.
Nitrogen enters the biosphere through the process of this.
Specialized bacteria in the soil then convert NH + to nitrite (NO –) and nitrate (NO –) 423 in a process known as this.
Nitrogen in soil and water is returned to the atmosphere by .
global circulation models (GCMs)
Climate scientists use computer programs called these to forecast climate change.
Haber- Bosch process
The situation changed dramatically in the early part of the 20th century when chemists discovered the this, a nonbiological method of nitrogen fixation.
igher concentrations of nitrogen encourage the rapid growth of algae. Their growth leads to a process called this, in which the abundant organic matter from the algae encourages high rates of respiration by decomposing organisms.
But even if we were to stop all emissions immediately, some warming would still occur. Climatologists call this this, and it is about 0.1 °C per decade.
carbon capture and storage (CCS).
rather than allowing CO2 to escape to the atmosphere, CCS technologies capture it and transfer it into a form that can be permanently stored underground
hotovoltaic (PV) cells
these are devices that directly convert sunlight to electrical current. At present, PV cells provide less than 0.1% of global electricity
These are derived directly from plant materials, such as corn or wood. Burning them has no net effect on CO2e emissions,
this refers to actions that increase the absorption and storage of CO2 in Earth’s ecosystems.