FACE
Free Air CO2 Enrichment (FACE) is a technique that is used to deliver CO2-enriched air to vegetation located out-of-doors in a natural field setting. The delivery system is usually constructed out of pipes and tubes that are arranged in a circle. Because these units do not employ walls or enclosures, FACE experiments are considered to be on the cutting edge of CO2 enrichment technology.
Fecundity
Fruitfulness or fertility. The quality or power of producing viable offspring in large numbers.
Feedback
The process by which a system responds to an initial forcing in such a way that it amplifies the original force (positive feedback) or reduces it (negative feedback).
Field capacity
The maximum amount of water that can be held by a soil.
Firn
An imperfectly consolidated mixture of granular snow and ice that will ultimately become ice alone as time progresses.
Fixation of carbon
Another name for the photosynthetic process, whereby carbon is removed from the air and "fixed" or incorporated into plant tissues.
Fixed
A shorthand term for the "fixation of carbon," which is the process by which plants remove CO2 from the air and incorporate it into their tissues.
Fledgling
A young bird in the process of acquiring a covering of feathers and the ability to fly.
Fluvial
An adjective used to describe something belonging to, found in, or produced by rivers.
Flux adjustment
A "correction" or "adjustment" term applied to coupled atmosphere and ocean sub-models experiencing climate drift. Such adjustments, however, are physically unfounded and often of larger magnitude than the climatological mean fluxes. In some models, flux corrections in certain regions exceed 200 Watts per square meter, which is 50 times greater than the surface radiative forcing, or impetus for warming, predicted to result from a doubling of atmospheric CO2!.
Food chain
A sequence of organisms in an ecosystem in which each member feeds on the member below it.
Foraminifera
Microscopic ocean-dwelling organisms having a shell perforated by pores (foramina) through which slender filaments project. Physical and chemical characteristics of their shells, deposited over time at the bottom of the ocean, are used to reconstruct histories of climatic conditions at the times the foraminifera lived.
Forb
An herbaceous plant that is not characterized as a grass. It often grows low to the ground with succulent leaves organized in a circular whorl about its base.
Fungal mycelium
The thread-like tubes of fungal organisms that are involved in water and nutrient transfer.