A (12) | B (11) | C (6) | D (11) | E (21) | F (9) | G (7) | H (2) | I (8) | K (1) | L (16) | M (5) | N (5) | O (2) | P (11) | Q (1) | R (2) | S (13) | T (1) | V (1) | W (8)
Title Definition

Choosing one action over other possible alternative actions.[fn]Source:(IISD 2005) from IISD website; http://www.iisd.org/sd/glossary.asp (updated: Aug 2005)[/fn]


Change of land cover with depletion of tree crown cover to less than 10 percent. Changes within the forest class (e.g., from closed to open forest) which negatively affect the stand or site, and... read more

Degradation of an ecosystem service

For provisioning services, decreased production of the service through changes in area over which the services is provided, or decreased production per unit area. For regulating and supporting... read more

Degradation of ecosystems

A persistent reduction in the capacity to provide ecosystem services.


land degradation in drylands resulting from various factors, including climatic variations and human activities.


a process of economic and social transformation that defies simple definition. Though often viewed as a strictly economic process involving growth and diversification of a country's economy,... read more


A small artificial watercourse designed to drain swampy areas or irrigated lands. Theoretically, it is actually a small canal, but it is referred to as a "drain" in many localities.

Drainage Area

The drainage area of a stream at the specific location of the site is that area, measured in a horizontal plane, enclosed by a topographic divide from which direct surface runoff from... read more

Drainage Basin

The area from which water is carried off by a drainage system, a watershed, or a catchment area.

Dryland system

Areas characterized by lack of water, which constrains the two major interlinked services of the system: primary production and nutrient cycling. Four dryland subtypes are widely recognized: dry... read more


See Dryland system.