[These definitions are provided solely for the purposes of this Special Report.]
Accuracy 
  The degree to which the mean of a sample approaches the true mean of the population;
  lack of bias. 
Activity 
  A practice or ensemble of practices that take place on a delineated area over
  a given period of time. 
Baseline
  A reference scenario against which a change in greenhouse gas emissions or removals
  is measured. 
Bias 
  Systematic over- or under-estimation of a quantity. 
Biosphere
  That component of the Earth system that contains life in its various forms,
  which includes its living organisms and derived organic matter (e.g., litter,
  detritus, soil). 
Carbon Flux 
  Transfer of carbon from one carbon pool to another in units of measurement of
  mass per unit area and time (e.g., t C ha-1 yr-1). 
Carbon Pool 
  A reservoir. A system which has the capacity to accumulate or release carbon.
  Examples of carbon pools are forest biomass, wood products, soils, and atmosphere.
  The units are mass (e.g., t C). 
Carbon Stock 
  The absolute quantity of carbon held within a pool at a specified time. 
Flux
  See "Carbon Flux." 
Forest Estate 
  A forested landscape consisting of multiple stands of trees. 
Forest Stand 
  A community of trees, including aboveground and below-ground biomass and soils,
  sufficiently uniform in species composition, age, arrangement, and condition
  to be managed as a unit. 
Heterotrophic Respiration 
  The release of carbon dioxide from decomposition of organic matter. 
Land Cover 
  The observed physical and biological cover of the Earth's land as vegetation
  or man-made features. 
Land Use 
  The total of arrangements, activities, and inputs undertaken in a certain land
  cover type (a set of human actions). The social and economic purposes for which
  land is managed (e.g., grazing, timber extraction, conservation). 
Permanence
  The longevity of a carbon pool and the stability of its stocks, given the management
  and disturbance environment in which it occurs. 
Pool 
  See "Carbon Pool." 
Practice 
  An action or set of actions that affect the land, the stocks of pools associated
  with it or otherwise affect the exchange of greenhouse gases with the atmosphere.
Precision 
  The repeatability of a measurement (e.g., the standard error of the sample mean).
Regeneration 
  The renewal of a stand of trees through either natural means (seeded on-site
  or adjacent stands or deposited by wind, birds, or animals) or artificial means
  (by planting seedlings or direct seeding). 
Reservoir 
  A pool. 
Sequestration 
  The process of increasing the carbon content of a carbon pool other than the
  atmosphere. 
Shifting Agriculture 
  A form of forest use common in tropic forests where an area of forest is cleared,
  or partially cleared, and used for cropping for a few years until the forest
  regenerates. Also known as "slash and burn agriculture," "moving agriculture,"
  or "swidden agriculture." 
Sink
  Any process or mechanism which removes a greenhouse gas, an aerosol, or a precursor
  of a greenhouse gas from the atmosphere. A given pool (reservoir) can be a sink
  for atmospheric carbon if, during a given time interval, more carbon is flowing
  into it than is flowing out. 
Source
  Opposite of sink. A carbon pool (reservoir) can be a source of carbon to the
  atmosphere if less carbon is flowing into it than is flowing out of it. 
Stand
  See "Forest Stand." 
Stock
  See "Carbon Stock." 
Soil Carbon Pool 
  Used here to refer to the relevant carbon in the soil. It includes various forms
  of soil organic carbon (humus) and inorganic soil carbon and charcoal. It excludes
  soil biomass (e.g., roots, bulbs, etc.) as well as the soil fauna (animals).
Uptake
  The addition of carbon to a pool. A similar term is "sequestration." 
Wood Products 
  Products derived from the harvested wood from a forest, including fuelwood and
  logs and the products derived from them such as sawn timber, plywood, wood pulp,
  paper, etc. 
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