Some useful definitions for interpreting the Woodlands data (from DeAngelis et al. 1981) are the following:
- Basal Area Increment
- The amount of woody tissue added to the stand basal area per year through growth.
- Compartment
- A division of the ecosystem for which we may measure organic matter in terms of dry weight.
- Increment (Net annual)
- The change in the size of a compartment during a year. For example, leaf mass in July 1970=812 g -2 and leaf mass in July 1971=826 g-2. The increment is therefore 14 g -2 yr -1. Note that increment in this case does not include leaf litterfall. Similar definitions are used for branch and bole increments, with branch and bole litterfall not included in the increment.
- Field Layer
- Herbaceous plants, mosses and lichens. Woody plants less than 50 cm in height are included here.
- Flux (Net annual)
- The annual amount of organic matter being transferred (e.g. by litterfall) from one compartment to another.
- Frass
- Includes insect excreta and may include other unidentifiable materials.
- Global Radiation
- The sum of irradiance on a horizontal surface caused by direct solar radiation and diffuse short-wave radiation due to clouds, dust and molecular scattering from all parts of the sky. (Definition from Van Wijk & Scholte Ubing, 1966).
- Overstory
- The trees forming the main canopy.
- Productivity (Net annual)
- The sum of litterfall plus all biomass increments plus consumption not accounted for in production.
- Radiation Balance
- The difference between short-wave radiation from the sky and the sum of short-wave reflected radiation and long-wave terrestrial radiation.
- Soil Top Organic
- Includes recently fallen litter (L layer) as well as decomposing organic layers on top of the mineral soil (F and H layers).
- Standing Dead
- Dead plants or parts of plants still standing in the forest.
- Stocking Density
- Number of stems per hectare.
- Understory (or Substory)
- The sum of sub-canopy and shrub layers.