Abundance
- Abundance
-
The total number of individuals or amount of resources present in a specific area. Typically, used qualitative, relative, or subjective manner rather than an absolute number or amount.
ACFOR
For convenient use
The species is
- A: abundant
- C: common
- F: frequent
- O: occasional
- R: rare
in the given area (or ecosystem)
- Unit
-
Cover (被度)
The area of ground covered by plants. Usually we use the marginal projection of the aboveground parts of plants, shown below.
A: An example of frame for the measurement of cover.
B: Cover is not for the absolute cover. We estiamte the projection of the plants, as indicated by interrupted lines.Cover-abundance scale, or dominance scale
by the Zurich-Montpellier School of phytosociology
r Solitary with small cover + Few, with small cover (pronounced 'cross') 1 Numerous, but less than 1/20 cover, or scattered, with cover up to 1/20 2 Any number, with 1/20-1/4 cover (5-25%) 3 Any number, with 1/4-1/2 cover (25-50%) 4 Any number, with 1/2-3/4 cover (50-75%) 5 Any number, with cover more than 3/4 of the reference area (> 75%) Daubenmire's cover classes
Class 1 2 3 4 5 % 0-5 5-25 25-50 50-75 75-100 Biomass (バイオマス)
The mass of living organisms in a given area (or ecosystem) at a given time. We often use dry mass for plant ecology. See also biome and productivity.
Density (密度)
The number of plants per unit area. Usually we use this parameter for trees and plants of which individuality is clearly recognized.
Frequency (頻度)
Number of plots that the target species occurs.
- References
-
- dominance
- field equipment (野外調査道具)
- quadrat (方形区)