Quadrat
方形区、方形枠
- Quadrat methods
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Quantitative evaluation: plot size is one of the most important decisions for the surveys of plant communities, because the size influences the analyses and interpretations.
- point quadrat
- quadrat
- belt transect
- Quadrat
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A square (sensu stricto) or rectangle (sensu lato), marked by stakes and/or frames to measure abundance within a given area.
This is the quadrat I usually use.Quadrat methods
Estimation of abundance, such as cover, density and height within quadrats. By monitoring quadrats, we can detect temporal changes in vegetaiton (see, LTER).
When we set up quadrats, we have to mention three characteristics.- alignment of quadrats (random, regular, or arbitrary)
- quadrat size (and shape)
- number of quadrats
- Optimal size of quadrats (in Hokkaido)
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These values are for vegetation survey. When we have different reseach objectives, the size should be changed depending on the purposes and costs.
Theoretical decision
making species-area curve
Empirical decision (for vegetation survey)
Roughly saying, the size is consistent with the vegetation height.
Physiognomy Vegetation height (m) Size (m) Moss / Lichens < 0.05 0.1 × 0.1 Short grassland (annual grassland)) < 1 1 × 1 Tall grassland (perennial grassland) < 2 2 × 2 Shrub < 4 5 × 5 Young forest (sub-forest)) < 8 10 × 10 Mature forest > 8 20 × 20 - References