Quadrat
A quadrat is a frame used in
A photo-quadrat is a photographic record of the area framed by a quadrat. It may use a physical frame to indicate the area, or may rely on fixed camera distance and lens field of view to automatically cover the specified area of substrate.[3] Parallel laser pointers mounted on the camera can also be used as scale indicators. The photo is taken perpendicular to the surface, or as close as possible to perpendicular for uneven surfaces.
History
The systematic use of quadrats was developed by the pioneering plant ecologists R. Pound and
The ecologist J. E. Weaver applied the use of quadrats to the teaching of ecology in 1918.[9]
Method
A quadrat can be used by researchers to methodically count organisms within a smaller, representative area in order to extrapolate to a larger habitat when comprehensive sampling is impossible or not practical. The quadrat's size corresponds to the size of the organism being sampled and the overall sampling area. To avoid selection bias, researchers will randomly distribute quadrats throughout the sampling area.[10]
See also
- Stand level modelling
References
- ^ Krebs, C.J. (1999). Ecological Methodology. Addison-Wesley.
- ^ Wheater, C. Philip; et al. (2011). Practical Field Ecology: Project Guide. John Wiley and Sons.
- ISBN 9780521249157.
- Clements, F. E.(June 1898). "A method of determining the abundance of secondary species". Minnesota Botanical Studies. 2: 19–24.
- Clements, F. E. (1900). Phytogeography of Nebraska (Second ed.). Lincoln, Neb. Published by the Seminar. pp. 61–63.
- Clements, F. E.(1916). Plant Succession. The Seminar, Lincoln, Nebraska. pp. 423–437.
- .
- ^ Tansley, A. G. (1911). Types of British vegetation. Cambridge University Press.
- JSTOR 43477708.
- ^ "Questions about Quadrats". Science and Plants for Schools. Retrieved 20 June 2018.
- .