quadrat

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Related to quadrats: quadrat sampling

quadrat

(kwŏd′rət, -răt′)
n.
Any of a group of small, usually rectangular plots of land used for sampling the occurrence of species or of archaeological artifacts.

quadrat

an area of ground surface, often 1 m2, used as a sampling unit in population studies.
References in periodicals archive ?
Four 2 m x 2 m quadrats were located within each block, each separated by 10 m.
Indeed, 84% of the exotic species that germinated from the seed bank were not found in any vegetation quadrat, suggesting the seeds may have come from further afield.
At each site, the frequency of occurrence of each species was recorded on 100 randomly distributed quadrats (each 10 X 10 cm).
To confirm that these two factors represented the most important environmental variables in the landscape of quadrats studied, we first conducted an ordination of quadrats in species space via nonmetric multidimensional scaling (NMS; Minchin 1987), as implemented in PC-ORD 3.
Two 100 m x 100 m sites were chosen at depths between -4 m and -8 m, hereafter referred to as subtidal quadrats 1 and 2, respectively [ILLUSTRATION FOR FIGURE 1 OMITTED].
The estimation procedure is based on a combination of quantitative measurements using quadrats and corrections by tidal-level bandwidths, as well as more general visual coverage estimates, together with a coverage-biomass regression model for biomass estimation.
This formed a uniform grid throughout the entire reach, with quadrats extending one after another across the width of the stream and 100 m both upstream and downstream from the crossing.
Wilcoxon tests were run for emergent amphibious tolerator, terrestrial damp and terrestrial dry functional groups comparing paired quadrats for each species before and after the watering event.
Every sampling of 300 sweeps covered in Site I and II four 20 m x 20 m quadrats (altogether 1,600 square metres) and in Site III and IV three 20 m x 20 m quadrats (altogether 1,200 square metres).
A list of the species that were identified in 60 quadrats can be found in Table 4.
Within each of these sites, each habitat type was sampled using a 200 m2 sampling unit; either a 10 m x 20 m quadrat or a 2 m x 100 m belt transect.