quadrat sampling

quadrat sampling

(in statistics) a method of examining the distribution of organisms by taking samples within squares of known size, normally 1 m2. Such squares are selected at random and marked usually with wire outlines. A series of quadrats is usually sampled so that comparisons are possible between, say, the distribution of a given plant in two different areas. The mean number in each series of quadrats can be compared. see SIGNIFICANCE.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
Reef condition was expressed in terms of live oyster density (#/[m.sup.2]), size (shell height) distribution, and total shell (live and dead) weight (kg/[m.sup.2]) based on the quadrat sampling. One-way ANOVA was used to test for significant (P < 0.05) differences in the oyster metrics among the means stratified into three geographic regions in the Bay.
A comparison of the effectiveness of timed searches vs quadrat sampling in mussel surveys.
When quadrat sampling is difficult or too costly (e.g., in low density populations or mountain areas) distance sampling is favored [11].
Mussels were collected during timed searches and quadrat sampling. Time searches involved a 45 minute visual search of a 200 meter reach of stream by two collectors for a total of 90 minutes per site.
This quantitative survey employed a quadrat sampling technique with multiple random starts.
These data were collected by random 0.25 [m.sup.2] quadrat sampling in shoal areas that typically contained the highest mussel densities at the respective sites to facilitate long-term monitoring.
The methods of estimating grasshopper numbers vary from state to state and include quadrat sampling, ring estimations, binomial sampling, pan trapping, roadside counts, and transect or visual estimation (Legg et al.
The rationale for establishing 12 sample plots included i) a limited sampling window to capture peak seasonal growth patterns; ii) the intensity and duration of within-plot quadrat sampling; and iii) travel time and distance to remote plot locations.
Thus, the quadrat sampling method produced adequate estimates of the actual seed density oc curring at each point.