A Floating Quadrat

CMEIAS Quadrat Maker: A Digital Software Tool to Optimize Grid Dimensions and Produce Quadrat Images for Landscape Ecology Spatial Analysis

Quadrats are standard sampling units of relatively small, uniformly defined areas that divide a habitat of interest into subregions of equal size. They are used in ecography for 2-dimensional sampling of plants, slowmoving animals, and (more recently) microorganisms to (i) estimate population sizes when it is not feasible to measure their abundance in entirety, (ii) define the patterns of their...

Quadrat Sampling in Population Ecology

Background Estimating the abundance of organisms. Ecology is often referred to as the "study of distribution and abundance". This being true, we would often like to know how many of a certain organism are in a certain place, or at a certain time. Information on the abundance of an organism, or group of organisms is fundamental to most questions in ecology. However, we can rarely do a complete c...

The Quadrat Method in Teaching Ecology

Estimating species richness from quadrat sampling data: a general approach.

We consider the problem of estimating the number of species (denoted by S) of a biological community located in a region divided into n quadrats. To address this question, different hierarchical parametric approaches have been recently developed. Despite a detailed modeling of the underlying biological processes, they all have some limitations. Indeed, some assume that n is theoretically infini...

Interpretation of scale in paired quadrat variance methods

Question: Previous interpretations of the variance plot of paired quadrat variance method (PQV) have been incomplete. The objective of this study was to clarify the interpretation of PQV, and to shed additional light on how different quadrat variance methods can be used, in concert, to measure scale in transect data. Methods: We used artificial and real data to examine how the PQV method elucid...