Effects of quadrat size and data measurement on the detection of boundaries


  • Marie-Josée Fortin

    1. Department of Ecology and Evolution, State University of New York, Stony Brook, NY 11794–5245, USA
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    • Current address: Département de géographie, Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, QC, Canada H3C 3J7; Fax +1 514 343 8008; E-mail form@poste.umontreal.ca


Abstract. With sampled field data, the accuracy of delineation of ecotones is directly related to the resolution of the data (i.e. spatial and measurement type) and to the edge detection algorithm used. In the present study the reliability is investigated of an edge detection algorithm (lattice-wombling) to delimit vegetation boundaries when different spatial resolutions (quadrat sizes) are used. To quantify whether the edge detection algorithm is robust, it was applied to data from woody species in a second-growth woodland measured at different spatial resolutions with different data types. Boundaries were found at similar locations using any reasonable quadrat size (ca. 200 m2) but there were some slight differences when using different vegetation measures (density versus presence/absence data).