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

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 investi- gated of an edge detection algorithm (lattice-wombling) to delimit vegetation boundaries when different spatial resolu- tions (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. Bounda- ries were found at similar locations using any reasonable quadrat size (ca. 200 m2) but there were some slight differ- ences when using different vegetation measures (density ver- sus presence/absence data).

[1]  D Hémon,et al.  Assessing the significance of the correlation between two spatial processes. , 1989, Biometrics.

[2]  Geoffrey M. Jacquez,et al.  Quantification of the Spatial Co-Occurrences of Ecological Boundaries , 1996 .

[3]  Marie-Josée Fortin,et al.  Edge detection algorithms for two-dimensional ecological data , 1993 .

[4]  Robert R. Sokal,et al.  Approximate analysis of variance of spatially autocorrelated regional data , 1990 .

[5]  T. Coburn.  Spatial Data Analysis by Example , 1991 .

[6]  William J. Sutherland,et al.  Ecological Census Techniques: Contents , 1996 .

[7]  P. Clifford,et al.  Modifying the t test for assessing the correlation between two spatial processes , 1993 .

[8]  P. Greig-Smith,et al.  QUANTITATIVE PLANT ECOLOGY , 1959 .

[9]  R. Hobbs.  Remote Sensing of Spatial and Temporal Dynamics of Vegetation , 1990 .

[10]  E. Maarel.  On the establishment of plant community boundaries , 1976 .

[11]  R. Haining.  Spatial Data Analysis in the Social and Environmental Sciences , 1990 .

[12]  E. Maarel,et al.  Ecotones and ecoclines are different , 1990 .

[13]  C. Johnston,et al.  Quantitative Methods for Studying Landscape Boundaries , 1992 .

[14]  Bernard Fingleton,et al.  Spatial Data Analysis by Example. Vol. 1. Point Pattern and Quantitative Data. , 1986 .

[15]  M. Fortin.  Effects of data types on vegetation boundary delineation , 1997 .

[16]  M. Fortin,et al.  Delineation of Ecological Boundaries: Comparison of Approaches and Significance Tests , 1995 .

[17]  Noel A Cressie,et al.  Statistics for Spatial Data. , 1992 .

[18]  J. Keith Ord,et al.  Spatial Processes Models and Applications , 1981 .

[19]  P. Greig-Smith,et al.  The Use of Random and Contiguous Quadrats in the Study of the Structure of Plant Communities , 1952 .

[20]  Quantitative Plant Ecology , 1960 .

[21]  Harold A. Mooney,et al.  Remote Sensing of Biosphere Functioning , 1990 .

[22]  P. Dixon,et al.  Small-scale environmental heterogeneity and the analysis of species distributions along gradients , 1990 .

[23]  William J. Sutherland,et al.  Ecological census techniques: A handbook: Edited by William J. Sutherland Cambridge University Press, 1996. £75.00/$125.00 hbk, £27.95/$44.95 pbk (xv + 336 pages) ISBN 0 521 66135 5 / 367921 1 , 1997 .