Supplement 1. Data used in the four applications of principal coordinates of neighbor matrices (PCNM) analysis: abundance of ferns, transect coordinates, and environmental variables (Peru); biomass of zooplankton, transect coordinates, and environmental variables (Guadeloupe); chlorophyll a and spatial coordinates (Thau, France); and oribatid mite species counts, spatial coordinates, and environmental variables (St-Hippolyte, Québec).

<h2>File List</h2><blockquote> <p><b>Amazonian fern example:</b></p> <p><a href="Nauta.txt">Nauta.txt</a> Response, spatial, and environmental variables for the Nauta transect<br> <a href="Huanta.txt">Huanta.txt</a> Response, spatial, and environmental variables for the Huanta transect<br> </p> <p><b>Guadeloupe zooplankton example:</b></p> <p><a href="Guadeloupe.txt">Guadeloupe.txt</a> Response, spatial, and environmental variables<br> </p> <p><b>Chlorophyll <i>a</i> example:</b></p> <p><a href="Thau_data.txt">Thau_data.txt</a> Response and spatial variables<br> </p> <p><b>Oribatid mites example:</b></p> <p><a href="Oribatida_species.txt">Oribatida_species.txt</a> Response variables<br> <a href="Oribatida_XY_envir.txt">Oribatida_XY_envir.txt</a> Spatial and environmental variables<br> </p> </blockquote><h2>Description</h2><blockquote> <p>Data used in the four examples. Quantitative values for the dependent and spatial variables. Environmental variables may be quantitative or binary.</p> <p><b>Amazonian fern example:</b></p> <p>Description of the variables for both transects:<br> Response variable: raw counts of the fern <i>Adiantum tomentosum</i> in 5 × 5 m quadrats.<br> Spatial variable: coordinate (m) of the center of the plot along the transect.<br> Environmental variables: elevation (m), number of stems of trees of five classes of diameters at breast height (cm), number of stems of lianas of three classes of stem diameter (cm), thickness of the layer of soil organic matter, drainage in five classes (0 = good, 5 = none), canopy height (m), canopy, shrub and herbaceous coverage (cm)<br> </p> <p><b>Guadeloupe zooplankton example:</b></p> <p>Response variable: log-transformed zooplankton biomasses of two size classes (original units: mg/m<sup>3</sup> ash-free dry mass).<br> Spatial variable: coordinate (km) of the sampling site along the transect.<br> Environmental variables: dissolved oxygen (mg/L), salinity (psu), wind speed (m/s), phytoplankton biomass (log-transformed, original units: µg/L), turbidity (NTU), swell height (m) and 14 binary variables coding for habitat classes.<br> </p> <p><b>Chlorophyll <i>a</i> example:</b></p> <p>Response variable: chlorophyll <i>a</i> biomass (µg/L).<br> Spatial variable: <i>X</i> and <i>Y</i> coordinates (km) of the site.<br> </p> <p><b>Oribatid mites example:</b></p> <p>Response variable: raw counts of 35 species of oribatid mites on a Sphagnum mat .<br> Spatial variable: <i>X</i> and <i>Y</i> coordinates (m) of the sampling cores.<br> Environmental variables: bulk density of the substratum (g/L of dry uncompressed matter), water content (g/L of raw uncompresed material) and 12 binary variables coding for classes of substratum: 4 species of <i>Sphagnum</i> moss, ligneous litter, bare peat, interface between two substrates, 3 categories of shrubs, microtopography (blanket or hummock).</p> </blockquote> <p> </p>