Figure 6.

Ordination (RDA) for the 25 families and the significant environmental variables (season and trap position (habitat), first and second axes, respectively), with the site as a co-variable. Each family is represented by an arrow that points in the direction of the steepest increase in abundance. The length of the arrow is a measure of the fit of each family to the ordination axes, namely the strength of multiple correlations between environmental variables and spider families. The distance between the centroids of environmental variables approximates the average dissimilarity between their family values as measured by the Euclidean distance. Diamonds = “NH” (natural habitat); circles = “BO” (border with the natural habitat); stars = “CE” (center of the vineyard); and X = “VV” position (focal vineyard closest to the neighboring vineyard).