Abstract. Four contrasting ecotones were sampled to address three questions: (1) Are there ‘ecotonal’ species, (2) Do ecotones possess higher (or lower) species richness than the adjacent communities? and (3) Are exotic species more likely to occur in ecotones? One ecotone was edaphic, one was apparently caused by a positive‐feedback switch, one was environmental/anthropogenic and one was entirely anthropogenic. The exact position of each ecotone was established from the spatial change in ordination scores. Ecotonal species, in the sense of species mainly restricted to the ecotone at the site, were present in all four ecotones. All but one of the ecotonal species were native. The switch ecotone and the purely anthropogenic ecotone also contained native species that were significantly more frequent in the ecotone than in either adjacent community. Species richness was intermediate between that of the two adjacent communities in three of the ecotones. In the environmental/anthropogenic ecotone, species richness was higher than in adjacent communities, but not significantly so. There were appreciable numbers of exotic species in the two ecotones with anthropogenic influence, one of which had a proportion of exotic species intermediate between the two adjacent communities. Contrary to theory, the proportion of exotic species in the second ecotone was significantly lower than in either adjacent community. We conclude that all three features we examined depend on the particular ecological conditions and the ecology of the species present; they are not intrinsic properties of ecotones.

Vegetation texture, describing plant communities by the range of characters present in them, can describe functional variation more effectively than using the identities of the species. We ask whether spatial trends, as seen in spatial autocorrelation (SAc), are stronger in vegetation texture. We also ask in what environment SAc is stronger, whether local or over longer distances, and with what measure of distance. Roadside vegetation was sampled across an orographic region of the South Island, New Zealand, from a high‐rainfall zone up to just above treeline (the “Wet” side) and then down into a rain‐shadow area (the “Dry” side). Species composition was recorded in quadrats placed in 30 clusters. Five functional plant characters were measured on all species encountered: characters that have been reported in the literature to correlate with light‐capture, heat budget and nutrient strategy. SAc was calculated using a saturation‐response type of relation in species composition, and also in texture using the five functional characters. There was significant species‐composition SAc in almost all comparisons, but the maximum percentage of variation explained was 25%. The fit was almost always higher using local, short‐distance, comparisons than using comparisons over a whole side (Wet or Dry). On average dissimilarity had reached 90% of its asymptote after ca 250 m. It is concluded that the SAc was mainly due to local factors. SAc relations almost always predicted the presence/absence of species more accurately than their abundance. Distances along the road generally gave a very slightly better fit to species composition than surface distances, suggesting that there might be dispersal limitation. On the Wet side, elevation in overall comparisons gave a still better fit, implying environmental control too. The strength of SAc in texture was strongest on the Dry side, and using overall comparisons, abundance weighting and surface distances, but in other cases texture SAc was weaker than SAc in species composition. It is concluded that the saturation‐response formula used here has theoretical advantages over previous approaches. The SAc in this vegetation seems to be caused by a combination of dispersal limitation, broad environmental trends and especially local environmental effects such as disturbance. SAc in texture may have been weaker overall on the Wet side than on the Dry because the main environmental difference across the former is in frost, and characters correlated with frost resistance have not yet been included in texture analyses.

Abstract. The vegetation of a mire in a medium‐high rainfall area of South Island, New Zealand is described. The central part of the bog is raised 6 m above the surroundings, suggesting that it is ombrotrophic, and the species present are those of apparently ombrotrophic bogs elsewhere in New Zealand. pH of < 4.0 and Ca/Mg molar quotient of < 1.0 also indicates ombrotrophic conditions. Within the mire, these criteria provide effective discrimination between the fen (rheotrophic) and bog (ombrotrophic) communities. A bimodal distribution of ordination scores suggests that the change in pH and in Ca/Mg quotients cause a switch to operate.