摘要：The negative effect of roads on wildlife is recognized as a major contributor to the globalbiodiversity crisis, with anurans being among the most vulnerable groups overall. The "road-effect zone,"i.e., the extent of significant ecological effects from the edge of a road (Forman and Alexander 1998), hasimportant management implications, but has never been quantified for anurans. In the first study of its kind,we measured the extent and type of relationship underlying the road-effect zones of a motorway with ahigh proportion of heavy-truck traffic, particularly at night (Highway 401) for anuran species richness andrelative abundance. We surveyed 34 ponds located 68–3262 m from the edge of the motorway, and usedpiecewise and linear regressions to determine if road-effect zones were clearly delineated by ecologicalthresholds. We found road-effect zones of 250–1000 m delineated by ecological thresholds for four ofseven species and species richness, and road-effect zones of well beyond 1000 m best described by linearregressions for two species. The negative effect of Highway 401 was unexpectedly strong for four of sevenspecies suggest that, in addition to road mortality, very high nighttime truck traffic can actually lead toreduced use of breeding habitat near the motorway either by acting as a barrier to forest habitat on the otherside of the highway and/or because of traffic noise. Our results show that most anurans are likely to havereduced abundances near motorways, but that both the extent of the effect of this type of road and theunderlying relationship vary considerably between species. Furthermore, the noise and/or barrier effect ofvery high nighttime traffic volumes can lead to negative effects of motorways even on species that arerelatively unaffected by direct road mortality
