Urban forests are often remnants of former larger forested areas, and traditionally considered as degraded habitats due to negative effects of urbanization. However, recent studies have shown that urban forests managed for recreational purposes can be structurally close to natural forests and may provide habitat features, such as dead wood, that are scarce in intensively managed forest landscapes. In this study, we assessed how urbanization affects polypore species richness and the number of red-listed polypore species in forest stands, and the occurrences of polypore species on individual units of dead wood. Spruce-inhabiting polypore assemblages and their associations to urbanization, local habitat connectivity and dead-wood abundance were investigated in southern Finland. The effects of urbanization on polypore species richness and individual species were largely negligible when other environmental variability was accounted for. Several red-listed polypore species were found in dead-wood hotspots of urban forests, though urbanization had a marginally significant negative effect on their richness. The main driver of total species richness was dead-wood abundance while the number of red-listed species was also strongly dependent on local habitat connectivity, implying that a high degree of fragmentation can decrease their occurrence in urban forests. We conclude that the highest potential for providing habitats for threatened species in the urban context lies in large peri-urban recreational forests which have been preserved for recreational purposes around many cities. On the other hand, overall polypore diversity can be increased simply by increasing dead-wood abundance, irrespective of landscape context.

城市森林通常是以前较大的森林地区的残余，传统上被认为是由于城市化的负面影响而退化的栖息地。然而，最近的研究表明，为娱乐目的而管理的城市森林在结构上可以接近天然森林，并且可能提供栖息地特征，例如在集约化管理的森林景观中稀少的枯木。在这项研究中，我们评估了城市化如何影响林分中多孔物种的丰富度和红色名录多孔物种的数量，以及单个枯木单位上多孔物种的出现情况。在芬兰南部调查了栖息在云杉的多孔组合及其与城市化、当地栖息地连通性和枯木丰度的关联。当考虑到其他环境变异性时，城市化对多孔物种丰富度和单个物种的影响在很大程度上可以忽略不计。在城市森林的枯木热点地区发现了几种列入红色名录的多孔物种，尽管城市化对其丰富度产生了略微显着的负面影响。总物种丰富度的主要驱动因素是枯木丰度，而红色名录物种的数量也强烈依赖于当地栖息地的连通性，这意味着高度的破碎化可以减少它们在城市森林中的出现。我们得出的结论是，在城市环境中为受威胁物种提供栖息地的最大潜力在于许多城市周围为娱乐目的而保留的大型城郊休闲森林。另一方面，