A growing proportion of the boreal biome consists of managed even-aged secondary forest stands regenerated after clear-cutting. Many disturbance-intolerant species may not be able to recolonize or reach their original abundance in these stands before the next clear-cutting, potentially causing large-scale biodiversity losses. Boreal bryophytes (mosses and liverworts) include many species intolerant to clear-cutting, and at small spatial scales species richness and occupancy has been shown to remain changed in secondary stands half a century after logging. To assess if such persistent changes occur also at the stand scale, we listed and estimated cover of all bryophyte species in 1-ha plots, comparing 14 secondary stands originating from clear-cutting 40–60 years earlier with 14 older semi-natural stands. The large plots also made it possible to assess differences in occupancy and abundance for more bryophyte species than in previous studies. Species composition differed significantly for both mosses and liverworts, but unlike earlier studies, we could not detect any significant difference between stand types in species numbers. Thirteen species were significantly associated with semi-natural stands and the total cover of liverworts was less than half in secondary stands. Secondary stands had significantly fewer species typically occurring under shady conditions and/or mostly growing on “tree substrates” (dead wood and/or bases and stems of living trees). Ordination analysis further emphasized the importance of shade and suitable deadwood substrates; the among-plot variation in bryophyte species composition was related to amount of coarse deadwood as well as to gradients from shady spruce dominated to open pine dominated stands and from polar- to equator-facing slopes. Besides lack of suitable habitat conditions in secondary stands, dispersal limitation may have caused a colonization time lag for some species. The clear importance of stand scale habitat conditions for bryophyte species composition calls for management adaptions to facilitate life boating and/or recolonization by ensuring availability of shade, coarse decomposing logs, and specific deciduous tree species (Populus, Salix, Sorbus) in secondary stands.

越来越多的北方生物区系由经过管理的，均匀砍伐后的次生林组成。在下次砍伐之前，许多不容忍干扰物种可能无法在这些林分中重新定殖或达到其原始数量，可能造成大规模的生物多样性丧失。北方苔藓植物（苔藓和地蒿）包括许多不易砍伐的物种，在小规模尺度上，采伐后半个世纪，次生林种的丰富度和占有率已显示出变化。为了评估这种持续变化是否也发生在林分尺度上，我们在1公顷的土地上列出并估算了所有苔藓植物的覆盖率，将40到60年前清晰的14个次生林分与14个较旧的半自然林分进行了比较。与以前的研究相比，较大的地块还可以评估更多苔藓植物物种在占有率和丰度上的差异。苔藓和艾蒿的物种组成均存在显着差异，但与早期研究不同，我们无法检测到林分类型之间物种数量的任何显着差异。13种物种与半自然林分显着相关，次生林分中的艾蒿总覆盖率不到一半。次生林分通常在阴凉条件下和/或主要生长在“树木基质”上的物种（死木和/或活树的基部和茎部）的种类明显减少。整理分析进一步强调了阴影和合适的沉木基材的重要性。苔藓植物种类组成的种间变化与粗沉材的数量有关，也与由云杉为主的云杉到松木为主的林分以及从极地到赤道的坡度的梯度有关。除了次生林中缺乏合适的生境条件外，散布限制还可能导致某些物种的定居时间延迟。林分规模生境条件对于苔藓植物物种组成的重要性非常明显，因此需要进行管理上的调整，以通过确保阴影，粗分解原木和特定落叶树种的可用性来促进生活划船和/或重新定殖（扩散限制可能导致某些物种的定居时间延迟。林分规模生境条件对于苔藓植物物种组成的重要性非常明显，因此需要进行管理上的调整，以通过确保阴影，粗分解原木和特定落叶树种的可用性来促进生活划船和/或重新定殖（扩散限制可能导致某些物种的定居时间延迟。林分规模生境条件对于苔藓植物物种组成的重要性非常明显，因此需要进行管理上的调整，以通过确保阴影，粗分解原木和特定落叶树种的可用性来促进生活划船和/或重新定殖（次生林中的杨，柳，山梨）。