Abstract Deadwood is an important structural feature in forests providing essential resources for various organisms. Both forest management and conservation are increasingly focusing on the integration of deadwood into forest management. Deadwood volume and composition are driven by forest type, stand age, natural tree mortality, tree species composition and harvesting intensity. Here, we used inventory data from 28 unmanaged natural forest reserves (NFR) in Austria to analyse the patterns and drivers of: (i) the volume of standing and lying deadwood, (ii) the diversity of deadwood in different forest types. Eight forest types are located in the investigated NFRs covering a wide range of vegetation types with altitudes of 140–1825 m asl. The volumes of living wood and deadwood differed markedly between forest types. The average deadwood volume per forest type ranged from 23 m3 ha−1 in larch forests to 109 m3 ha−1 in spruce-fir-beech forests. Likewise, deadwood diversity (species diversity as well as diversity in diameter classes and degree of decomposition) differed significantly among forest types, with the highest deadwood diversity found in beech and spruce forests and the lowest in hardwood floodplain forests, carbonate pine forests and larch forests. Our results show that volume and composition of deadwood vary greatly among different forest types. Regression models revealed that the availability of deadwood was mainly driven by tree- and stand related factors (e.g. forest type, diameter at breast height and volume of living stand), whereas site-related (e.g. altitude) and climatic factors (e.g. mean annual precipitation) had a minor influence. The variables tree species diversity, aspect and slope showed no significance and were therefore not integrated into the final model. This study provides insights into deadwood availability and diversity in NFRs on a national scale, providing reference data for unmanaged temperate forests and aiding decision-making in nature conservation and forest management, since NFRs are reference areas for close-to-nature forestry.

中文翻译：

---

奥地利天然林保护区不同森林类型枯木数量和组成的模式和驱动因素

摘要 枯木是森林中重要的结构特征，为各种生物提供必需的资源。森林管理和保护都越来越注重将枯木整合到森林管理中。枯木的数量和组成受森林类型、林龄、自然树木死亡率、树种组成和采伐强度的影响。在这里，我们使用来自奥地利 28 个非管理天然林保护区 (NFR) 的清单数据来分析以下模式和驱动因素：(i) 立木和卧木的数量，(ii) 不同森林类型中枯木的多样性。八种森林类型位于调查的 NFR 中，覆盖范围广泛的植被类型，海拔高度为 140-1825 m asl。活木和枯木的数量在不同森林类型之间存在显着差异。每种森林类型的平均枯木量从落叶松林的 23 m3 ha-1 到云杉-冷杉-山毛榉林的 109 m3 ha-1 不等。同样，枯木多样性（物种多样性以及直径等级和分解程度的多样性）在森林类型之间存在显着差异，山毛榉和云杉林的枯木多样性最高，阔叶漫滩森林、碳酸盐松林和落叶松林最低. 我们的结果表明，不同森林类型之间枯木的数量和组成差异很大。回归模型显示，枯木的可用性主要受树木和林分相关因素（例如森林类型、胸高直径和活林分枝量）驱动，而场地相关（例如海拔）和气候因素（例如年平均降水量） ) 的影响较小。变量树种多样性、坡向和坡度没有显着意义，因此没有整合到最终模型中。这项研究深入了解了全国范围内 NFR 的枯木可用性和多样性，为未管理的温带森林提供了参考数据，并有助于自然保护和森林管理方面的决策，因为 NFR 是近自然林业的参考区域。