Intensive forest management has drastically reduced the amount and diversity of dead wood resulting in population decline of saproxylic species. Forestry practices can also disrupt spatiotemporal continuity of dead wood habitats. We studied the effects of stand- and landscape-level densities of host trees on the incidence (proportion of occupied trees) of saproxylic beetles inhabiting recently dead standing Scots pines, a common host-tree type both in natural and managed boreal forests. We compared the occurrence patterns of eight rare specialist and eight common generalist species. Saproxylic beetles were collected from a total of 315 trees in 67 forest stands, including both managed and natural forests, located in three regions which form a gradient in forest-use intensity. Species richness of the entire community at tree and stand level did not respond to the stand- and landscape-level host-tree density. The incidence of six common generalist species did not depend on the stand-level host-tree density, whereas the incidences of four rare specialist species increased with increasing host-tree density. Five out of eight rare specialist species were either significantly less common or absent from the region with the lowest landscape-level density of host trees. We conclude that rare specialist species living in recently dead pines are susceptible to changes in spatiotemporal dynamics of their host trees. To conserve rare early-successional species, it is necessary to ensure continuous input of dying trees by prolonging rotation times in mature forests, regenerating stands using seed-tree cutting and leaving as many permanent retention trees as possible.

密集的森林管理已大大减少了死木的数量和多样性，从而导致saproxylic种的种群减少。林业实践也会破坏枯木栖息地的时空连续性。我们研究了寄主树的林分和景观水平密度对居住在最近死亡的苏格兰松树中的鼠脚形甲虫的发生率（占树的比例）的影响，这是天然林和经管理的北方森林中常见的寄主树类型。我们比较了8种稀有专科和8种普通通识物种的发生模式。在三个区域形成的森林利用强度梯度梯度分布的67个林分中，包括管理林和天然林，共收集了315棵树中的鼠尾草甲虫。树木和林分层次上整个社区的物种丰富度并没有对林分和景观水平寄主树的密度做出反应。六个普通通才种的发生率不取决于林分水平的寄主树密度，而四种稀有专长种的发生率随寄主树密度的增加而增加。该地区八种稀有专业树种中有五分之一在该地区的树木密度水平最低的地区不常见或缺乏。我们得出的结论是，生活在最近死亡的松树中的稀有专业树种易受其寄主树时空动态变化的影响。为了保护稀有的早期成功物种，有必要通过延长成熟森林的轮作时间来确保不断输入垂死的树木，