Red-listed saproxylic beetles in a beech reserve versus logged, unlogged, and mature spruce stands in Central Europe

Abstract Background Red-listed saproxylic beetles are frequently studied because they have significant bioindicative potential for assessing various forest ecosystems. A major recent trend in nature conservation, also reflected in conservation policy, is the protection of forests in Central Europe. This primarily involves protecting formerly managed beech stands. The study aimed to evaluate sample coverage of species richness, conservation value (community‐weighted means; CWMs), and beta community composition across four distinct forest stand types in two protected areas of Central Europe: (1) a protected old‐growth European beech ( Fagus sylvatica L.) reserve, (2) logged dead Norway spruce ( Picea abies [L.] H. Karst.) stands, (3) unlogged dead spruce stands, and (4) mature spruce stands serving as a control. Saproxylic beetles were collected in these four stand types over three consecutive years. Results Of the 31,549 saproxylic beetles collected, 2328 individuals belonging to 88 red-listed species were identified. The total red-listed species richness based on the same level of sample coverage (75%) revealed minor differences among beech, unlogged spruce, logged spruce, and mature spruce stands. However, in beech stands, significantly less sampling effort was required to achieve coverage (75%) compared to spruce types. Paradoxically, the CWMs of red-listed species relative to all saproxylic beetles showed that the conservation value was highest in the unlogged spruce stands. When considering red-listed species only, logged and unlogged spruce stands showed the highest conservation values, indicating that the average red-listed individuals captured in these habitats corresponded to the Endangered (EN) category. In contrast, the conservation value analysis showed that beech reserve and mature spruce stands exhibited the lowest, nearly identical values. Community composition differed significantly among all forest types, and a greater number of indicator species were associated with the beech reserve. Conclusions Despite being a primary focus of Central European conservation, our findings indicate that protected beech forests may not offer the highest conservation value for red-listed saproxylic beetles. Unlogged spruce stands exhibited the highest conservation value among the forest types studied. These findings suggest that at least a portion of disturbed spruce stands should be allowed to develop naturally. Commonly occurring managed early-stage habitats, such as open-canopy clear-cuts, can also be valuable for red-listed saproxylic beetles without eliminating the forest’s timber production, which is often disrupted by strict conservation strategies. Sensitive silviculture systems that maintain open habitats and deadwood retention may be the key to integrated forest management. Moving away from management activities that create temporary, open habitats may have a negative impact on biodiversity.