Logging to "salvage" economic returns from forests affected by natural disturbances has become increasingly prevalent globally. Despite potential negative effects on biodiversity, salvage logging is often conducted, even in areas otherwise excluded from logging and reserved for nature conservation, inter alia because strategic priorities for post-disturbance management are widely lacking.A review of the existing literature revealed that most studies investigating the effects of salvage logging on biodiversity have been conducted less than 5 years following natural disturbances, and focused on non-saproxylic organisms.A meta-analysis across 24 species groups revealed that salvage logging significantly decreases numbers of species of eight taxonomic groups. Richness of dead wood dependent taxa (i.e. saproxylic organisms) decreased more strongly than richness of non-saproxylic taxa. In contrast, taxonomic groups typically associated with open habitats increased in the number of species after salvage logging.By analysing 134 original species abundance matrices, we demonstrate that salvage logging significantly alters community composition in 7 of 17 species groups, particularly affecting saproxylic assemblages.Synthesis and applications. Our results suggest that salvage logging is not consistent with the management objectives of protected areas. Substantial changes, such as the retention of dead wood in naturally disturbed forests, are needed to support biodiversity. Future research should investigate the amount and spatio-temporal distribution of retained dead wood needed to maintain all components of biodiversity.
Abstract Aim Global warming is assumed to restructure mountain insect communities in space and time. Theory and observations along climate gradients predict that insect abundance and richness, especially of small‐bodied species, will increase with increasing temperature. However, the specific responses of single species to rising temperatures, such as spatial range shifts, also alter communities, calling for intensive monitoring of real‐world communities over time. Location German Alps and pre‐alpine forests in south‐east Germany. Methods We empirically examined the temporal and spatial change in wild bee communities and its drivers along two largely well‐protected elevational gradients (alpine grassland vs. pre‐alpine forest), each sampled twice within the last decade. Results We detected clear abundance‐based upward shifts in bee communities, particularly in cold‐adapted bumble bee species, demonstrating the speed with which mobile organisms can respond to climatic changes. Mean annual temperature was identified as the main driver of species richness in both regions. Accordingly, and in large overlap with expectations under climate warming, we detected an increase in bee richness and abundance, and an increase in small‐bodied species in low‐ and mid‐elevations along the grassland gradient. Community responses in the pre‐alpine forest gradient were only partly consistent with community responses in alpine grasslands. Main Conclusion In well‐protected temperate mountain regions, small‐bodied bees may initially profit from warming temperatures, by getting more abundant and diverse. Less severe warming, and differences in habitat openness along the forested gradient, however, might moderate species responses. Our study further highlights the utility of standardized abundance data for revealing rapid changes in bee communities over only one decade.
Increasing natural disturbances in conifer forests worldwide complicate political decisions about appropriate land management. In particular, allowing insects to kill trees without intervention has intensified public debate over the dual roles of strictly protected areas to sustain ecosystem services and to conserve biodiversity. Here we show that after large scale bark beetle Ips typographus infestation in spruce Picea abies forests in southeastern Germany, maximum nitrate concentrations in runoff used for drinking water increased significantly but only temporarily at the headwater scale. Moreover, this major criterion of water quality remained consistently far below the limit recommended by the World Health Organization. At the same time, biodiversity, including numbers of Red-listed species, increased for most taxa across a broad range of lineages. Our study provides strong support for a policy to allow natural disturbance-recovery processes to operate unimpeded in conifer-dominated mountain forests, especially within protected areas.
It is well-known that over-harvesting of timber threatens saproxylic fungal diversity. However, quantifying species loss is difficult due to the lack of spatial explicit baseline studies and related continuous temporal investigations. The first step to achieve basic information are systematic inventories in a given area. The Hyrcanian forest is among the most important forest biodiversity hotspots in Iran, which has been added to the UNESCO World Heritage List in 2019. Therefore, we collected 193 samples of wood-inhabiting fungi based on systematic surveys considering all seasons in Hyrcanian old-growth forests during five years (2016-2021). Species collected belonged to the fungal phylum <em>Basidiomycota</em> (169 species, 99 genera, 48 family and 1 <em>incertae sedis</em> family, 11 orders and 3 classes) and <em>Ascomycota</em> (24 species, 17 genera, 12 family, 6 orders and 4 classes). One collected species fall within the kingdom Protozoa, <em>Lycogala epidendrum</em>. 58 species and 16 genera were new for the Iranian funga; 11 and seven species were new for Gilan and Mazandaran province respectively; 20 species and one genus were new for Golestan province and one genus was a new record for the Hyrcanian forests funga. Our inventory highlights the need for documenting saproxylic fungi and to quantify the diversity in hotspot regions. This inventory might serve as a baseline for further studies to track diversity change due to forest management and climate change and to provide concepts to prevent fungal diversity from future loss.
Spruce forests face many threats such as climate change and bark beetle outbreaks.Yet, bark beetle dynamics have a long co-evolutionary history strongly linked to spruce forest structural dynamics.Disturbed spruce forest sites resulting from bark beetle outbreaks therefore should not be regarded as degraded land, but as early successional stages following natural forest dynamics.Three post-bark-beetle disturbance sites and one closed-canopy site in the Bavarian Forest and Šumava National Parks were investigated with the focus on moth communities.The three disturbed sites had undergone different post-disturbance management regimes, with one being treated by salvage logging, while at the other two forest sites deadwood was kept in the forest.To avoid the spread of bark beetles, however, the bark of dead trees was either gouged or removed.The aim was to determine how many moths can be found at the undisturbed and disturbed forest sites and if differences in community composition can be explained by different management regimes.The results highlight that natural forest disturbance can increase moth diversity, especially by favouring species that are associated with open and shrub habitats.Many rare and endangered species benefi t from bark beetle outbreaks, indicating that accepting natural forest dynamics is an important part of conservation management.Postbark beetle management seems to have a minor effect on moth communities.
