@article{VoulgariKokotaSteffanDewenterKeller2020, author = {Voulgari-Kokota, Anna and Steffan-Dewenter, Ingolf and Keller, Alexander}, title = {Susceptibility of Red Mason Bee Larvae to Bacterial Threats Due to Microbiome Exchange with Imported Pollen Provisions}, series = {Insects}, volume = {11}, journal = {Insects}, number = {6}, issn = {2075-4450}, doi = {10.3390/insects11060373}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-207948}, year = {2020}, abstract = {Solitary bees are subject to a variety of pressures that cause severe population declines. Currently, habitat loss, temperature shifts, agrochemical exposure, and new parasites are identified as major threats. However, knowledge about detrimental bacteria is scarce, although they may disturb natural microbiomes, disturb nest environments, or harm the larvae directly. To address this gap, we investigated 12 Osmia bicornis nests with deceased larvae and 31 nests with healthy larvae from the same localities in a 16S ribosomal RNA (rRNA) gene metabarcoding study. We sampled larvae, pollen provisions, and nest material and then contrasted bacterial community composition and diversity in healthy and deceased nests. Microbiomes of pollen provisions and larvae showed similarities for healthy larvae, whilst this was not the case for deceased individuals. We identified three bacterial taxa assigned to Paenibacillus sp. (closely related to P. pabuli/amylolyticus/xylanexedens), Sporosarcina sp., and Bacillus sp. as indicative for bacterial communities of deceased larvae, as well as Lactobacillus for corresponding pollen provisions. Furthermore, we performed a provisioning experiment, where we fed larvae with untreated and sterilized pollens, as well as sterilized pollens inoculated with a Bacillus sp. isolate from a deceased larva. Untreated larval microbiomes were consistent with that of the pollen provided. Sterilized pollen alone did not lead to acute mortality, while no microbiome was recoverable from the larvae. In the inoculation treatment, we observed that larval microbiomes were dominated by the seeded bacterium, which resulted in enhanced mortality. These results support that larval microbiomes are strongly determined by the pollen provisions. Further, they underline the need for further investigation of the impact of detrimental bacterial acquired via pollens and potential buffering by a diverse pollen provision microbiome in solitary bees.}, language = {en} } @article{SiegerHovestadt2020, author = {Sieger, Charlotte Sophie and Hovestadt, Thomas}, title = {The degree of spatial variation relative to temporal variation influences evolution of dispersal}, series = {Oikos}, volume = {129}, journal = {Oikos}, number = {11}, doi = {10.1111/oik.07567}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239049}, pages = {1611 -- 1622}, year = {2020}, abstract = {In the face of ongoing global climate and land use change, organisms have multiple possibilities to cope with the modification of their environment. The two main possibilities are to either adapt locally or disperse to a more suitable habitat. The evolution of both local adaptation and dispersal interacts and can be influenced by the spatial and temporal variation (of e.g. temperature or precipitation). In an individual based model (IBM), we explore evolution of phenotypes in landscapes with varying degree of spatial relative to global temporal variation in order to examine its influence on the evolution of dispersal, niche optimum and niche width. The relationship between temporal and spatial variation did neither influence the evolution of local adaptation in the niche optimum nor of niche widths. Dispersal probability is highly influenced by the spatio-temporal relationship: with increasing spatial variation, dispersal probability decreases. Additionally, the shape of the distribution of the trait values over patch attributes switches from hump- to U-shaped. At low spatial variance more individuals emigrate from average habitats, at high spatial variance more from extreme habitats. The comparatively high dispersal probability in extreme patches of landscapes with a high spatial variation can be explained by evolutionary succession of two kinds of adaptive response. Early in the simulations, extreme patches in landscapes with a high spatial variability act as sink habitats, where population persistence depends on highly dispersive individuals with a wide niche. With ongoing evolution, local adaptation of the remaining individuals takes over, but simultaneously a possible bet-hedging strategy promotes higher dispersal probabilities in those habitats. Here, in generations that experience extreme shifts from the temporal mean of the patch attribute, the expected fitness becomes higher for dispersing individuals than for philopatric individuals. This means that under certain circumstances, both local adaptation and high dispersal probability can be selected for for coping with the projected environmental changes in the future.}, language = {en} } @article{MuellerUlyshenSeiboldetal.2020, author = {M{\"u}ller, J{\"o}rg and Ulyshen, Mike and Seibold, Sebastian and Cadotte, Marc and Chao, Anne and B{\"a}ssler, Claus and Vogel, Sebastian and Hagge, Jonas and Weiß, Ingmar and Baldrian, Petr and Tl{\´a}skal, Vojtěch and Thorn, Simon}, title = {Primary determinants of communities in deadwood vary among taxa but are regionally consistent}, series = {Oikos}, volume = {129}, journal = {Oikos}, number = {10}, doi = {10.1111/oik.07335}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228201}, pages = {1579 -- 1588}, year = {2020}, abstract = {The evolutionary split between gymnosperms and angiosperms has far-reaching implications for the current communities colonizing trees. The inherent characteristics of dead wood include its role as a spatially scattered habitat of plant tissue, transient in time. Thus, local assemblages in deadwood forming a food web in a necrobiome should be affected not only by dispersal ability but also by host tree identity, the decay stage and local abiotic conditions. However, experiments simultaneously manipulating these potential community drivers in deadwood are lacking. To disentangle the importance of spatial distance and microclimate, as well as host identity and decay stage as drivers of local assemblages, we conducted two consecutive experiments, a 2-tree species and 6-tree species experiment with 80 and 72 tree logs, respectively, located in canopy openings and under closed canopies of a montane and a lowland forest. We sampled saproxylic beetles, spiders, fungi and bacterial assemblages from logs. Variation partitioning for community metrics based on a unified framework of Hill numbers showed consistent results for both studies: host identity was most important for sporocarp-detected fungal assemblages, decay stage and host tree for DNA-detected fungal assemblages, microclimate and decay stage for beetles and spiders and decay stage for bacteria. Spatial distance was of minor importance for most taxa but showed the strongest effects for arthropods. The contrasting patterns among the taxa highlight the need for multi-taxon analyses in identifying the importance of abiotic and biotic drivers of community composition. Moreover, the consistent finding of microclimate as the primary driver for saproxylic beetles compared to host identity shows, for the first time that existing evolutionary host adaptions can be outcompeted by local climate conditions in deadwood.}, language = {en} } @article{ThornSeiboldLeverkusetal.2020, author = {Thorn, Simon and Seibold, Sebastian and Leverkus, Alexandro B and Michler, Thomas and M{\"u}ller, J{\"o}rg and Noss, Reed F and Stork, Nigel and Vogel, Sebastian and Lindenmayer, David B}, title = {The living dead: acknowledging life after tree death to stop forest degradation}, series = {Frontiers in Ecology and the Environment}, volume = {18}, journal = {Frontiers in Ecology and the Environment}, number = {9}, doi = {10.1002/fee.2252}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218575}, pages = {505 -- 512}, year = {2020}, abstract = {Global sustainability agendas focus primarily on halting deforestation, yet the biodiversity crisis resulting from the degradation of remaining forests is going largely unnoticed. Forest degradation occurs through the loss of key ecological structures, such as dying trees and deadwood, even in the absence of deforestation. One of the main drivers of forest degradation is limited awareness by policy makers and the public on the importance of these structures for supporting forest biodiversity and ecosystem function. Here, we outline management strategies to protect forest health and biodiversity by maintaining and promoting deadwood, and propose environmental education initiatives to improve the general awareness of the importance of deadwood. Finally, we call for major reforms to forest management to maintain and restore deadwood; large, old trees; and other key ecological structures.}, language = {en} } @article{BoetzlSchueleKraussetal.2020, author = {Boetzl, Fabian A. and Schuele, Maren and Krauss, Jochen and Steffan-Dewenter, Ingolf}, title = {Pest control potential of adjacent agri-environment schemes varies with crop type and is shaped by landscape context and within-field position}, series = {Journal of Applied Ecology}, volume = {57}, journal = {Journal of Applied Ecology}, number = {8}, doi = {10.1111/1365-2664.13653}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218265}, pages = {1482 -- 1493}, year = {2020}, abstract = {Increasing natural pest control in agricultural fields is an important aim of ecological intensification. Combined effects of landscape context and local placement of agri-environmental schemes (AES) on natural pest control and within-field distance functions of natural pest control agents have rarely been addressed but might affect the distribution of biocontrol providers. Importantly, it is currently unknown whether ecosystem services provided by adjacent AES are consistent for different crop types during crop rotation. In this study, we assessed whether crop rotation from oilseed rape to cereals altered within-field distance functions of ground-dwelling predators from adjacent agri-environmental fields along a gradient in landscape context. Additionally, we recorded crop pests, predation rates, parasitoids as well as crop yields on a total of 30 study sites. Distance functions varied between trophic levels: Carabid richness decreased while densities of carabid beetles, staphylinid beetles as well as crop yields increased towards the field centres. Distance functions of parasitoids and pests were modulated by the amount of semi-natural habitat in the surrounding landscape, while the effects of adjacent AES were limited. Distance decay functions found for ground-dwelling predators in oilseed rape in the previous year were not always present in cereals. Increasing distance to the field edge also increased effects of crop rotation on carabid beetle assemblages, indicating a source habitat function of field edges. Synthesis and applications. Distance functions of natural pest control are not universal and the effects of agri-environmental schemes (AES) in different adjacent crops during crop rotation vary and depend on ecological contrasts. A network of semi-natural habitats and spatially optimized AES habitats can benefit pest control in agricultural landscapes, but constraints as a result of crop type need to be addressed by annually targeted, spatially shifting agri-environment schemes for different crops.}, language = {en} } @article{HabensteinAminiGruebeletal.2020, author = {Habenstein, Jens and Amini, Emad and Gr{\"u}bel, Kornelia and el Jundi, Basil and R{\"o}ssler, Wolfgang}, title = {The brain of Cataglyphis ants: Neuronal organization and visual projections}, series = {Journal of Comparative Neurology}, volume = {528}, journal = {Journal of Comparative Neurology}, number = {18}, doi = {10.1002/cne.24934}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218212}, pages = {3479 -- 3506}, year = {2020}, abstract = {Cataglyphis ants are known for their outstanding navigational abilities. They return to their inconspicuous nest after far-reaching foraging trips using path integration, and whenever available, learn and memorize visual features of panoramic sceneries. To achieve this, the ants combine directional visual information from celestial cues and panoramic scenes with distance information from an intrinsic odometer. The largely vision-based navigation in Cataglyphis requires sophisticated neuronal networks to process the broad repertoire of visual stimuli. Although Cataglyphis ants have been subjected to many neuroethological studies, little is known about the general neuronal organization of their central brain and the visual pathways beyond major circuits. Here, we provide a comprehensive, three-dimensional neuronal map of synapse-rich neuropils in the brain of Cataglyphis nodus including major connecting fiber systems. In addition, we examined neuronal tracts underlying the processing of visual information in more detail. This study revealed a total of 33 brain neuropils and 30 neuronal fiber tracts including six distinct tracts between the optic lobes and the cerebrum. We also discuss the importance of comparative studies on insect brain architecture for a profound understanding of neuronal networks and their function.}, language = {en} } @article{StieglervonHoermannMuelleretal.2020, author = {Stiegler, Jonas and von Hoermann, Christian and M{\"u}ller, J{\"o}rg and Benbow, M. Eric and Heurich, Marco}, title = {Carcass provisioning for scavenger conservation in a temperate forest ecosystem}, series = {Ecosphere}, volume = {11}, journal = {Ecosphere}, number = {4}, doi = {10.1002/ecs2.3063}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218054}, year = {2020}, abstract = {Carrion plays an essential role in shaping the structure and functioning of ecosystems and has far-reaching implications for biodiversity conservation. The change in availability and type of carcasses throughout ecosystems can involve negative effects for scavenging communities. To address this issue, there have been recent conservation management measures of carrion provision in natural systems. However, the optimal conditions under which exposing carcasses to optimize conservation outcomes are still limited. Here, we used camera traps throughout elevational and vegetational gradients to monitor the consumption of 48 deer carcasses over a study period of six years by evaluating 270,279 photographs resulting out of 15,373 trap nights. We detected 17 species visiting carcass deployments, including five endangered species. Our results show that large carcasses, the winter season, and a heterogeneous surrounding habitat enhanced the frequency of carcass visits and the species richness of scavenger assemblages. Contrary to our expectations, carcass species, condition (fresh/frozen), and provision schedule (continuous vs single exposure) did not influence scavenging frequency or diversity. The carcass visitation frequency increased with carcass mass and lower temperatures. The effect of large carcasses was especially pronounced for mesopredators and the Eurasian lynx (Lynx lynx). Lynx were not too influenced in its carrion acquisition by the season, but exclusively preferred remote habitats containing higher forest cover. Birds of prey, mesopredators, and top predators were also positively influenced by the visiting rate of ravens (Corvus corax), whereas no biotic or abiotic preferences were found for wild boars (Sus scrofa). This study provides evidence that any ungulate species of carrion, either in a fresh or in previously frozen condition, attracts a high diversity of scavengers especially during winter, thereby supporting earlier work that carcass provisions may support scavenger communities and endangered species.}, language = {en} } @article{DoerflerCadotteWeisseretal.2020, author = {Doerfler, Inken and Cadotte, Marc W. and Weisser, Wolfgang W. and M{\"u}ller, J{\"o}rg and Gossner, Martin M. and Heibl, Christoph and B{\"a}ssler, Claus and Thorn, Simon and Seibold, Sebastian}, title = {Restoration-oriented forest management affects community assembly patterns of deadwood-dependent organisms}, series = {Journal of Applied Ecology}, volume = {57}, journal = {Journal of Applied Ecology}, number = {12}, doi = {10.1111/1365-2664.13741}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217918}, pages = {2429 -- 2440}, year = {2020}, abstract = {Land-use intensification leads to loss and degradation of habitats and is thus a major driver of biodiversity loss. Restoration strategies typically focus on promoting biodiversity but often neglect that land-use intensification could have changed the underlying mechanisms of community assembly. Since assembly mechanisms determine the diversity and composition of communities, we propose that evaluation of restoration strategies should consider effects of restoration on biodiversity and community assembly. Using a multi-taxon approach, we tested whether a strategy that promotes forest biodiversity by restoring deadwood habitats also affects assembly patterns. We assessed saproxylic (i.e. deadwood-dependent) beetles and fungi, as well as non-saproxylic plants and birds in 68 beech forest plots in southern Germany, 8 years after the commencement of a restoration project. To assess changes in community assembly, we analysed the patterns of functional-phylogenetic diversity, community-weighted mean (CWM) traits and their diversity. We hypothesized that restoration increases habitat amount and heterogeneity of deadwood and reduces canopy cover and thereby decreases the strength of environmental filters imposed by past silvicultural intensification, such as a low amount in deadwood. With the restoration of deadwood habitats, saproxylic beetle communities became less functionally-phylogenetically similar, whereas the assembly patterns of saproxylic fungi and non-saproxylic taxa remained unaffected by deadwood restoration. Among the traits analysed, deadwood diameter niche position of species was most strongly affected indicating that the enrichment of large deadwood objects led to lower functional-phylogenetical similarity of saproxylic beetles. Community assembly and traits of plants were mainly influenced by microclimate associated with changes in canopy cover. Synthesis and applications. Our results indicate that the positive effects of deadwood restoration on saproxylic beetle richness are associated with an increase in deadwood amount. This might be linked to an increase in deadwood heterogeneity, and therefore decreasing management-induced environmental filters. Deadwood enrichment can thus be considered an effective restoration strategy which reduces the negative effects of intense forest management on saproxylic taxa by not only promoting biodiversity but also by decreasing the environmental filters shaping saproxylic beetle communities, thus allowing the possibly for more interactions between species and a higher functional diversity.}, language = {en} } @article{HardulakMoriniereHausmannetal.2020, author = {Hardulak, Laura A. and Morini{\`e}re, J{\´e}r{\^o}me and Hausmann, Axel and Hendrich, Lars and Schmidt, Stefan and Doczkal, Dieter and M{\"u}ller, J{\"o}rg and Hebert, Paul D. N. and Haszprunar, Gerhard}, title = {DNA metabarcoding for biodiversity monitoring in a national park: Screening for invasive and pest species}, series = {Molecular Ecology Resources}, volume = {20}, journal = {Molecular Ecology Resources}, number = {6}, doi = {10.1111/1755-0998.13212}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217812}, pages = {1542 -- 1557}, year = {2020}, abstract = {DNA metabarcoding was utilized for a large-scale, multiyear assessment of biodiversity in Malaise trap collections from the Bavarian Forest National Park (Germany, Bavaria). Principal component analysis of read count-based biodiversities revealed clustering in concordance with whether collection sites were located inside or outside of the National Park. Jaccard distance matrices of the presences of barcode index numbers (BINs) at collection sites in the two survey years (2016 and 2018) were significantly correlated. Overall similar patterns in the presence of total arthropod BINs, as well as BINs belonging to four major arthropod orders across the study area, were observed in both survey years, and are also comparable with results of a previous study based on DNA barcoding of Sanger-sequenced specimens. A custom reference sequence library was assembled from publicly available data to screen for pest or invasive arthropods among the specimens or from the preservative ethanol. A single 98.6\% match to the invasive bark beetle Ips duplicatus was detected in an ethanol sample. This species has not previously been detected in the National Park.}, language = {en} } @article{LeverkusGustafssonLindenmayeretal.2020, author = {Leverkus, Alexandro B and Gustafsson, Lena and Lindenmayer, David B and Castro, Jorge and Rey Benayas, Jos{\´e} Mar{\´i}a and Ranius, Thomas and Thorn, Simon}, title = {Salvage logging effects on regulating ecosystem services and fuel loads}, series = {Frontiers in Ecology and the Environment}, volume = {18}, journal = {Frontiers in Ecology and the Environment}, number = {7}, doi = {10.1002/fee.2219}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216111}, pages = {391 -- 400}, year = {2020}, abstract = {Salvage logging, or logging after natural disturbances such as wildfires, insect outbreaks, and windstorms, is carried out to recover some of a forest's natural and/or economic capital. However, trade-offs between management objectives and a lack of consensus on the ecological consequences of salvage logging impair science-based decision making on the management of forests after natural disturbances. We conducted a global meta-analysis of the impacts of salvage logging on regulating ecosystem services and on fuel loads, as a frequent post-disturbance objective is preventing subsequent wildfires that could be fueled by the accumulation of dead trunks and branches. Salvage logging affected ecosystem services in a moderately negative way, regardless of disturbance type and severity, time elapsed since salvage logging, intensity of salvage logging, and the group of regulating ecosystem services being considered. However, prolonging the time between natural disturbance and salvage logging mitigated negative effects on regulating ecosystem services. Salvage logging had no overall effect on surface fuels; rather, different fuel types responded differently depending on the time elapsed since salvage logging. Delaying salvage logging by ~2-4 years may reduce negative ecological impacts without affecting surface fuel loads.}, language = {en} }