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Past failures of monocultures, caused by wind-throw or insect damages, and ongoing climate change currently strongly stimulate research into mixed-species stands. So far, the focus has mainly been on combinations of species with obvious complementary functional traits. However, for any generalization, a broad overview of the mixing reactions of functionally different tree species in different mixing proportions, patterns and under different site conditions is needed, including assemblages of species with rather similar demands on resources such as light. Here, we studied the growth of Scots pine and oak in mixed versus monospecific stands on 36 triplets located along a productivity gradient across Europe, reaching from Sweden to Spain and from France to Georgia. The set-up represents a wide variation in precipitation (456–1250 mm year−1), mean annual temperature (6.7–11.5 °C) and drought index by de Martonne (21–63 mm °C−1). Stand inventories and increment cores of trees stemming from 40- to 132-year-old, fully stocked stands on 0.04–0.94-ha-sized plots provided insight into how species mixing modifies stand growth and structure compared with neighbouring monospecific stands. On average, the standing stem volume was 436 and 360 m3 ha−1 in the monocultures of Scots pine and oak, respectively, and 418 m3 ha−1 in the mixed stands. The corresponding periodical annual volume increment amounted to 10.5 and 9.1 m3 ha−1 year−1 in the monocultures and 10.5 m3 ha−1 year−1 in the mixed stands. Scots pine showed a 10% larger quadratic mean diameter (p < 0.05), a 7% larger dominant diameter (p < 0.01) and a 9% higher growth of basal area and volume in mixed stands compared with neighbouring monocultures. For Scots pine, the productivity advantages of growing in mixture increased with site index (p < 0.01) and water supply (p < 0.01), while for oak they decreased with site index (p < 0.01). In total, the superior productivity of mixed stands compared to monocultures increased with water supply (p < 0.10). Based on 7843 measured crowns, we found that in mixture both species, but especially oak, had significantly wider crowns (p < 0.001) than in monocultures. On average, we found relatively small effects of species mixing on stand growth and structure. Scots pine benefiting on rich, and oak on poor sites, allows for a mixture that is productive and most likely climate resistant all along a wide ecological gradient. We discuss the potential of this mixture in view of climate change.

Dead wood is one of the most important indicators of forest naturalness and the most important manageable habitat for biodiversity in forests. Standing and lying dead wood, and especially coarse woody debris, plays an important part in creating habitats for many highly specialized organisms, e.g., insects, fungi, lichens and bacteria. Temperate mixed deciduous forests, rich in species, have been studied only to a small extent from the point of view of the ecology of wood-related cryptogams. Our study aimed at the reduction of the gap in knowledge about the ecological characteristics of dead wood-dependent organisms by focusing on species of cryptogams developing on various dead wood structures typical of temperate non-beech forests. Studies were performed in forests located in Lithuania, Poland, Belarus and Russia. We recorded 48 species of cryptogams: 18 species of bryophytes, 24 species of fungi and 6 species of lichens developing on dead wood. Our study stresses the importance of all types of dead wood as a substrate for the development of rare cryptogam species. Logs were the most important substratum type for cryptogams, followed by snags, dead trees and stumps. The cryptogam species richness on logs was several times higher than on the three other types of substrata. Coarse logs of intermediate decay stages hosted the highest number of cryptogams, followed by freshly fallen logs and, finally, well decayed logs. Assessing the importance of dead wood quality for the studied cryptogams, we found that intermediate decay stages are extremely important for fungi, while bryophytes or lichens do not show a clear preference. The highest number of cryptogams was found on Fraxinus excelsior, Quercus robur and Picea abies, while other tree species had less than half cryptogam species.

Establishing mixed-species stands is frequently proposed as a strategy to adapt forests to the increasing risk of water scarcity, yet contrasted results have been reported regarding mixing effects on tree drought exposure. To investigate the drivers behind the spatial and temporal variation in water-related mixing effects, we analysed the δ13C variation in 22-year tree ring chronologies for beech and pine trees sampled from 17 pure and mixed pine–beech stands across a large gradient of environmental conditions throughout Europe. In the pure stands, average δ13C values were lower for beech (−27.9‰ to −22.2‰) than for pine (−26.0‰ to −21.1‰), irrespective of site conditions. Decreasing SPEI values (calculated over June to September) were associated with an increase in δ13C for both species, but their effect was influenced by stand basal area for pine and site water availability for beech. Mixing did not change the temporal constancy of δ13C nor the tree reaction to a drought event, for any of the species. While the mixing effect (Δ δ13C = δ13C pure stands − δ13C mixed stands) was on average positive for beech and non-significant for pine across the whole gradient, this effect strongly differed between sites. For both species, mixing was not significant at extremely dry sites and positive at dry sites; on moderately wet sites, mixing was positive for beech and negative for pine; at sites with permanent water supply, no general patterns emerge for any of the species. The pattern of mixing effect along the gradient of water availability was not linear but showed threshold points, highlighting the need to investigate such relation for other combinations of tree species.

1. There is increasing evidence that species diversity enhances the temporal stability (TS) of community productivity in different ecosystems, although its effect at the population and tree levels seems to be negative or neutral. Asynchrony in species responses to environmental conditions was found to be one of the main drivers of this stabilizing process. However, the effect of species mixing on the stability of productivity, and the relative importance of the associated mechanisms, remain poorly understood in forest communities. 2. We investigated the way mixing species influenced the TS of productivity in Pinus sylvestris L. and Fagus sylvatica L. forests, and attempted to determine the main drivers among overyielding, asynchrony between species annual growth responses to environmental conditions, and temporal shifts in species interactions. We used a network of 93 experimental plots distributed across Europe to compare the TS of basal area growth over a 15-year period (1999-2013) in mixed and monospecific forest stands at different organizational levels, namely the community, population and individual tree levels. 3. Mixed stands showed a higher TS of basal area growth than monospecific stands at the community level, but not at the population or individual tree levels. The TS at the community level was related to asynchrony between species growth in mixtures, but not to overyielding nor to asynchrony between species growth in monospecific stands. Temporal shifts in species interactions were also related to asynchrony and to the mixing effect on the TS. 4. Synthesis. Our findings confirm that species mixing can stabilize productivity at the community level, whereas there is a neutral or negative effect on stability at the population and individual tree levels. The contrasting findings regarding the relationships between the temporal stability and asynchrony in species growth in mixed and monospecific stands suggest that the main driver in the stabilizing process may be the temporal niche complementarity between species rather than differences in species' intrinsic responses to environmental conditions.

Mixing of complementary tree species may increase stand productivity, mitigate the effects of drought and other risks, and pave the way to forest production systems which may be more resource-use efficient and stable in the face of climate change. However, systematic empirical studies on mixing effects are still missing for many commercially important and widespread species combinations. Here we studied the growth of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in mixed versus pure stands on 32 triplets located along a productivity gradient through Europe, reaching from Sweden to Bulgaria and from Spain to the Ukraine. Stand inventory and taking increment cores on the mainly 60-80 year-old trees and 0.02-1.55 ha sized, fully stocked plots provided insight how species mixing modifies the structure, dynamics and productivity compared with neighbouring pure stands. In mixture standing volume (+12 %), stand density (+20 %), basal area growth (+12 %), and stand volume growth (+8 %) were higher than the weighted mean of the neighbouring pure stands. Scots pine and European beech contributed rather equally to the overyielding and overdensity. In mixed stands mean diameter (+20 %) and height (+6 %) of Scots pine was ahead, while both diameter and height growth of European beech were behind (-8 %). The overyielding and overdensity were independent of the site index, the stand growth and yield, and climatic variables despite the wide variation in precipitation (520-1175 mm year(-1)), mean annual temperature (6-10.5 A degrees C), and the drought index by de Martonne (28-61 mm A degrees C-1) on the sites. Therefore, this species combination is potentially useful for increasing productivity across a wide range of site and climatic conditions. Given the significant overyielding of stand basal area growth but the absence of any relationship with site index and climatic variables, we hypothesize that the overyielding and overdensity results from several different types of interactions (light-, water-, and nutrient-related) that are all important in different circumstances. We discuss the relevance of the results for ecological theory and for the ongoing silvicultural transition from pure to mixed stands and their adaptation to climate change.

The networking in this study has been supported by COST Action FP1206 EUMIXFOR. All contributors thank their national funding institutions to establish, measure, and analyze data from the triplets. The first author thanks the Austrian Science Fund, which supported his work under project number P24433-B16. We also want to thank the two anonymous reviewers for their constructive criticism.

Mixing of complementary tree species may increase stand productivity, mitigate the effects of drought and other risks, and pave the way to forest production systems which may be more resource-use efficient and stable in the face of climate change. However, systematic empirical studies on mixing effects are still missing for many commercially important and widespread species combinations. Here we studied the growth of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in mixed versus pure stands on 32 triplets located along a productivity gradient through Europe, reaching from Sweden to Bulgaria and from Spain to the Ukraine. Stand inventory and taking increment cores on the mainly 60-80 year-old trees and 0.02-1.55 ha sized, fully stocked plots provided insight how species mixing modifies the structure, dynamics and productivity compared with neighbouring pure stands. In mixture standing volume (+12 %), stand density (+20 %), basal area growth (+12 %), and stand volume growth (+8 %) were higher than the weighted mean of the neighbouring pure stands. Scots pine and European beech contributed rather equally to the overyielding and overdensity. In mixed stands mean diameter (+20 %) and height (+6 %) of Scots pine was ahead, while both diameter and height growth of European beech were behind (−8 %). The overyielding and overdensity were independent of the site index, the stand growth and yield, and climatic variables despite the wide variation in precipitation (520-1175 mm year−1), mean annual temperature (6-10.5 °C), and the drought index by de Martonne (28-61 mm °C−1) on the sites. Therefore, this species combination is potentially useful for increasing productivity across a wide range of site and climatic conditions. Given the significant overyielding of stand basal area growth but the absence of any relationship with site index and climatic variables, we hypothesize that the overyielding and overdensity results from several different types of interactions (light-, water-, and nutrient-related) that are all important in different circumstances. We discuss the relevance of the results for ecological theory and for the ongoing silvicultural transition from pure to mixed stands and their adaptation to climate change.

We propose how quantitative knowledge about specialised birds and spatially explicit land cover data describing the terrestrial vegetation can be used to build Habitat Suitability Index models for the assessment and planning of representative habitat networks at the scale of landscapes and regions. Using specialised forest-dwelling species listed in the EC Birds directive, we review the quantitative knowledge, and identify knowledge gaps, about the requirements of species at different spatial scales from individuals to local populations. We also assess to what extent the selected species cover different forest types and ecoregions associated with the drainage basin of the Baltic Sea. We then use this information to estimate the tentative size of planning units for the assessment of habitat networks aimed at maintaining biodiversity. The estimated mean minimum size of planning units where suitable habitat dominate the landscape was ca 40 000 ha, while in managed landscapes with minimum amount of habitat the unit size averaged 250 000 ha. By contrast, the size of individual conservation areas such as woodland key biotopes and protected reserves from which habitat network can be built in a managed matrix was ca 1-1000 ha. We conclude that when managing for the maintenance of forest biodiversity there is a need to extend the spatial and temporal scale from the stand scale to that of landscapes within large management units. Finally, we discuss perspectives and limitations in using ecological knowledge about birds, landcover information and GIS-modelling as an integrated tool for tactical conservation planning.

The incidence of traumatic brain injury (TBI) in the United States was 3.5 million cases in 2009, according to the Centers for Disease Control and Prevention. It is a contributing factor in 30.5% of injury-related deaths among civilians. Additionally, since 2000, more than 260,000 service members were diagnosed with TBI, with the vast majority classified as mild or concussive (76%). The objective assessment of TBI via imaging is a critical research gap, both in the military and civilian communities. In 2011, the Department of Defense (DoD) prepared a congressional report summarizing the effectiveness of seven neuroimaging modalities (computed tomography [CT], magnetic resonance imaging [MRI], transcranial Doppler [TCD], positron emission tomography, single photon emission computed tomography, electrophysiologic techniques [magnetoencephalography and electroencephalography], and functional near-infrared spectroscopy) to assess the spectrum of TBI from concussion to coma. For this report, neuroimaging experts identified the most relevant peer-reviewed publications and assessed the quality of the literature for each of these imaging technique in the clinical and research settings. Although CT, MRI, and TCD were determined to be the most useful modalities in the clinical setting, no single imaging modality proved sufficient for all patients due to the heterogeneity of TBI. All imaging modalities reviewed demonstrated the potential to emerge as part of future clinical care. This paper describes and updates the results of the DoD report and also expands on the use of angiography in patients with TBI.

Background and Objectives: The menisci are crucial fibrocartilaginous structures of the knee joint and have to be repaired in case of a tear. However, not all meniscal tears heal, even in young patients. Fibrin clot (FC) started to be used to reduce the failure rates following meniscus repair. The purpose of this study is to evaluate and compare outcomes after isolated arthroscopic meniscal repair augmented with FC versus without FC. Materials and Methods: Fifty-nine patients aged under 19 with isolated meniscal tears were randomized into two groups: one group underwent the meniscal repair with FC (FC-augmented), and the other group did not receive FC (control). The evaluation and comparison between the groups based on FC augmentation included secondary arthroscopy rates, patient-reported outcome measures (Pedi-IKDC, Lysholm, and Tegner), and clinical and radiological (MRI) assessments at a median follow-up of 12 months. Results: No statistically significant difference was observed between FC-augmented and control groups in Pedi-IKDC, Lysholm, and TAG scores, or following clinical and radiological (MRI) evaluation. Patients in the FC-augmented group reported fewer clinical symptoms at the final follow-up across unstable and demanding (bucket-handle and complex) tear type subgroups (p = 0.012 and 0.041, respectively). Overall, nine revision arthroscopies occurred in both groups (2 and 7, respectively), all across bucket-handle and complex tears with no significant difference between the FC-augmented and control groups (p = 0.072). Conclusions: This pilot study found that FC usage during meniscal repair reduces clinical symptoms for patients with unstable, bucket-handle, or complex meniscal tears at the final follow-up of 12 months postoperatively. Nonetheless, no statistically significant differences were observed within the other outcome measures between the FC-augmented and control groups and subgroups based on meniscal tear types. Level of evidence: Level II.