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Biogenic volatile organic compound (BVOC) emissions from trees subjected to biotic stress are higher compared to healthy trees, and they may also have a different compound composition. This in turn affects atmospheric chemistry and can lead to either positive or negative feedback to the climate. Climate change favors the abundance of the European spruce bark beetle (Ips typographus) which attacks the bark of Norway spruce (Picea abies) trees, causing induced BVOC emissions from the trees as a response to the insect stress. Here, results are reported from a study analyzing the difference in emission rates between healthy and bark-beetle-infested Norway spruce trees, changes in emission rates over time since the infestation started, and differences in emission rates from bark-beetle-drilled entry and exit holes. Bark chamber measurements on both healthy and infested trees were performed during the summer of 2019 at Hyltemossa and Norunda research stations in Sweden. The measurements showed that induced BVOC emissions following the bark beetle infestation were dominated by entry hole emissions in the early growing season and exit hole emissions in the later season. The results showed a significant difference in emission rates between healthy and infested trees during both seasons. The seasonal average standardized BVOC emission rate of healthy trees was 32 ± 52 µg m−2 h−1 (mean ± standard deviation), while the average standardized BVOC emission rates of infested trees were 6700 ± 6900 and 2000 ± 1300 µg m−2 h−1 during the early and late season respectively. BVOC emission rates were highest at the start of the infestation and decreased exponentially with time, showing induced emission rates for up to 1 year after which the emission rates were similar to those from healthy bark. Constitutive needle emission rates from healthy trees were found to be 11 times higher than bark emissions from healthy trees. However, when Norway spruce trees were infested, the bark emission rates were instead 6 to 20 times higher than the needle emissions, causing substantial increases in the total tree BVOC emission rate. This could lead to high impacts on atmospheric processes, specifically the formation of secondary organic aerosols, which have a higher yield from some monoterpene compounds, which increased from infested trees.

The transition to a fossil-free society in Sweden is expected to cause an increased demand for forest-derived products which may intensify existing conflicts between environmental goals. This study investigated the role of non-industrial private forest owners in sustaining multiple forest values and their prioritizations among forest ecosystem services, management strategies, as well as their views on future needs. The study results were generated through the means of a survey which revealed a consistent high valuation among all respondents of ecosystem services relating to water quality, timber quality, recreation, and biodiversity. A majority of the respondents desired increasing proportions of mixed species and broadleaved stands within the future forest landscape. Certified forest owners who were members of a forest owner association (CMs) were characterized by favoring values relating to forest production, such as high stand growth and high timber quality, with carbon substitution as the preferred means of mitigating climate change. Forest owners lacking both certification and membership in a forest owner association valued the ecosystem services recreation and biodiversity significantly higher, and also preferred retaining more old forest within the landscape. The survey results revealed a higher management activity among CMs, resulting in a more frequent establishment of mixed and broadleaved stands. Forest owners with medium to large scale properties were well-represented within the CM-category. The results indicated that while the CMs are more interested in production than owners of small properties, they are also more likely to have taken adaptive measures favoring risk management and biodiversity.

Recent rapid warming has caused uneven impacts on the composition, structure, and functioning of northern ecosystems. It remains unknown how climatic drivers control linear and non-linear trends in ecosystem productivity. Based on a plant phenology index (PPI) product at a spatial resolution of 0.05° over 2000–2018, we used an automated polynomial fitting scheme to detect and characterize trend types (i.e., polynomial trends and no-trends) in the yearly-integrated PPI (PPIINT) for northern (> 30°N) ecosystems and their dependence on climatic drivers and ecosystem types. The averaged slope for the linear trends (p < 0.05) of PPIINT was positive across all the ecosystems, among which deciduous broadleaved forests and evergreen needle-leaved forests (ENF) showed the highest and lowest mean slopes, respectively. More than 50% of the pixels in ENF, arctic and boreal shrublands, and permanent wetlands (PW) had linear trends. A large fraction of PW also showed quadratic and cubic trends. These trend patterns agreed well with estimates of global vegetation productivity based on solar-induced chlorophyll fluorescence. Across all the biomes, PPIINT in pixels with linear trends showed lower mean values and higher partial correlation coefficients with temperature or precipitation than in pixels without linear trends. Overall, our study revealed the emergence of latitudinal convergence and divergence in climatic controls on the linear and non-linear trends of PPIINT, implying that northern shifts of vegetation and climate change may potentially increase the non-linear nature of climatic controls on ecosystem productivity. These results can improve our understanding and prediction of climate-induced changes in plant phenology and productivity and facilitate sustainable management of ecosystems by accounting for their resilience and vulnerability to future climate change.

Dead standing trees (DSTs) generally decompose slower than wood in contact with the forest floor. In many regions, DSTs are being created at an increasing rate due to accelerating tree mortality caused by climate change. Therefore, factors determining DST fall are crucial for predicting dead wood turnover time but remain poorly constrained. Here, we conduct a re-analysis of published DST fall data to provide standardized information on the mean time to fall (MTF) of DSTs across biomes. We used multiple linear regression to test covariates considered important for DST fall, while controlling for mortality and management effects. DSTs of species killed by fire, insects and other causes stood on average for 48, 13 and 19 years, but MTF calculations were sensitive to how tree size was accounted for. Species’ MTFs differed significantly between DSTs killed by fire and other causes, between coniferous and broadleaved plant functional types (PFTs) and between managed and unmanaged sites, but management did not explain MTFs when we distinguished by mortality cause. Mean annual temperature (MAT) negatively affected MTFs, whereas larger tree size or being coniferous caused DSTs to stand longer. The most important explanatory variables were MAT and tree size, with minor contributions of management and plant functional type depending on mortality cause. Our results provide a basis to improve the representation of dead wood decomposition in carbon cycle assessments.

Climate change and human activities influence the development of ecosystems, with human demand of ecosystem services altering both land use and land cover. Fossil pollen records provide time series of vegetation characteristics, and the aim of this study was to create spatially continuous reconstructions of land cover through the Holocene in southern Sweden. The Landscape Reconstruction Algorithm (LRA) was applied to obtain quantitative reconstructions of pollen-based vegetation cover at local scales, accounting for pollen production, dispersal, and deposition mechanisms. Pollen-based local vegetation estimates were produced from 41 fossil pollen records available for the region. A comparison of 17 interpolation methods was made and evaluated by comparing with current land cover. Simple kriging with cokriging using elevation was selected to interpolate the local characteristics of past land cover, to generate more detailed reconstructions of trends and degree of variability in time and space than previous studies based on pollen data representing the regional scale. Since the Mesolithic, two main processes have acted to reshape the land cover of southern Sweden, originally mostly covered by broad-leaved forests. The natural distribution limit of coniferous forest has moved southward during periods with colder climate and retracted northward during warmer periods, and human expansion in the area and agrotechnological developments has led to a gradually more open landscape, reaching maximum openness at the beginning of the 20th century. The recent intensification of agriculture has led to abandonment of less fertile agricultural fields and afforestation with conifer forest.

Emissions of biogenic volatile organic compound (BVOC) from the bark of Norway spruce (Picea abies) trees can be affected by stress, such as infestation of spruce bark beetles (Ips typographus). We studied the difference in emission rates from healthy spruce bark and infested spruce bark, the influence of time since spruce bark beetle infestation started and the difference in emission rates from bark beetle drilled entry holes and exit holes. Bark chamber measurements on both healthy trees and infested trees were performed during the summer of 2019 at two sites in Sweden. To consider the seasonal pattern of the spruce bark beetle, we divided the emission rates from infested trees into two seasons, an early season dominated by entry holes and a late season with mainly exit holes. Our findings show a significant difference in emission rates from healthy and infested trees, independent of season. The seasonal average standardized emission rate from healthy trees was 31.89 ± 51.67 μg m-2 h-1 (mean ± standard deviation), while the average standardized emission rates from infested trees were 6385 μg m-2 h-1 and 2102 μg m-2 h-1 during early and late season respectively. We also found an exponentially decreasing relationship with BVOC emission rates and time since infestation started where the emission rates reached the same level as the constitutive BVOC emission rates from bark after around one year. When comparing bark monoterpene BVOC emission rates with emission rates from needles, we found that the constitutive needle emission rates were 11 times higher than the constitutive bark emissions. However, the emission rates from infested Norway spruce tree bark were instead 6 to 20 times higher than the constitutive needle emissions, causing substantial increases in the total tree BVOC emission rate (550 % to 1900 % increase). This study adds evidence that spruce bark beetle induced bark BVOC emissions are higher than previously thought and highlights the need for further research with more samples more frequently throughout the season to fully understand the impact, which is required to quantify spruce bark beetle infestations impacts on the atmospheric chemistry and climate change.

Convergent evidence associates exposure to endocrine disrupting chemicals (EDCs) with major human diseases, even at regulation-compliant concentrations. This might be because humans are exposed to EDC mixtures, whereas chemical regulation is based on a risk assessment of individual compounds. Here, we developed a mixture-centered risk assessment strategy that integrates epidemiological and experimental evidence. We identified that exposure to an EDC mixture in early pregnancy is associated with language delay in offspring. At human-relevant concentrations, this mixture disrupted hormone-regulated and disease-relevant regulatory networks in human brain organoids and in the model organisms Xenopus leavis and Danio rerio , as well as behavioral responses. Reinterrogating epidemiological data, we found that up to 54% of the children had prenatal exposures above experimentally derived levels of concern, reaching, for the upper decile compared with the lowest decile of exposure, a 3.3 times higher risk of language delay.

The Eurasian spruce bark beetle, Ips typographus, is a major pest, capable of killing spruce forests during large population outbreaks. Recorded dispersal distances of individual beetles are typically within hundreds of meters or a few kilometers. However, the connectivity between populations at larger distances and longer time spans and how this is affected by the habitat is less studied, despite its importance for understanding at which distances local outbreaks may spread. Previous population genetic studies in I. typographus typically used low resolution markers. Here, we use genome-wide data to assess population structure and connectivity of I. typographus in Sweden. We used 152 individuals from 19 population samples, distributed over 830 km from Strömsund (63° 46′ 8″ N) in the north to Nyteboda (56° 8′ 50″ N) in the south, to capture processes at a large regional scale, and a transect sampling design adjacent to a recent outbreak to capture processes at a smaller scale (76 km). Using restriction site-associated DNA sequencing (RADseq) markers capturing 1409–1997 SNPs throughout the genome, we document a weak genetic structure over the large scale, potentially indicative of high connectivity with extensive gene flow. No differentiation was detected at the smaller scale. We find indications of isolation-by-distance both for relative (FST) and absolute divergence (Dxy). The two northernmost populations are most differentiated from the remaining populations, and diverge in parallel to the southern populations for a set of outlier loci. In conclusion, the population structure of I. typographus in Sweden is weak, suggesting a high capacity to disperse and establish outbreak populations in new territories.

While much of the literature on complex global environments builds on studies of multinationals from mature markets, little is known about how firms from emerging markets understand and cope with complexity. This paper builds on a longitudinal case study of Zhejiang Geely Holding Group (ZGH) in the post-acquisition process of Volvo Car Group (VCG) and its efforts to learn how to learn in order to catch up with the internationalization process as means for developing capabilities and compete in the global automotive industry. Building on the Uppsala model, we contribute with insights how an emerging market multinational understands complexity and organize the post-acquisition process to explicitly emphasize the importance of mutual learning to develop and exploit opportunities to improve the business. Managerial Summary: A key finding is that ZGH does not understand complexity only as a risk that should be coped with, managed and controlled—following the western idea of risk management—but also as an opportunity for learning. While the importance of knowledge management and organizational learning is often emphasized as a means to achieve competitive advantage, it is seldom as easily managed in practice. Building on insights from ZGH we illustrate that to enable knowledge development and mutual learning, top-management from the acquiring firm needs to emphasize learning and trust the acquired firm rather than controlling it. It is equally important that the acquired firm trust the intentions of the new owner and reflect on the interest in learning—not least to improve and remain valuable.

The viability of wild bee populations and the pollination services that they provide are driven by the availability of food resources during their activity period and within the surroundings of their nesting sites. Changes in climate and land use influence the availability of these resources and are major threats to declining bee populations. Because wild bees may be vulnerable to interactions between these threats, spatially explicit models of population dynamics that capture how bee populations jointly respond to land use at a landscape scale and weather are needed. Here, we developed a spatially and temporally explicit theoretical model of wild bee populations aiming for a middle ground between the existing mapping of visitation rates using foraging equations and more refined agent-based modeling. The model is developed for

In late summer-early autumn, trees undergo growth cessation culminating in bud set. For a wide range of plants, including Populus, photoperiod is considered as the primary environmental cue determining timing of growth cessation and shoot to bud transition. However, studies on Populus have revealed temperature influence on seasonal growth cessation and bud set. In this study we examine the role of temperature in regulating the transition between phenological stages of bud development, from a growing apex to a closed bud. We test different model structures incorporating cues from both temperature and photoperiod (M1 and M2) as compared to the previously established model based on photoperiod only (M0, null hypothesis). All models simulate the date of bud set for Populus trees from 12 latitudinal populations grown in the common garden of Savar. For two of the three years (2005 and 2007) M1 and M2 models outperformed the null model in predicting bud set date. Poor predictions for 2006 were related to stressful weather conditions. This indicates that under non-stressful conditions temperature can be a factor modifying the photoperiod response, while other regulatory mechanisms can be at play during stressful conditions. A phenological model of bud development has to account for both types of responses. Thus, our study highlights the importance of temperature as a factor that should be considered in addition to the well-established photoperiodic signal in studies on autumnal bud set under natural conditions.

Recent climate warming has altered plant phenology at northern European latitudes, but conclusions regarding the spatial patterns of phenological change and relationships with climate are still challenging as quantitative estimates are strongly diverging. To generate consistent estimates of broad-scale spatially continuous spring plant phenology at northern European latitudes (>50 degrees N) from 2000 to 2016, we used a novel vegetation index, the plant phenology index (PPI), derived from MODerate-resolution Imaging Spectroradiometer (MODIS) data. To obtain realistic and strong estimates, the phenology trends and their relationships with temperature and precipitation over the past 17years were analyzed using a panel data method. We found that in the studied region the start of the growing season (SOS) has on average advanced by 0.30dayyear(-1). The SOS showed an overall advancement rate of 2.47day degrees C-1 to spring warming, and 0.18daycm(-1) to decreasing precipitation in spring. The previous winter and summer temperature had important effects on the SOS but were spatially heterogeneous. Overall, the onset of SOS was delayed 0.66day degrees C-1 by winter warming and 0.56day degrees C-1 by preceding summer warming. The precipitation in winter and summer influenced the SOS in a relatively weak and complex manner. The findings indicate rapid recent phenological changes driven by combined seasonal climates in northern Europe. Previously unknown spatial patterns of phenological change and relationships with climate drivers are presented that improve our capacity to understand and foresee future climate effects on vegetation.

A 6–9 month backward time shift of the carbon uptake gave the highest correlation between annual biomass increment and carbon uptake in this old even aged forest. Plants’ carbon uptake and allocation to different biomass compartments is an important process for both wood production and climate mitigation. Measurements of the net ecosystem carbon dioxide exchange between ecosystems and the atmosphere provide insights into the processes of photosynthesis, respiration and accumulation of carbon over time, and the increase in woody biomass can be assessed by allometric functions based on stem diameter measurements. The fraction of carbon allocated to radial stem growth varies over time, and a lag between carbon uptake and growth can be expected. The dynamics of non-structural carbohydrates and autotrophic and heterotrophic respiration are key mechanisms for understanding this lag effect. In this study, a 9-year record of carbon flux and tree-ring data from Norunda, Sweden was used to investigate the relationship between net and gross carbon uptake and carbon allocated to growth. The flux data were aggregated to monthly sums. When full 12-month periods of accumulated carbon exchange were successively shifted backwards in time, the highest correlation was found with a 6–9 month shift, showing that a large part of the previous growing season was important for explaining the biomass increment of the following year.

In 2018, up to 4 million m3 Norway spruce was killed by the spruce bark beetle Ips typographus in Sweden. The event was unique for Sweden, in terms of both affected volume and the fact that it was triggered by severe drought stress, not by ample availability of relatively defenseless storm-felled trees. The outbreak continued in 2019 and 2020, each year with twice as many trees killed as in 2018. The aim of this study was to quantify seasonal variation and potential lag-effects in tree defense capacity the year after a severe drought stress. Inoculation with a bark beetle-associated bluestain fungus, repeated four times with one-month-intervals between May and August 2019, were carried out at three field sites with spruce provenances of Swedish and East European origin representing early and late bud burst, respectively. All sites had experienced moderate to severe drought stress in 2018, and site-specific defense capacity correlated positively with the cumulative precipitation two months before inoculation. Sites with two-month precipitation levels

Overexpression of the receptor tyrosine kinase MET has been linked to poor survival in several cancer types, and MET has been suggested to interact with stem cell networks. In vitro studies have further suggested a possible benefit of a combined treatment using PARP and MET inhibitors. We used a tissue microarray (TMA) with 130 samples of advanced-stage high-grade serous fallopian tube/ovarian cancer (HGSC) to investigate the prognostic value of MET protein expression alone and in combination with the stem cell factor SOX2. The possible synergistic effects of a PARP and MET inhibitor treatment were evaluated in two cell lines with BRCA1 or BRCA2 deficiency and in their BRCA1/2-proficient counterparts. Patients with tumors positive for MET had worse overall survival (log-rank test, p = 0.015) compared to patients with MET-negative tumors. The prognostic role of MET was even more prominent in the subgroup of patients with SOX2-negative tumors (p = 0.0081). No synergistic effects of the combined treatment with PARP and MET inhibitors were found in the cell lines examined. We conclude that MET expression could be used as a marker for OS in HGSC and that stemness should be taken into consideration when evaluating the mechanisms of this effect.

Tree killing by spruce bark beetles (Ips typographus) is one of the main disturbances to Norway spruce (Picea abies) forests in Europe and the risk of outbreaks is amplified by climate change with effects such as increased risk of storm felling, tree drought stress and an additional generation of spruce bark beetles per year[1]. The warm and dry summer of 2018 triggered large outbreaks in Sweden, the increased outbreaks are still ongoing and affected about 8 million m3 forest in 2020[2]. This is the so far highest record of trees killed by the spruce bark beetle in a single year in Sweden[2]. In 1990-2010, the spruce bark beetle killed on average 150 000 m3 forest per year in southern Sweden[3]. Bark beetles normally seek and attack Norway spruces with lowered defense, i.e. trees that are wind-felled or experience prolonged drought stress[4]. However, as the number of bark beetle outbreaks increase, the risk of attacks on healthy trees also increase[5]. This causes a higher threat to forest industry, and lowers the possibilities to mitigate climate change in terms of potential decreases in carbon uptake if the forests die[4,5]. Norway spruce trees normally defend themselves by drenching the beetles in resin[6]. The resin in turn contains different biogenic volatile organic compounds (BVOCs), which can vary if the spruce is attacked by bark beetles or not [4,6]. The most abundant group of terpenoids (isoprene, monoterpenes and sesquiterpenes), is most commonly emitted from conifers, such as Norway spruce[7,8]. The aim of this study was to enable a better understanding of the direct defense mechanisms of spruce trees by quantifying BVOC emissions and its composition from individual trees under attackTo analyze the bark beetles’ impact on Norway spruce trees a method was developed using tree trunk chambers and adsorbent tubes. This enables direct measurements of the production of BVOCs from individual trees. Three different sites in Sweden, with different environmental conditions were used for the study and samples were collected throughout the growing season of 2019. After sampling, the tubes were analyzed in a lab using automated thermal desorption coupled to a gas chromatograph and a mass spectrometer to identify BVOC species and their quantity.The preliminary results show a strong increase in BVOC emissions from a healthy tree that became infested during the data collection. The finalized results expect to enable better understanding of how spruce trees are affected by insect stress from bark beetles, and if bark beetle infestation will potentially result in increased carbon emission in the form of BVOCs.References[1] Jönsson et al. (2012). Agricultural and Forest Meteorology 166: 188–200[2] Skogsstyrelsen, (2020). https://via.tt.se/pressmeddelande/miljontals-granar-dodades-av-granbarkborren-2020?publisherId=415163&releaseId=3288473[3] Marini et al. (2017). Ecography, 40(12), 1426–1435.[4] Raffa (1991). Photochemical induction by herbivores. pp. 245-276[5] Seidl, et al. (2014). Nature Climate Change, 4(9), 806-810. [6] Ghimire, et al. (2016). Atmospheric Environment, 126, 145-152.[7] Niinemets, U. and Monson, R. (2013). ISBN 978-94-007-6606-8[8] Kesselmeier, J. and Staudt, M. (1999). Journal of Atmospheric Chemistry, 33(1), pp.23-88

Serous endometrial cancer (SEC) resembles high-grade serous ovarian cancer (HGSOC) genetically and clinically, with recurrent copy number alterations, TP53 mutations and a poor prognosis. Thus, SEC patients may benefit from targeted treatments used in HGSOC, e.g., PARP inhibitors. However, the preclinical and clinical knowledge about SEC is scarce, and the exact role of defective DNA repair in this tumor subgroup is largely unknown. We aimed to outline the prevalence of homologous recombination repair deficiency (HRD), copy-number alterations, and somatic mutations in SEC. OncoScan SNP arrays were applied to 19 tumors in a consecutive SEC series to calculate HRD scores and explore global copy-number profiles and genomic aberrations. Copy-number signatures were established and targeted sequencing of 27 HRD-associated genes was performed. All factors were examined in relation to HRD scores to investigate potential drivers of the HRD phenotype. Ten of the 19 SEC tumors (53%) had an HRD score &gt, 42, considered to reflect an HRD phenotype. Higher HRD score was associated with loss of heterozygosity in key HRD genes, and copy-number signatures associated with non-BRCA1/2 dependent HRD in HGSOC. A high number of SECs display an HRD phenotype. It remains to be elucidated whether this also confers PARP inhibitor sensitivity.

How issues are framed in journalism in terms of problems, solutions, and levels of responsibility is of great importance in order to engage and lead toward individual and collective action. Data journalism has been acknowledged as a practice that often features a high level of interactivity, with the potential to engage the public. In this study, we investigate the content and production of climate change reporting in Swedish public service data journalism and discuss how frames are used in this alternative form of moderated science communication. Our results indicate an unconventional merger between science communication and data journalistic practices where motivational framing is used only to some extent as a way to increase public engagement with climate change. We also found that producers focus on educating and raising awareness rather than engaging the public and that they are guided by the ideal of objectivity.

Forestry is raising concern about the outbreaks of European spruce bark beetle, Ips typographus, causing extensive damage to the spruce forest and timber values. Precise monitoring of these beetles is a necessary step towards preventing outbreaks. Current commercial monitoring methods are catch-based and lack in both temporal and spatial resolution. In this work, light scattering from beetles is characterized, and the feasibility of entomological lidar as a tool for long-term monitoring of bark beetles is explored. Laboratory optical properties, wing thickness, and wingbeat frequency of bark beetles are reported, and these parameters can infer target identity in lidar data. Lidar results from a Swedish forest with controlled bark beetle release event are presented. The capability of lidar to simultaneously monitor both insects and a pheromone plume mixed with chemical smoke governing the dispersal of many insects is demonstrated. In conclusion, entomological lidar is a promising tool for monitoring bark beetles.

Climate change can lead to an increased frequency of extreme weather events, which may induce a decline in tree vitality, rendering the forest more vulnerable to other stress factors. In this study we used the ecosystem model LPJ-GUESS to compare the NPP of boreal conifers on till soil and sandy soil, simulating the growth of Norway spruce during the 21st century using climate model projections corresponding to RCP 8.5. Model runs with and without nitrogen cycling enabled, in combination with two different approaches to implement the dynamics of non-structural carbohydrates (NSC) were compared. The simulations showed that the forest productivity in Sweden is influenced by an interplay between site-specific temperature conditions and precipitation. Local differences in soil conditions can have an impact on the productivity, mediated by soil water and nutrient content. A warmer climate will lead to a longer growing season, but the productivity increase will partly be offset by a higher frequency of drought stress in summer and higher autotrophic respiration in winter. The ecosystem model runs indicated that periods with drought stress can cause low NSC levels, leading to time periods with decreased defence capacity against attacks by secondary agents such as bark beetles. The risks may however not become apparent until the forest stands are middle-aged. The model results are discussed in relation to current forestry practice, with Norway spruce (Picea abies) commonly being planted on dry soils better suited for Scots pine (Pinus sylvestris) in order to reduce moose browsing damage of seedlings, which in the longer term may create a forest landscape more sensitive to spruce bark beetle attacks.

In 2010, the first, and so far only, infestation of the Hungarian spruce scale (Physokermes inopinatus) and accompanying sooty mould occurred in Scania, southernmost Sweden. About 1000 ha of Norway spruce (Picea abies) were affected, and the trees suffered from the sucking of the insects as well as from the dense sooty mould that covered the needles. Salvage cuttings were carried out in many of the massively attacked forest stands, both in response to the fear that the trees otherwise would die, e.g. from secondary bark beetle attacks and to prevent spreading of the infestation. The aim of this study was to provide basic, quantitative knowledge on the aftermath response of trees that were heavily infested, but not exposed to salvage cutting. Growth characteristics, in terms of needle weight, shoot length and tree-ring size were measured on infested and uninfested trees to compare and contrast the spruce growth before, during and after the scale outbreak. The infestation resulted in dwarf annual sh...

Forests provide a wide range of ecosystem services, and ecosystem models can be applied to assess the contribution of different forest management strategies to climate mitigation and adaptation. Complex model output and trade-offs between environmental, economic, and social sustainability dimensions are difficult to convey. To facilitate stakeholder communication, we developed composite indicators based on ten ecosystem service indicators obtained from ecosystem model simulations representing 19 forestry management strategies across three ecoregions and climate scenario projections in Sweden. Eight alternative composites were generated around a central framework addressing sustainability aspects in terms of wood production, preservation of biodiversity, climate change mitigation and adaptation (risk management). A combination of principal component analysis, exploratory factor analysis, Cronbach’s coefficient alpha, and hierarchical cluster analysis was applied to account for the statistical relationships between indicators. Z-score normalization was superior to min-max normalization in capturing differences among management strategies. Two weighting schemes were applied, based on policy prioritizations between sub-components that reflected 1) current policy with an equal emphasis on production and biodiversity, and 2) a stronger focus on nature protection. Equal emphasis generated a larger range of scores (76.0 ± 21.2) than the focus on nature protection (32.0 ± 5.8), as the latter would provide less production benefits and thereby fewer trade-offs between production and other aspects. The final scores of the 19 management strategies fell within a variance boundary of each other, showing their contribution to different policy targets and the usefulness of combining strategies at the landscape level. The composites displayed agreement across regions and scenarios. They indicated that a shift from even-aged conifer monocultures towards a combination of continuous cover, broadleaf-mixture, and unmanaged would work well for balancing goals under changing climate conditions.

Budburst is regulated by temperature conditions, and a warming climate is associated with earlier budburst. A range of phenology models has been developed to assess climate change effects, and they tend to produce different results. This is mainly caused by different model representations of tree physiology processes, selection of observational data for model parameterization, and selection of climate model data to generate future projections. In this study, we applied (i) Bayesian inference to estimate model parameter values to address uncertainties associated with selection of observational data, (ii) selection of climate model data representative of a larger dataset, and (iii) ensembles modeling over multiple initial conditions, model classes, model parameterizations, and boundary conditions to generate future projections and uncertainty estimates. The ensemble projection indicated that the budburst of Norway spruce in northern Europe will on average take place 10.2 ± 3.7 days earlier in 2051–2080 than in 1971–2000, given climate conditions corresponding to RCP 8.5. Three provenances were assessed separately (one early and two late), and the projections indicated that the relationship among provenance will remain also in a warmer climate. Structurally complex models were more likely to fail predicting budburst for some combinations of site and year than simple models. However, they contributed to the overall picture of current understanding of climate impacts on tree phenology by capturing additional aspects of temperature response, for example, chilling. Model parameterizations based on single sites were more likely to result in model failure than parameterizations based on multiple sites, highlighting that the model parameterization is sensitive to initial conditions and may not perform well under other climate conditions, whether the change is due to a shift in space or over time. By addressing a range of uncertainties, this study showed that ensemble modeling provides a more robust impact assessment than would a single phenology model run.

Weather and climate conditions can have large impacts on the outcome of forest management operations: Suboptimal conditions can increase the amount of driving damage to forest ground caused by the heavy machines used for harvesting, forwarding and soil scarification. Planting of tree seedlings is commonly practised after clear cutting, and drought in summer or soil frost uplifting in autumn reduces the likelihood of successful plant establishment. Weather and climate also influence the risk of forest fires and the occurrence and development of pest and pathogens, and thereby the timing suitable for surveillance and countermeasures. In this study, the potential use of seasonal forecasts to support the operational planning of forest management in northern Europe was assessed. The analysis was based on temperature and precipitation data from WFDEI System 4 with 15 ensemble members representing seasonal hindcasts (retrospective predictions) for the period of 1981–2010. The data was used directly and as input to a soil model from which monthly indices of frozen soil and plant water stress were calculated. Relatively low skills were found for most months, and in particular for longer lead times. Highest skill was found for bias corrected temperature of January to March, with one month lead time. The skill was higher for the soil model indices, in particular those related to soil frost, as they are influenced by cumulative processes and the initial model conditions contribute to the skill. Probabilistic forecasts on frozen soil can thus be valuable for planning of which areas to harvest, taking the risk of driving damage to forest soils and forest roads into account.

Early agriculture can be detected in palaeovegetation records, but quantification of the relative importance of climate and land use in influencing regional vegetation composition since the onset of agriculture is a topic that is rarely addressed. We present a novel approach that combines pollen-based REVEALS estimates of plant cover with climate, anthropogenic land-cover and dynamic vegetation modelling results. This is used to quantify the relative impacts of land use and climate on Holocene vegetation at a sub-continental scale, i.e. northern and western Europe north of the Alps. We use redundancy analysis and variation partitioning to quantify the percentage of variation in vegetation composition explained by the climate and land-use variables, and Monte Carlo permutation tests to assess the statistical significance of each variable. We further use a similarity index to combine pollen based REVEALS estimates with climate-driven dynamic vegetation modelling results. The overall results indicate that climate is the major driver of vegetation when the Holocene is considered as a whole and at the sub-continental scale, although land use is important regionally. Four critical phases of land-use effects on vegetation are identified. The first phase (from 7000 to 6500 BP) corresponds to the early impacts on vegetation of farming and Neolithic forest clearance and to the dominance of climate as a driver of vegetation change. During the second phase (from 4500 to 4000 BP), land use becomes a major control of vegetation. Climate is still the principal driver, although its influence decreases gradually. The third phase (from 2000 to 1500 BP) is characterised by the continued role of climate on vegetation as a consequence of late-Holocene climate shifts and specific climate events that influence vegetation as well as land use. The last phase (from 500 to 350 BP) shows an acceleration of vegetation changes, in particular during the last century, caused by new farming practices and forestry in response to population growth and industrialization. This is a unique signature of anthropogenic impact within the Holocene but European vegetation remains climatically sensitive and thus may continue to respond to ongoing climate change. (C) 2017 Elsevier Ltd. All rights reserved.