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Abstract Litter decomposition determines carbon and nutrient cycling in terrestrial ecosystems. Prior research has addressed the importance of litter quality and microclimate on litter decomposition. However, the interacting relationships among litter chemical quality, the microenvironment, and micro-organisms - as well as their subsequent influence on litter decomposition - remain poorly understood. We sampled five forest types with varying overstory compositions in the subtropical forest of China and set up a reciprocal transplant litter decomposition experiment using a split-plot design. We used structural equation modeling (SEM) to examine the effects of litter species diversity and composition on litter decomposition rate through litter chemical properties. We also examined the effects of tree species diversity and composition on litter decomposition rate via litter moisture, microbial chemistry, and fungal diversity. Increased coniferous litter proportion restrained litter decomposition by decreasing litter N content. Litter species diversity and functional dispersion of litter C, N, and P contents had insignificant effects on litter decomposition. Overstory coniferous proportion and tree species diversity enhanced litter decomposition rates indirectly through their positive effects on litter moisture, fungal properties (a composite variable of fungal richness and squared fungal guild diversity), and microbial chemistry (a composite variable of microbial carbon and phosphorus). Our results highlighted that coniferous litter proportion and overstory coniferous proportion had opposite effects on litter decomposition via litter nitrogen content and the microenvironment, respectively. Furthermore, fungal community plays a key role in how overstory species composition and microclimate affect litter decomposition. Highlights • Coniferous litter inhibits litter decomposition by reducing litter N content. • Coniferous litter and tree have opposite effects on litter decomposition. • Overstory trees enhance litter decomposition via promoting moisture and microbes. • Fungi play key roles in how overstory composition affects litter decomposition. [ABSTRACT FROM AUTHOR]

The positive species mixture effects on both above- and below-ground productivity have been well documented in diverse ecosystem types. However, whether the results obtained on productivity can be generalized to other ecosystem processes remains unclear. We investigated the effects of tree species mixtures on fine root biomass turnover and biomass loss from mortality by sampling 18 stands dominated by Populus tremuloides and Pinus banksiana , respectively, and their relatively even mixtures in post-fire boreal forests of two stand ages (8 and 34 years following stand-replacing fire). Fine root biomass turnover and mortality were higher in mixtures than expected from those of single species-dominated stands in both stand ages, with a higher magnitude of mixture effects in the 34-year-old than in the 8-year-old stands. Mixture effects on turnover and mortality did not differ with soil depth in 8-year-old stands, but turnover increased while mortality decreased from the forest floor to the mineral layers in 34-year-old stands. Both turnover and mortality significantly increased with tree species evenness in 34-year-old stands, but not in 8-year-old stands. Root turnover and biomass loss from mortality were positively associated with annual fine root production across all stand types and ages. Our results provide the first evidence for positive mixture effects on fine root biomass turnover and biomass loss from mortality in natural forests. Moreover, our results suggest that the positive mixture effects resulted from increased competition induced by the increase of fine root biomass production in tree species mixtures. [ABSTRACT FROM AUTHOR]

Although the importance of coarse woody debris (CWD) to understory species diversity has been recognized, the combined effects of CWD decay and substrate species on abundance and species diversity of epixylic vegetation have received little attention. We sampled a wide range of CWD substrate species and decay classes, as well as forest floors in fire-origin boreal forest stands. Percent cover, species richness, and evenness of epixylic vegetation differed significantly with both CWD decay class and substrate species. Trends in cover, species richness, and evenness differed significantly between nonvascular and vascular taxa. Cover, species richness, and species evenness of nonvascular species were higher on CWD, whereas those of vascular plants were higher on the forest floor. Epixylic species composition also varied significantly with stand ages, overstory compositions, decay classes, substrate species, and their interactions. Our findings highlight strong interactive influences of decay class and substrate species on epixylic plant communities and suggest that conservation of epixylic diversity would require forest managers to maintain a diverse range of CWD decay classes and substrate species. Because stand development and overstory compositions influence CWD decay classes and substrate species, as well as colonization time and environmental conditions in the understory, our results indicate that managed boreal landscapes should consist of a mosaic of different successional stages and a broad suite of overstory types to support diverse understory plant communities. [ABSTRACT FROM AUTHOR]

Question Although the importance of coarse woody debris ( CWD) for understorey species diversity has been recognized, the relative effects of coarse woody debris decay class and substrate species on understorey species composition have received little attention. We examined how the species composition of understorey vegetation change with CWD decay class and substrate species. Location Boreal mixed-wood forests, Ontario, Canada. Methods To cover a wide range of CWD decay classes and substrate species, we sampled fire-origin boreal forest stands that varied in stand age and canopy tree species composition. Vegetation on CWD was sampled by visually estimating percentage cover of each species within a 0.1 m × 0.5 m quadrat, randomly laid lengthwise on top of each sampled CWD log. We also recorded the forest floor vegetation by establishing an adjacent plot of the same size at a distance of 1.0 m in a random direction from the CWD vegetation sample. Results Multivariate analysis showed that understorey species composition differed among decay classes and substrate species. A NMDS ordination of understorey species composition revealed a clear separation of decay classes 1 and 2 from higher decay classes, and that decay classes 4 and 5 shared several species with the forest floor. The species composition on the forest floor was completely different from the species composition on CWD decay classes 1, 2 and 3. Two distinct groupings of substrates according to CWD species composition were found: conifer species ( Pinus banksiana and Picea spp.) and broad-leaf species ( Betula papyrifera and Populus spp.), with Abies balsamea taking an intermediate position. Indicator species analysis showed distinct understorey species affiliations to substrate species at advanced decay classes. Understorey species composition on the CWD of P. banksiana showed particularly pronounced changes from the dominance of lichens on decay classes 2 and 3 to dominance by mosses and vascular species on decay classes 4 and 5. Conclusions Understorey species composition on CWD not only differed with decay class, but also with CWD substrate species. Conservation strategies should aim at retaining diversity of CWD in terms of both decay classes and species composition in boreal forests. [ABSTRACT FROM AUTHOR]

Thinning is a silvicultural tool that is used to facilitate the growth of timber plantations worldwide. Plantations are important CO 2 sinks, but the mechanism by which thinning affects the quantity and stability of soil organic carbon (SOC) is poorly understood. In this study, we examined the effects of different thinning intensities (low-intensity thinning treatment with 30% of the trees removed; high-intensity thinning treatment with 70% of the trees removed; control treatment without tree removal) on the quantity and stability of SOC in Chinese fir ( Cunninghamia lanceolata [Lamb.] Hook) plantations in southeastern China. The amounts of SOC, microbial biomass carbon (MBC), easily oxidizable carbon (EOC), cold-water- soluble organic carbon (CWSOC) and hot-water- extractable organic carbon (HWEOC) and the carbon-cycle-related enzyme activities (β-glucosidase, invertase and cellulose) were quantified. We found that thinning significantly decreased the amount of SOC compared with the control treatment, but the effect differed by sampling date. The MBC and EOC were significantly higher in the high-intensity thinning treatment than in the control and low-intensity thinning treatments, whereas the invertase and β-glucosidase activities were significantly higher in the control treatment. However, the amounts of CWSOC, HWEOC and cellulose activity did not differ among the treatments, which indicates that the MBC, EOC and the activities of invertase and β-glucosidase were better indicators of changes in SOC to thinning. In addition, the MBC, EOC, CWSOC and the β-glucosidase and cellulase activities peaked in the warmer months. Our results indicate that thinning treatments in Chinese fir plantations decreased the SOC quantity and enzyme activities and that high-intensity thinning may lead to an increase of labile SOC. [ABSTRACT FROM AUTHOR]

Understanding species diversity and disturbance relationships is important for biodiversity conservation in disturbance-driven boreal forests. Species richness and evenness may respond differently with stand development following fire. Furthermore, few studies have simultaneously accounted for the influences of climate and local site conditions on species diversity. Using forest inventory data, we examined the relationships between species richness, Shannon's index, evenness, and time since last stand-replacing fire ( TSF) in a large landscape of disturbance-driven boreal forest. TSF has negative effect on species richness and Shannon's index, and a positive effect on species evenness. Path analysis revealed that the environmental variables affect richness and Shannon's index only through their effects on TSF while affecting evenness directly as well as through their effects on TSF. Synthesis and applications. Our results demonstrate that species richness and Shannon's index decrease while species evenness increases with TSF in a boreal forest landscape. Furthermore, we show that disturbance frequency, local site conditions, and climate simultaneously influence tree species diversity through complex direct and indirect effects in the studied boreal forest. [ABSTRACT FROM AUTHOR]

Questions (1) How is the abundance of individual epiphytic macrolichen species affected by host tree species and stand development, where canopy succession takes place in prolonged absence of stand-replacing disturbance? (2) Do the associations between individual epiphytic macrolichen species and host tree species change through stand development? Location The central boreal forest of Canada (49°23′ N-49°36′ N, 89°31′ W-89°44′ W). Methods We estimated the percentage cover of epiphytic macrolichens on individual trees in 51 post-fire successional stands of varying tree species composition, ranging from 7 to 209 yr since fire. We analysed how epiphytic macrolichen species cover on individual host tree species and community composition change with time since fire and host tree species using GLM and permutational multivariate ANOVA. Results Cover of individual epiphytic macrolichen species on the host tree species increased continuously, peaked at different time scales or gradually declined through stand development in which canopy succession took place. Some lichen species exhibited exclusive association to particular host tree species. Moreover, stand age-related trends of the cover of some epiphytic macrolichen species differed with host species. Multivariate analysis indicated that host tree species at each stand development stage supported different epiphytic macrolichen species composition. Conclusion Epiphytic macrolichen species dynamics is strongly influenced by time since fire and host tree species identity. Host-specific preferences and their interaction with time since fire suggest that epiphytic lichen composition on a particular host tree species is not merely a random sample of the local species pool, but rather related to their time since fire-dependent preferences for their hosts. [ABSTRACT FROM AUTHOR]

Nutrient resorption (NR) plays a key role in the nutrient conservation of plants. However, a fundamental understanding of the mechanisms that control NR remains limited. In this review, we examine how intrinsic controls (e.g., genetic variability and plant development) and extrinsic environmental controls (e.g., climate and soil fertility) influence NR. We also examined conceptual NR advances, mass loss correction, measurement in non-leaf plant tissues for whole-plant nutrient budget accounting, and the use of stoichiometric ratios in place of individual elements. Nutrient resorption from senescing leaves is greater than that from stems/culms or roots. Nutrients resorbed from stems and roots in woody plants are lower than in non-woody plants. Deciduous plants are more efficient in resorbing leaf nutrients prior to senescence than are evergreen plants. Furthermore, reproductive efforts tend to increase NR. Along a latitudinal gradient of terrestrial biomes, nitrogen resorption efficiency decreases and phosphorus resorption efficiency increases with increasing temperature and precipitation; however, latitudinal patterns reflect the influences of several coupling factors such as genetic variation, climate, soil, and disturbance history. Nutrient fertilization experiments have demonstrated that increased soil fertility reduces NR. The inquiries into the impacts of ongoing climate change on NR are still at a nascent stage. Future NR studies are needed to better understand the independent effects of a wide range of genetic variation, plant development, and environment, and possibly the different responses of plants to environmental change; particularly elevated atmospheric CO2concentrations and global warming. [ABSTRACT FROM PUBLISHER]

Questions Understanding factors that contribute to the stability of an ecosystem following harvesting is central to predicting responses of boreal ecosystems to increasing human disturbances. While the response of understorey vegetation to harvesting is well understood for upland sites, little is known about compositional stability of riparian understorey vegetation. We examined how compositional stability changes with or without harvesting along an upland to streamside gradient and tested whether compositional stability is affected by pre-harvest species diversity and composition. Location Lower Foothills sub-region of the Boreal Plain, ca. 20 km northwest of Whitecourt, Alberta, CA. Methods We repeatedly sampled understorey vegetation of four winter-harvested and four unharvested sites in western Canadian boreal forest. Species covers were measured during the summer prior to harvesting in 2003 (year 0) and in 2004, 2008 and 2010 (1, 5 and 7 yrs after, respectively). We used non-metric multidimensional scaling to ordinate plots using species covers, and measured vector length in the ordination space to quantify floristic dissimilarity of each plot between year 0 and years 1, 5 and 7, an inverse measure of compositional stability. Results Floristic dissimilarity between year 0 and subsequent years was significantly greater in harvested than unharvested sites for all subsequent sampling years. Furthermore, along the upland to stream gradient, floristic dissimilarity was larger on upland than stream sites. Additional analyses revealed that floristic dissimilarity was related negatively to pre-harvesting species richness and evenness, but positively to bryophyte cover. Conclusions Our results demonstrate that understorey compositional stability is strongly influenced by harvesting, and streamside communities are more stable than upland communities. Our results indicate that compositional stability of understorey vegetation in response to harvesting is associated positively with pre-disturbance species richness and evenness, but negatively with bryophyte dominance. [ABSTRACT FROM AUTHOR]

Epiphytic macrolichen lichens are important components of forest ecosystems, but their responses to stand-replacing fire and multiple successional pathways of the canopy tree layer are poorly understood., We examined the dynamics of epiphytic macrolichens following wildfire and tested the independent and interactive effects of time since fire and overstorey composition on epiphytic macrolichen abundance, diversity and composition in boreal forests of Canada. Epiphytic macrolichens were sampled in 51 stands of conifer, mixed-wood and broadleaf overstorey types ranging from 7 to 209 years since fire., Macrolichen abundance estimated as percentage cover continuously increased with stand age with highest cover in 209-year-old stands for all overstorey types. Mixed-wood and conifer stands had higher macrolichen abundance than broadleaf stands in all age classes except similarly low abundances in stands ≤15 years old for all overstorey types. Species richness of epiphytic macrolichens reached peaks in 98- or 146-year-old stands. Mixed-wood stands had higher macrolichen species richness than broadleaf and conifer stands at 98 years old, but not at other age classes. Multivariate analysis indicated that the macrolichen communities were compositionally distinct for all age classes and overstorey types., Synthesis and applications. Epiphytic macrolichen abundance continuously increases with time since fire. Our results also show that macrolichen diversity peaks at intermediate stand ages with highest diversity in mixed-wood stands. Our findings of distinct macrolichen communities supported by each age class and overstorey compositional type suggest that conservation of epiphytic macrolichen diversity would require forest managers to maintain a diverse age structure and overstorey composition in forest landscapes. [ABSTRACT FROM AUTHOR]

Questions What is the nature of the interactions between higher vegetation strata (overstorey) and lower strata (understorey vegetation) and among understorey vegetation layers in closed canopy forests? How does the abundance or richness of one vegetation layer affect the abundance or richness of the other? Location Boreal mixed-wood forests of Ontario and Quebec, Canada. Methods We sampled fire-origin stands of varying overstorey composition from broad-leaf-dominated to mixed to conifer-dominated stands on mesic sites in Ontario and subhydric sites in Quebec. Overstorey tree species composition and understorey shrub, herb, bryophyte and lichen species cover and richness were estimated within 400-m2 circular plots. In addition, soil nutrients, coarse woody debris and light conditions were measured. Overstorey composition was expressed as the percentage basal area of broad-leaf tree species. Path analysis was used to examine interactions among the forest layers. Results Overstorey broad-leaf composition had positive effects on shrub and herb layer cover and herb layer richness, and negative effects on bryophyte and lichen species cover and richness. Shrub layer cover had no effect on herb layer cover, but shrub layer richness had a positive effect on herb layer richness. Herb layer cover and richness had negative effects on bryophyte species cover and richness. Bryophyte cover had no effect on lichen cover, but its richness was positively related to lichen richness. In both regions, soil p H, total nitrogen, total phosphorus and cation exchange capacity of the forest floor were positively correlated with overstorey broad-leaf composition and with shrub layer cover and herb layer cover. Conclusions Increasing overstorey broad-leaf composition, through its influence on soil nutrients, promotes shrub and herb layer species, but limits bryophyte and lichen species. In the overstorey-controlled understorey resource environment, cover and richness of shrub and herb layers increase with resource availability, whereas bryophytes and lichens show positive associations with abundance of coarse woody debris. [ABSTRACT FROM AUTHOR]

Abstract: Sequential soil coring is a commonly used approach to measure seasonal root biomass and necromass, from which root production can be estimated by maximum–minimum, sum of changes, compartment-flow model, and/or decision matrix methods. Among these methods, decision matrix is the most frequently used. However, the decision matrix, often underestimating fine root production, is frequently misused in research due to inadequate documentation of its underlying logic. In this paper, we reviewed the decision matrix method and provided mathematical logic for the development of the matrix, by which not only root production but also mortality and decomposition rates can be calculated. To ease its use for large datasets, we developed simplified equations to facilitate computation of root production, mortality and decomposition to be used in MS Excel or R. We also presented results from calculations by an example using empirical data from boreal forests to show proper calculations of root production, mortality and decomposition. The simplified decision matrix presented here shall promote its application in ecology, especially for large datasets. [Copyright &y& Elsevier]

Abstract: A 35kWh Superconductor Flywheel Energy Storage system (SFES) using hybrid bearing sets, which is composed of a high temperature superconductor (HTS) bearing and an active magnet damper (AMD), has been developed at KEPCO Research Institute (KEPRI). Damping is a source of energy loss but necessary for the stability of the flywheel system. We found that the damping of HTS bearings can be improved by thermal insulating bolts, which play a role of passive type external damper. To investigate the source of the increased damping, damping coefficients were measured with HTS bearings using insulating bolts made of three kinds of polymer materials. The damping coefficient was raised over 3000Ns/m in the case of PEEK bolts. The value was almost a quarter of the AMD. In this study, thermoelastic and Coulomb friction damping mechanisms are discussed. The main damping mechanism was the thermoelastic damping of the bolts themselves. And interfacial gap between the insulating bolt and metal chamber, which increased during the cooling process, was considered to be the cause of the anisotropic damping coefficients. Finally, the effects of the HTS bearings on the first critical speed are shown. [Copyright &y& Elsevier]

Abstract: A Superconductor Flywheel Energy Storage system (SFES) is used as an electro-mechanical battery which transforms electrical energy into mechanical energy and vice versa. A 35kWh SFES using hybrid bearing sets was developed in KEPRI. Mechanical properties of HTS bearings are the critical factors for stability of the flywheel and the main parameter in designing the system. The properties of the HTS bearing were studied. The stiffness and the damping coefficient of the HTS bearing were 346.6±6.7kN/m and 1255±102Ns/m, respectively. The damping coefficient was twelve times bigger than the estimate value. Therefore, we concluded that there were some external damping mechanisms. Finally, the 35kWh SFES was test operated up to 4000rpm. After passing two predicted critical speeds, the amplitude of vibration decreased and reached a stable rotation state. [Copyright &y& Elsevier]

Abstract: Soil organic carbon (SOC) in mineral soil accounts for a large portion of total ecosystem carbon (C) in boreal forests. We evaluated the effects of stand age and disturbance origin on SOC, soil aggregate stability, and aggregate-associated SOC in the boreal forests of Ontario, Canada. Mineral soils at 0–15 cm depth were sampled in 27 stands of six post-fire age classes (2- to 203-year-old) and three post-clearcut age classes (2- to 29-year-old), each with three replications. In post-fire stands, the SOC pool increased from 2- and 10-year-old to 29-, 85- and 140-year-old, and then decreased in 203-year-old stands. Aggregate-associated SOC showed a similar trend. Abundance of water stable aggregates (>0.25 mm in diameter) was the highest in 2-year-old stands. Compared with the same-aged post-fire stands, the SOC pool and aggregate-associated SOC were higher, and aggregate stability was lower in 2- and 10-year-old post-clearcut stands. But the differences in SOC pool, aggregate-associated SOC, and aggregate stability between the two stand origins diminished or became less dramatic in 29-year-old stands. Our results indicate that aggregate stability is more dependent on thermal modification of SOC by fire than on aggregate-associated SOC. Our results also show higher SOC pool and aggregate-associated SOC but lower aggregate stability in post-clearcut than post-fire stands shortly after disturbance; however, differences between the two stand origins diminish when stands become older. [Copyright &y& Elsevier]

Abstract: Although coarse root (diameter > 1 cm) biomass can account for approximately 30% of total biomass in forest ecosystems, coarse root biomass models are rarely available, especially for larger trees. In this study, we used a back-hoe excavator and pressurized water to excavate the coarse root systems of large size trees of Abies balsamea L., Picea mariana (Mill.) BSP, Pinus banksiana Lamb., and Populus tremuloides Michx. in the boreal mixedwood forest of central Canada in order to develop allometric equations that link stem diameter at breast-height (DBH) and height to coarse root biomass. All regressions for coarse root biomass using DBH or height alone, or both DBH and height as predictors were significant (R 2 ≥ 0.796, P < 0.05). The DBH – coarse root biomass models had higher R2 values than the height – coarse root biomass models for all four species, indicating that DBH was a better predictor of coarse root biomass than height. In addition, the DBH-height – coarse root biomass models did not have higher R2 values than the DBH – coarse root biomass models. All but one DBH – coarse root biomass model from the published literature with similar DBH range underestimated or overestimated coarse root biomass using the data from this study. It would appear that coarse root biomass allometric equations are probably site-specific because above- and below-ground biomass allocation differs with site condition. However, differences among studies may also be attributable to sampling methodologies. [Copyright &y& Elsevier]

Abstract: A layer of boron doped diamond (BDD) film was deposited selectively on a diamond anvil and employed as electrodes for measuring the electrical resistivity of matter under high pressure. Both heavily doped and lightly doped electrodes were characterized by Raman spectroscopy and scanning electron microscopy. Though the BDD film electrodes contain sp 2 carbon, it is still suitable for in situ high pressure electrical measurements. The dependability of diamond film electrodes was tested at high pressure up to 36GPa, by measuring the electric resistance of C60 fullerene powder, and no damage of the electrodes was observed. [Copyright &y& Elsevier]

Abstract: A superconductor flywheel energy storage system (SFES) is mainly used as an electro-mechanical battery which transforms electrical energy into mechanical energy and vice versa. Many aspects of the dynamic behavior of flywheel rotors still need to be examined closely, and the rotors require a high capacity supporting system such as high temperature superconductor (HTS) bearings, which offer dynamic stability without the use of active control. Static properties of HTS bearings provide data to solve problems which may occur easily in a running system. Since stiffness in countering rotor vibration is the main parameter for designing an HTS bearing system, we investigated the static properties of the magnetic force between permanent magnets (PMs) and HTS bearings. We measured axial and radial stiffness, and discovered that bearing stiffness varied greatly depending on the direction of vibration of PM relative to the HTS bulk. Especially, when the rotor vibrated in the radial direction of the HTS bearing, HTS bulks of the bearing showed a large difference in stiffness depending on the orientation of the HTS bulk relative to the direction of vibration. As a result, we discussed the critical factors that affect the stiffness of HTS bearings and studied efficient ways to increase bearing stiffness. These results are used to determine the optimal design for a 10kWh class SFES. [ABSTRACT FROM AUTHOR]

Stand structure diversity is hypothesized (i) to increase with stand development and (ii) to be greater in mixedwood stands than in conifer and broadleaf stands. We examined the effects of time since stand-replacing fire (TSF) and overstory type on stand volume, stand density, and tree-size variability, which is measured using Shannon’s diversity index (H′) and coefficient of variation, in fire-origin boreal forest stands. We sampled 36 stands representing conifer, mixedwood, and broadleaf overstory types, ranging in ages from 72 to 201 years TSF on upland mesic sites in northwestern Ontario, Canada. Stand volume decreased in older mixedwood and broadleaf stands, but followed a U-shaped pattern in conifer stands with TSF. Diameter-at-breast-height-based H′ followed an inverse U-shaped pattern with TSF for all overstory types. Height-based H′ decreased with TSF in conifer and mixedwood stands but peaked at the intermediate age class in broadleaf stands. Diameter-at-breast-height- and height-based coefficient of variation indices followed an inverse U-shaped distribution with TSF. Our results partially supported the two hypotheses, as (i) the 124- to 139-year-old stands were most diverse and (ii) mixedwood stands were more than or as equally diverse as conifer and broadleaf stands, depending on stand development stage and the diversity indices used. Nous posons les hypothèses que (i) la diversité de la structure des peuplements augmente au fil de leur développement et (ii) cette diversité est plus grande dans les peuplements mixtes que dans les peuplements résineux et feuillus. Dans des peuplements boréaux issus de feu, nous avons étudié les effets du temps écoulé depuis le dernier feu (TDF) et de la composition du couvert dominant sur le volume et la densité du peuplement et sur la variabilité de la taille des arbres, déterminée à l’aide de l’indice de diversité de Shannon (H′) et du coefficient de variation. Sur des stations mésiques et bien drainées du nord-ouest de l’Ontario, au Canada, nous avons échantillonné 36 peuplements représentant des peuplements résineux, mixtes et feuillus pour lesquels le TDF variait de 72 à 201 ans. Le volume à l’hectare diminuait dans les vieux peuplements mixtes et feuillus, mais la relation entre le volume et le TDF suivait une trajectoire en U dans les peuplements résineux. La relation entre la valeur de H′ basée sur le diamètre à hauteur de poitrine et le TDF suivait une trajectoire en U inversé pour tous les types de peuplement. La valeur de H′ basée sur la hauteur diminuait avec une augmentation du TDF pour les peuplements résineux et mixtes, mais a atteint un sommet à la classe d’âge intermédiaire dans les peuplements feuillus. Les relations entre le TDF et la valeur du coefficient de variation basée sur le diamètre à hauteur de poitrine et sur la hauteur suivaient des trajectoires en U inversé. Nos résultats n’ont que partiellement supporté les deux hypothèses puisque (i) les peuplements de 124 à 139 ans étaient les plus diversifiés et (ii) la diversité des peuplements mixtes était supérieure ou égale à celle des peuplements résineux et feuillus, dépendamment du stade de développement des peuplements et de l’indice de diversité utilisé. [ABSTRACT FROM AUTHOR]

Abstract: TiO2 films with high crystallinity were produced at a high deposition rate by inductively coupled plasma (ICP) assisted reactive magnetron sputtering. X-ray diffraction, UV–VIS spectrophotometer, and an α-step profilometer were used for the analysis of film characterization. The deposition rate was >20 nm/min and the structure of the TiO2 film changed with the deposition pressure. Anatase phase was obtained at 4 Pa without after-heat treatment, while amorphous and rutile phases were produced at <2.67 Pa. The optical transmission was changed according to the target surface condition, and was as high as >80% in the transition mode. [Copyright &y& Elsevier]

Abstract: Al doped ZnO (AZO) films were synthesized by inductively coupled plasma (ICP) assisted DC magnetron sputtering at low temperatures (<150 °C). A two-turn rf coil was inserted in the process chamber between the substrate and magnetron to generate the ICP. In order to obtain the optimum film properties even at a low temperature, high-density plasma was used to activate the sputtered metals and oxygen. The deposition process could be stabilized by controlling the target voltage in the transition region. The electrical resistivity of the films was ∼10−3 Ω cm, and the optical transmittance in the visible range was >80%. As the working pressure was increased, the visible transmittance of films was increased but the low resistivity processing window became narrower. [Copyright &y& Elsevier]

A separation method for the hepatoprotective drug silybin and its metabolites by RP-HPLC was described. Based on this separation, the stereoselectivity of the metabolism of silybin was investigated by incubation of the drug and its two diastereoisomers with bovine liver microsomes. Information about the structures of these metabolites was obtained, using UV, HPLC/MS and NMR spectra. Four major metabolites (M1, M4 of silybin A and M2, M5 of silybin B), were prepared by preparative HPLC, and their configurations were accomplished by NMR spectra. A HPLC method was used to quantify the metabolites. The results showed that silybin was extensively metabolized and the major sites for glucuronidation were the C-20, C-7, at phenolic OH groups. Furthermore, the results obtained reveal that there was significant stereoselectivity in the glucuronidation process of silybin. Silybin B was glucuronidated at a more efficient rate than its diastereoisomer, and glucuronidation of silybin B was much preferred at the 20 position, while that of silybin A was similar at both 7 and 20 position. [Copyright &y& Elsevier]

Describes the patterns and processes of North American boreal mixed woods (BMW) created by natural disturbances. Forest management implications related to stand development; Four stages of BMW stand development; Dependence of multiple pathways during BMW stand development on disturbances, neighbor effects and stand condition.

A vertical axis flywheel system was conceptualized, which uses a hybrid superconductor bearing set to carry the wheel part load. Multiple designs of magnetic bearing and superconductor bearing were analyzed by using conventional numerical magnetostatic analysis method. The best models were selected among four different types of permanent magnet bearings for upper bearing and two types of superconductor bearings for lower bearing, respectively. The vertical magnetic force of the high Tc superconductor radial bearing was experimentally estimated. These results were discussed in regard of application to the flywheel system with a passive hybrid magnetic bearing set. [Copyright &y& Elsevier]

Evaluates the variation in trembling aspen productivity in British Columbia. Relationships between site index and environmental factors; Effect of topography on aspen growth; Soils associated with aspen stands.

• Fungi:bacteria ratio increased with drought stress. • Labile organic C and N contents influenced microbial communities greatly. • These responses kept consistent across different soil depths. Soil microbial communities are key to ecosystem processes in terrestrial ecosystems. Although droughts are projected to be more frequent with the intensifying effects of climate change, our understanding of the responses of soil microbial communities to drought remains incomplete. For this study, we employed 30% and 50% throughfall reduction manipulation experiments to simulate different drought intensities, and collected soil samples at three depths (0–15, 15–30 and 30–45 cm) for each season in a poplar plantation. We analyzed the physical and chemical properties of the soil samples (e.g., soil moisture, pH, total C, total N, and labile organic C and N contents represented by extractable organic C and N contents, microbial biomass C and N contents) and microbial communities, via phospholipid fatty acid (PLFA) and high-throughput sequencing methods, from November 2018 to August 2019. We found that drought significantly decreased soil moisture, the content of soil labile organic C and N, and total microbial biomass; however, it increased soil pH and microbial biomass C:N across all soil depths. Furthermore, fungi:bacteria and Gram+:Gram- bacterial ratios increased with drought treatments across all three soil depths. Drought reduced the relative abundance of Proteobacteria, but increased the relative abundance of Acidobacteria across the three soil depths. In contrast, drought had no significant influence on the relative abundance of fungal phyla. The changes in soil properties and microbial communities increased with drought intensity. Regression analysis demonstrated that changes in the total PLFA, fungi:bacteria and Gram+:Gram- bacterial ratios were significantly correlated with soil moisture, pH, and the soil labile organic C and N content. Redundancy analysis revealed that soil pH, extractable organic C and extractable organic N accounted for the majority of the variabilities in the bacterial communities. The patterns of fungal community structures in the drought treatment plots were not distinct from the control groups across three soil depths. Our results suggested that droughts induce significant increases in fungi:bacteria and Gram+:Gram- bacterial ratios in forest soils, primarily through changes in soil pH, moisture, and soil labile organic C and N content. [ABSTRACT FROM AUTHOR]

Abstract: A project of a high-power FEL at Korea Atomic Energy Research Institute is described. The FEL is driven by a superconducting energy recovery linac. The future ERL will be connected to the existing machine without any modification. It consists of two 180° bents and two straight sections: one is for the FEL, another for a Compton X-ray source. One can choose the regime controlling the lenses. The total ERL is isochronous to avoid any problem with longitudinal beam instability. The total relative emittance degradation through the whole machine is ≈1.5. The FEL will be based on a 2m helical in-vacuum undulator made of permanent magnets. One mirror of the optical cavity is blind and made of copper, the other one, the outcoupler, is semi-transparent and made of CVD diamond. The expected average power is a few kW, the tuning range 35–70μm. [Copyright &y& Elsevier]

Abstract: A quasi-monochromatic X-ray source based on a KAERI SC linac system has been designed and is being manufactured now. 10MeV 10mA electron beam together with 20W 1.06μm laser beam will be used for 1.8keV Compton X-ray generation with a few percentage of energy spread and 107 photons/s flux. A simple straight beamline was designed to deliver the electron beam with no degradation of its emittance and energy spread and to focus it to a proper size to produce the desired X-rays. We expect the first demonstration of 1.8keV Compton X-ray generation in autumn 2006. [Copyright &y& Elsevier]

• Soil pH decreased over the last 60 years across the whole soil profile. • Exchangeable Ca2+ and Mg2+ decreased similarly or greater in deep soil as compared to topsoil. • The magnitudes of acidification varied among ecosystems and elevations. • Multiple global change drivers contributed to the soil acidification. Soil acidity plays a central role in the diversity and function of terrestrial ecosystems. Recent studies have revealed that acid deposition has acidified topsoil over time. However, uncertainties relating to how the acidity of the entire soil profile, including deep soil, responds to multiple global change drivers make it challenging to predict the effects of the ongoing global change on soil functions. Using data from 2952 observations of 200 montane sites in subtropical China, we show that the soil pH decreased over the last 60 years across the whole soil profile (0–150 cm), though there was less reduction in deep soils. The contents of exchangeable Ca2+ and Mg2+ decreased at the same rate, or more quickly, in the deep soil than topsoil. Soil pH and base cations decreased more in forests and shrublands at low elevations, but less in mountain meadows at high elevations. Our sensitivity analysis indicated that regional N deposition, S deposition, warming, and decreasing water availability have contributed to the temporal decreases in pH and base cations in natural ecosystems across tropical and subtropical China. The results extend the previous findings of changes in acidity in surface soil layers and demonstrate that deep soils of natural systems across a large area can be acidified over a few decades. Our results suggest that ongoing global changes are reducing the base nutrients across the entire soil profile, and thus, the diversity and functionality of subtropical forests. [ABSTRACT FROM AUTHOR]

• Forest conversion has a profound impact on soil nanoscale pores. • Vegetation types alter soil nanoscale pores in different diameter ranges. • Soil microbes may be one of the factors that affects soil nanoscale pores. Long term land-use change, such as forest conversion, has been shown to strongly affect soil pore properties. The soil pores mediate soil processes and determine how soil functions. Despite their importance for understanding biological, water, and carbon stability, the properties of soil pores following long term forest conversion remain unclear in subtropical forests. We examined soil nanoscale pores in response to conversion from native forests to plantations and addressed how bacterial and fungal communities influenced soil pore properties. We found significant changes in soil pores 40 years after the conversion from native forests to Chinese fir forests or bamboo forests. The pores in mixed forest soils were similar to those in native forests, while Chinese fir forest soils contained the most pores, followed by bamboo forest soils. Chinese fir forests also had a higher surface area and volume of both total soil pores and macropores, whereas bamboo forests had a higher volume of mesopores and larger specific surface areas of the total, macro-, and mesopores. Both soil bacteria and fungi significantly influenced soil pore properties. The relative abundance of soil bacterial phyla (Planctomycetes and Verrucomicrobia), fungal phylum (Chytridiomycota), and bacterial and fungal diversity negatively affected average pore diameter. In addition, soil fungal phylum (Basidiomycota) and the total sequencing number positively affected soil mesopore volume and the specific surface areas of both total pores and mesopores. Our study demonstrated that forest conversion drove the changes in soil pores at the nanoscale. Changes in soil microbial abundance and diversity may be one of the factors that affect soil nanoscale pores, while soil fungal compositions influence soil mesopores and soil specific surface area. [ABSTRACT FROM AUTHOR]

The vertical distribution of microbial biomass carbon (MBC) is important for terrestrial soil C cycling. However, we still do not understand what controls the vertical distribution of MBC along the soil profile, which limits our ability to estimate C cycling, especially in deep soils. Here, we conducted a global synthesis of 163 observations from 82 published studies to examine the direct and indirect effects of climate, soil physicochemical properties and ecosystem type on the vertical distribution of MBC. We further explored how climate and soil physicochemical properties influence the relationship between the vertical distributions of MBC and SOC. We used decrease rates of MBC and SOC with soil depth (k MBC and k SOC) to describe the vertical distribution of MBC and SOC, with a greater decrease rate indicating a more surface-skewed distribution. k SOC in our analysis was the main predictor of k MBC. Ecosystem type and clay concentration had indirect positive and negative, respectively, effects on k MBC , through k SOC. Although forests had steeper decrease rates of SOC than agriculture and grasslands, k MBC was invariable across ecosystem types, which we attributed to the effects of k SOC on k MBC being pH-dependent. The on average lower pH of forests might have slowed down decrease rates in MBC, notwithstanding the steeper changes in SOC with depth. We show that the vertical distribution of SOC is a robust indicator of the vertical distribution of MBC; however, the vertical distribution of MBC in soils with high pH was, nonetheless, more sensitive to the decrease in SOC with depth, leading to a greater decrease in MBC along the soil profile. Our analysis offers important insights into the spatial patterns of soil microbial communities and their activities and thus improves our understanding of soil C cycling. [ABSTRACT FROM AUTHOR]

Presents information on a study which investigated the effect of oxygen partial pressure during sintering process on the electromagnetic properties of Manganese-Zinc (Mn-Zn) ferrites. Description of Mn-Zn ferrites; Weight change during sintering process; Comparison on the effects of oxidation degree on the microstructure and on the electromagnetic properties.

• Even so-called favourable climate change adversely affects sapling recruitment. • The direct effect of climate change on sapling recruitment is minimal. • Climate change increases tree growth, mortality, and neighbourhood competition. • Increased tree growth, mortality, and competition reduce sapling recruitment. Sapling recruitment within established stands plays an important role in the long-term functionality of forest ecosystems. However, the specific impacts of climate change on sapling recruitment and its underlying mechanisms remain unclear. We hypothesized that sapling recruitment is directly affected by climate change and indirectly through the responses of tree mortality and growth to climate change as well as their induced modification of neighbourhood conditions. We employed a dataset of 173 permanent sample plots with individual stems that were spatially mapped and monitored at 5-year intervals from 1986 to 2010 in the central boreal forests of North America. By constructing structural equation models (SEMs), we examined how sapling recruitment probability may, directly and indirectly, respond to climate change through the mortality and growth of established trees, neighbourhood crowding, and functional and phylogenetic dissimilarities. We used the middle calendar year of a 5-year census period to represent recent systematic temporal trends in climate change. Our SEMs revealed that sapling recruitment probability did not respond significantly directly to temporal climate change in the studied forests, where atmospheric CO 2 concentration, air temperature, and climatic water availability simultaneously increased temporally. However, the temporally increased mortality and growth of neighbourhood established trees (all stems except for new recruits) exerted indirect negative effects on sapling recruitment probability. Furthermore, temporally increased neighbourhood crowding had an indirect adverse effect, while temporally increased neighbourhood shade tolerance and phylogenetic dissimilarities had weak indirect positive effects on sapling recruitment probability. Collectively, temporal climate change had a significant total negative effect on sapling recruitment probability. Our analysis demonstrated multiple mechanisms that simultaneously regulated the effect of temporal climate change on sapling recruitment. Our results emphasized that sapling recruitment does not compensate for increased tree mortality. We suggest that even so-called favourable climate change could threaten the long-term functionality of boreal forest ecosystems. [ABSTRACT FROM AUTHOR]

Intensive forest management activities that maximize economic gains could have a negative impact on the ecosystems and generate environmental conflicts, which may in turn translate to poor delivery of ecosystems services. Although plant diversity is positively associated with multiple ecosystem functions, it remains unclear how economic gains influence plant diversity across vegetation strata. We analyzed the relationships between economic gains, assessed as profit, and plant species richness following forest management alternatives (managing rotation age and overstorey composition) for the boreal forests of Canada. We found a hump-shaped relationship between total plant richness and profit, with total plant richness increasing initially, reaching a peak, and then declining with increasing profits. The relationship between profit and plant diversity differed among vegetation strata. Understorey plant richness followed similar trends to total plant richness, but overstorey tree richness increased linearly. The results of path analysis presented management alternatives as major drivers determining profit and plant diversity across vegetation strata. Our analysis indicated that maximum profit ($5000/ha) could lead to 20% loss of total plant species richness. Among the alternatives we compared, we conclude that managing for mixedwood with approximately a rotation of 100 years is an optimal compromise between economic and plant diversity objectives. [ABSTRACT FROM AUTHOR]

As atmospheric nitrogen (N) concentrations increase, it can wreak havoc on the entire planet, as well as the fragile ecosystems, once it exceeds the demand of ecosystems. Chronically elevated N deposition affects litter decomposition, which is a crucial process that controls nutrient cycling, soil fertility, and primary productivity. Nevertheless, the responses of litter decomposition and nutrient release to N addition remain elusive. Here we conduct a meta-analysis using 3434 paired observations from 55 publications to evaluate these responses. We found that although litter decomposition rate did not change significantly under N addition when averaged across all studies, it decreased with N application rate and experimental duration, showing that it was stimulated at low levels but suppressed at high levels of N application and duration. Phosphorus released more slowly under N enrichment, and this response became greater with longer duration. Moreover, the decomposition of lignin was depressed under N addition, and this effect was more pronounced with the increase of N application rate and experimental duration. Importantly, in terms of different ecosystems, the decomposition of litter was significantly inhibited by N addition in plantations, but was promoted in secondary forests, and there were no significant changes in primary forests, grasslands and wetlands. The responses of litter mass loss, along with the release of nutrients to N fertilization, changed with mean annual temperature and mean annual precipitation of the study sites. Our results provided a synthetic understanding of the effects of N addition on the decomposition of litter and nutrient release under climate change scenarios. [ABSTRACT FROM AUTHOR]

Aim To investigate nurses' opinions and practices of providing information in a global context through cultural comparison. Background and Introduction Providing sufficient information to patients about nursing interventions and plans is essential for patient-centred care. While many countries have specific legislation making information delivery to patients a legal duty of nurses, no such legislation exists in both the Republic of Korea and Italy; nurses' only guidance is the deontological code. Methods This was a cross-sectional survey study involving a convenience sample of 174 Korean nurses and 121 Italian nurses working in internal medicine and surgery at university hospitals. Data were collected using a self-administered questionnaire between February and November 2014. The questionnaire assessed demographic and professional characteristics, and difficulties and practices regarding information provision. Results Korean and Italian nurses significantly differed in all demographic and professional characteristics. More Korean than Italian participants reported that their role in providing information was well explained within their teams, but both groups reported the same level and type of difficulties in delivering information. Nurses in both countries regularly informed patients about medications and nursing procedures, but provided information about nursing care plans less frequently. Few nurses frequently provided information to relatives instead of patients. Conclusions Despite cultural, demographic and professional differences between Korean and Italian nurses, their difficulties and practices in information delivery to patient were similar. Implications for nursing and health policy Hospital managers and policymakers should be aware that nurse-patient communication can be impaired by organizational factors, patient characteristics or the interaction among providers. Educational interventions and strategies are needed to increase information provision to patients about nursing care plans. [ABSTRACT FROM AUTHOR]

• N deposition reduces soil microbial biomass (SMB) in grasslands and forests. • N deposition increases SMB in croplands. • SMB was most negatively affected by N deposition in acid soils. • Soil acidification act as a key mechanism in the responses of SMB to N deposition. • N deposition overall increased SMB by 10.0% across the globe during 2000–2020. Soil microorganisms are key for biodiversity and ecosystem processes. Recent meta -analyses based on nitrogen (N) addition experiments reported an overall negative impact of elevated N on soil microbial biomass on a global scale. However, individual studies have reported divergent effects of N addition, ranging from strongly negative to even positive. Moreover, N deposition varies temporally and spatially worldwide. It remains uncertain how the effects of N deposition on soil microbial biomass vary across global terrestrial ecosystems over time. Through the synthesis of 374 N addition experiments across six continents, we revealed that low quantities of N increased the soil microbial biomass, but high N amounts strongly reduced it. Moreover, the N addition effects were strongly contingent on the ecosystem type, being highly negative in grasslands (−19.3 ± 6.2%, mean and 95% confidence intervals), negative in forests (−8.6 ± 4.2%), and positive in croplands (15.1 ± 12.3%). Further, the soil microbial biomass was most negatively affected by N addition in acidic soils. By combining our meta -analysis results from N addition experiments and global N deposition data, we revealed that the global soil microbial biomass increased by 10.0% in response to cumulative N deposition from 2000–2020. However, regions encompassing the Eastern U.S., Southern Brazil, Europe, and Eastern Asia, with high N deposition rates and large forested areas of acidic soils, were hotspots for microbial biomass loss. Our findings challenge the long-held notion that N deposition has universal negative impacts on soil microbial biomass. Instead, we show that the N deposition impacts on soil microbial biomass are dependent on the amounts of elevated N, ecosystem type, and soil pH, for which N-deposition-induced soil acidification acts as an internal mechanism. [ABSTRACT FROM AUTHOR]

Fertilization and drought are two of the most important global change drivers that impacting greenhouse gas (GHG) emissions. Soil organisms are among the fundamental biotic drivers of biogeochemical cycles and can play critical roles in mitigating global change. However, the contributions of soil macrofauna in explaining the responses of GHG emissions to fertilization and drought remain poorly understood. Here, we designed a three-factor microcosm experiment to examine how soil macrofauna (no fauna, earthworms, and millipedes) alter the responses of CO 2 , N 2 O, and CH 4 emissions, as well as the C and N contents in response to contrasting levels of N (N 0 : without N addition, N + : N addition) and available soil water (40% and 60% of soil water holding capacity). We show that soil fauna were significant regulators of CO 2 and N 2 O emissions in response to changes in water and N availability, as supported by multiple identified statistical interactions. Millipedes were observed to reduce the positive influence of soil water availability on soil CO 2 emissions in response to the addition of N. Similarly, earthworms weakened the effects of elevated N and water availability on soil N 2 O emissions. Moreover, CH 4 emissions occurred only when millipedes were present. The structural equation models revealed that earthworms and millipedes modified soil CO 2 and N 2 O emissions through their influences on soil total dissolved nitrogen and microbial biomass carbon. Overall, this study demonstrated that soil macrofauna can notably mediate the responses of GHG emissions and soil biogeochemical cycles to global environmental changes. [Display omitted] • Soil macrofauna can notably alter soil greenhouse gases (GHGs) emission. • Earthworms weakened Nitrogen (N) and water effects on N 2 O emissions. • Millipedes reduced positive impact of water on CO 2 emissions in response to N. • Fauna altered GHGs emission by modifying dissolved N and microbial C. [ABSTRACT FROM AUTHOR]

Intensive forest management practices for production forestry can potentially impact the sustainability of ecological functions and associated forest ecosystem services. Understanding the trade-offs between economic gains and ecological losses is critical for the sustainable management of forest resources. However, economic and ecological trade-offs are typically uncertain, vary at temporal and spatial scales, and are difficult to measure. Moreover, the methods used to quantify economic and ecological trade-offs might have conflicting priorities. We reviewed the most current published literature related to trade-off analysis between economic gains and sustainability of forest ecosystem functions and associated services, and we found that most economic and ecological trade-offs studies were conducted in tropical and temperate forests, with few having their focus on boreal forests. Analytical methods of these published studies included monetary valuation, biophysical models, optimization programming, production possibility frontier, and multi-objective optimization. This review has identified the knowledge gaps in the understanding and measurement of the economic and ecological trade-offs for the sustainable management of boreal forests. While it remains uncertain how economic activities might best maintain and support multiple ecological functions and associated services in the boreal forests, which are susceptible to climate change and disturbances, we propose the use of optimization methods employing multiple objectives. For any tool to provide sustainable and optimal forest management solutions, we propose that appropriate and robust data must be collected and analyzed. [ABSTRACT FROM AUTHOR]

In the experiments reported here, we used the female ladybird Coccinella septempunctata L. as a model to identify diapause-associated proteins using proteomics technology. Our results indicated that protein expression patterns of diapausing and nondiapausing individuals were highly differentiated. A total of 58 spots showed significant differences in abundance (Ratio > 2 and P < 0.05) according to two-dimensional electrophoresis and GE Image Scanner III analysis. Sixteen protein spots were further investigated using mass spectrometry. Eight proteins were characterized, including chaperones and proteins involved in glucose metabolism, lipid metabolism, and the tricarboxylic acid cycle. Among these proteins, five proteins were upregulated in diapausing female adults, including a chaperone (Symbionin symL), malate dehydrogenase (putative), two proteins linked to lipid metabolism (unknown and conserved hypothetical protein) and phosphoglyceromutase (partial). By contrast, isocitrate dehydrogenase (RH49423p), fumarylacetoacetate hydrolase (AGAP001942-PA), and a putative medium chain acyl-CoA dehydrogenase were downregulated. These results contribute to the understanding of diapause mechanisms of the ladybird C. septempunctata and may suggest methods for improving the application of this natural enemy insect. [ABSTRACT FROM AUTHOR]

[Display omitted] • We investigated the assembly of soil bacteria, fungi, archaea, protists & animals across different soil depths in five stand ages. • Soil biotic communities exhibited a decreasing trend in alpha diversity with increasing soil depth. • Acidobacteriia, Agaricomycetes, Bathyarchaeia, Chlorophyceae and Clitellata, were most abundant classes. • Total nitrogen, available phosphorus and pH were the most influencing factors for changes in soil biotic communities. • As compared to soil depth, stand age was not dominatingly influencing the structure of other biotic communities. Soil biota plays a crucial role in the terrestrial ecosystem. There is growing momentum to understand the community structure and diversity of total belowground soil biota across large ecological scales. Soil biota follow divergent trends with respect to soil physiochemical properties in different ecosystems; however, little is known about their response to stand development across multiple soil depths in Chinese fir plantations, which is the most important tree species across all over China, popular for its timber production. Here, we investigated the community assembly of soil bacteria, fungi, archaea, protists and animals across three different vertical soil profiles (0–10, 10–20, 20–40 cm) using a chronosequence of Chinese fir representing five different stand ages (5, 8, 21, 27, 40 years) in South China. High throughput illumine Hiseq2500 sequencing. Our results showed that soil biotic communities exhibited a decreasing trend in alpha diversity of bacteria, fungi, protists and animals with increasing soil depth; however, archaea showed an opposite trend. Most abundant soil bacterial, fungal, archaeal, protist and animal classes were Acidobacteriia, Agaricomycetes, Bathyarchaeia, Chlorophyceae and Clitellata, respectively. Correlation of vertical distribution of biotic communities and variations in soil physiochemical properties explained that total nitrogen (TN), available phosphorus (AP) and pH were the most influencing factors for changes in soil biotic communities. Although the stand age was a contributing factor for fungal and animal beta diversity, however, as compared to soil depth, it was not dominatingly influencing the structure of other biotic communities. Collectively, these results reveal a new perspective on the vertical variation and distinct response patterns of soil biotic communities at a fine scale across different stand ages of Chinese fir plantations. [ABSTRACT FROM AUTHOR]

• Warming effects increased with warming duration and magnitudes. • Warming effects on C and N concentrations remain globally invariant. • [C] and [N] responded inconsistently to warming between above- and belowground. • Warming effects on [C] and [N] are linked to soil moisture and soil pH. Global warming has significantly affected the terrestrial C and N cycling processes. Whereas, it is unclear how global warming impacts the C and N concentrations in the above- and belowground ecosystems. We performed a meta-analysis with the results presented in 136 papers and 1886 observations. The data reveals that global warming increased C concentrations in leaf, shoot, and microbial biomass and N concentrations in the shoot. The C:N ratios of microbial biomass also increased under conditions of warming. However, the soil C concentration and soil C:N ratios decreased. Furthermore, these responses are more evident with longer warming duration and elevated warming magnitudes. The warming effects on C and N concentrations and C:N ratios never changed with warming methods, ecosystem types, or background climates. Also, in response to warming, soil moisture was negatively correlated with leaf C concentration as well as C:N ratio in microbial biomass. Soil pH response to warming was in a negative correlation with those of soil C concentration, soil C:N ratio, and microbial biomass C concentration. Our analysis has identified some key ecosystem processes that can be potentially implemented into the ecosystem models for predicting how warming affects future terrestrial C and N dynamics. [ABSTRACT FROM AUTHOR]

Soil microbial extracellular polymeric substances (EPS) are important components of soil organic carbon (SOC), which are thought to promote the formation of soil structures and induce the stabilization of SOC. Earthworms may not only stimulate the production of EPS through the promotion of microbial activity and microbial biomass, but might also accelerate the decomposition of EPS via ingestion, resulting in SOC sequestration or loss. However, the exact impacts of earthworms on EPS in soils have never been evaluated. Here, a pioneering experiment involving two species of endogeic earthworms (Drawida gisti and Metaphire guillelmi) with different body sizes was conducted to investigate their impacts on soil EPS. It was found that the D. gisti and M. guillelmi earthworms reduced the soil EPS-protein concentrations by 12.6 % and 17.6 %, respectively; however, they did not affect the EPS-polysaccharide concentration. Moreover, the presence of these endogeic earthworms increased soil microbial biomass, and elevated microbial respiration, microbial metabolic quotient, dissolved organic carbon, and soil pH. The results of this study provide the first evidence for the decoupling effects of earthworms on extracellular residual components. This suggests that earthworms may alter the molecular composition of SOM, thereby influencing its persistence and soil-atmosphere carbon exchange. [Display omitted] [ABSTRACT FROM AUTHOR]

• Forest restoration increases lignin and microbial necromass in the subsoil. • Lignin decreased faster in topsoil's particulate organic matte than amino sugars. • Microbial necromass builds quicker in subsoil's mineral-bound organic than lignin. • Subtropical forest restoration has a greater impact on subsoil than topsoil. Soil organic carbon (SOC) represents the largest carbon reservoir in terrestrial ecosystems. Therefore, understanding how to enhance SOC is crucial for the global carbon cycle and atmospheric CO 2 removal. While there has been reported on SOC accumulation following forest restoration efforts, changes in plant lignin and microbial necromass across soil fractions and depths remain unclear. To address this gap, we investigated the SOC-standardized concentrations of lignin phenols and amino sugars in bulk soil and soil fractions (particulate organic matter (POM) and mineral-associated organic matter (MAOM)) during subtropical forest restoration, as tracers for change in plant lignin components and microbial necromass respectively. Our findings indicate that forest restoration does not affect SOC concentrations, but does result in changes in plant lignin and microbial necromass. Specifically, in the subsoil, lignin phenols and amino sugars concentrations in bulk soil and soil fractions rise significantly with restoration time, with lignin phenols and amino sugars concentrations in bulk soil rising by 29.6% and 53.0%, respectively. This suggests that as forests recover, lignin and microbial necromass have a higher contribution to SOC accumulation in the subsoil, while the contribution of low-molecular plant-derived organic matter decreases. The relative change rate of lignin phenols (relative to SOC) is greater than that of amino sugars in POM in the topsoil, while in the subsoil, the relative change rate of amino sugars in MAOM is greater than that of lignin phenols. These results indicate that lignin in POM declines more rapidly than amino sugars during restoration, whereas in MAOM, amino sugars accumulate faster than lignin. Overall, these findings provide important insights into the regulation of SOC accumulation during forest restoration by the combination of plant lignin and microbial necromass in various stabilization pathways. [ABSTRACT FROM AUTHOR]

Question: The effect of overstorey composition on above-ground dynamics of understorey vegetation is poorly understood. This study examines the understorey biomass, production and turnover rates of vascular and non-vascular plants along a conifer-broadleaf gradient of resource availability and heterogeneity. Location: Canadian boreal forests of northwest Quebec and Ontario. Methods: We sampled mature stands containing various proportions of black spruce ( Picea mariana (Mill.) BSP), trembling aspen ( Populus tremuloides Michx.) and jack pine ( Pinus banksiana Lamb.). Above-ground biomass of the understorey vegetation was assessed through harvesting; annual growth rates were calculated as the differences between biomass in 2007 and 2008, as estimated by allometric relationships, and turnover rates were estimated as net primary production divided by the biomass in 2007. Results: Higher aspen presence, linked to greater nutrient availability in the forest floor, was generally associated with higher vascular biomass and production in the understorey. This effect was less pronounced in sites of high intrinsic fertility. In contrast, bryophyte biomass was positively associated with conifer abundance, particularly in wet sites of the Quebec study area. Non-linear responses resulted in total understorey biomass being lower under mixed canopies than under pure aspen or pure conifer canopies. Turnover rates did not differ with overstorey composition. Conclusions: While resource availability is a main driver of understorey productivity, resources as drivers appear to differ with differences in understorey strata components, i.e. vascular versus non-vascular plants. Resource heterogeneity induced by a mixed canopy had overall negative effects on understorey above-ground productivity, as this productivity seemed to rely on species adapted to the specific conditions induced by a pure canopy. [ABSTRACT FROM AUTHOR]

Abstract: The Refining of Y2BaCuO5 (Y211) is crucial in the fabrication of YBa2Cu3O x (Y123) bulk superconductors with a high critical current density (Jc ) for power engineering applications. In this work, the influence of an addition of Y211 and CeO2 of different sizes on the Y211 refinement and superconducting properties of melt-textured Y123 superconductors is investigated. Nano-size Y211 and nano-size CeO2 were prepared by attrition-milling (250rpm and 2h). Using mixed powders consisting of 85wt.% Y123, 15wt.% Y211, and 1wt.% CeO2, Y123 quasi-single crystals were fabricated via a top seed melt-textured growth process. The interaction between Y211 and CeO2 of different particle sizes was examined in terms of the size, uniformity and density of the Y211 particles that existed in the melt-textured samples. The reaction between the nano-size Y211 and the nano-size CeO2 was more violent due to the more frequent collisions compared to the other reactions (micro-size Y211/nano-size CeO2 or micro-size Y211/micro-size CeO2), resulting in the most effective for refinement of Y211 particles and the best Jc value of 4.2×104 (A/cm2) (at 77K and a zero-field). [Copyright &y& Elsevier]

Abstract: The effect of inductively coupled plasma (ICP) treatment on the surface activation of the polycarbonate (PC) substrate was studied. At high working pressure and ICP power the wetting angle could be decreased as low as 5°. The wetting angle was decreased effectively when the impinging ions had proper energy ∼ 8 eV. Excess ion energy interfered with reducing the wetting angle. The polar functional group (Cicantly affected the change of surface energy. Compared with the deposited Al2O3 film on the PC substrate treated at a low wetting angle, that on the PC substrate treated at a high wetting angle adhered very well. [Copyright &y& Elsevier]

Abstract: Al-doped ZnO (AZO) films were deposited by inductively coupled plasma (ICP) assisted DC magnetron sputtering at low temperatures. The AZO films were produced by sputtering a metallic target (Zn/Al) in a mixture of argon and oxygen gases. AZO films with an electrical resistivity of 6.3×10−4 Ω cm and an optical transmittance of 82% were obtained even at a low deposition temperature (&#60;150 °C). In situ process control methods were used to obtain stable deposition conditions in the transition region without any hysteresis effect. The target voltage was changed using oxygen flow or DC power as control-parameter. It was found that the ratio of the oxygen to zinc emission intensity, I (O 777 nm)/ I (Zn 481 nm) decreased with increasing the target voltage in the transition region. [Copyright &y& Elsevier]