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Fsigure GA. Synthesis and application of composite materials. Ni Al-LDH was originally grown on MPC. After PEG was compounded, the light absorption capacity of CuS was utilized to carry out photothermal energy storage through the phase change heat storage capacity of PEG, and the composite material showed electromagnetic shielding performance as well as excellent mechanical properties. [Display omitted] • MPC@Ni Al-LDH was synthesized and then combined with PEG to form composites. • Multifunctional bilayer films were synthesized two-step filtration method. • CuS and MPC in MLPC composite film effectively improve the thermal conductivity. • Latent heat of MLPC is 155.2 J/g, and its conversion efficiency is high. • It is an innovative application for composite phase change materials. CuS-based composites are widely used in the fields related to photothermal energy storage and electromagnetic shielding and are excellent candidates for composites with phase change materials. To meet the requirements of micro-integration and electromagnetic resistance of electronic products and optimize the thermal management of electronic products, it is necessary to prepare new flexible composite phase change materials. In this paper, through the design of MPC@Ni Al-LDH/CuS double-layer structure, two-step vacuum filtration method is used, and the highly conductive materials CuS and MPC are introduced into the manufacture of PCM films. With the help of Ni Al-LDH, flame retardancy is introduced. The electromagnetic wave absorption performance is enhanced, and the existence of nano-cellulose (CNF) makes the film have excellent mechanical properties. Ni Al-LDH/MPC and CuS substrates with stable and high mechanical properties are prepared by ultrasonic treatment. According to scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC) and thermogravimetry (TG) characterizations, PEG successfully entered the MPC/CuS skeleton by vacuum filtration, and flexible phase change composite bilayers (MLPC) were obtained. Due to the synergistic effect of structure and components, the obtained composite film has many different excellent functions. Specifically, when MPC@Ni Al-LDH is 15 wt%, the phase transition enthalpy, thermal conductivity, electromagnetic shielding, and electrical conductivity are 146.8 J/g, 1.07 W/m·K, 38.8 dB and 126.4 S/m, respectively. The 3600 s infrared temperature measurement results show that the sample has stable thermal properties. Due to the presence of CuS, when MPC@Ni Al-LDH is 5 wt%, its absorbance can be kept at 1.51 L/(g·cm), and its photothermal conversion efficiency can reach 90.6 %. The MPC/CuS structure in the composite film provides many heat transfer channels, which reduces the phonon scattering in the heat transfer process and significantly increases thermal conductivity. Therefore, this multifunctional flexible phase change film can be used in photothermal conversion devices and for thermal management of electronic equipment, and it has broad application prospects in wearable equipment design due to its excellent electromagnetic shielding ability and infrared thermal stealth ability. [ABSTRACT FROM AUTHOR]

Porous carbon network-based phase change composites have been widely used in energy storage and thermal management related fields. At present, the demand of energy crisis for photothermal energy storage and the prevention and management of thermal abuse of electronic equipment constantly promote the development of carbon-based composite phase change materials (PCMs). Therefore, a series of new composite materials filled with PCMs and polyethylene glycol (PEG) and added with flame-retardant magnesium hydroxide were developed, which makes the composites show certain flame-retardant ability in high-temperature environments. The results show that the thermal conductivity increases from 0.25 to 0.94 W/m·K, and the latent heat of phase change remains at 142.7 J/g. In addition, due to the capillary effect caused by the synergistic effect of multi-pore carbon (MPC) structure and cellulose macromolecular chain, the composite material has good shape stability, which effectively prevents the leakage behavior of PCMs during solid-liquid phase change. Moreover, the absorbance of the composite material can reach 1.28 L/(g cm) in the ultraviolet–visible light range of 200 nm–800 nm, and its photothermal conversion efficiency can reach 90.8 %. Therefore, this material has a broad application prospect in the thermal management of electronic equipment and photothermal energy storage devices. A series of composite membranes with enhanced mechanical properties were prepared by self-assembly of MPC, polyethylene glycol (PEG) and Mg(OH) 2. It is an innovative application for composite phase change materials in thermal energy storage, battery thermal management system, microelectronics packaging and intelligent buildings. [Display omitted] • Composite films with enhanced mechanical properties were prepared. • MPC@PEG/Mg(OH) 2 is a novel composite with superior characteristics. • The addition of MPC in composite films effectively improved thermal conductivity. • The form-stable composite films had a phase change enthalpy of 142.7 J/g. • It is an innovative application for composite phase change materials. [ABSTRACT FROM AUTHOR]

For mine dust deflagration accidents deflagration accident that occur frequently all over the world and are likely to lead to profound consequences, apart from the traditional methods of dust suppression and dust removal, the use of flame retardants can play an important role in suppressing the occurrence and development of mine dust deflagration accidents. Therefore, this paper mainly summarizes the mechanism of various typical flame retardants to suppress mine dust explosion and the changes in the occurrence and development process of their reaction and summarizes the advantages and disadvantages of various typical flame retardants that can be used to suppress mine dust explosion, the factors that affect the flame retardancy of flame retardants, the practicability of new nano-flame retardants and the feasibility of synergistic action of various flame retardants. Figure GA. An overview of flame retardant for mine dust deflagration. The three typical flame retardants can play a role in suppressing mine dust deflagration accidents, and the synergistic effect of flame retardants provides more feasibility for the use of flame retardants. [Display omitted] [ABSTRACT FROM AUTHOR]

The obstruction of fine mesh bag has been widely applied to study the functions of plant fine roots and soil fauna in ecosystems. However, plant fine roots and soil fauna can both be either excluded from the soil within fine mesh bags or admitted into the soil without mesh bags or within coarse mesh bags, because of their similar ranges of body width. As a result, both their effects could be influenced by fine mesh bags. In this study, we investigated the effects of soil fauna and understory fine roots on soil organic carbon, with a special type of fine mesh bags designed for obstructing the growth of understory fine roots into soil with free access of soil fauna. Results showed that both the biomass of understory fine roots and soil faunal diversity along with soil total carbon and microbial biomass carbon were significantly reduced by the fine mesh bags ( P < 0.01). Boosting regression tree models showed that the understory fine roots contributed more in the variations of soil organic carbon than soil faunal properties. Faunal biodiversity represented by Pielou’s evenness index was more important than taxa richness and individual abundances of taxa. Results suggest that understory fine roots may be more influential in soil organic carbon than faunal factors, and both their functions could be influenced by fine mesh bags in a mesh bag study. Evenness of individual abundances between taxa could be more important than taxa richness for the influence of soil fauna community on soil organic carbon. [ABSTRACT FROM AUTHOR]

Phi coefficient directly depends on the frequencies of occurrence of organisms and has been widely used in vegetation ecology to analyse the associations of organisms with site groups, providing a characterization of ecological preference, but its application in soil ecology remains rare. Based on a single field experiment, this study assessed the applicability of phi coefficient in indicating the habitat preferences of soil fauna, through comparing phi coefficient-induced results with those of ordination methods in charactering soil fauna-habitat(factors) relationships. Eight different habitats of soil fauna were implemented by reciprocal transfer of defaunated soil cores between two types of subtropical forests. Canonical correlation analysis (CCorA) showed that ecological patterns of fauna-habitat relationships and inter-fauna taxa relationships expressed, respectively, by phi coefficients and predicted abundances calculated from partial redundancy analysis (RDA), were extremely similar, and a highly significant relationship between the two datasets was observed (Pillai's trace statistic = 1.998, P = 0.007). In addition, highly positive correlations between phi coefficients and predicted abundances for Acari, Collembola, Nematode and Hemiptera were observed using linear regression analysis. Quantitative relationships between habitat preferences and soil chemical variables were also obtained by linear regression, which were analogous to the results displayed in a partial RDA biplot. Our results suggest that phi coefficient could be applicable on a local scale in evaluating habitat preferences of soil fauna at coarse taxonomic levels, and that the phi coefficient-induced information, such as ecological preferences and the associated quantitative relationships with habitat factors, will be largely complementary to the results of ordination methods. The application of phi coefficient in soil ecology may extend our knowledge about habitat preferences and distribution-abundance relationships, which will benefit the understanding of biodistributions and variations in community compositions in the soil. Similar studies in other places and scales apart from our local site will be need for further evaluation of phi coefficient. [ABSTRACT FROM AUTHOR]

In Yingzuijie National Nature Reserve, Pinus massoniana forest, mixed broadleaf-coniferous forest and evergreen broad-leaf forest were investigated to study the changing characteristics of woody debris (WD) during various succession stages of evergreen broad-leaf forest. The results showed that during various succession stages of evergreen broad-leaf forest in Yingzuijie National Nature Reserve, WD storage of each forest ranged from 1. 26 to 8.82 t/hm2, with the order of P. massoniana forest < mixed broadleaf-coniferous forest < evergreen broad-leaf forest, that is, it increased from early to late stages of the succession. At different succession stages, coarse woody debris (CWD) storage was 2 - 9 times more than fine woody debris (FWD) storage, revealing that CWD was dominant in WD of each forest. CWD biomass accounted for 0.66% - 2.21% of arbor biomass, so the forests were at the developmental stage. [ABSTRACT FROM AUTHOR]

Abstract: Soil organic carbon (SOC) dynamics and nutrient availability determine the soil quality and fertility in a Chinese fir plantation forest in subtropical China. Uniformly 13C-labeled Chinese fir (Cunninghamia lanceolata) and alder (Alnus cremastogyne) leaf litter with or without 100mg NH4 + or NO3 − were added to the soil. The purpose was to investigate the influence of N availability on the decomposition of the litter and native SOC. The production of CO2, the natural abundance of 13C–CO2, and the inorganic N dynamics were monitored. The results showed that Chinese fir (with a high C:N ratio) and alder (with a low C:N ratio) leaf litter caused significant positive priming effects (PEs) of 24% and 42%, respectively, at the end of the experiment (235d). The PE dynamics showed that positive PE can last for at least 87d. However, the possible occurrence of a significant negative PE with a sufficient incubation period is difficult to confirm. The application of both NH4 + and NO3 − was found to have a stimulating effect on the decomposition of Chinese fir and alder leaf litter in the early stage (0–15d) of incubation, but an adverse effect in the late stage. Compared with NO3 −, NH4 + caused a greater decrease in the PE induced by both Chinese fir and alder leaf litter. The effects of NH4 + and NO3 − on the PE dynamics had different patterns for different incubation stages. This result may indicate that the stability or recalcitrance of SOC, especially in such plantation forest soils, strongly depends on available leaf litter and application of N to the soil. [Copyright &y& Elsevier]

Abstract: Labile soil organic matter (SOM) can sensitively respond to changes in land use and management practices, and has been suggested as an early and sensitive indicator of SOM. However, knowledge of effects of forest vegetation type on labile SOM is still scarce, particularly in subtropical regions. Soil microbial biomass C and N, water-soluble soil organic C and N, and light SOM fraction in four subtropical forests were studied in subtropical China. Forest vegetation type significantly affected labile SOM. Secondary broadleaved forest (SBF) had the highest soil microbial biomass, basal respiration and water-soluble SOM, and the pure Cunninghamia lanceolata plantation (PC) the lowest. Soil microbial biomass C and N and respiration were on average 100%, 104% and 75%, respectively higher in the SBF than in the PC. The influence of vegetation on water-soluble SOM was generally larger in the 0–10cm soil layer than in the 10–20cm. Cold- and hot-water-soluble organic C and N were on average 33–70% higher in the SBF than in the PC. Cold- and hot-soluble soil organic C concentrations in the coniferous-broadleaved mixed plantations were on average 38.1 and 25.0% higher than in the pure coniferous plantation, and cold- and hot-soluble soil total N were 51.4 and 14.1% higher, respectively. Therefore, introducing native broadleaved trees into pure coniferous plantations increased water-soluble SOM. The light SOM fraction (free and occluded) in the 0–10cm soil layer, which ranged from 11.7 to 29.2gkg−1 dry weight of soil, was strongly affected by vegetation. The light fraction soil organic C, expressed as percent of total soil organic C, ranged from 18.3% in the mixed plantations of C. lanceolata and Kalopanax septemlobus to 26.3% in the SBF. In addition, there were strong correlations among soil organic C and labile fractions, suggesting that they were in close association and partly represented similar C pools in soils. Our results indicated that hot-water-soluble method could be a suitable measure for labile SOM in subtropical forest soils. [Copyright &y& Elsevier]

Abstract: Geographic variation in species richness has been explained by different theories such as energy, productivity, energy–water balance, habitat heterogeneity, and freezing tolerance. This study determines which of these theories best account for gradients of breeding bird richness in China. In addition, we develop a best-fit model to account for the relationship between breeding bird richness and environment in China. Breeding bird species richness in 207 localities (3271 km2 per locality on average) from across China was related to thirteen environmental variables after accounting for sampling area. The Akaike''s information criterion (AIC) was used to evaluate model performance. We used Moran''s I to determine the magnitude of spatial autocorrelation in model residuals, and used simultaneous autoregressive model to determine coefficients of determination and AIC of explanatory variables after accounting for residual spatial autocorrelation. Of all environmental variables examined, normalized difference vegetation index, a measure of plant productivity, is the best variable to explain the variance in breeding bird richness. We found that species richness of breeding birds at the scale examined is best predicted by a combination of plant productivity, elevation range, seasonal variation in potential evapotranspiration, and mean annual temperature. These variables explained 47.3% of the variance in breeding bird richness after accounting for sampling area; most of the explained variance in richness is attributable to the first two of the four variables. [Copyright &y& Elsevier]

• Ag 3 PO 4 /AgBr/Ti 3 C 2 Tx with dual channel carrier transfer structure was fabricated. • Ti 3 C 2 Tx not only served as a template but also was used to accommodate holes. • Dual channel was proved by in situ irradiated X-ray photoelectron spectroscopy. • The internal electric field facilitated the separation and transfer of carriers. • The utilization rate of carrier in Z-scheme heterojunction was improved. With high redox ability of electrons and holes, Z-scheme heterojunction is a promising composite structure in the photocatalysis. However, it is challenging to inhibit the recombination of carriers by Z-scheme transfer. Herein, a novel Ag 3 PO 4 /AgBr/Ti 3 C 2 Tx hybrid with dual channel carrier transfer structure was fabricated. Ti 3 C 2 Tx not only serves as a template for growth of Z-scheme Ag 3 PO 4 /AgBr, but also can be used to accommodate holes transferred from Ag 3 PO 4 and AgBr. The first channel is consisted of Z-scheme transfer of carriers in Ag 3 PO 4 /AgBr. And the hole transfer from the AgBr valence band to Ti 3 C 2 Tx constitutes the second channel, which avoids directly carrier recombination in AgBr valence band. Dual channel carrier transfer pathway was proved by in situ irradiated X-ray photoelectron spectroscopy (ISI-XPS). After Ti 3 C 2 Tx was introduced, the quantum efficiency of Ag 3 PO 4 /AgBr increased from 10.59% to 12.50% with reducing Cr(VI), indicating an increase in carrier utilization. The improvement of the degradation efficiency of rhodamine B from 80.77% to 94.72% is benefited from the enhanced quantum efficiency. The dual channel carrier transfer heterojunctions design provides a new idea for constructing an efficient composite photocatalytic structure. [ABSTRACT FROM AUTHOR]

The LES and nutrient resorption are thought to jointly modulate leaf litter traits, including the litter decomposition, but it is unknown how the two factors affect the temperature sensitivity of litter decomposition (Q10). The Q10 of litter decomposition was evaluated for 15 co-occurring subtropical woody species under laboratory conditions. The LES of these species, as well as species-specific N (NRE) and P resorption efficiency (PRE) during leaf senescence, were also determined. Results showed that the Q10 values were significantly correlated to LES, with litters from resource-conservative species having higher Q10 values than those from resource-acquisitive species. Among the parameters characterizing LES, leaf N concentration, C:N ratio, and lignin:N ratio were correlated to Q10, whereas leaf P and lignin concentrations, specific leaf area, and C:P ratio showed no relationships. The LES was correlated to litter C:N and lignin:N ratios, and, in turn, litter C:N and lignin:N ratios were correlated to Q10. This result suggested that LES affects litter quality and thus the Q10 of litter decomposition. However, NRE and PRE were not correlated to Q10. In addition, the LES effects on litter quality and the Q10 of decomposition did not depend on nutrient resorption, as indicated by the lack of correlation between LES and NRE or PRE. Our results reveal an association between plant functional features and forest C dynamics in a warmer future. [ABSTRACT FROM AUTHOR]

Living roots and their rhizodeposits can accelerate or decelerate the decomposition of soil organic matter which refers to the rhizosphere priming effect (RPE). However, whereas plant traits are thought to be key factors controlling the RPE, little is known about how root traits representative of plant biomass allocation, morphology, architecture, or physiology influence the magnitude of the RPE. Using a natural abundance 13C tracer method allowing partitioning of native soil organic carbon (SOC) decomposition and plant rhizosphere respiration, we studied here the effects of eight C3 tree species featuring contrasting functional traits on C4 soil respiration over a 204‐day period in a microcosm experiment. All tree species enhanced the rate of SOC decomposition, by 82% on average, but the strength of the rhizosphere priming significantly differed among species. Mean diameter of first‐order roots and root exudate‐derived respiration were positively correlated with the RPE, together explaining a large part of observed variation in the RPE (R2 = 0.72), whereas root branching density was negatively associated with the RPE. Path analyses further suggested that mean diameter of first‐order roots was the main driver of the RPE owing to its positive direct effect on the RPE and its indirect effects via root exudate‐derived respiration and root branching density. Our study demonstrates that the magnitude of the RPE is regulated by complementary aspects of root morphology, architecture and physiology, implying that comprehensive approaches are needed to reveal the multiple mechanisms driving plant effects on the RPE. Overall, our results emphasize the relevance of integrating root traits in biogeochemical cycling models to improve model performance for predicting soil C dynamics. [ABSTRACT FROM AUTHOR]

Background: Plants can directly affect litter decomposition by producing litter materials of different qualities. However, whether living plants have indirect effects on litter decomposition by affecting changes in forest microenvironments is presently unclear in plantation forests. Methods: We addressed this issue by studying the decomposition of the leaf litter and fine roots of Chinese fir [Cunninghamia lanceolata (Lamb.) Hook.], a timber species widely planted in China, in 113 non-neighboring quadrats of varying basal area of the dominant plant species (i.e., Chinese fir) and distinct basal areas and species richness of regenerated woody plants (i.e., species other than Chinese fir) in a subtropical Chinese fir forest. Results: Our results showed that fine roots decomposed significantly more rapidly than leaf litter possibly because fine roots were easier access to mineralized nutrients and microbes compared with leaf litter. Further analyses showed that leaf litter and fine root decomposition rates were significantly controlled by the plant community attributes. The decomposition of both leaf litter and fine roots was mainly controlled by woody species regenerated during stand development rather than by Chinese fir. Specifically, leaf litter and fine root decomposition rates decreased with increasing basal area of regenerated woody plants, possibly due to nutrient competition and/or reduced photodegradation. Conclusions: This study provides empirical evidence that woody species regenerated during stand development play a certain role in determining litter decomposition rates through plant-soil interactions in Chinese fir plantations. Regenerated woody plants should be considered in future studies on soil carbon and nutrient cycling in plantation forest. [ABSTRACT FROM AUTHOR]

The availabilities of carbon (C) and nitrogen (N) in soil play an important role in soil carbon dioxide (CO2) emission. However, the variation in the soil respiration (Rs) and response of microbial community to the combined changes in belowground C and N inputs in forest ecosystems are not yet fully understood. Stem girdling and N addition were performed in this study to evaluate the effects of C supply and N availability on Rs and soil microbial community in a subtropical forest. The trees were girdled on 1 July 2012. Rs was monitored from July 2012 to November 2013, and soil microbial community composition was also examined by phospholipid fatty acids (PLFAs) 1 year after girdling. Results showed that Rs decreased by 40.5% with girdling alone, but N addition only did not change Rs. Interestingly, Rs decreased by 62.7% under the girdling with N addition treatment. The reducing effect of girdling and N addition on Rs differed between dormant and growing seasons. Girdling alone reduced Rs by 33.9% in the dormant season and 54.8% in the growing season compared with the control. By contrast, girdling with N addition decreased Rs by 59.5% in the dormant season and 65.4% in the growing season. Girdling and N addition significantly decreased the total and bacterial PLFAs. Moreover, the effect of N addition was greater than girdling. Both girdling and N addition treatments separated the microbial groups on the basis of the first principal component through principal component analysis compared with control. This indicated that girdling and N addition changed the soil microbial community composition. However, the effect of girdling with N addition treatment separated the microbial groups on the basis of the second principal component compared to N addition treatment, which suggested N addition altered the effect of girdling on soil microbial community composition. These results suggest that the increase in soil N availability by N deposition alters the effect of belowground C allocation on the decomposition of soil organic matter by altering the composition of the soil microbial community. [ABSTRACT FROM AUTHOR]

Highlights: [•] Most litter-C was converted into CO2 during decomposition. [•] Litter-C changed the decomposition rate of native soil organic carbon. [•] The effects of inorganic N addition on the fates of litter-C depend on the inorganic N form. [ABSTRACT FROM AUTHOR]

Highlights: [•] Contributions of aboveground litter and roots to total soil CO2 efflux were similar. [•] Litter addition and root trenching reduced effect of soil moisture on respiration. [•] C input manipulation altered the composition of soil microbial community. [•] Root inputs exerted more impact on the soil microbial community than litter inputs. [Copyright &y& Elsevier]

Plant functional traits can serve as indicators of plant resource-use strategies in response to environmental changes. Plants growing in acidified soil exhibit conservative traits and limit growth, but there is still little known about changes in above- and belowground functional traits and their coordination under alleviation of soil acidification. Here, we conducted a pot experiment on raising soil pH by liming in Chinese fir (Cunninghamia lanceolata) saplings in southern China. The experiment involved in two degrees of acidified soil (Mild, pH = 4.3; Severe, pH = 3.6) and three liming treatments: Control (CK, 0), low liming treatment (L, 1000 kg CaO hm−2) and high liming treatment (H, 4000 kg CaO hm−2). We measured 22 above- and belowground functional traits of Chinese fir including allocation, morphological, photosynthetic, and chemical traits to assess their response to liming. The results show that liming enhanced aboveground mass fraction and total leaf area (TLA), and reduced construction cost (lower C concentration). However, specific leaf area (SLA), nutrient concentrations of N and P, and photosynthetic rate (Pn) remained unchanged. These results suggest that aboveground components exhibited acquisitive strategies in response to liming with greater TLA and lower construction cost. Moreover, liming reduced root mass fraction (RMF), increased specific root length (SRL), specific root area (SRA), and root N and Ca nutrient concentrations. These results suggest that belowground components also exhibited acquisitive strategies through constructing longer and thinner roots with greater metabolic rates. Our findings show that liming shifts above- and belowground resource-use strategies of Chinese fir from conservative to acquisitive. These changes in functional traits support the ability of Chinese fir to grow rapidly in response to alleviation of soil acidification. Our research not only contributes to a deeper understanding of plant adaptation mechanisms in the face of environment changes but also provides valuable insights for improving carbon sequestration of plantations in subtropical China. • 22 functional traits of Chinese fir were measured to assess their response to liming. • Liming elevated total leaf area and reduced leaf construction cost. • Liming elevated specific root length, specific root area and root N concentration. • Liming shifts resource-use strategies of Chinese fir towards acquisitive. [ABSTRACT FROM AUTHOR]

Background: Extensive studies have been conducted to evaluate the effect of external organic Carbon on native soil organic carbon (SOC) decomposition. However, the direction and extent of this effect reported by different authors is inconsistent. Objective: The objective was to provide a synthesis of existing data that comprehensively and quantitatively evaluates how the soil chemical properties and incubation conditions interact with additional external organic C to affect the native SOC decomposition. Data Source: A meta-analysis was conducted on previously published empirical studies that examined the effect of the addition of external organic carbon on the native SOC decomposition through isotopic techniques. Results and Conclusions: The addition of external organic C, when averaged across all studies, enhanced the native SOC decomposition by 26.5%. The soil with higher SOC content and fine texture showed significantly higher priming effects, whereas the soil with higher total nitrogen content showed an opposite trend. The soils with higher C:N ratios had significantly stronger priming effects than those with low C:N ratios. The decomposition of native SOC was significantly enhanced more at early stage of incubation (<15d) than at the later stages (>15d). In addition, the incubation temperature and the addition rate of organic matter significantly influenced the native SOC decomposition in response to the addition of external organic C. [ABSTRACT FROM AUTHOR]

Abstract: Potential changes in the quality and quantity of C inputs in soil during environmental changes may affect soil CO2 efflux in forest ecosystems. Therefore, a field debris exclusion experiment and a laboratory debris addition experiment were conducted to assess the response of soil CO2 efflux to C input manipulation. Our experiments were the first to be conducted in a subtropical Chinese fir (Cunninghamia lanceolata) plantation. The field debris exclusion experiment included the following treatments: leaf litter exclusion (NL), leaf litter and root exclusion (NLR), and control (CT). In the laboratory experiment, leaf litter and fine and coarse roots were added to soils collected from the same site and incubated for 100days at 15.0°C using the isotopic partitioning approach to determine the priming effect on soil C. The field-experimental results showed that soil CO2 efflux decreased significantly by 22.9% and 49.1% in the NL and NLR plots, respectively, compared with the CT plots. However, debris exclusion did not affect the diurnal and seasonal patterns of soil CO2 efflux. The contributions of leaf litter and roots to total soil CO2 efflux were 22.9% and 26.2%, respectively, which were positively related to soil temperature and moisture. In the laboratory experiment, the cumulative amount of soil CO2 efflux increased 1.25, 0.51, and 0.43 times in the soils with leaf litter, fine root, and coarse root additions, respectively, compared with the control soil (without debris addition) at the end of the incubation period. The amount of CO2 derived from leaf litter, fine root, and coarse root additions accounted for 44.0%, 31.1%, and 27.9% of the total amount of soil CO2 efflux, respectively. During the experimental period, the priming effect induced by fast-decomposing leaf litter (25.9%) was significantly higher than the priming effect induced by slow-decomposing fine roots (3.8%) and coarse roots (2.9%). The priming effect was negatively correlated with the initial lignin content and the lignin:N ratios of the added debris. The similar contributions of leaf litter and roots to soil CO2 efflux from the field experiment and the greater contributions of the priming of leaf litters to the fluxes from the laboratory experiment suggest that root inputs are more important than litter inputs in regulating soil C storage in Chinese fir forests. [Copyright &y& Elsevier]

Abstract: Stumps are an important component of coarse woody debris in intensively managed forest ecosystems. However, the effect of stumps on soil biological properties is poorly understood. Therefore, the present work investigated soil microbial biomass C, soil respiration, potentially mineralizable N, and enzyme activities related to nutrient cycling (invertase, urease and acid phosphatase) in both bulk and stump soils with four different stump “ages” (stumps 5, 11, 20 and 27 years after tree cutting) in Chinese fir (Cunninghamia lanceolata Hook.) plantation ecosystems. The presence of stumps significantly enhanced invertase and acid phosphatase activities, but reduced soil microbial biomass C and urease activity. However, the effect of stump presence on soil respiration and potentially mineralizable N had an inverse pattern. Additionally, the effect of stump presence on soil biological properties depended upon stump age. Soil respiration and invertase activity were highly and positively related to stump presence, but negatively related to stump age and soil pH. On the other hand, soil microbial biomass C and urease activity showed inverse results. Acid phosphatase activity was highly and positively related to soil total P and organic C, but negatively related to Olsen-P. Potentially mineralizable N was negatively related to NO3-N content and stump age. Using variation partitioning, stumps and soil chemical variables together explained 88.3% of the total variance in soil biological properties. When either stumps or soil chemical variables was adjusted, soil chemical properties and stumps explained 30.8% and 13.7% of the total variance, respectively. These results suggest that soil chemical properties should be considered when assessing the effect of stumps on soil biological properties. [Copyright &y& Elsevier]

Polymer-based composites with high thermal conductivity and dielectric breakdown strength have gained increasing attention due to their significant application potential in both power electronic devices and power equipment. In this study, we successfully prepared novel sandwich AlN/epoxy composites with various layer thicknesses, showing simultaneously and remarkably enhanced dielectric breakdown strength and thermal conductivity. The most optimized sandwich composite, with an outer layer thickness of 120 μm and an inner layer thickness of 60 μm (abbreviated as 120-60) exhibits a high through-plane thermal conductivity of 0.754 W/(m·K) (4.1 times of epoxy) and has a dielectric breakdown strength of 69.7 kV/mm, 8.1% higher compared to that of epoxy. The sandwich composites also have higher in-plane thermal conductivity (1.88 W/(m·K) for 120-60) based on the novel parallel models. The sandwich composites with desirable thermal and electrical properties are very promising for application in power electronic devices and power equipment. [ABSTRACT FROM AUTHOR]

Aims: Mixed-species plantations are generally thought to increase soil carbon stocks, but it is unclear whether they can enhance soil water-holding capacity. By quantifying the contribution of rainwater to soil water (CRSW) following three different scales of rainfall events in Pinus massoniana and Schima superba monoculture plantations and a mixed P. massoniana and S. superba plantation, we aimed to examine the variations in CRSW and influencing factors for different plantations. Methods: Stable hydrogen isotope compositions of rainwater, soil water and groundwater were analyzed to assess the CRSW of three plantations following three rainfall events in a subtropical monsoon region in China. We further used regression analysis to quantify the relative importance of canopy openness, litter characteristics, soil physical properties and root biomass to the CRSW. Results: The CRSW in the P. massoniana monoculture plantation and mixed plantation was higher than that in the S. superba monoculture plantation following the three rainfall events. No significant difference in the CRSW was found between the P. massoniana plantation and the mixed plantation within nine days following the 8.7 mm rainfall event. Furthermore, the CRSW was significantly higher in the mixed plantation than in the two monoculture plantations within 11 days following the 15.3 mm and 36.9 mm rainfall events. The most important factors affecting the CRSW were canopy openness and root biomass after the 8.7 mm rainfall event, whereas root biomass and litter characteristics acted as the primary regulatory factors after the 15.3 mm rainfall event. Under the 36.9 mm rainfall event, dry weight and saturation moisture capacity within the semi-decomposed litter layer had the greatest influence on the CRSW. Conclusion: Mixed-species plantations in humid subtropical regions have a higher capacity to intercept and maintain heavy rainfall than their respective monoculture plantations, and thus can enhance their adaptation to extreme rainfall events, as well as after frequent droughts. [ABSTRACT FROM AUTHOR]

[Display omitted] • BiOBr/Mn-Ti 3 C 2 T x composite photocatalysts designed by surface modification. • Synergistic effect of surface modification and built-in electric field was study. • Synergy promotes photogenerated carrier separation and light utilization efficiency. • Efficient light absorption and carrier separation efficiency improve photocatalytic. • CIP degradation pathway and mechanism were revealed. The low separation efficiency and light utilization of photogenerated carriers are one of the key problems in photocatalysis. This, Mn-Ti 3 C 2 T x was prepared by surface modification of Ti 3 C 2 T x , BiOBr/Mn-Ti 3 C 2 T x composite photocatalysts were synthesized through in situ ion modification. The synergy of surface modification and built-in electric field improves carrier separation efficiency and weak electron utilization. This can promote electrocatalytic reduction of peroxymonosulfate (PMS) to produce SO 4 ·- and improve electron utilization. The various photovoltaic properties characterization found that BiOBr/Mn-Ti 3 C 2 T x exhibited superior light capture ability and carrier separation efficiency compared to BiOBr/Ti 3 C 2 T x , and thus had more efficient photocatalytic degradation performance, which was found to be increased from 90.88% to 98.29% using emerging contaminants as the target pollutant. Secondly, the migration path of carriers in BiOBr/Mn-Ti 3 C 2 T x was analyzed by In Situ Irradiated X-Ray Photoelectron Spectroscopy (ISI-XPS) as well as the proposed mechanism of ciprofloxacin (CIP) degradation by BiOBr/Mn-Ti 3 C 2 T x photo-assisted activation of PMS. The possible pathways of CIP degradation were further explored by liquid chromatograph mass spectrometer (LC-MS), revealing that the BiOBr/Mn-Ti 3 C 2 T x photocatalytic degradation pathways. In this work, a strategy of surface modification and built-in electric field synergy is proposed to improve the photogenerated carrier separation and light utilization efficiency for enhancing the emerging contaminants removal. [ABSTRACT FROM AUTHOR]

• Stable residue size increases with litter initial concentrations of N and lignin; • Stable residue size decreases with litter initial Mn concentration; • Stable residue size shows hump-shaped relationships with MAT and latitude; • Stable residue size increases with MAP; • Longer field incubation results in smaller stable residue size. Stable residue from decomposing leaf litter is related to humus buildup in the forest floor and thus to the accumulation of carbon in the soil organic layer (OLC). However, the global pattern and controls of stable residue size remains poorly understood. Herein, the spatial pattern of stable residue size and its association with a series of potential drivers were evaluated by synthesizing available data worldwide. The results showed that stable residue size had a significant and positive correlation with the litter initial nitrogen (N) and lignin concentrations, and a negative correlation with the initial manganese concentration. Larger stable residues were found from decomposing broadleaf litter vs. coniferous litter. The decomposition of green leaf litter produces an equal amount of stable residue as that of brown litter. Stable residue size correlated quadratically with mean annual temperature and latitude, and linearly with mean annual precipitation. Methodological factor also matters, because stable residue size decreased as field incubation time increased. The boosted regression tree model indicated that litter initial traits have the most explanative ability for the variance in stable residue size. We highlighted that litter initial traits exert a predominant role over climate in shaping the stable residue size globally. Our findings are beneficial for a more accurate prediction of global-scale OLC accumulation. [ABSTRACT FROM AUTHOR]

Thinning and understory removal are two common silvicultural practices used in plantation ecosystems, and both are expected to influence soil respiration (R S). However, little is known about how the two practices, particularly their interaction, affect the heterotrophic (R H) and autotrophic (R A) components of R S. This knowledge gap further constrains our accurate evaluation on the carbon balance in plantations upon both thinning and understory removal, because the two practices are often conducted simultaneously in plantation management. Thus, we partitioned R S into R H and R A using trenched plots in a Chinese fir (Cunninghamia lanceolata) plantation subject to thinning and understory removal. The R S and its two components were measured in 2013 and 2014 at approximately monthly intervals. The potential control factors such as soil temperature, soil moisture and soil chemical properties were also determined. We found that thinning marginally significantly (P = 0.059) increased R S in 2013 by 17.32%, while it had no influence on R S in 2014 (P > 0.1), indicating that the influence of thinning on R S weakened with time. Similarly, a significant increase in R H toward thinning also occurred in 2013 (by 32.5%) but not in 2014. However, R A showed no response to thinning in either year. No interaction effect between thinning and understory removal was found on R S , R H , and R A. The increased soil temperature in the thinned stands in 2013 played a key role in raising the post-thinning R H and R S in this year. Generally, the temperature sensitivity (Q 10) value of R S and its components increased in the order of R H < R S < R A regardless of treatment. The Q 10 value of R S showed negligible variation among different treatments, and thus was likely not affected by thinning, understory removal, or their interactions. The results highlighted that understory removal in thinned stands would not exacerbate soil carbon emission in this plantation. • The effect of thinning on the soil respiration (R S) weakened over time. • The response of R S to thinning was mainly driven by the heterotrophic respiration. • Soil temperature played a key role in regulating the effect of thinning on the R S. • No interaction between understory removal and thinning was found on the R S. [ABSTRACT FROM AUTHOR]

Soil organic matter (SOM) mineralization represents one of the largest fluxes in the global carbon cycle. Numerous studies have shown that soil organic carbon decomposition was largely changed owing to the addition of litter, however very few studies have focused on the role of plant organs in the priming effects (PEs). Here, we studied the effects of different Pinus massoniana organs (fresh leaf, leaf litter, twigs, absorptive fine roots, and transport fine roots) on C4 soil respiration by applying the 13C isotopic natural abundance method. Results showed that the effects of plant organs on PEs were significantly different at the end of 210 days incubation, which can be ascribed to contrasting organs traits especially non-structural carbohydrates and water-soluble compounds. Transport fine roots and fresh leaf induced positive PE, whereas absorptive fine roots induced negative PE. Leaf litter did not change the native SOC decomposition. Plant organ addition can change the microbial community and result in the reduction of bacteria-to-fungi ratio. Our results suggest that with regard to determining the PE of the entire ecosystem, using fresh leaf to represent leaf litter and aboveground to represent underground is implausible. [ABSTRACT FROM AUTHOR]

[Display omitted] • MIL-101(Fe)/TiO 2 (M/P) was constructed using surface-coated FeOOH as the precursor. • MC-LR could be efficiently removed by M/P from HA-rich Water. • HA exerted non-inhibitory effect on MC-LR removal by M/P. • The key toxicity functional groups of MC-LR were destroyed by M/P with or without HA. Humic acids (HA) released during algal bloom poses a key challenge for efficient photocatalytic degradation of Microcystin-LR (MC-LR) due to their scavenging function on active species. Herein, MIL-101(Fe)/TiO 2 -P25 (M/P) was constructed to diminish the inhibitory effect of HA on the photocatalytic degradation of MC-LR. Results showed that MC-LR could be efficiently removed assigning to the photogenerated holes (h+) and superoxide radical (O 2 •−) oxidation under visible light irradiation, where the carboxy groups of D -glutamic acid (Glu) and methyl- D -aspartic acid (MeAsp), and Adda side chain related to MC-LR biotoxicity were selectively destroyed to achieve MC-LR detoxication. More importantly, HA exerted non-inhibitory effect on MC-LR removal by M/P. The counteracting mechanisms were studied. Firstly, the location of TiO 2 in the pore structure of MIL-101(Fe) could occupy the adsorption sites of HA, and decrease the HA adsorption on M/P. Furthermore, XPS analyses suggested the coordination of unsaturated Fe metal sites on the surface of M/P hybrids complexed with –OH and –COOH of HA, which could accelerate the electron transfer and reduce hole consumption. Thus, the inhibitory effect of HA was alleviated during photocatalytic MC-LR treatment. This work offers a possible way to remove MC-LR in an abundant HA matrix water system efficiently. [ABSTRACT FROM AUTHOR]

Chemiluminescence (CL) bioassay has become an increasingly area of interest in recent years. This review systematically presents the recent developments of emerging CL assay and their application in bioanalysis. A brief overview of the CL development history and classical CL substances commonly used in the bioassay is firstly provided. Then a detailed explanation in CL amplification system, CL joint technology and their application in bioassay are highlighted with recent illustrative examples. Furthermore, the future prospectives of CL bioassay are analyzed with the critical eyes. • The recent developments of chemiluminescent (CL) assay and their application in bioanalysis was systematically introduced. • A brief overview of the CL development history, mechanisms and classical substances commonly used in bioassay is provided. • The future prospectives and challenges of CL bioassay are commented. [ABSTRACT FROM AUTHOR]

Forests are critical for supporting multiple ecosystem services such as climate change mitigation. Microbial diversity in soil provides important functions to maintain and regenerate forest ecosystems, and yet a critical knowledge gap remains in identifying the linkage between attributes of regenerated woody plant (RWP) communities and the diversity patterns of soil microbial communities in subtropical plantations. Here, we investigated the changes in soil microbial communities and plant traits in a nine hectare Chinese fir (Cunninghamia lanceolata ; CF) plantation to assess how non-planted RWP communities regulate soil bacterial and fungal diversity, and further explore the potential mechanisms that structure their interaction. Our study revealed that soil bacterial richness was positively associated with RWP richness, whereas soil fungal richness was negatively associated with RWP basal area. Meanwhile, RWP richness was positively correlated with ectomycorrhizal (ECM) fungal richness but negatively correlated with the richness of both pathogenic and saprotrophic fungi, suggesting that the RWP-fungal richness relationship was trophic guild-specific. Soil microbial community beta diversity (i.e., dissimilarity in community composition) was strongly coupled with both RWP beta diversity and the heterogeneity of RWP basal area. Our study highlights the importance of community-level RWP plant attributes for the regulation of microbial biodiversity in plantation systems, which should be considered in forest management programs in the future. • Soil bacterial richness was positively associated with regenerated woody plant (RWP) richness. • Soil fungal richness was negatively associated with RWP basal area. • RWP-fungal richness relationship was trophic guild-specific. • Soil microbial community beta diversity was strongly coupled with RWP beta diversity. [ABSTRACT FROM AUTHOR]

Plant litter inputs can promote the decomposition of soil organic matter (OM) through the priming effect (PE). However, whereas leaf litter chemistry has long been identified as the primary driver of litter decomposition within biomes world‐wide, little is known about how litter chemical traits influence the occurrence and strength of the PE.Here, we studied the effects of 15 co‐occurring C3 leaf litters of contrasting chemistry on C4 soil respiration by analysing changes in 13C natural abundance during early and later stages of litter decomposition (up to 125 days).Besides an apparent PE of 16% in the first 3 days, soil C respiration was increased by 24% on average with leaf litter addition in the initial stage of decomposition (4–26 days) and by 8% at later stages (27–125 days). Most interestingly, soil PE related well to initial litter chemistry and the dominant factors influencing the magnitude of the PE changed with decomposition stage. In the early stage of decomposition, litter leachate C content and litter hemicellulose concentration were positively correlated with the strength of the PE, whereas tannin concentration was negatively associated with soil PE. Together, tannin and hemicellulose explained half of the observed variation in the PE (R2 = 0.58). In the later phase of decomposition, lignin and lignin:N ratios were negatively related to the PE, whereas Ca, K and Mg concentrations were positively related to the PE; lignin alone gave the best prediction of the PE (R2 = 0.58) at later decomposition stages.Our findings provide evidence that the magnitude and direction of the PE is influenced by the chemistry of OM inputs and suggest that, as decomposition proceeds differently among litter of contrasting chemistry, litters can also have variable effect on soil PE through time. The predictive power of litter chemical traits on soil PE opens new perspectives for improving our mechanistic understanding of soil PE and improving our abilities to model soil C dynamics at variable scales. A plain language summary is available for this article. [ABSTRACT FROM AUTHOR]

Highlights • Girdling significantly affected stem CO 2 efflux by altered substrate availability. • Effects of girdling on stem CO 2 efflux differed in degree and timing with season. • Apparent Q 10 of the stem CO 2 efflux increased above the girdle. Abstract The effect of carbohydrate supply on stem CO 2 efflux and its temperature sensitivity is crucial in predicting forest carbon cycling under climate change and forest management but has been rarely reported. In this study, we altered carbohydrate supply via stem girdling and investigated the effect of nonstructural carbohydrate concentration on stem CO 2 efflux and its temperature sensitivity in Chinese fir and sweetgum trees in spring and winter. The stem CO 2 efflux of Chinese fir increased significantly above the girdle in spring and winter, but decreased below the girdle in winter. The stem CO 2 efflux of sweetgum increased above the girdle and decreased below the girdle in spring but not in winter. Seasonal variations in the response of stem CO 2 efflux to girdling were associated with the changes in stem soluble sugar and starch concentration, especially in sweetgum tree. Girdling altered Q 10 of the stem CO 2 efflux, and this effect was dependent on location, season and species. Compared with the Q 10 of the stem CO 2 efflux in non-girdled trees, that of CO 2 efflux in Chinese fir increased by 45% above the girdle but decreased by 16% below the girdle in winter. These values also exhibited 6% and 11% responses in spring. By contrast, the Q 10 of the stem CO 2 efflux in sweetgum increased by 95% above the girdle and decreased by 45% below the girdle in spring. However, these values were nearly constant in winter. We concluded that the effect of carbohydrate supply on stem CO 2 efflux and its temperature sensitivity depends on season and species. Therefore, the vital role of carbohydrate supply that regulates stem CO 2 efflux and its temperature sensitivity should be considered for the understanding and modeling of forest carbon cycling response to forest management, especially under global climate changes. [ABSTRACT FROM AUTHOR]

It is critical to accurately estimate carbon (C) turnover time as it dominates the uncertainty in ecosystem C sinks and their response to future climate change. In the absence of direct observations of ecosystem C losses, C turnover times are commonly estimated under the steady state assumption (SSA), which has been applied across a large range of temporal and spatial scales including many at which the validity of the assumption is likely to be violated. However, the errors associated with improperly applying SSA to estimate C turnover time and its covariance with climate as well as ecosystem C sequestrations have yet to be fully quantified. Here, we developed a novel model‐data fusion framework and systematically analyzed the SSA‐induced biases using time‐series data collected from 10 permanent forest plots in the eastern China monsoon region. The results showed that (a) the SSA significantly underestimated mean turnover times (MTTs) by 29%, thereby leading to a 4.83‐fold underestimation of the net ecosystem productivity (NEP) in these forest ecosystems, a major C sink globally; (b) the SSA‐induced bias in MTT and NEP correlates negatively with forest age, which provides a significant caveat for applying the SSA to young‐aged ecosystems; and (c) the sensitivity of MTT to temperature and precipitation was 22% and 42% lower, respectively, under the SSA. Thus, under the expected climate change, spatiotemporal changes in MTT are likely to be underestimated, thereby resulting in large errors in the variability of predicted global NEP. With the development of observation technology and the accumulation of spatiotemporal data, we suggest estimating MTTs at the disequilibrium state via long‐term data assimilation, thereby effectively reducing the uncertainty in ecosystem C sequestration estimations and providing a better understanding of regional or global C cycle dynamics and C‐climate feedback. Underestimated ecosystem carbon turnover time and sequestration under the steady state assumption (SSA) written summary: Considerable biases may arise when improperly invoking the SSA to estimate carbon turnover time at realistic dynamic disequilibrium state. This issue has not yet been carefully examined. Our finding provides a better understanding of the SSA‐induced uncertainty and the global carbon cycle dynamics and carbon‐climate feedback for future research. The SSA significantly underestimates the carbon turnover time by 29% and its sensitivity to temperature and precipitation by 22% and 42%, respectively, thereby leading to a 4.83‐fold underestimation of NEP in China's monsoonal forests, a principal C sink globally. These biases are negatively associated with forest age. [ABSTRACT FROM AUTHOR]

• Effect of wollastonite addition on SOC mineralization is evaluated. • Wollastonite addition increases SOC mineralization. • Greater wollastonite effect occurs on soils with lower pH values. • Soil trait change account for SOC mineralization response to wollastonite addition. Enhanced rock weathering through adding silicate rock powder to soil has been increasingly considered as an effective means of removing CO 2 from the atmosphere. However, the potential impact of silicate rock powder addition on the stability of soil organic carbon remains largely unknown, which adds an uncertainty to its effectiveness in mitigating atmospheric CO 2. In this study, the response of soil CO 2 efflux to wollastonite addition was evaluated for 12 land-use types in a subtropical region of China through an incubation experiment. Results showed that wollastonite addition significantly (P < 0.05) increased soil CO 2 efflux over the control by an average of 330.97 ± 29.25% during the incubation period. Approximately 90% of the variance in soil CO 2 efflux was explained by soil properties in this study. Increased soil pH, dissolved organic carbon and available silicon induced by wollastonite addition were the main reasons responsible for the increase in soil CO 2 emission. Soils having lower pH values responded to wollastonite addition with a higher increase in CO 2 emissions. Based on numerous land-use types, our study showed that wollastonite application will cause substantial increase in the mineralization of soil organic carbon in acidic soil, which may weaken the effectiveness of enhanced rock weathering strategies as a tool for CO 2 sequestration. [ABSTRACT FROM AUTHOR]

Background and aims: The canopies in evergreen coniferous plantations are often composed of various-aged needles. Plantation management, such as thinning, produced abundant harvest residue, including needles with different needle ages. However, little attention was paid to the effect of needle age on decomposition, although the needle chemical properties varied substantially with leaf ages.Methods: A field experiment was conducted for 3 years to investigate the decomposition of harvest residue needles at different needle ages, and determine the main controlling factors in different stages of decomposition in a Chinese fir plantation.Results: We found that the initial decomposition rate varied 5-fold among different needle ages in a Chinese fir plantation. Litter quality controlled the overall litter decomposition rate, especially the initial decomposition rate. Needle nitrogen content was positively correlated to decomposition rate during the early stage of decomposition. However, it was negatively correlated to decomposition rate during the later stage of decomposition. The contents of needle tannins increased the asymptotic mass remaining (A, proportion of mass remaining at which decomposition approaches zero, i.e., the fraction of slowly decomposing litter). We also found that the initial litter decomposition rates in soil fauna presence were significantly higher than those in soil fauna absence across different needle ages. Moreover, the effect of soil fauna on initial litter decomposition is independent of needle quality.Conclusions: Our results suggest that needle age and plant secondary metabolites should be considered to understand the response of litter decomposition and nutrient cycling to management practices, such as thinning, in conifer plantations. [ABSTRACT FROM AUTHOR]

Nitrogen addition has been shown to affect plant litter decomposition in terrestrial ecosystems. The way that nitrogen deposition impacts the relationship between plant litter decomposition and altered soil nitrogen availability is unclear, however. This study examined 18 co-occurring litter types in a subtropical forest in China in terms of their decomposition (1 yr of exposure in the field) with nitrogen addition treatment (0, 0.4, 1.6, and 4.0 mol·N·m−2·yr−1) and soil fauna exclusion (litter bags with 0.1 and 2 cm mesh size). Results showed that the plant litter decomposition rate is significantly reduced because of nitrogen addition; the strength of the nitrogen addition effect is closely related to the nitrogen addition levels. Plant litters with diverse quality responded to nitrogen addition differently. When soil fauna was present, the nitrogen addition effect on medium-quality or high-quality plant litter decomposition rate was −26% ± 5% and −29% ± 4%, respectively; these values are significantly higher than that of low-quality plant litter decomposition. The pattern is similar when soil fauna is absent. In general, the plant litter decomposition rate is decreased by soil fauna exclusion; an average inhibition of −17% ± 1.5% was exhibited across nitrogen addition treatment and litter quality groups. However, this effect is weakly related to nitrogen addition treatment and plant litter quality. We conclude that the variations in plant litter quality, nitrogen deposition, and soil fauna are important factors of decomposition and nutrient cycling in a subtropical forest ecosystem. [ABSTRACT FROM AUTHOR]

In this study, BiOBr/Ti 3 C 2 Tx/AgBr ternary materials were successfully synthesized by a two-step method. The photocatalytic performance of the prepared materials was systematically evaluated. The results showed excellent light trapping ability and carrier separation efficiency of prepared BiOBr/Ti 3 C 2 Tx/AgBr, the photodegradation efficiency of TBBPA was 97.16% within 60 min, and the degradation rate was 1.8 times higher than BiOBr/AgBr. The enhanced photocatalytic efficiency of BiOBr/Ti 3 C 2 Tx/AgBr is attributed to the increased light-harvesting capacity and the fast transport and separation of photogenerated electron-hole in the Z-scheme structure. In situ irradiation X-ray photoelectron spectroscopy (ISI-XPS) successfully revealed Ti 3 C 2 Tx as a channel for rapid electron-hole transfer in Z-scheme heterojunctions. In addition, the TBBPA degradation pathways and toxicity changes were further explored by LC-MS and toxicity assessment. Ti 3 C 2 Tx as an electron-hole transfer medium for the construction of Z-scheme photocatalysts can provide new ideas for the structural design of new high-efficiency photocatalysts. [Display omitted] • A novel Z-scheme heterojunction BiOBr/Ti 3 C 2 Tx/AgBr was successfully constructed. • Achieved excellent photocatalytic activity under visible light. • Ti 3 C 2 Tx shows faster carrier migration in Z-scheme heterojunctions. • Verification of carrier migration paths based on in situ irradiated X-ray photoelectron spectroscopy. • The mechanism, intermediates and pathways of photodegradation of TBBPA were proposed. [ABSTRACT FROM AUTHOR]

Photodegradation is a new approach for the removal of pentachlorophenol (PCP). Photooxidation degradation (using hydroxyl radicals) exhibits better performance to remove PCP than photoreduction degradation, but the former will lead to an increase in the production of toxic by-products such as tetrachloro-1,4-benzoquinone (TCBQ). Thus, a new strategy is required to enhance PCP photodegradation and simultaneously inhibit toxic intermediates production. Herein, TiO 2 (P25)/polydopamine (PDA)/BiOBr was synthesized and used to photodegrade PCP. Based on the relative position of the CB and VB of P25 and BiOBr, and PDA as an electron transfer mediator, a high number of holes, electrons, and superoxide anions were produced instead of hydroxyl radicals. The photocatalytic activity of P25/PDA/BiOBr exhibited the best performance among as-prepared samples, reaching a k (pcp) value of 0.4 min−1 (20 μM PCP) under UV light irradiation within 10 min. According to chemiluminescence and acute toxicity assays, relative to P25, the toxic intermediates of TCBQ and trichlorohydroxy-1,4-benzoquinone (OH-TrCBQ) generation was greatly reduced over P25/PDA/BiOBr, with a lack of toxic product generation during PCP photodegradation process. These findings provide an alternative strategy to achieve greener and more efficient organic pollutant photodegradation. [Display omitted] • PCP photodegradation may produce toxic intermediates and cause secondary pollution. • P25/PDA/BiOBr synthesized to regulate PCP photodegradation process. • P25/PDA/BiOBr can generate more h+, e−, and O 2.•− but not •OH. • PCP degradation was enhanced and limited toxic intermediates were produced. • It is suggestive for establishing a green and efficient photodegradation pathway. [ABSTRACT FROM AUTHOR]

• Species richness indirectly increases temporal biomass stability by promoting species asynchrony, rather than through a direct influence. • Forest age and structural diversity increased temporal mean biomass and biomass variability significantly and simultaneously. • Soil nitrogen enhanced biomass stability directly and indirectly through its effects on mean biomass. • The direct and indirect effects of soil properties on temporal biomass stability were greater than that of climate variables. There is mounting evidence that biodiversity promotes ecological stability in changing environments. However, understanding diversity–stability relationships and their underlying mechanisms across large-scale tree diversity and natural environmental gradients are still controversial and largely lacking. We used thirty-nine 0.12 ha long-term permanent forest plots spanning China's various forest types to test the effects of multiple abiotic (climate, soil, age and topography) and biotic factors (taxonomic and structural diversity, functional diversity and community-mean traits, and species asynchrony) on biomass stability and its components (mean biomass and biomass variability) over time. We used multiple analytical methods to identify the best explanatory variables and complicated causal relationships for community biomass stability. Our results showed that species richness increased biomass stability by promoting species asynchrony. Structural and functional diversity had a weaker effect on biomass stability. Forest age and structural diversity increased mean biomass and biomass variability significantly and simultaneously. Communities dominated by tree species with high wood density had high biomass stability. Soil nitrogen enhanced biomass stability directly and indirectly through its effects on mean biomass. Soil nitrogen to phosphorus ratio increased biomass stability via increasing species asynchrony. Precipitation indirectly increased biomass stability by affecting tree diversity. Moreover, the direct and indirect effects of soil nutrients on biomass stability were greater than that of climate variables. Our results suggest that species asynchrony is the main mechanism proposed to explain the stabilizing effect of diversity on community biomass, supporting two mechanisms, namely, the biodiversity insurance hypothesis and complementary dynamics. Soil and climate factors also play an important role in shaping diversity–stability relationships. Our results provide a new insight into how tree diversity affects ecosystem stability across diverse community types and large-scale environmental gradients. [ABSTRACT FROM AUTHOR]

• Initial litter decomposition rates increased with litter quality. • Stable residue remaining after decay correlated negatively with litter quality. • Soil mesofauna had no effect on initial rates of litter decomposition. • Soil mesofauna decreased stable residue remaining regardless of litter quality. The regulation of factors like litter quality and soil mesofauna on litter decomposition in the early stage has been studied extensively in forest ecosystems. However, how litter decomposition was influenced by its quality and soil mesofauna in the late stage is largely unclear, especially in subtropical forest ecosystem. In the present study, litters from 16 species with contrasting chemical traits were incubated in a subtropical broadleaved forest for 2 years, and then the initial decomposition rate in early stage and stable residue remaining in late stage were calculated by using an asymptotic decomposition model. Litter bags with different mesh sizes (0.1 or 2 mm) were used to evaluate the role of soil mesofauna in regulating litter decomposition. Our results showed that litters with higher quality decomposed faster in early stage, and also had a larger fraction of stable residue remaining in the late stage. In addition, soil mesofauna exclusion had no influence on the decomposition rate at early stage, but significantly increased the stable residue remaining from 8.71% to 17.96%. We highlighted that the quality of plant litters play an important role in regulating the decomposition process in both early and late stage of decomposition, and thus the nutrient cycling and soil carbon (C) sink, in subtropical forest ecosystem. [ABSTRACT FROM AUTHOR]

Nine new diterpenes named lanceolatanol hydroperoxide ( 1 ), epilanceolatanol hydroperoxide ( 2 ), lanceolatanoic acid hydroperoxide ( 3 ), epilanceolatanoic acid hydroperoxide ( 4 ), lanceolatanol ( 5 ), lanceolatanoic acid ( 6 ), 11-acetoxylanceolatanoic acid ( 7 ), 11-acetoxylanceolatanoic acid methyl ester ( 8 ) and epoxyhinokiol ( 13 ) were characterized from the leaves of plantation-grown Cunninghamia lanceolata along with twelve known compounds. The compounds were evaluated for their growth inhibitory activities against the human prostate cell line (PC-3). [ABSTRACT FROM AUTHOR]

A continuous three-year observation (from May 2008 to April 2011) was conducted to characterize the spatial variation of dissolved inorganic nitrogen (DIN) deposition at eight main forest ecosystems along the north-south transect of eastern China (NSTEC). The results show that both throughfall DIN deposition and bulk DIN deposition increase from north to south along the NSTEC. Throughfall DIN deposition varies greatly from 2.7 kg N/(ha·yr) to 33.0 kg N/(ha·yr), with an average of 10.6 kg N/(ha·yr), and bulk DIN deposition ranges from 4.1 kg N/(ha·yr) to 25.4 kg N/(ha·yr), with an average of 9.8 kg N/(ha·yr). NH-N is the dominant form of DIN deposition at most sampling sites. Additionally, the spatial variation of DIN deposition is controlled mainly by precipitation. Moreover, in the northern part of the NSTEC, bulk DIN deposition is 17% higher than throughfall DIN deposition, whereas the trend is opposite in the southern part of the NSTEC. The results demonstrate that DIN deposition would likely threaten the forest ecosystems along the NSTEC, compared with the critical loads (CL) of N deposition, and DIN deposition in this region is mostly controlled by agricultural activities rather than industrial activities or transportation. [ABSTRACT FROM AUTHOR]

There is evidence that climate change induced tree mortalities in boreal and temperate forests and increased forest turnover rates (both mortality and recruitment rates) in Amazon forests. However, no study has examined China's tropical and subtropical evergreen broadleaved forests ( TEBF) that cover >26% of China's terrestrial land. The sustainability of this biome is vital to the maintenance of local ecosystem services (e.g., carbon sequestration, biodiversity conservation, climatic regulation), many of which may influence patterns of atmospheric circulation and composition at regional to global scales. Here, we analyze time-series data collected from thirteen permanent plots within China's unmanaged TEBF to study whether and how this biome has changed over recent decades. We find that the numbers of individuals and species for shrub and small tree have increased since 1978, whereas the numbers of individuals and species for tree have decreased over this same time period. The shift in species composition is accompanied by a decrease in the mean diameter at breast height ( DBH) for all individuals combined. China's TEBF may thereby be transitioning from cohorts of fewer and larger individuals to ones of more and smaller individuals, which shows a unique change pattern differing from the documented. Regional-scale drying is likely responsible for the biome's reorganization. This biome-wide reconstitution would deeply impact the regimes of carbon sequestration and biodiversity conservation and have implications for the sustainability of economic development in the area. [ABSTRACT FROM AUTHOR]

Background and aims: Freeze events can strongly influence many ecosystem processes. However, the effects of freeze events on litter production, litter quality, and decomposition are rarely documented. Methods: In this study, litter fall was measured monthly for 2 years. Two litter decomposition experiments were also performed using freeze-damaged litter and non-damaged litter in a loblolly pine forest. Results: The freeze event in November 2009 caused a pronounced pulse of needle litter fall. The freeze-damaged needle litter was shown to have higher N concentration and lower C/N ratio compared with the normal falling needle litter. This finding indicates that freeze damage significantly increased needle quality because of incomplete nutrient resorption. The decomposition of freeze-damaged needle litter was faster than that of normal falling yellow needle litter and slower than that of hand-picked green needle litter. The decomposition rate constant ( k) was negatively correlated with the C/N ratio in the needle litter. Our results also showed that the different climatic conditions influence patterns of litter decomposition. Conclusions: This study suggests that freeze events significantly alter litter quantity and quality, thus affecting litter decomposition rates in a loblolly pine forest in central China. [ABSTRACT FROM AUTHOR]

Abstract: The characteristics of the faunal community in soil are closely related to soil quality. Using the soil faunal community as an indicator of soil quality is not cost-effective because of the complex taxonomic distinction and identification required, moreover; the power of the assessment is weak in relation to soil function. Recently, a functional method incorporating eco-morphological traits has been proposed, but it depends upon presence/absence data of soil arthropod community exclusively. To overcome the limitation, we designed a novel index using the diversity of the soil faunal community along with its functional traits, and the abundance of its members (Abundance-based Fauna Index, referred as FAI). The FAI method supports both the presence/absence data and its abundance. Using real and simulated data sets with eco-morphological and niche breadth traits, two taxonomic independent functional traits, we tested associations of FAI values with soil quality and found a good relationship. In addition to its usefulness for measuring soil quality, FAI may provide valuable information for linking functional traits of soil fauna and the belowground environmental condition. [Copyright &y& Elsevier]

Thinning and understory removal, which are commonly used in forest management, are expected to affect litter decomposition. However, little is known about how litter decomposition rates change in stands subject to both thinning and understory removal. This knowledge gap is urgent to be filled because the two practices are often applied simultaneously. In the present study, an experiment containing a complete factorial combination of thinning and understory removal was arranged in a Chinese fir (Cunninghamia lanceolata) plantation. Litter decomposition rate was determined by using litter bags, and litter bags with different mesh sizes (0.1 mm and 2 mm) were used to identify the effect of soil mesofauna on decomposition. The temperature, moisture, and microbial abundance of surface soil were also measured. Results showed that thinning did not change litter decomposition rate, partly because of the unresponsive soil temperature, moisture, and abundance of microbial groups following thinning. Understory removal markedly restricted litter mass loss by more than 20%. Despite an obvious decrease in soil microbial abundance following understory removal, this should not account for why understory removal lowered litter decomposition rate, because this negative effect on litter mass loss disappeared when soil mesofauna was excluded. In addition, no interaction between thinning and understory removal was detected on litter decomposition. We emphasized that (1) Understory removal retard litter decomposition by suppressing the activity of soil mesofauna rather than by reducing microbial abundance; (2) Understory removal caused an equal reduction in litter mass loss regardless of thinning treatment. We believe that these results provide an important guidance for evaluating the effect of thinning and understory removal on some ecological processes associated with litter decomposition (i.e. soil formation and CO 2 emission from the soil to the atmosphere) in a fir plantation. [ABSTRACT FROM AUTHOR]

• Green leaf litter (GL) experienced a faster decay than senescence leaf litter (SL). • The temperature sensitivity (Q 10) of decomposition of GL was lower than that of SL. • The Q 10 of litter decomposition was negatively controlled by litter quality. • The faster litter decay after warm was due to reduced microbial carbon use efficiency. In the context of climate change, more frequent and severe extreme climate events are expected, which could lead to increased leaf fall before senescence. The decomposition of those abnormal fallen leaf litters may play a pivotal role in affecting the carbon (C) cycle in terrestrial ecosystems. Nevertheless, how their decomposition responds to temperature increase has rarely been studied, which limits the accurate estimation of the response of soil C dynamics to global warming and associated feedback. In the present study, green leaves (GL) were used to represent abnormal fallen leaf litters, and we compared the temperature sensitivity (Q 10) of the decomposition of GL with that of the corresponding senescent litters (SL) from nine species, which are widely distributed in subtropical China. Results showed that GL experienced a faster decomposition than SL. Conversely, the Q 10 of GL decomposition was significantly lower than that of SL decomposition. We also found that the Q 10 values of litter decomposition correlated positively with the C:N ratio and the lignin:N ratio, which supported the "C quality temperature" hypothesis. Furthermore, Q 10 was negatively controlled by phospholipid fatty acids of total microbes, fungi, and bacteria in soils. Experimental warming evidently increased the metabolic quotient of litter decomposition (q CO 2); a greater increase occurred in the decomposition of SL rather than that of GL. A positive correlation between Q 10 and warming-induced relative change in q CO 2 was also detected. We highlighted that the increasing inputs of abnormal fallen leaf litters caused by climate change could decrease the Q 10 of litter decomposition. [ABSTRACT FROM AUTHOR]

• Ni(II) ions were introduced into MIL-101(Cr) structure by pre-synthesis. • Enhanced water stability without introducing hydrophobic groups or other modifiers. • Ni/MIL-101(Cr) maintained the original morphology and characteristic. • The stability of Ni/MIL-101(Cr) in different pH aqueous solutions was reported. Ni(II) ions doped MIL-101(Cr) metal organic framework materials were synthesized for the first time by pre-synthesis doping to improve their water stability. The samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), energy-dispersive spectroscopy instrument (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and N 2 adsorption-desorption measurements, which persuasively demonstrated the effective combination of Ni(II) ions with the framework. The results showed that compared with undoped MIL-101(Cr), Ni-doped MIL-101(Cr) retained the original large specific surface area and pore size characteristics, and significantly improves the water stability of the skeleton. The water stability of Ni-doped MIL-101(Cr) in water environment with different pH has been significantly improved, which has important guiding significance for the application of MOFs in practical engineering. [ABSTRACT FROM AUTHOR]

A new lignan ( 1) along with a known one ( 2) has been isolated from the fine roots of Chinese fir ( Cuuninghamia lanceolata). The structure of the new compound was elucidated on the basis of detailed 1D NMR, 2D NMR, and HR-ESI-MS spectroscopic analysis. To our knowledge, 1 represents the first 8,8′-dihydroxyl substituted dibenzylbutyrolactone lignan. [ABSTRACT FROM AUTHOR]