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Highlights • Up-regulated P2X 4 in DRG SGCs companied with diabetic neuropathic pain. • Osthole decreased up-regulated P2X 4 and hyperalgesia in diabetic rats. • Osthole inhibited SGC activation in DRG of diabetic rats. • Osthole alleviate diabetic neuropathic pain by inhibiting P2X 4. Abstract Diabetes mellitus (DM) is considered the primary cause of neuropathic pain. Osthole (7-methoxy-8[3-methylpent 2-enyl]coumarin) is a component extracted from Cnidium monnieri (L.) cusson plant seeds and has anti-inflammatory and anti-oxidative properties. The aim of the present study was to investigate the effects of osthole on diabetic neuropathic pain (DNP) involving the P2X 4 receptor on satellite glial cells (SGCs) in the dorsal root ganglia (DRG) of type 2 diabetic rats. These data showed that the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) in DM rats were lower than those in control rats. MWT and TWL in DM rats treated with osthole were higher compared with those in untreated DM rats. The expression levels of P2X 4 mRNA and protein in the DRG of DM rats were higher compared with those in the control rats, while those in DM rats treated with osthole were significantly lower compared with those in the untreated DM rats. Osthole treatment decreased the co-expression levels of P2X 4 and glial fibrillary acidic protein (GFAP) and reduced the up-regulated expression of interleukin-1 beta (IL-1β), tumour necrosis factor-α (TNF-α), brain-derived neurotrophic factor (BDNF) and phosphorylated-p38MAPK and enhanced the down-regulation of IL-10 in DM rats. Thus, osthole treatment may act on the P2X 4 receptor to alleviate the mechanical and thermal hyperalgesia in DM rats. [ABSTRACT FROM AUTHOR]

Carbon and water cycles in forest ecosystems are tightly coupled, but global warming-induced soil and atmospheric droughts alter the coupling, thereby greatly increasing uncertainty in predicting carbon and water cycles. Therefore, a carbon–water coupled model (TRIPLEX-CW-Flux) was developed, and an R package (rTRIPLEXCWFlux) was created to facilitate model application. TRIPLEX-CW-Flux integrates vapor pressure deficit and soil moisture into a stomatal conductance submodule to estimate forest carbon and water fluxes. Prediction accuracy of TRIPLEX-CW-Flux and rTRIPLEXCWFlux application were evaluated in a Chinese fir (Cunninghamia lanceolata) plantation. Simulated net ecosystem production (NEP) and evapotranspiration (ET) were in good agreement with flux observations (R 2 : 0.76 for NEP ; 0.71 for ET). Thus, the TRIPLEX-CW-Flux model can be used to predict and quantify effects of global warming-induced droughts on forest carbon and water cycles. The open-access rTRIPLEXCWFlux package facilitates estimations of carbon sequestration and water consumption in forest ecosystems using the observed flux data. • A physiological process model that couples carbon and water flux was developed. • Both atmospheric and soil drought stress were also integrated into the model. • An R package was encoded for the model to predict forest carbon and water flux. • The simulated values were comparable to the flux data observed in the forest. • This R package can be used to evaluate forest functions under climate change. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tree mycorrhizal dominance drives soil P bioavailable in subtropical forests. • Available inorganic P but not organic P increased with ECM tree dominance. • AM and ECM forest soil had similar activity of acid phosphatase. • ECM tree dominance increases leaf litter C/N ratio but decreased soil pH. Many forest tree species form symbiotic associations with either arbuscular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi to increase access to nutrients. ECM and AM differ in strategies for acquiring nitrogen (N) and phosphorus (P), however, little is known about the degree to which mycorrhiza mediate the effects of tree species on soil P bioavailability outside of the temperate zone. Here, we established a natural gradient with increasing ECM tree dominance in subtropical secondary forests, and investigated the linkages between the ECM tree dominance and soil bioavailable P content. We quantified the contents of four soil bioavailable P pools (CaCl 2 -P, citric-P, enzyme-P and HCl-P) using the recently developed biologically-based P extraction method, as well as acid phosphatase activity, litter biomass and quality, microbial biomass carbon (C), and soil abiotic variables. We found that CaCl 2 -P, citric-P and HCl-P increased with ECM tree dominance, while enzyme-P did not. Specially, ECM-dominated soils displayed markedly higher (1.2–2.9 times) citric-P and HCl-P than AM soils, indicating that ECM forests can effectively obtain inorganic P by releasing organic acids and through proton excretion. The acid phosphatase involved in the acquisition of organic P had similar activity between AM and ECM forests. Structural equation models indicated that increasing ECM tree dominance increases litter C/N ratio and soil organic matter, but decreases pH and microbial biomass C/P ratio, all of which are critical in mediating P bioavailability. Collectively, our findings confirm that tree mycorrhizal associations affect soil P bioavailability, which have implications for understanding species coexistence and guiding forest managements in subtropics. [ABSTRACT FROM AUTHOR]

Subtropical forests across south China have been extensively affected by anthropogenic disturbances with potential profound effects on plant biodiversity and ecosystem function (BEF). However, whether and to what degree biodiversity influences biomass of subtropical forests remains uncertain. In this study, we analyzed the effects of tree biodiversity (species diversity, functional diversity and phylogenetic diversity) on stand biomass at three stages (early, mid and late) of succession in subtropical forests. As forest succession progressed, we found that the changes in species diversity were different compared with those of functional and phylogenetic diversity. Most of the indices of species and functional and phylogenetic diversity were not significantly correlated with stand biomass at two spatial grains (plot sizes of 10 m × 10 m and 20 m × 30 m). However, when other abiotic and biotic factors (i.e., altitude, canopy light, stem density and forest phase) were included with diversity indices in mixed models to explain biomass, the effect of functional diversity on biomass was significant at both resolution. For species diversity indices, the effect was significant at the 20 m × 30 m resolution, and phylogenetic diversity had no significant effect. Our results indicate that biodiversity affects forest biomass during the succession of a subtropical forest and suggest that functional diversity may provide a better metric than species or phylogenetic diversity for determining the biodiversity effect on biomass. Moreover, our results indicate that the diverse conclusions reached in other BEF analyses might be explained by differences in the plot size examined and the diversity metrics selected. Because the bivariate relationship between biodiversity and biomass can be strongly confounded by covarying abiotic and biotic factors, we suggest that the effects of abiotic factors, succession stage, and management practices on BEF should be carefully considered in future research. [ABSTRACT FROM AUTHOR]

Abstract: The emergency of satellite-borne light detecting and ranging (LiDAR) technology in recent years have provided a promising way to monitor worldwide patterns of forest biomass and carbon sources/sinks. However, few studies have examined the roles of various abiotic and biotic factors in modulating the relationship between forest biomass and height at a large scale. This is important given the growing dependence on LiDAR derived forest height as a predictor of forest biomass. In this analysis, we used 529plots across northeast China to examine this question, and to explore the method to estimate forest biomass from height. Our results showed that, while forest height and average tree height showed close relationships with stand biomass or mean biomass per stem (R 2 between 0.57 and 0.78), stand biomass could not be reliably predicted with two methods based on average tree height. In contrast, when the effects of climate and forest groups were included in the models, forest height could predict biomass patterns with a R 2 between 0.74 (belowground) and 0.91 (total biomass), which was comparable to the widely accepted biomass expansion factor method (R 2 between 0.72 and 0.98). We also showed that the ratio of both aboveground and belowground biomass to forest height (B/H ratio) was roughly similar at a large scale, suggesting that forest biomass patterns are strongly shaped by forest height. However, B/H ratio showed significant difference between deciduous and evergreen forests across northeast China. The life form of canopy trees was the major factor modulating the relationships between stand biomass and forest height, while climate, forest type and forest origin played a secondary role. Our results strongly support the use of LiDAR to monitor the large-sale patterns of both above and belowground forest biomass. Our analysis also found that the lack of forest height information in previous literatures has caused most of the biomass data could not be utilized to estimate biomass patterns from height, and we advocate future analyses to report forest height together with field-observed biomass. [Copyright &y& Elsevier]

The continuous global climate change has affected the living habits, morphological characteristics and spatial distribution of tree species. Chinese fir (C. lanceolata (Lamb.) Hook) is one of the most important conifer tree species in China, which plays a major role in terms of timber supplies and environment protection. Predict the potential suitable habitats of Chinese fir under different climatic scenarios, can not only provide scientific theoretical basis for the planning and planting of Chinese fir, but also have great significance for maintaining the stability of the plantation ecosystem. Here, we used the maximum entropy (Maxent) model which optimized by the ENMeval package, to predicted the potential suitable habitats for Chinese fir under current climatic conditions and two climatic scenarios in 2070s. Our results showed that the complexity of the model was relative low, when the regularization multiplier (RM) was 0.5 and feature combination (FC) was linear (L) and quadratic (Q). Under this parameter setting, the high and moderate suitable habitat area of Chinese fir were 83.90 × 104 km2 and 97.62 × 104 km2, respectively, which suggested we can carry out Chinese fir planting activities with different cultivation purposes. The minimum temperature of the coldest month, annual precipitation, annual mean temperature and mean temperature of warmest quarter were identified as the essential factors shaping habitat suitability for Chinese fir. Under future climate scenarios, the high suitable habitat was reduced and the degree of fragmentation was increased, and the total potential suitable habitat of Chinese fir had the tendency to migrate to high-altitude regions. Managers should be cautious about the cultivation area selection of Chinese fir plantation as the potential suitable habitat changed under the global climate change continuously. It is therefore imperative to adjust the long-term management and protection strategy of Chinese fir plantation. • Maxent was used to predicted the potential habitat of Chinese fir. • R package ENMeval was used to optimized the Maxent model. • Potential habitat of Chinese fir were concentrated in subtropical regions. • Potential habitat had a tendency to migrate to high-altitude regions. • Temperature and precipitation were main factors affecting potential distribution. [ABSTRACT FROM AUTHOR]

• Equations were based on rates of change rather than state variables. • Self-thinning equations accounted for species mixing, dominance, site, and climate. • All-species equations were also developed, and could be used for rarer species. • Based on temperate, Mediterranean and subtropical stands in Australia, China and Switzerland (1579 plots). Self-thinning dynamics are often considered when managing stand density in forests and are used to constrain forest growth models. However, self-thinning relationships are often quantified using only data at a conceptualised self-thinning line, even though self-thinning can begin before the stand actually reaches a self-thinning line. Also, few self-thinning relationships account for the effects of species composition in mixed-species forests, and stand structure such as relative height of species (in mixtures), and/or size or age cohorts in uneven-aged forests. Such considerations may be important given the effects of global climate change and interest in mixed-species and uneven-aged forests. The objective of this study was to develop self-thinning relationships based on changes in the tree density relative to mean tree diameter, instead of focusing only on data for state variables (e.g. tree density) at the self-thinning line. This was done while also considering how the change in tree density is influenced by site quality and stand structure (species composition and relative height). The relationships were modelled using data from temperate Australian Eucalyptus plantations (436 plots), subtropical forests in China (88 plots), and temperate forests in Switzerland (1055 plots). Zero-inflated and hurdle generalized linear models with Poisson and negative binomial distributions were fit for several species, as well as for all-species equations. The intercepts and slopes of the self-thinning lines were higher than many published studies which may have resulted from both the less restrictive equation form and data selection. The rates of self-thinning often decreased as the proportion of the object species increased, as relative height increased (species or size cohort became more dominant), and as site (quality) index increased. The effects of aridity varied between species, with self-thinning increasing with aridity index for Abies alba, Pinus sylvestris, Quercus petraea and Quercus robur , but decreasing with aridity index for Eucalyptus nitens, Fagus sylvatica and Picea abies as sites became wetter and cooler. Self-thinning model parameters were not correlated with species traits, including specific leaf area, wood basic density or crown diameter – stem diameter allometry. All-species self-thinning relationships based on all data could be adjusted using a correction factor for rarer species where there were insufficient data to develop species-specific equations. The approach and equations developed could be used in forest growth models to calculate how the tree density declines as mean tree size increases, as height changes relative to other cohorts or species, as species proportions change, and as climatic and edaphic conditions change. [ABSTRACT FROM AUTHOR]

• Change of soil N contents as stands age was pronounced in the topsoil. • Ratios of NO 3 −: NH 4 + increased while MBN: (NH 4 + + NO 3 −) decreased as stands aged. • Soil N availability increases and N cycling becomes more open in older stands. • Soil total N is co-regulated by trees' N demand and litter biomass return. • Gross N mineralization and nitrification control mineral N availability. Soil nitrogen (N) is frequently limiting forest productivity, especially in plantations. To investigate the soil N dynamics and the consequences of N accumulation as well as the losses in the ecosystem, we studied a chronosequence of Chinese-fir (Cunninghamia lanceolata [Lamb.] Hook) plantations with stands aged 3, 16, 25, 32, and >80 years. Total N (TN), dissolved organic N (DON), microbial biomass N (MBN) and mineral N (i.e., ammonium (NH 4 +) and nitrate (NO 3 −)) in the top 0–5 cm and 5–15 cm soils were compared with the annual N accumulation by trees, annual litter N return and microbial N transformation rates. Stronger changes with stand age were observed in all N forms in the top 5 cm compared to the 5–15 cm layer. Topsoil TN and DON increased steadily in stands from ages 3- to >80-years-old by 1.9-times and 2.1-times, respectively. MBN increased from 206 mg kg−1 to 327 mg kg−1 in the first 25 years and stabilized thereafter. NH 4 + content increased sharply from 3 to 16 years and then stabilized, while NO 3 − increased linearly with stand age. Both N demand of Chinese-fir and litter N input were clearly age dependent and defined the soil N status: rapid tree biomass accumulation in younger stands greatly depleted soil N, while the older stands with larger litter return and slower growth enabled N re-accumulation in the topsoil. The close positive correlation between total mineral N and gross mineralization rate, as well as between NO 3 − and gross nitrification rate indicated that the mineralization of soil organic matter and the nitrification of released NH 4 + were the two primary microbial processes controlling the available N supply. The topsoil NO 3 −: NH 4 + ratio in older stands (32- and >80 years) was greater than 1.0, and the MBN: (NH 4 + + NO 3 −) ratio was greatly reduced. This indicates that N availability increase and N cycling is accelerated with stands age. [ABSTRACT FROM AUTHOR]

• How nutrient limitation and nutrient-use strategy change with stand age are unknown. • Driver effects on resorption are differentiated by variation partitioning analyses. • Soil nutrient shift from N limitation to P limitation with plantation ageing. • Young plantations adopt more conservative nutrient-use strategy than older stands. • Tree growth (demand) and soil nutrient (supply) co-determine nutrient resorption. Nutrient resorption is a key nutrient-use strategy exhibited by perennial plants to overcome nutrient limitations and meet their nutritional demands. However, the factors that drive nutrient resorption with stand development remain largely unknown. In this study, we examined how a nutrient source (soil) and sink (trees) affected the resorption efficiency (RE) of nitrogen (N) and phosphorus (P). Fresh leaves, leaf litterfall, and soil samples were collected from a chronosequence of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook., Taxodiaceae) plantations at the ages of 3, 8–11, 16, 20, 25, 29, and 32 years. The N and P concentrations in stems, branches, leaves, coarse roots, and fine roots, stocks of N and P in soils, and the relative growth rate (RGR) of trees were measured. Fresh leaf N and P concentrations and RE decreased with stand age, while the N:P ratio in fresh leaves as well as the N and P concentrations in leaf litterfall increased. The RGR of trees declined with stand age. Soil P stocks increased but soil N stocks slightly decreased with stand age. A variation partitioning analysis revealed that the combined effect of RGR and soil P stocks on the RE of P (PRE) was stronger than the individual effect of each factor, while the RE of N (NRE) was greatly affected by the individual effect of RGR. With increasing age, Chinese fir plantations shifted from N-limiting to P-limiting conditions, and the nutrient-use strategy changed from "conservative consumption" to "resource spending". These patterns were co-regulated by the tree growth rate and soil nutrient status. Thus, supply-demand relationships reflected the nutrient cycling status and could provide valuable information for sustainable nutrient management practices in tree plantations. [ABSTRACT FROM AUTHOR]

• Late stage forest supplied higher overall and more evenly distributed ES benefits. • Magnitudes of trade-offs between paired ESs changed with restoration stages. • The beneficiary in several paired trade-offs changed along the restoration gradient. • Tree functional groups are important to ES trade-offs and ecosystem management. Secondary forests have received more attention in recent decades because their total area is increasing and the greater recognition of ecological and economical benefits provided by forest ecosystems. Therefore, the Chinese government has given high priority to implementing its Natural Forest Program that includes the restoration of degraded secondary forests. Hence, how ecosystem services (ESs) and their trade-offs are altered during the restoration process of secondary forests merits research. Here, we selected five key ecological indicators of forests, namely plant diversity and four ESs—air quality regulation, maintenance of soil fertility, global climate regulation, and timber provisioning—to examine the trends and patterns in the variation of multiple indicators and their trade-offs during forest restoration. Furthermore, secondary forests in subtropical China are characterized by a diverse tree species community that transitions from conifers in the early stage of restoration, to deciduous broadleaf and evergreen broadleaf species in its mid and late stages; this provides an excellent opportunity to investigate the influences of different tree functional groups on ESs and the trade-offs among them. Our results showed that late-forest had a greater capacity to supply higher and more evenly distributed benefits of ESs than did early or mid-stage restored forests. We also found that the magnitude of trade-offs between paired ESs changed with the stage of restoration. Furthermore, the variation of the beneficiary in critical trade-offs corresponded to the patterns of change in benefits of specific ESs. Trade-offs between plant diversity and other ESs were significantly influenced by tree functional group, in that the deciduous broadleaved species had significant positive effects whereas the conifer and evergreen broadleaved species had negative effects. We conclude that accurate prediction and management of ESs in restoration forests should explicitly account for tree functional groups, in addition to the effects from combined trade-offs among multiple ESs. [ABSTRACT FROM AUTHOR]

• Long-term iTBS ameliorated neurological deficits and neurological damage. • Long-term iTBS could consistently improve the neuronal microenvironment. • iTBS treatment altered miRNA expression in the peri-infarcted area. • iTBS inhibit neuronal apoptosis via miR-34c-5p/p53/Bax signaling pathway. To investigate intermittent theta-burst stimulation (iTBS) effect on ischemic stroke and the underlying mechanism of neurorehabilitation, we developed an ischemia/reperfusion (I/R) injury model in Sprague-Dawley (SD) rats using the middle cerebral artery occlusion/reperfusion (MCAO/r) method. Next, using different behavioral studies, we compared the improvement of the whole organism with and without iTBS administration for 28 days. We further explored the morphological and molecular biological alterations associated with neuronal apoptosis and neuroinflammation by TTC staining, HE staining, Nissl staining, immunofluorescence staining, ELISA, small RNA sequencing, RT-PCR, and western blot assays. The results showed that iTBS significantly protected against neurological deficits and neurological damage induced by cerebral I/R injury. iTBS also significantly decreased brain infarct volume and increased the number of surviving neurons after 28 days. Additionally, it was observed that iTBS decreased synaptic loss, suppressed activation of astrocytes and M1-polarized microglia, and simultaneously promoted M2-polarized microglial activation. Furthermore, iTBS intervention inhibited neuronal apoptosis and exerted a positive impact on the neuronal microenvironment by reducing neuroinflammation in cerebral I/R injured rats. To further investigate the iTBS mechanism, this study was conducted using small RNA transcriptome sequencing of various groups of peri-infarcted tissues. Bioinformatics analysis and RT-PCR discovered the possible involvement of miR-34c-5p in the mechanism of action. The target genes prediction and detection of dual-luciferase reporter genes confirmed that miR-34c-5p could inhibit neuronal apoptosis in cerebral I/R injured rats by regulating the p53/Bax signaling pathway. We also confirmed by RT-PCR and western blotting that miR-34c-5p inhibited Bax expression. In conclusion, our study supports that iTBS is vital in inhibiting neuronal apoptosis in cerebral I/R injured rats by mediating the miR-34c-5p involvement in regulating the p53/Bax signaling pathway. [ABSTRACT FROM AUTHOR]

Glycoprotein 120 (gp120) is an HIV envelope glycoprotein. Gp120 can directly stimulate the primary sensory afferent neurons and cause hyperalgesia. The P2X 3 receptor in dorsal root ganglia (DRG) is involved in the transmission of pain. In this study, we aimed to explore the role of the P2X 3 receptor in gp120-induced neuropathic pain. Our data showed that mechanical and thermal hyperalgesia in rats treated with gp120 were increased compared to those in the control group. The expression levels of the P2X 3 mRNA and protein in rats treated with gp120 were higher than those in the control group. The P2X 3 antagonist A317491 decreased mechanical hyperalgesia and thermal hyperalgesia and the up-regulated expression levels of P2X 3 mRNA and protein in rats treated with gp120. A317491 decreased ERK1/2 phosphorylation levels in the gp120-treated rat DRG. In addition, P2X 3 agonist α,β-methylene ATP (α,β-meATP)-activated currents in DRG neurons cultured with gp120 were higher than those in control neurons. The inhibitory effect of A317491 on α,βme-ATP-induced currents in DRG neurons from the gp120-treated neurons was larger than that for control neurons. Molecular docking data showed that A317491 may be acted in the gp120 protein to inhibit the gp120 initiated the P2X 3 activation, decrease the sensitizing DRG primary afferents and reduce the signal transmission of neuropathic pain in gp120-treated rats. Therefore, the inhibition of the P2X 3 receptor in rat DRG neurons relieved gp120-induced mechanical hyperalgesia. [ABSTRACT FROM AUTHOR]

[Display omitted] • A spatially explicit planning model was developed to adjust forest age structure. • Smart management could improve stand volume and carbon stocks. • Social preferences had less effects on stand quality after forest structure adjustment. • Forest management was more sensitive to carbon prices than timber prices. Forest farms are the main body of forest management at the landscape-scale in China, and have long sought ways to jointly maximize timber production and other ecosystem services. Carbon sequestration is of particular interest because China has established the goal of becoming carbon neutral by 2060. However, optimizing the balance between timber production and carbon sequestration is a challenge due to a lack of methods that account for the spatial arrangement of forest management activities within a landscape. This study developed a multi-objective planning model for forest management approaches to promote natural forest regeneration, adjusting the stand age structure of plantation forests to an even distribution across a landscape, and quantified the effects of social preferences and market prices on optimal management. The results show that depending on the dominant ecosystem services provided by the forests, forest management could promote an increased timber volume and stand carbon stock that is sustainable in the long-term. Social preferences have a relatively small influence on optimal management plans after forests are restructured to a normal forest age class distribution. In addition, forest management dynamics are more sensitive to carbon prices than timber prices. Hence, the spatial allocation of different management practices and forest restructuring, rather than protecting forests or managing them less intensively, is more effective for improving forest carbon stocks. More importantly, an urgent need also exists to increase the carbon price to guide and strengthen the attention of forest managers to forest carbon sequestration, with the goal of achieving a win–win strategy. [ABSTRACT FROM AUTHOR]

• Ordered weighted averaging method was used to handle ecosystem service trade-offs. • Ecological sources were selected based on the conservation efficiency. • Proposed a resistance surface framework considering the characteristics of the karst. • Ecological security patterns showed that large-scale farmland hampered connectivity. The construction of ecological security patterns (ESPs) from the perspective of ecosystem services is vital in regional sustainability. However, previous approaches have often not considered the complex trade-offs between ecosystem services during the construction of ESPs. Taking the Daning river basin in karst areas of southwest China as our study area, we improve the current methodological framework to construct an ESP by integrating ecosystem service trade-offs, typical characteristics of the karst area, and circuit theory. The multi-criterion decision method of ordered weighted averaging was used to balance ecosystem service trade-offs and to determine the ecological sources with the optimum conservation efficiency. The resistance surface based on land use was modified by the nighttime light intensity and rocky desertification index. Circuit theory was then applied to identify corridors, pinch points and barriers. The results showed that the spatial patterns of the six ecosystem services (food provision, carbon sequestration, soil retention, water yield, habitat quality and ecological recreation) varied considerably within the study area. By comparing the conservation efficiencies, scenario 5 was selected as the optimal scenario, and the conservation efficiencies of six ecosystem services within the ecological sources were > 1 and were more balanced, illustrating the flexibility and feasibility of our method. The modified resistance surface comprehensively reflected the dual influence of human activity and rocky desertification on ecosystems. The ESP in the Daning river basin included 34 ecological sources, 66 key corridors, ecological corridors with an area of 957 km2, and 100 pinch points and 36 barriers distributed on the corridors. The ecological sources mostly covered by forest land were mainly distributed in the north and east of the study area. The key and ecological corridors were densely located in the south and central areas, where pinch points were also mainly concentrated. Barriers were distributed on the edge of ecological sources and corridors. Based on ESP, the Daning river basin was divided into ecologically important areas in northern and eastern and ecologically improving areas in central and southern, the corresponding ecological restoration measures were also proposed. In summary, this study makes up for the shortcomings of constructing ESPs by the simple spatial overlaying of ecosystem services. Our findings could also effectively enhance the robustness and sustainability of ESPs in karst areas. [ABSTRACT FROM AUTHOR]

• Homogeneous and heterogeneous CaCO 3 precipitation were distinguished using magnetite as seeds. • Increasing SI preferentially promoted heterogeneous crystallization at low SI, but homogeneous at high SI. • High seed dosage and small seed particle size facilitate heterogeneous crystallization. • Heterogeneous nuclei adhered to seed surfaces, exhibiting better settleability than homogeneous ones. Homogeneous and heterogeneous crystallization of CaCO 3 simultaneously occur in seed-induced crystallization during water softening, while suppressing homogeneous crystallization is necessary due to the production of fine particulates that poorly precipitate. However, homogeneous crystallization is difficult to distinguish from heterogeneous crystallization. Consequently, a central focus in improving water softening is understanding their competing activities. In this study, a novel method for distinguishing homogeneous and heterogeneous calcium carbonate crystallization is described that utilizes magnetite as seed particles. Results showed that saturation index (SI) was the primary driver of both homogeneous and heterogeneous crystallizations. Heterogeneous crystallization was preferentially promoted at low SI, while homogeneous crystallization was promoted at high SI. The highest suppression effect to homogeneous crystallization occurred at SI of about 1.01. Seed dosage and mean particle size were the primary parameters related to the competition of the crystallization types. Higher seed dosage and smaller seed particle sizes promoted heterogeneous crystallization and suppressed homogeneous crystallization. Due to the good adaptability of heterogeneous crystallization at low SI, the absorption of CO 2 from the air into the solutions also improved the efficiency of hardness removal. The introduction of seed particles did not change crystalline product phases, with calcite being the only observed phase and possessing rhombohedral forms with highly regular and smooth edges. Water softening pilot test results showed that SI of 1.5 was more favorite for CaCO 3 layer formation on seed surface and hardness removal in comparison with SI of 1.0 and 2.0. Overall, the results from this study demonstrate that the introduction of seed particles is a promising approach to suppress the homogeneous crystallization of CaCO 3. Moreover, these results can serve as a framework for improved seed-induced crystallization during water softening. [Display omitted] [ABSTRACT FROM AUTHOR]

A comprehensive understanding of ecosystem service (ES) bundles and their socioecological drivers is vital for ecological management and policymaking. However, the underlying mechanisms are still unclear due to less attention being paid to their historical dynamics. Taking the Three Gorges Reservoir Area as a case study, this study used Pearson parametric correlation analysis, k-means clustering analysis, and redundancy analysis to investigate how the ESs and their interactions have changed over time, and to identify historical spatial patterns of ES bundles and their associations with socioecological drivers. Results showed that: (1) most ESs improved over time but soil retention, water yield, and habitat provision showed slightly decreasing trends; (2) intensive agriculture and advances in technology diminished potential ES trade-offs related to food production, while the decrease in soil retention led to a decline in its synergistic relationships with water yield and nitrogen retention; (3) three ES bundles were identified at the watershed scale. The trajectory of each ES bundle could be attributed to the common effects of ecological projects and rapid urbanization. In particular, ecological projects have promoted the transformation of the ES bundle to the direction of high supply and low trade-off, yet trade-offs between ESs have not significantly improved because of constant urban expansion in a major city and its surrounding area; (4) the socioecological drivers determining ESs and ES bundles were also time-dependent, with the ratio of forest to land, slope, and population density being the major drivers. However, other random drivers (e.g., climate change) should also be highlighted as they generate great uncertainty for predicting future ES bundles and further ES management. Overall, our results advocate the historical assessment of the relationships between multiple ESs and socioecological drivers and emphasize the necessity of embracing a historical dynamic perspective in the sustainable management of ESs. [Display omitted] • Both ecosystem services (ESs) and their interactions changed over time. • Three ES bundles were identified and mapped for each time point. • Forest to land ratio, slope, and population density were the major drivers. • Analyzing historical spatial patterns of ES bundles is fundamental for their future management. [ABSTRACT FROM AUTHOR]

Stand development affects soil properties, nitrogen (N) dynamics, and soil microbial community composition, but the question remains whether differences in N mineralization rates are mirrored by the abundance of relevant functional genes. In this study, we used the 15N pool-dilution method to estimate N mineralization (i.e. , ammonification and nitrification) rates across a Chinese fir (Cunninghamia lanceolata) chronosequence, with stands aged 7, 16, 29, 36, and >80 years. Gene copy numbers of bacteria (16S rRNA), fungi (ITS), ammonia-oxidizing archaea (AOA) and bacteria (AOB) (amoA), denitrifiers (nirS , nirK), N 2 fixers (nifH) and organic N decomposers (chiA) were quantified by qPCR. Gross ammonification and nitrification rates increased linearly with stand age in the topsoil (0–5 cm depth) and were strongly positively correlated with the abundance of the bacterial 16S rRNA gene and AOA amo A, respectively. Higher net nitrification but lower NO 3 − immobilization rates in older stands (32 and > 80 years) drove higher N availability for vegetation than in young stands (7 years). Older stands also had higher rates of NH 4 + consumption than younger stands due to the increased fungal ITS abundance and higher microbial biomass N (MBN), and AOA amoA was more abundant and active than AOB amoA due to the more acid conditions characteristic of mature forests. Redundancy analysis showed that functional gene abundance was strongly affected by soil properties such as pH, NH 4 +-N content, and MBN. We also found that microbial N storage potential was lower, and the NO 3 −-N leaching and gaseous N loss potential were higher in older stands than in younger stands. Collectively, stand developmental stage gave rise to the observed spatial gradient of gross ammonification and nitrification rates by altering the abundance of microbial functional genes, which affected plantation productivity via its modulation of the supply of bioavailable N. [Display omitted] [ABSTRACT FROM AUTHOR]

• Mean concentration and annual output fluxes of DOC were the highest in the deciduous broadleaved forest. • Mean concentration of TDN tended to increase but annual TDN output fluxes decreased with forest restoration. • DOC cycle in the deciduous broadleaved forest was relatively open whereas TDN cycle turned to be closed as forest restored. In the restoration of subtropical forests, the hydrological fluxes of dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) have not been fully investigated in different stages dominated by different tree species. The concentrations of DOC and TDN in rainfall, throughfall, stemflow, and surface runoff were measured for two years in each of the three forests at different restoration stages: early coniferous forest (Pinus massoniana - Lithocarpus glaber), intermediate deciduous broadleaved forest (Choerospondias axillaris), and late evergreen broadleaved forest (L. glaber - Cyclobalanopsis glauca). Input and output fluxes as well as leaching and migration coefficients of DOC and TDN were calculated to examine the nutrient cycling status in the processes of forest restoration. In stemflow, DOC concentrations in the evergreen broadleaved forest differed significantly from those in the coniferous and deciduous broadleaved forests, whereas TDN concentrations differed significantly between the coniferous forest and other two forests. In throughfall, DOC and TDN concentrations were not significantly different among the three forests. The amount of DOC leached was primarily influenced by rainfall and was significantly related to fluxes in throughfall, with the highest value in the deciduous broadleaved forest (57.78 kg C ha−1). However, the amount of TDN leached was affected by rainfall and the absorption of vegetation and was not significantly related to fluxes in throughfall, except for the deciduous broadleaved forest. The highest value of TDN leached was in the coniferous forest (11.90 kg N ha−1). Mean TDN concentration in surface runoff tended to increase but annual TDN output fluxes decreased with forest restoration. However, both mean concentration and annual output fluxes of DOC in surface runoff were the highest in the deciduous broadleaved forest at the intermediate restoration stage. The concentrations were closely related to surface runoff, decomposition rate of litterfall, and soil organic matter content. The annual output fluxes of DOC and TDN in surface runoff were less than 30% of the input in throughfall, indicating nutrient accumulation in subtropical secondary forests. [ABSTRACT FROM AUTHOR]

Abstract Plant interactions and feedbacks with soil microorganisms play an important role in sustaining the functions and stability of terrestrial ecosystems, yet the effects of tree species diversity on soil microbial community in forest ecosystems are still not well understood. Here, we examined the effects of tree species richness (1–12 species) and the presence of certain influential tree species (sampling effect) on soil bacterial and fungal communities in Chinese subtropical forests, using high-throughput Illumina sequencing for microbial identification. We observed that beta rather than alpha diversities of tree species and soil microorganisms were strong coupled. Multivariate regression and redundancy analyses revealed that the effects of tree species identity dominated over tree species richness on the diversity and composition of bacterial and fungal communities in both organic and top mineral soil horizons. Soil pH, nutrients and topography were always identified as significant predictors in the best multivariate models. Tree species have stronger effect on fungi than bacteria in organic soil, and on ectomycorrhizal fungi than saprotrophic fungi in mineral topsoil. Concluding, tree species identity, along with abiotic soil and topographical conditions, were more important factors determining the soil microbial communities in subtropical forests than tree diversity per se. Highlights • Soil bacterial and fungal beta diversities couples well with tree beta diversity. • Effects of tree identity dominate over richness on bacterial and fungal communities. • Soil pH, nutrient contents and topography were always identified as key drivers. • Tree species have stronger effect on fungi than bacteria in organic soil. • Differential responses of ectomycorrhizal and saprotrophic fungi to tree effects. [ABSTRACT FROM AUTHOR]

Fine root production accounts for a large proportion of net primary production (NPP) in forest ecosystems that is highly responsive to environmental and biotic changes. The underlying mechanisms of the relationship between tree species richness and fine root production have not been fully examined. Here we hypothesized that: (i) the relationship between aboveground species richness and fine root production could be attributable to belowground spatial resource partitioning; (ii) either symmetrical or asymmetrical root proliferation to obtain nutrients leads to increased fine root production; and (iii) stand density affects the relationship between species richness and fine root production. We used an ingrowth core method to estimate fine root production coupled to molecular approaches for identifying the tree species of sampled fine roots within each ingrowth core. There was a significant and positive relationship between aboveground species richness and fine root production. The increase in fine root production might partially be attributed to asymmetrical root proliferation rather than belowground spatial resource partitioning. A piecewise structural equation model (SEM) linking stand density and soil nutrients revealed that both factors play dominant roles in mediating the effects of aboveground species richness on fine root production. Moreover, fine root production and relative abundance of fine root distribution within-layers both depended on the effects of aboveground species richness × stand density × soil phosphorus (P) interactions. Therefore, soil P concentration and stand density partially explained the positive aboveground species richness–fine root production relationship. Unlabelled Image • Fine root production was positively related to tree species richness. • Causes of the positive relationship were determined by piecewise structure equation modeling. • Stand density and asymmetric foraging for soil nutrients were the main explanations. • Our results support the stress-gradient hypothesis. • Phosphorus limitation and high stand density favored belowground complementary effect. [ABSTRACT FROM AUTHOR]