Assessing the vulnerability of ecosystems to climate change based on climate exposure, vegetation stability and productivity

Background: Global warming has brought many negative impacts on terrestrial ecosystems, which makes the vulnerability of ecosystems one of the hot issues in current ecological research. Here, we proposed an assessment method based on the IPCC definition of vulnerability. The exposure to future climate was characterized using a moisture index(MI) that integrates the effects of temperature and precipitation. Vegetation stability, defined as the proportion of intact natural vegetation that remains unchanged under changing climate, was used together with vegetation productivity trend to represent the sensitivity and adaptability of ecosystems. Using this method, we evaluated the vulnerability of ecosystems in Southwestern China under two future representative concentration pathways(RCP 4.5 and RCP 8.5) with MC2 dynamic global vegetation model.Results:(1) Future(2017–2100) climate change will leave 7.4%(under RCP 4.5) and 57.4% of(under RCP 8.5) of areas under high or very high vulnerable climate exposure;(2) in terms of vegetation stability, nearly 45% of the study area will show high or very high vulnerability under both RCPs. Beside the impacts of human disturbance on natural vegetation coverage(vegetation intactness), climate change will cause obvious latitudinal movements in vegetation distribution, but the direction of movements under two RCPs were opposite due to the difference in water availability;(3) vegetation productivity in most areas will generally increase and remain a low vulnerability in the future;(4) an assessment based on the above three aspects together indicated that future climate change will generally have an adverse impact on all ecosystems in Southwestern China, with non-vulnerable areas account for only about 3% of the study area under both RCPs. However, compared with RCP 4.5, the areas with mid-and highvulnerability under RCP 8.5 scenario increased by 13% and 16%, respectively.Conclusion: Analyses of future climate exposure and projected vegetation distribution indicate widespread vulnerability of ecosystems in Southwestern China, while vegetation productivity in most areas will show an increasing trend to the end of twenty-first century. Based on new climate indicators and improved vulnerability assessment rules, our method provides an extra option for a more comprehensive evaluation of ecosystem vulnerability, and should be further tested at larger spatial scales in order to provide references for regional, or even global, ecosystem conservation works.

Altitudinal patterns of stand structure and herb layer diversity of Picea schrenkiana forests in the central Tianshan Mountains,Northwest China

Altitude is a useful indicator to examine patterns of forest structure and species diversity in relation to environmental factors.In this study,the altitude patterns of forest stand structure and species diversity were analyzed across 20 plots in the Tianchi Nature Reserve,Northwest China.The results showed that mean stem height（Hm）,maximum stem height（Hmax） and mean stem diameter at breast height（Dm） of Picea schrenkiana trees all decreased significantly with increasing altitude.Potential tree height（H＊） decreased while stem taper increased significantly as altitude increased,suggesting remarkable altitudinal changes in biomass allocation between the diameter and height growth of Picea schrenkiana.Understory herbaceous richness increased significantly with increasing altitude,or with decreasing total basal area（TBA）,Hm and stand volume（Volume）.High light availability for understory herbs might account for the higher species richness at high altitude.Sorensen Index decreased significantly with the increase in altitude intervals,while the Cody Index demonstrated a converse pattern,suggesting greater differences in species composition with larger distances.

Analytical modeling and vibration analysis of fiber reinforced composite hexagon honeycomb sandwich cylindrical-spherical combined shells

This study analyzes and predicts the vibration characteristics of fiberreinforced composite sandwich(FRCS)cylindrical-spherical(CS)combined shells with hexagon honeycomb core(HHC)for the first time based on an analytical model developed,which makes good use of the advantage of the first-order shear deformation theory(FSDT),the multi-segment decomposition technique,the virtual spring technology,the Jacobi-Ritz approach,and the transfer function method.The equivalent material properties of HHC are firstly determined by the modified Gibson’s formula,and the related energy equations are derived for the HHC-FRCS-CS combined shells,from which the fundamental frequencies,the mode shapes,and the forced vibration responses are solved.The current model is verified through the discussion of convergence and comparative analysis with the associated published literature and finite element(FE)results.The effects of geometric parameters of HHC on the dynamic property of the structure are further investigated with the verified model.It reveals that the vibration suppression capability can be greatly enhanced by reducing the ratio of HHC thickness to total thickness and the ratio of wall thickness of honeycomb cell to overall radius,and by increasing the ratio of length of honeycomb cell to overall radius and honeycomb characteristic angle of HHC.

Effects of Nitrogen-phosphorus-potassium Combined Fertilization on Rice Yield and Fertilizer Use Efficiency in Jianghan Plain

[Objectives]This study was conducted to explore the rational formula for rice fertilization in Jianghan Plain.[Methods]An experiment on the combined application of nitrogen,phosphorus and potassium fertilizers was carried out in Jianghan Plain,an important rice producing area in Hubei,with a total of five treatments to study the effects of nitrogen,phosphorus and potassium fertilizers on the fertilizer use efficiency and yield of rice.[Results]Fertilization had a significant effect on improving rice yield,and nitrogen fertilizer had the greatest effect on rice yield,followed by potassium fertilizer and phosphorous fertilizer.[Conclusions]This study provides a scientific basis for the application of rice fertilizers and the reduction and efficiency improvement of chemical fertilizers in Jianghan Plain.

Routine clinical administration of 4-week alverine citrate and simeticone combination relief global IBS symptoms

Introduction: The primary treatment aim for irritable bowel syndrome (IBS) is to relieve overall symptoms which can significantly impair the patient’s quality of life (QOL);however, it generally requires a high pill burden that may be improved by administration of combinatorial formulations. Thus, the effectiveness of alverine citrate and simeticone combination (ACS) for global symptom relief for IBS was investigated in this non-interventional study. Patients and Methods: ROME III IBS patients (n = 640;52.3% male: mean age: 43.6 ± 12.5 years) with abdominal pain and discomfort ≥60 of 0-100 visual analogue scale (VAS) were included in a prospective, multicenter, non-interventional study at 26 Chinese sites from December 2010 to January 2012. Patients received alverine citrate (60 mg) with simeticone (300 mg) (ACS) 3× daily for 4 weeks. Pain/discomfort and bloating/distension were assessed by VAS. Global symptoms and QOL were assessed by 7-point and 5-point Likert scales, respectively. Post-treatment bowel function was assessed by Bristol Stool Form Scale (BSFS) and treatment-related adverse events (AEs) were recorded. Results: Of 640 patients, 540 (84.4%) completed the study, and 100 (15.6%) withdrew. In total, 87.5% reported bloating at baseline. After 4-week ACS treatment, 89.1% reported global symptom improvement. Furthermore, 4-week ACS treatment reduced pain and bloated VAS scores significantly from 78.4 ± 9.9 to 32.1 ± 21.0 and from 63.2 ± 27.2 to 22.6 ± 20.9, respectively (both p < 0.001), decreased diarrhea or constipation occurrence from 67.2% to 10.2% (p < 0.001), and reduced IBS impact on QOL with only 2 treatment-related AEs. Conclusion: Routine clinical administration of ACS for IBS over a 4-week period provides effective relief of IBS symptoms and improves QOL in IBS patients.

Effects of climate,biotic factors,and phylogeny on allometric relationships:testing the metabolic scaling theory in plantations and natural forests across China

Background:Metabolic scaling theory(MST)is still in debate because observed allometric exponents often deviate from MST predictions,and can change significantly depending on environment,phylogeny,and disturbance.We assembled published scaling exponents from literatures for three allometric relationships linked to biomass allocation:leaf biomassdiameter(LD),stem biomassdiameter(SD),and root biomassdiameter(RD).We used data from natural forests and plantations across China to test the following hypotheses:1)the allometric relationships of trees support the predictions of MST on a broad scale;2)the observed deviations from MST predictions are caused by climate,biotic factors,and/or phylogeny;3)abiotic and biotic factors influence allometric relationships in plantations and natural forests differently,and different allometric relationships(i.e.LD,SD,and RD)are affected differently.We related these scaling exponents to geographic climate gradient,successional stage,stand density,leaf form and phenology,and phylogeny.We used mixedeffect models to examine the major factors affecting tree allometries.Results:In natural forests,SD and RD scaling exponents were consistent with MST predictions in primary forests,but were significantly lower in secondary forests.Both SD and RD scaling exponents in plantations had a medium value that fell between those of the secondary and primary forests,despite plantations being similar in species characteristics and age to secondary forests.The SD and RD exponents were significantly affected by factors that are not yet considered in MST,including winter coldness which explained 2.76%–3.24%of variations,successional stage(7.91%–8.20%of variations),density(a surrogate for competition,5.86%–8.54%of variations),and especially phylogeny(45.86%–56.64%of variations explained).However,the LD scaling exponents conformed to MST predictions in primary,secondary,and plantation forests,and was not strongly explained by most factors.Conclusion:MST is only applicable to primary(steadystate)forests,and climate,biotic factors and phylogeny are causes of the observed deviations of allometric relationships from MST predictions.Forest management practices in plantations have a strong influence on tree allometries.LD allometry is more strongly controlled by biophysical constraints than SD and RD allometries,however,the mechanisms behind this difference still need further examinations.

An improved method for edge detection based on neighbor distance for processing hemispheric photography

Hemisphere photos are now widely applied to provide information about solar radiation dynamics,canopy structure and their contribution to biophysical processes,plant productivity and ecosystem properties.The present study aims to improve the original‘edge detection’method for binary classifcation between sky and canopy,which works not well for closed canopies.We supposed such inaccuracy probably is due to the infuence of sky pixels on their neighbor canopy pixels.Here,we introduced a new term‘neighbor distance’,defned as the distance between pixels participated in the calculation of contrast at the edges between classifed canopy and sky,into the‘edge detection’method.We showed that choosing a suitable neighbor distance for a photo with a specifc gap fraction can signifcantly improve the accuracy of the original‘edge detection’method.We developed an ND-IS(Neighbor Distance-Iteration Selection)method that can automatically determine the threshold values of hemisphere photos with high accuracy and reproductivity.It combines the modifed‘edge detection’method and an iterative selection method,with the aid of an empirical power function for the relationship between neighbor distance and manually verifed gap fraction.This procedure worked well throughout a broad range of gap fractions(0.019-0.945)with different canopy compositions and structures,in fve forest biomes along a broad gradient of latitude and longitude across Eastern China.Our results highlight the necessity of integrating neighbor distance into the original‘edge detection’algorithm.The advantages and limitations of the method,and the application of the method in the feld were also discussed.

Terrestrial carbon sinks in China and around the world and their contribution to carbon neutrality

Enhancing the terrestrial ecosystem carbon sink(referred to as terrestrial C sink) is an important way to slow down the continuous increase in atmospheric carbon dioxide(CO_(2)) concentration and to achieve carbon neutrality target.To better understand the characteristics of terrestrial C sinks and their contribution to carbon neutrality,this review summarizes major progress in terrestrial C budget researches during the past decades,clarifies spatial patterns and drivers of terrestrial C sources and sinks in China and around the world,and examines the role of terrestrial C sinks in achieving carbon neutrality target.According to recent studies,the global terrestrial C sink has been increasing from a source of (-0.2±0.9) Pg C yr^(-1)(1 Pg=1015g)in the 1960s to a sink of (1.9±1.1) Pg C yr^(-1) in the 2010s.By synthesizing the published data,we estimate terrestrial C sink of 0.20–0.25 Pg C yr^(-1) in China during the past decades,and predict it to be 0.15–0.52 Pg C yr^(-1) by 2060.The terrestrial C sinks are mainly located in the mid-and high latitudes of the Northern Hemisphere,while tropical regions act as a weak C sink or source.The C balance differs much among ecosystem types:forest is the major C sink;shrubland,wetland and farmland soil act as C sinks;and whether the grassland functions as C sink or source remains unclear.Desert might be a C sink,but the magnitude and the associated mechanisms are still controversial.Elevated atmospheric CO_(2) concentration,nitrogen deposition,climate change,and land cover change are the main drivers of terrestrial C sinks,while other factors such as fires and aerosols would also affect ecosystem C balance.The driving factors of terrestrial C sink differ among regions.Elevated CO_(2) concentration and climate change are major drivers of the C sinks in North America and Europe,while afforestation and ecological restoration are additionally important forcing factors of terrestrial C sinks in China.For future studies,we recommend the necessity for intensive and long-term ecosystem C monitoring over broad geographic scale to improve terrestrial biosphere models for accurately evaluating terrestrial C budget and its dynamics under various climate change and policy scenarios.

Relative effects of phylogeny,biological characters and environments on leaf traits in shrub biomes across central Inner Mongolia,China

Aims Understanding the drivers for leaf traits is critical to improving our predictions on ecosystems'responses to global changes.Geographic patterns of leaf traits are shaped by phylogenetic,biological and environmental factors simultaneously.However,till now few studies have examined how these factors influenced leaf traits together,and how their effects differed at the within-and among-site levels.Methods We sampled leaf traits from a 1100 km shrub-biome transect across central Inner-Mongolia,including leaf mass per area(LMA),mass-based photosynthetic rate,nitrogen(N)and phosphorus(P)concentrations.We examined the effects of phylogenetic,biological(height and growth rate)and environmental(climate and soil)fac-tors on leaf traits with mixed-model analyses of variance.Variation partitioning method was used to separate the joint and independent effects of these three types of factors.Important Findings(i)Climate and soil fertility(total or available nutrient concentra-tions)together explained 11.4-41.4%of among-site variations,with remarkable difference among traits.(i)Height and height growth rate together explained 0.4--31.9%of trait variations(mostly among-site variations).Our results could only weakly support the ability of leaf traits as predictors for whole-plant growth.(ii)LMA was negatively related to height,which was consistent with the resource-use strategy hypothesis but incon-sistent with the hypotheses proposed for coexisting trees,suggest-ing that the LMA--height relationship is shaped by rather different mechanisms between the within-and among-communities lev-els.(iv)The variation partitioning analysis showed that,the rela-tionships between leaf traits and biological characters largely reflected the differences in both leaf traits and biological char-acters among species that occupying different sites.The relative importance of phylogenetic,biological and environmental fac-tors differed remarkably among leaf traits,between the within-and among-communities levels,and between different biomes.(v)Our results strongly suggest the necessity of examining the three types of factors simultaneously,and at both the within-and among-communities levels,for a better understanding of the drivers for leaf traits patterns.

Short-term effects of biochar and gypsum on soil hydraulic properties and sodicity in a saline-alkali soil

Salt and sodicity of saline-alkali soil adversely affect the construction of ecological landscapes and negatively impact crop production.The reclamation potential of biochar(BC,wheat straw biochar applied at\%by weight),gypsum(G,0.4%by weight),and gypsum coupled with biochar(GBC)was examined in this laboratory-based study by evaluating their effects on a saline-alkali soil(silt loam)with no amendment as a control(CK).Saline ice and fresh water(simulated rainfall)were leached through soil columns to investigate changes in salt content,sodium adsorption ratio(SAR),alkalinity,and pH of the leachate and the soil.Results showed that saturated water content and field water capacity(FWC)significantly increased by 4.4%and 5.6%,respectively,in the BC treatment after a short incubation time.Co-application of biochar and gypsum(GBC)increased soil saturated hydraulic conductivity(Ks)by 58.4%,which was also significantly higher than the sole addition.Electrical conductivity(EC)of the leachate decreased sharply after saline ice leaching;subsequent freshwater leaching accelerated the removal of the rest of the salts,irrespective of the amendment application.However,the application of gypsum(G and GB)significantly enhanced the removal of exchangeable Na^+and reduced leachate SAR.After leaching,the soil salt content decreased significantly for all treatments.The application of gypsum resulted in a significantly lower soil pH,exchangeable sodium percentage(ESP),SAR,and alkalinity values than those recorded for the CK and BC treatments.These results demonstrated that the co-application of gypsum and biochar could improve saline-alkali soil hydraulic conductivity and decrease leaching-induced sodicity over a short period.

Contrasting responses of net primary productivity to inter-annual variability and changes of climate among three forest types in northern China

Aims A lack of explicit information on differential controls on net primary productivity(NPP)across regions and ecosystem types is largely responsible for uncertainties in global trajectories of terrestrial carbon balance with changing environment.The objectives of this study were to determine how NPP of different forest types would respond to inter-annual variability of climate and to examine the responses of NPP to future climate change scenarios across contrasting forest types in northern China.Methods We investigated inter-annual variations of NPP in relation to climate variability across three forest types in northern China,including a boreal forest dominated by Larix gmelinii Rupr.,and two temperate forests dominated by Pinus tabulaeformis Carr.and Quercus wutaishanica Mayr.,respectively,and studied the responses of NPP in these forests to predicted changes in climate for the periods 2011–40,2041–70 and 2070–100 under carbon emission scenarios A2 and B2 of Intergovernmental Panel on Climate Change.We simulated the responses of NPP to predicted changes in future climate as well as inter-annual variability of the present climate with the Biome-BGC version 4.2 based on site-and species-specific parameters.The modeled forest NPP data were validated against values in literature for similar types of forests and compared with inter-annual growth variations reflected by tree-ring width index(RWI)at the study sites.Important Findings Inter-annual variations in modeled NPP during the period 1960–06 were mostly consistent with the temporal patterns in RWI.There were contrasting responses of modeled NPP among the three forest types to inter-annual variability of the present climate as well as to predicted changes in future climate.The modeled NPP was positively related to annual mean air temperature in the L.gmelinii forest(P<0.001),but negatively in the P.tabulaeformis forest(P=0.05)and the Q.wutaishanica forest(P=0.03),while the relationships of modeled NPP with annual precipitation for the three forest types were all positive.Multiple stepwise regression analyses showed that temperature was a more important constraint of NPP than precipitation in the L.gmelinii forest,whereas precipitation appeared to be a prominent factor limiting the growth in P.tabulaeformis and Q.wutaishanica.Model simulations suggest marked,but differential increases in NPP across the three forest types with predicted changes in future climate.

A test of BIOME-BGC with dendrochronology for forests along the altitudinal gradient of Mt. Changbai in northeast China

Aims Process-based models are basic tools for predicting the response of forest carbon to future climate change.The models have commonly been tested for their predictions of spatial variation in forest produc-tivity,but much less for their ability to predict temporal variation.Here,we explored methods to test the models with tree rings,using BIOME-BGC as an example.Methods We used net primary productivity(NPP)data and tree rings col-lected from five major forest types along the altitudinal gradient of Mt.Changbai,northeast China,to test local-parameterized BIOME-BGC model.We first test the model’s predictions of both spatial(Test 1)and temporal changes(Test 2)in productivity.Then we test if the model can detect the climatic factors limiting forest productiv-ity during historical climate change,as revealed by dendroclimatic analyses(Test 3).Important Findings Our results showed that BIOME-BGC could well simulate NPP of five forest types on Mt.Changbai,with an r^(2) of 0.69 between mod-eled and observed NPP for 17 plots along the altitudinal gradient(Test 1).Meanwhile,modeled NPP and ring-width indices were cor-related and showed similar temporal trends for each forest type(Test 2).While these tests suggest that the model’s predictions on spatial and temporal variation of NPP were acceptable,a further test that relate the correlations of modeled NPP with climate variables to the correlations of ring widths with climate(Test 3)showed that the model did not well identify the climatic factors limiting historical productivity dynamics for some forest types,and thus cannot reli-ably predict their future.Both dendrochronology and BIOME-BGC showed that forest types differed markedly in the climate factors limiting productivity because of differences in tree species and cli-mate condition,and thus differed in responses to climate change.Our results showed that a successful prediction of spatial NPP pat-terns cannot assure that BIOME-BGC can well simulate histori-cal NPP dynamics.Further,a correlation between modeled NPP and tree-ring series cannot assure that the limiting climatic factors for productivity have been correctly identified by the model.Our results suggest the necessity to test the temporal predictions of pro-cess-based models in a more robust way,and further integration of dendrochronology and biogeochemistry modeling may be helpful for this purpose.

Forest biomass is strongly shaped by forest height across boreal to tropical forests in China

Forest height is a major factor shaping geographic biomass patterns,and there is a growing dependence on forest height derived from satellite light detecting and ranging(LiDAR)to monitor large-scale biomass patterns.However,how the relationship between forest biomass and height is modulated by climate and biotic factors has seldom been quantified at broad scales and across various forest biomes,which may be crucial for improving broad-scale biomass estimations based on satellite LiDAR.Methods We used 1263 plots,from boreal to tropical forest biomes across China,to examine the effects of climatic(energy and water avail-ability)and biotic factors(forest biome,leaf form and leaf phenol-ogy)on biomass-height relationship,and to develop the models to estimate biomass from forest height in China.Important Findings(i)Forest height alone explained 62%of variation in forest biomass across China and was far more powerful than climate and other biotic factors.(ii)However,the relationship between biomass and forest height were significantly affected by climate,forest biome,leaf phenology(evergreen vs.deciduous)and leaf form(needleleaf vs.broadleaf).among which,the effect of climate was stronger than other factors.The intercept of biomass-height relationship was more affected by precipitation while the slope more affected by energy availability.(iii)When the effects of climate and biotic factors were considered in the models,geographic biomass patterns could be well predicted from forest height with an r2 between 0.63 and 0.78(for each forest biome and for all biomes together).For most biomes,forest biomass could be well predicted with simple models includ-ing only forest height and climate.(iv)We provided the first broad-scale models to estimate biomass from forest height across China,which can be utilized by future LiDAR studies.(v)our results suggest that the effect of climate and biotic factors should be carefully considered in models estimating broad-scale forest biomass patterns with satellite LiDAR.

Alien woody plant invasions in natural forests across China

Aims Alien plant invasion has become a major global environmental issue,causing severe economic and ecological damages.Severe invasions have been reported in some regions of China.However,most studies have been conducted at local and provincial levels,and the overall degree of invasion in natural forests across China remains unclear.Here,we explored the biogeographic patterns and their environmental and socioeconomic controls of the invaded alien woody plants in natural forests across the country.Methods We compiled the data of 3573 natural forest plots across the China's Mainland and mapped spatial distribution of alien woody plant invasion.We also used logistic regression models to identify the key socioeconomic and environmental factors that were associated with the observed invasion patterns.Important Findings We found that only 271 plots among 3573 natural forest plots were invaded by alien woody plants,accounting for 7.58%of all plots.Among all 2825 woody plant species across all plots surveyed,only 5 alien species(0.177%)were found.Both human activities and climate factors were related to the observed invasion patterns.Since China’s natural forests are mostly located in remote mountainous areas with limited human disturbance,alien woody plant invasions are less than those reported in North America and Europe.However,with the development of transportation and increased economic activities in mountainous areas,more invasions by alien plants may be expected in the future.Therefore,proactive management and policy making are desired to prevent or slow down the invasion processes.

Seasonal dynamic variation of pollination network is associated with the number of species in flower in an oceanic island community

Aims Plant-pollinator interaction networks are dynamic entities,and seasonal variation in plant phenology can reshape their structure on both short and long timescales.However,such seasonal dynamics are rarely considered,especially for oceanic island pollination networks.Here,we assess changes in the temporal dynamics of plant-pollinator interactions in response to seasonal variation in floral resource richness in oceanic island communities.Methods We evaluated seasonal variations of pollination networks in the Yongxing Island community.Four temporal qualitative pollination networks were analyzed using plant-pollinator interaction data of the four seasons.We collected data on plant-pollinator interactions during two consecutive months in each of the four seasons.Four network-level indices were calculated to characterize the overall structure of the networks.Statistical analyses of community dissimilarity were used to compare this community across four seasons to explore the underlying factors driving these patterns.We also evaluated the temporal variation in two species-level indices of plant and pollinator functional groups.Important Findings Both network-level specialization and modularity showed a significantly opposite trend compared with plant species richness across four seasons.Increased numbers of plant species might promote greater competition among pollinators,leading to increased niche overlap and causing decreased specialization and modularity and vice versa.Further analyses suggested that the season-to-season turnover of interactions was dominated by interaction rewiring.Thus,the seasonal changes in niche overlap among pollinators lead to interaction rewiring,which drives interaction turnover in this community.Hawkmoths had higher values of specialization and Apidae had higher values of species strength compared with other pollinator functional groups.These findings should be considered when exploring plant-pollinator interactions in ecosystems of isolated oceanic islands and in other ecosystems.

Effects of biodiversity,stand factors and functional identity on biomass and productivity during the restoration of subtropical forests in Central China

Biodiversity is found to have a significant promotion effect on ecosystem functions in manipulation experiments on grassland communities.However,its relative role compared with stand factors or functional identity is still controversial in natural forests.Here,we examined their relative effects on biomass and productivity during forest restoration.We investigated stand biomass and productivity for 24 plots(600 m2)across restoration stages in the subtropical forests of Mt.Shennongjia,Central China.We measured five key functional traits and calculated functional diversity(functional richness,evenness and dispersion)and community-weighted mean of traits.We used general linear models,variation partitioning methods to test the relative importance of stand factors(density,stand age,maximum height,etc.),functional identity,species and functional diversity on biomass and productivity.Our results illustrated that stand biomass and productivity increased significantly as forest restoration,and that community species richness increased,while functional dispersion decreased significantly.Variation partitioning analyses showed that diversity had no significant pure effects on biomass and productivity.However,diversity may affect biomass and productivity through the joint effect with stand factors and functional identity.Overall,we found that stand factors had the strongest effect on biomass and productivity,while functional identity significantly affects productivity but not biomass,suggesting that modulating stand structure and species identity are effective ways to enhance forest carbon storage and sequestrations potential in forest management.