In recent years,the study of production-living-ecological space has progressively expanded from urban to rural areas.With the onset of a new era in rural development,diverse requirements for rural landscapes have emer...In recent years,the study of production-living-ecological space has progressively expanded from urban to rural areas.With the onset of a new era in rural development,diverse requirements for rural landscapes have emerged.Consequently,rural landscape planning in this new era is incorporating the three-pillar conception of sustainability.Island villages,with their distinct natural ecology and marine resources compared to inland villages,offer unique conditions,resulting in the production of diversified landscape types with significant development potential.Despite the limited attention given to the domestic development of island villages,this paper delves into the analysis of the three-pillar conception of sustainability and explores landscape protection strategies and renewal modes specific to island villages.To illustrate these concepts,East Xiaoqing Island Village in Rushan City,Weihai City serves as a case study.展开更多
Atmospheric nitrogen(N)deposition is predicted to increase,especially in the subtropics.However,the responses of soil microorganisms to long-term N addition at the molecular level in N-rich subtropical forests have no...Atmospheric nitrogen(N)deposition is predicted to increase,especially in the subtropics.However,the responses of soil microorganisms to long-term N addition at the molecular level in N-rich subtropical forests have not been clarified.A long-term nutrient addition experiment was conducted in a subtropical evergreen old-growth forest in China.The four treatments were:control,low N(50 kg N ha^(-1)a^(-1)),high N(100 kg N ha^(-1)a^(-1)),and combined N and phosphorus(P)(100 kg N ha^(-1)a^(-1)+50 kg P ha^(-1)a^(-1)).Metagenomic sequencing characterized diversity and composition of soil microbial communities and used to construct bacterial/fungal co-occurrence networks.Nutrient-treated soils were more acidic and had higher levels of dissolved organic carbon than controls.There were no significant differences in microbial diversity and community composition across treatments.The addition of nutrients increased the abundance of copiotrophic bacteria and potentially beneficial microorganisms(e.g.,Gemmatimonadetes,Chaetomium,and Aureobasidium).Low N addition increased microbiome network connectivity.Three rare fungi were identified as module hubs under nutrient addition,indicating that low abundance fungi were more sensitive to increased nutrients.The results indicate that the overall composition of microbial communities was stable but not static to long-term N addition.Our findings provide new insights that can aid predictions of the response of soil microbial communities to long-term N addition.展开更多
Cyclocarya paliurus, an economically valuable tree species, has traditionally been used as a nutraceutical food or medicine in China. However, limited information is available on its genotype selection and cultivation...Cyclocarya paliurus, an economically valuable tree species, has traditionally been used as a nutraceutical food or medicine in China. However, limited information is available on its genotype selection and cultivation under a wide range of environmental conditions for growth and targeted health-promoting substances. We studied the effects of genotype and environment, and their interaction on leaf triterpenoid content and tree growth for 12 genotypes of C. paliurus grown at four sites. We quantified the correlation between leaf triterpenoid accumulation and tree growth. The contents of cyclocaric acid B, cyclocarioside I, and arjunolic acid ranged from 0.06 to 3.89, 0 to 3.71, and 0.65 to 8.86 mg g^-1, respectively. Three individual triterpenoids were primarily influenced by genotype (variation ranged from 53.7 to 68.0%), while environment accounted for most of the variation in total triterpenoid content and tree growth (71.3–89.5%). Most tested environmental parameters were significantly correlated to total triterpenoid content, but not to the contents of the individual triterpenoids measured. Growth in tree height and diameter at breast height were significantly negatively correlated with total triterpenoid content but were non-significantly correlated with individual triterpenoid contents. We conclude that genotypic selection, manipulation of environmental conditions, and implementation of appropriate silvicultural operations would be important strategies for increasing the accumulation of health-promoting phytochemicals.展开更多
In this paper,dynamics analysis of a delayed HIV infection model with CTL immune response and antibody immune response is investigated.The model involves the concentrations of uninfected cells,infected cells,free viru...In this paper,dynamics analysis of a delayed HIV infection model with CTL immune response and antibody immune response is investigated.The model involves the concentrations of uninfected cells,infected cells,free virus,CTL response cells,and antibody antibody response cells.There are three delays in the model:the intracellular delay,virus replication delay and the antibody delay.The basic reproductive number of viral infection,the antibody immune reproductive number,the CTL immune reproductive number,the CTL immune competitive reproductive number and the antibody immune competitive reproductive number are derived.By means of Lyapunov functionals and LaSalle’s invariance principle,sufficient conditions for the stability of each equilibrium is established.The results show that the intracellular delay and virus replication delay do not impact upon the stability of each equilibrium,but when the antibody delay is positive,Hopf bifurcation at the antibody response and the interior equilibrium will exist by using the antibody delay as a bifurcation parameter.Numerical simulations are carried out to justify the analytical results.展开更多
Background:Litter traits critically affect litter decomposition from local to global scales.However,our understanding of the temporal dynamics of litter trait-decomposition linkages,especially their dependence on plan...Background:Litter traits critically affect litter decomposition from local to global scales.However,our understanding of the temporal dynamics of litter trait-decomposition linkages,especially their dependence on plant functional type remains limited.Methods:We decomposed the leaf litter of 203 tree species that belong to two different functional types(deciduous and evergreen)for 2 years in a subtropical forest in China.The Weibull residence model was used to describe the different stages of litter decomposition by calculating the time to 10%,25%and 50%mass loss(Weibull t_(1/10),t_(1/4),and t_(1/2)respectively)and litter mean residence time(Weibull MRT).The resulting model parameters were used to explore the control of litter traits(e.g.,N,P,condensed tannins and tensile strength)over leaf litter decomposition across different decomposition stages.Results:The litter traits we measured had lower explanatory power for the early stages(Weibull t_(1/10)and t_(1/4))than for the later stages(Weibull t_(1/2)and MRT)of decomposition.The relative importance of different types of litter traits in influencing decomposition changed dramatically during decomposition,with physical traits exerting predominant control for the stages of Weibull t_(1/10)and MRT and nutrient-related traits for the stages of Weibull t_(1/4),and t_(1/2).Moreover,we found that litter decomposition of the early three stages(Weibull t_(1/10),t_(1/4),and t_(1/2))of the two functional types was controlled by different types of litter traits;that is,the litter decomposition rates of deciduous species were predominately controlled by nutrient-related traits,while the litter decomposition rates of evergreen species were mainly controlled by carbon-related traits.Conclusions:This study suggests that litter trait-decomposition linkages vary with decomposition stages and are strongly mediated by plant functional type,highlighting the necessity to consider their temporal dynamics and plant functional types for improving predictions of litter decomposition.展开更多
Estimating the volume growth of forest ecosystems accurately is important for understanding carbon sequestration and achieving carbon neutrality goals.However,the key environmental factors affecting volume growth diff...Estimating the volume growth of forest ecosystems accurately is important for understanding carbon sequestration and achieving carbon neutrality goals.However,the key environmental factors affecting volume growth differ across various scales and plant functional types.This study was,therefore,conducted to estimate the volume growth of Larix and Quercus forests based on national-scale forestry inventory data in China and its influencing factors using random forest algorithms.The results showed that the model performances of volume growth in natural forests(R^(2)=0.65 for Larix and 0.66 for Quercus,respectively)were better than those in planted forests(R^(2)=0.44 for Larix and 0.40 for Quercus,respectively).In both natural and planted forests,the stand age showed a strong relative importance for volume growth(8.6%–66.2%),while the edaphic and climatic variables had a limited relative importance(<6.0%).The relationship between stand age and volume growth was unimodal in natural forests and linear increase in planted Quercus forests.And the specific locations(i.e.,altitude and aspect)of sampling plots exhibited high relative importance for volume growth in planted forests(4.1%–18.2%).Altitude positively affected volume growth in planted Larix forests but controlled volume growth negatively in planted Quercus forests.Similarly,the effects of other environmental factors on volume growth also differed in both stand origins(planted versus natural)and plant functional types(Larix versus Quercus).These results highlighted that the stand age was the most important predictor for volume growth and there were diverse effects of environmental factors on volume growth among stand origins and plant functional types.Our findings will provide a good framework for site-specific recommendations regarding the management practices necessary to maintain the volume growth in China's forest ecosystems.展开更多
There are many types of wetlands around the Chaohu Lake,and wetland biodiversity is rich. The protection of wetland biodiversity is of great significance for regional sustainable development. In this paper,the wetland...There are many types of wetlands around the Chaohu Lake,and wetland biodiversity is rich. The protection of wetland biodiversity is of great significance for regional sustainable development. In this paper,the wetlands around the Chaohu Lake are taken as the research objects. Based on the investigation and analysis of the biodiversity in the wetlands,combing the threats to the biodiversity of the wetland around the Chaohu Lake at the present stage,the biodiversity protection countermeasures of the wetlands around the Chaohu Lake are put forward.展开更多
The coal resources are abundant in Huainan City,but with development and utilization of coal mine,the water surface formed by mining subsidence increases gradually,and more and more people pay great attention on the r...The coal resources are abundant in Huainan City,but with development and utilization of coal mine,the water surface formed by mining subsidence increases gradually,and more and more people pay great attention on the research of the wetland in the subsidence area. Through on-site review,the status of the wetland resources is explored,and wetland ecosystem of the region is analyzed. In this paper,the red line delimitation,functional zoning,overall layout and basic engineering planning and design of Suocao Bay Wetland Park are carried out. The planning and design of Suocao Bay Wetland Park mean to provide new support for ecological protection,accelerate the ecological restoration in Maoji Experimental Area,vigorously carry forward the wetland culture,and make it become an important wetland demonstration base in coal mine subsidence area.展开更多
Chemical components are the main factors affecting the mechanical properties of wood fibers. Lignin is one of the main components of wood cell walls and has a critical effect on the mechanical properties of paper pulp...Chemical components are the main factors affecting the mechanical properties of wood fibers. Lignin is one of the main components of wood cell walls and has a critical effect on the mechanical properties of paper pulp and wood fiber based composites. In this study, we carried out tensile tests on single mature latewood tracheids of Chi- nese fir (Cunninghamia lanciolata (Lamb.) Hook.), using three different delignified treatment methods to obtain different amounts of lignin. We applied single fiber tests to study the effect of the amount of lignin on mechanical tensile proper- ties of single wood fibers at the cellular level. The results show that in their dry state, the modulus of elasticity of single fi- bers decreased with the reduction in the amount of Iignin; even their absolute values were not high. The amount of lignin affects the tensile strength and elongation of single fibers considerably. Tensile strength and elongation of single fibers increase with a reduction in the amount of lignin.展开更多
Bamboo harvesting residues are wastes by-products of bamboo industries that contain holocellulose for about 63.14%to 70.71%,which often be discarded,incinerated or buried.In this study,carboxymethyl cellulose was prep...Bamboo harvesting residues are wastes by-products of bamboo industries that contain holocellulose for about 63.14%to 70.71%,which often be discarded,incinerated or buried.In this study,carboxymethyl cellulose was prepared from bamboo harvesting residues(bamboo-branch and bamboo-tip)as raw materials.The chemical composition of bamboo harvesting residues,the viscosity and degree of substitution of carboxymethyl cellulose were determined.Carboxymethyl cellulose obtained was further characterized and compared by means of FTIR,SEM,XRD and TG.Results showed that under the optimized identical conditions,the viscosity and degree of substitution of carboxymethyl cellulose from bamboo-branch and bamboo-tip were 6.0 and 78.9 mPa·s,0.75 and 0.89,respectively.Carboxymethyl cellulose obtained from bamboo-tip displayed a lower crystallinity and a better thermal stability as compared to synthetic carboxymethyl cellulose obtained from bamboo-branch and bamboo-culm.展开更多
Leaf area index (LAI) is a key parameter for studying global terrestrial ecology and environment and has great ecological significance. How to accurately measure and calculate structural parameters of trees has become...Leaf area index (LAI) is a key parameter for studying global terrestrial ecology and environment and has great ecological significance. How to accurately measure and calculate structural parameters of trees has become an urgent matter. This paper reports the use of terrestrial laser scanning (TLS) as a measurement tool to achieve accurate LAI estimation through point cloud preprocessing measures, the LeWos algorithm, and voxel methods. The accuracy and feasibility of this indirect measurement method were explored. It is found that the single wood structure parameters extracted from TLS have a good linear relationship with manual measurement, and the extraction errors meet the requirements of real-scene conversion. The study also found when the voxel size is consistent with the minimum distance of the point cloud set by TLS instrument, it has a strong correlation with the measured value of canopy analyser. These results lay the foundation for conveniently and quickly obtaining structural parameters of trees, tree growth state detection, and canopy ecological benefit assessment.展开更多
In order to improve hydrophobic characteristics which will affect the service performance of fast-growing poplar due to growing bacteria in the humid environment.In this study,a simple method was proposed to treat pop...In order to improve hydrophobic characteristics which will affect the service performance of fast-growing poplar due to growing bacteria in the humid environment.In this study,a simple method was proposed to treat poplar via the high voltage electric field(HVEF)with copper as the electrode plate.Scanning electron microscope(SEM),Fourier transforms infrared spectroscopy(FTIR),X-ray diffraction(XRD)and contact angle tester were adopted to evaluate the surface morphology,surface group of poplar,crystallinity and wettability under HVEF.It was found by SEM that a large number of copper particles were uniformly attached to the surface of poplar.In all three sections,the weight percentage of the Cu element was accounting for more than half.The diffraction peaks of copper-containing compounds appeared in the(XRD).FTIR analysis confirmed that the reaction between copper and poplar took place.The surface contact angle of three sections of poplar increased in the following order:cross section<radial section<tangential section(increased by 34°,45°and 53°,respectively).An environmentfriendly and efficient method of HVEF treating fast-growing wood with copper as the electrode plate can promote its outdoor application.展开更多
We evaluated the attraction ofMonochamus alternatus Hope (Coleoptera: Cerambycidae), Dryocoetes luteus Blandford and Orthotomicus erosus Wollaston (Coleoptera: Curculionidae: Scolytinae) to multiple-funnel trap...We evaluated the attraction ofMonochamus alternatus Hope (Coleoptera: Cerambycidae), Dryocoetes luteus Blandford and Orthotomicus erosus Wollaston (Coleoptera: Curculionidae: Scolytinae) to multiple-funnel traps baited with the pine volatiles, ethanol and (+)-α-pinene and the bark beetle pheromones, ipsenol and ipsdienol. M. alternatus were attracted to traps baited with ethanol and (+)-α-pinene but not those baited with ipsdienol and ipsenol. Ipsdienol and ipsenol decreased catches ofM. alternatus in traps baited with ethanol and (+)-α-pinene. Traps baited with either binary combinations of ethanol and (+)-α-pinene or ipsdienol and ipsenol were attractive to D. luteus and O. erosus. The addition of ipsenol and ipsdienol to traps baited with ethanol and (+)-α-pinene synergized attraction of O. erosus but not D. luteus .展开更多
Aims Terrestrial net primary production(NPP),the balance of gross primary production(GPP)and autotrophic respiration(AR),is a critical measure of carbon sequestration capacity for the Earth’s land surface.The aim of ...Aims Terrestrial net primary production(NPP),the balance of gross primary production(GPP)and autotrophic respiration(AR),is a critical measure of carbon sequestration capacity for the Earth’s land surface.The aim of this study was to understand the spatio-temporal variability of NPP associated with GPP and AR in the Yangtze River Basin(YRB),China,from 2000 to 2009 during which the basin warmed significantly.Methods We first derived AR and carbon-use efficiency(CUE)from the improved Moderate Resolution Imaging Spectroradiometer GPP/NPP products(MOD17)and then conducted spatial analysis to quantify how NPP relates to GPP,AR and their relationship with key observed climate variables(temperature,precipitation and sunshine percentage)in the YRB during 2000–2009.Important Findings The spatial pattern of NPP in the YRB was predominantly determined by GPP and further modified by AR.Higher GPP and relatively low AR made the southern Jinshajiang sub-basin the most productive area in NPP in the YRB.A large portion of the YRB experienced a warmer and drier climate trend in the growing season during 2000–2009.In the upper reaches of the basin,possessing a relatively low temperature base,increases in temperature led to greater increases in GPP than those in AR,resulting in greater increased NPP.However,in the middle and lower reaches of the basin where the base temperature is relatively high,increases in temperature led to greater increases in AR than those in GPP,leading to decreases in NPP.Overall,86.7%of the vegetated area showed a consistent GPP and NPP trend through time with 71.3%of the vegetated area having a positive trend both in GPP and NPP,and the remaining 13.3%of vegetated areas showed an opposite trend in GPP and NPP,with positive GPP and negative NPP trajectories dominating(10.1%of vegetated area)the trend.Although climate warming generally had positive effects on vegetation growth in most areas of the basin,areas with increased NPP(74.5%)were less extensive than those with increased GPP(81.4%)due to the wider increase in AR(82.2%).During the study period,increases in AR offset 62%of the total increased GPP,leading to a substantial decline of CUE,particularly in the warmer lower altitude regions in the southeast.Our work reveals the diverse responses of NPP associated with GPP and AR as the climate warms and generally suggests that NPP in the middle and lower sub-basins in the YRB is more sensitive to future climate warming.These findings enhance our understanding of terrestrial ecosystem carbon dynamics in response to global warming and provide a scientific basis for managing ecosystem productivity in the YRB,China.展开更多
BURP domain-containing proteins have a conserved structure and are found extensively in plants.The functions of the proteins in this family are diverse,but remain unknown in Populus trichocarpa.In the present study,a ...BURP domain-containing proteins have a conserved structure and are found extensively in plants.The functions of the proteins in this family are diverse,but remain unknown in Populus trichocarpa.In the present study,a complete genome of P.trichocarpa was analyzed bioinformatically.A total of 18 BURP family genes,named PtBURPs,were identified and characterized according to their physical positions on the P.trichocarpa chromosomes.A phylogenetic tree was generated from alignments of PtBURP protein sequences,while phylogenetic relationships were also examined between PtBURPs and BURP family genes in other plants,including rice,soybean,maize and sorghum.BURP genes in P.trichocarpa were classified into five classes,namely PG1β-like,BNM2-like,USP-like,RD22-like and BURP V.The multiple expectation maximization for motif elicitation(MEME) and multiple protein sequence alignments of PtBURPs were also performed.Results from the transcript level analyses of 10 PtBURP genes under different stress conditions revealed the expression patterns in poplar and led to a discussion on genome duplication and evolution,expression profiles and function of PtBURP genes.展开更多
文摘In recent years,the study of production-living-ecological space has progressively expanded from urban to rural areas.With the onset of a new era in rural development,diverse requirements for rural landscapes have emerged.Consequently,rural landscape planning in this new era is incorporating the three-pillar conception of sustainability.Island villages,with their distinct natural ecology and marine resources compared to inland villages,offer unique conditions,resulting in the production of diversified landscape types with significant development potential.Despite the limited attention given to the domestic development of island villages,this paper delves into the analysis of the three-pillar conception of sustainability and explores landscape protection strategies and renewal modes specific to island villages.To illustrate these concepts,East Xiaoqing Island Village in Rushan City,Weihai City serves as a case study.
基金supported by the National Science Foundation of China(No.31770672 and 3137062)the National Basic Research Program of China(No.2010CB950602)。
文摘Atmospheric nitrogen(N)deposition is predicted to increase,especially in the subtropics.However,the responses of soil microorganisms to long-term N addition at the molecular level in N-rich subtropical forests have not been clarified.A long-term nutrient addition experiment was conducted in a subtropical evergreen old-growth forest in China.The four treatments were:control,low N(50 kg N ha^(-1)a^(-1)),high N(100 kg N ha^(-1)a^(-1)),and combined N and phosphorus(P)(100 kg N ha^(-1)a^(-1)+50 kg P ha^(-1)a^(-1)).Metagenomic sequencing characterized diversity and composition of soil microbial communities and used to construct bacterial/fungal co-occurrence networks.Nutrient-treated soils were more acidic and had higher levels of dissolved organic carbon than controls.There were no significant differences in microbial diversity and community composition across treatments.The addition of nutrients increased the abundance of copiotrophic bacteria and potentially beneficial microorganisms(e.g.,Gemmatimonadetes,Chaetomium,and Aureobasidium).Low N addition increased microbiome network connectivity.Three rare fungi were identified as module hubs under nutrient addition,indicating that low abundance fungi were more sensitive to increased nutrients.The results indicate that the overall composition of microbial communities was stable but not static to long-term N addition.Our findings provide new insights that can aid predictions of the response of soil microbial communities to long-term N addition.
基金supported by the National Natural Science Foundation of China(Grant No.31470637)the Collaborative Innovation Plan of Jiangsu Higher Educationthe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Cyclocarya paliurus, an economically valuable tree species, has traditionally been used as a nutraceutical food or medicine in China. However, limited information is available on its genotype selection and cultivation under a wide range of environmental conditions for growth and targeted health-promoting substances. We studied the effects of genotype and environment, and their interaction on leaf triterpenoid content and tree growth for 12 genotypes of C. paliurus grown at four sites. We quantified the correlation between leaf triterpenoid accumulation and tree growth. The contents of cyclocaric acid B, cyclocarioside I, and arjunolic acid ranged from 0.06 to 3.89, 0 to 3.71, and 0.65 to 8.86 mg g^-1, respectively. Three individual triterpenoids were primarily influenced by genotype (variation ranged from 53.7 to 68.0%), while environment accounted for most of the variation in total triterpenoid content and tree growth (71.3–89.5%). Most tested environmental parameters were significantly correlated to total triterpenoid content, but not to the contents of the individual triterpenoids measured. Growth in tree height and diameter at breast height were significantly negatively correlated with total triterpenoid content but were non-significantly correlated with individual triterpenoid contents. We conclude that genotypic selection, manipulation of environmental conditions, and implementation of appropriate silvicultural operations would be important strategies for increasing the accumulation of health-promoting phytochemicals.
基金The work was supported by NSF of China(11201002)Natural Science Foundation of Universities in Anhui Province(KJ2017A815).
文摘In this paper,dynamics analysis of a delayed HIV infection model with CTL immune response and antibody immune response is investigated.The model involves the concentrations of uninfected cells,infected cells,free virus,CTL response cells,and antibody antibody response cells.There are three delays in the model:the intracellular delay,virus replication delay and the antibody delay.The basic reproductive number of viral infection,the antibody immune reproductive number,the CTL immune reproductive number,the CTL immune competitive reproductive number and the antibody immune competitive reproductive number are derived.By means of Lyapunov functionals and LaSalle’s invariance principle,sufficient conditions for the stability of each equilibrium is established.The results show that the intracellular delay and virus replication delay do not impact upon the stability of each equilibrium,but when the antibody delay is positive,Hopf bifurcation at the antibody response and the interior equilibrium will exist by using the antibody delay as a bifurcation parameter.Numerical simulations are carried out to justify the analytical results.
基金supported by the National Natural Science Foundation of China(Grant Nos.31830015 and 32171752)。
文摘Background:Litter traits critically affect litter decomposition from local to global scales.However,our understanding of the temporal dynamics of litter trait-decomposition linkages,especially their dependence on plant functional type remains limited.Methods:We decomposed the leaf litter of 203 tree species that belong to two different functional types(deciduous and evergreen)for 2 years in a subtropical forest in China.The Weibull residence model was used to describe the different stages of litter decomposition by calculating the time to 10%,25%and 50%mass loss(Weibull t_(1/10),t_(1/4),and t_(1/2)respectively)and litter mean residence time(Weibull MRT).The resulting model parameters were used to explore the control of litter traits(e.g.,N,P,condensed tannins and tensile strength)over leaf litter decomposition across different decomposition stages.Results:The litter traits we measured had lower explanatory power for the early stages(Weibull t_(1/10)and t_(1/4))than for the later stages(Weibull t_(1/2)and MRT)of decomposition.The relative importance of different types of litter traits in influencing decomposition changed dramatically during decomposition,with physical traits exerting predominant control for the stages of Weibull t_(1/10)and MRT and nutrient-related traits for the stages of Weibull t_(1/4),and t_(1/2).Moreover,we found that litter decomposition of the early three stages(Weibull t_(1/10),t_(1/4),and t_(1/2))of the two functional types was controlled by different types of litter traits;that is,the litter decomposition rates of deciduous species were predominately controlled by nutrient-related traits,while the litter decomposition rates of evergreen species were mainly controlled by carbon-related traits.Conclusions:This study suggests that litter trait-decomposition linkages vary with decomposition stages and are strongly mediated by plant functional type,highlighting the necessity to consider their temporal dynamics and plant functional types for improving predictions of litter decomposition.
基金supported by the Major Program of the National Natural Science Foundation of China(No.32192434)the Fundamental Research Funds of Chinese Academy of Forestry(No.CAFYBB2019ZD001)the National Key Research and Development Program of China(2016YFD060020602).
文摘Estimating the volume growth of forest ecosystems accurately is important for understanding carbon sequestration and achieving carbon neutrality goals.However,the key environmental factors affecting volume growth differ across various scales and plant functional types.This study was,therefore,conducted to estimate the volume growth of Larix and Quercus forests based on national-scale forestry inventory data in China and its influencing factors using random forest algorithms.The results showed that the model performances of volume growth in natural forests(R^(2)=0.65 for Larix and 0.66 for Quercus,respectively)were better than those in planted forests(R^(2)=0.44 for Larix and 0.40 for Quercus,respectively).In both natural and planted forests,the stand age showed a strong relative importance for volume growth(8.6%–66.2%),while the edaphic and climatic variables had a limited relative importance(<6.0%).The relationship between stand age and volume growth was unimodal in natural forests and linear increase in planted Quercus forests.And the specific locations(i.e.,altitude and aspect)of sampling plots exhibited high relative importance for volume growth in planted forests(4.1%–18.2%).Altitude positively affected volume growth in planted Larix forests but controlled volume growth negatively in planted Quercus forests.Similarly,the effects of other environmental factors on volume growth also differed in both stand origins(planted versus natural)and plant functional types(Larix versus Quercus).These results highlighted that the stand age was the most important predictor for volume growth and there were diverse effects of environmental factors on volume growth among stand origins and plant functional types.Our findings will provide a good framework for site-specific recommendations regarding the management practices necessary to maintain the volume growth in China's forest ecosystems.
文摘There are many types of wetlands around the Chaohu Lake,and wetland biodiversity is rich. The protection of wetland biodiversity is of great significance for regional sustainable development. In this paper,the wetlands around the Chaohu Lake are taken as the research objects. Based on the investigation and analysis of the biodiversity in the wetlands,combing the threats to the biodiversity of the wetland around the Chaohu Lake at the present stage,the biodiversity protection countermeasures of the wetlands around the Chaohu Lake are put forward.
文摘The coal resources are abundant in Huainan City,but with development and utilization of coal mine,the water surface formed by mining subsidence increases gradually,and more and more people pay great attention on the research of the wetland in the subsidence area. Through on-site review,the status of the wetland resources is explored,and wetland ecosystem of the region is analyzed. In this paper,the red line delimitation,functional zoning,overall layout and basic engineering planning and design of Suocao Bay Wetland Park are carried out. The planning and design of Suocao Bay Wetland Park mean to provide new support for ecological protection,accelerate the ecological restoration in Maoji Experimental Area,vigorously carry forward the wetland culture,and make it become an important wetland demonstration base in coal mine subsidence area.
基金supported by the Key Program of the National Natural Science Foundation of China (Grant No. 30730076)
文摘Chemical components are the main factors affecting the mechanical properties of wood fibers. Lignin is one of the main components of wood cell walls and has a critical effect on the mechanical properties of paper pulp and wood fiber based composites. In this study, we carried out tensile tests on single mature latewood tracheids of Chi- nese fir (Cunninghamia lanciolata (Lamb.) Hook.), using three different delignified treatment methods to obtain different amounts of lignin. We applied single fiber tests to study the effect of the amount of lignin on mechanical tensile proper- ties of single wood fibers at the cellular level. The results show that in their dry state, the modulus of elasticity of single fi- bers decreased with the reduction in the amount of Iignin; even their absolute values were not high. The amount of lignin affects the tensile strength and elongation of single fibers considerably. Tensile strength and elongation of single fibers increase with a reduction in the amount of lignin.
基金This work is supported by the National Forestry and Grassland Administration/Beijing Open Fund of Key Laboratory of Bamboo and Rattan Science and Technology(Grant No.ICBR-2020-10)University Scientific Research Project of Anhui Province(Grant No.KJ2020A0130).
文摘Bamboo harvesting residues are wastes by-products of bamboo industries that contain holocellulose for about 63.14%to 70.71%,which often be discarded,incinerated or buried.In this study,carboxymethyl cellulose was prepared from bamboo harvesting residues(bamboo-branch and bamboo-tip)as raw materials.The chemical composition of bamboo harvesting residues,the viscosity and degree of substitution of carboxymethyl cellulose were determined.Carboxymethyl cellulose obtained was further characterized and compared by means of FTIR,SEM,XRD and TG.Results showed that under the optimized identical conditions,the viscosity and degree of substitution of carboxymethyl cellulose from bamboo-branch and bamboo-tip were 6.0 and 78.9 mPa·s,0.75 and 0.89,respectively.Carboxymethyl cellulose obtained from bamboo-tip displayed a lower crystallinity and a better thermal stability as compared to synthetic carboxymethyl cellulose obtained from bamboo-branch and bamboo-culm.
文摘Leaf area index (LAI) is a key parameter for studying global terrestrial ecology and environment and has great ecological significance. How to accurately measure and calculate structural parameters of trees has become an urgent matter. This paper reports the use of terrestrial laser scanning (TLS) as a measurement tool to achieve accurate LAI estimation through point cloud preprocessing measures, the LeWos algorithm, and voxel methods. The accuracy and feasibility of this indirect measurement method were explored. It is found that the single wood structure parameters extracted from TLS have a good linear relationship with manual measurement, and the extraction errors meet the requirements of real-scene conversion. The study also found when the voxel size is consistent with the minimum distance of the point cloud set by TLS instrument, it has a strong correlation with the measured value of canopy analyser. These results lay the foundation for conveniently and quickly obtaining structural parameters of trees, tree growth state detection, and canopy ecological benefit assessment.
文摘In order to improve hydrophobic characteristics which will affect the service performance of fast-growing poplar due to growing bacteria in the humid environment.In this study,a simple method was proposed to treat poplar via the high voltage electric field(HVEF)with copper as the electrode plate.Scanning electron microscope(SEM),Fourier transforms infrared spectroscopy(FTIR),X-ray diffraction(XRD)and contact angle tester were adopted to evaluate the surface morphology,surface group of poplar,crystallinity and wettability under HVEF.It was found by SEM that a large number of copper particles were uniformly attached to the surface of poplar.In all three sections,the weight percentage of the Cu element was accounting for more than half.The diffraction peaks of copper-containing compounds appeared in the(XRD).FTIR analysis confirmed that the reaction between copper and poplar took place.The surface contact angle of three sections of poplar increased in the following order:cross section<radial section<tangential section(increased by 34°,45°and 53°,respectively).An environmentfriendly and efficient method of HVEF treating fast-growing wood with copper as the electrode plate can promote its outdoor application.
基金Acknowledgments This work was funded by the State Key Laboratory of Integrated Management of Pest Insects and Rodents (Grant No. ChineselPM0904) and the National Nature Science Foundation of China (30800107, 30621003, 30525009). All experiments were done in China according to the rules of the ethical board for animal experiments, complying with the current laws of this country.
文摘We evaluated the attraction ofMonochamus alternatus Hope (Coleoptera: Cerambycidae), Dryocoetes luteus Blandford and Orthotomicus erosus Wollaston (Coleoptera: Curculionidae: Scolytinae) to multiple-funnel traps baited with the pine volatiles, ethanol and (+)-α-pinene and the bark beetle pheromones, ipsenol and ipsdienol. M. alternatus were attracted to traps baited with ethanol and (+)-α-pinene but not those baited with ipsdienol and ipsenol. Ipsdienol and ipsenol decreased catches ofM. alternatus in traps baited with ethanol and (+)-α-pinene. Traps baited with either binary combinations of ethanol and (+)-α-pinene or ipsdienol and ipsenol were attractive to D. luteus and O. erosus. The addition of ipsenol and ipsdienol to traps baited with ethanol and (+)-α-pinene synergized attraction of O. erosus but not D. luteus .
基金The National Natural Science Foundation of China(31130010)The Chinese Academy of Sciences(XDA05060500).
文摘Aims Terrestrial net primary production(NPP),the balance of gross primary production(GPP)and autotrophic respiration(AR),is a critical measure of carbon sequestration capacity for the Earth’s land surface.The aim of this study was to understand the spatio-temporal variability of NPP associated with GPP and AR in the Yangtze River Basin(YRB),China,from 2000 to 2009 during which the basin warmed significantly.Methods We first derived AR and carbon-use efficiency(CUE)from the improved Moderate Resolution Imaging Spectroradiometer GPP/NPP products(MOD17)and then conducted spatial analysis to quantify how NPP relates to GPP,AR and their relationship with key observed climate variables(temperature,precipitation and sunshine percentage)in the YRB during 2000–2009.Important Findings The spatial pattern of NPP in the YRB was predominantly determined by GPP and further modified by AR.Higher GPP and relatively low AR made the southern Jinshajiang sub-basin the most productive area in NPP in the YRB.A large portion of the YRB experienced a warmer and drier climate trend in the growing season during 2000–2009.In the upper reaches of the basin,possessing a relatively low temperature base,increases in temperature led to greater increases in GPP than those in AR,resulting in greater increased NPP.However,in the middle and lower reaches of the basin where the base temperature is relatively high,increases in temperature led to greater increases in AR than those in GPP,leading to decreases in NPP.Overall,86.7%of the vegetated area showed a consistent GPP and NPP trend through time with 71.3%of the vegetated area having a positive trend both in GPP and NPP,and the remaining 13.3%of vegetated areas showed an opposite trend in GPP and NPP,with positive GPP and negative NPP trajectories dominating(10.1%of vegetated area)the trend.Although climate warming generally had positive effects on vegetation growth in most areas of the basin,areas with increased NPP(74.5%)were less extensive than those with increased GPP(81.4%)due to the wider increase in AR(82.2%).During the study period,increases in AR offset 62%of the total increased GPP,leading to a substantial decline of CUE,particularly in the warmer lower altitude regions in the southeast.Our work reveals the diverse responses of NPP associated with GPP and AR as the climate warms and generally suggests that NPP in the middle and lower sub-basins in the YRB is more sensitive to future climate warming.These findings enhance our understanding of terrestrial ecosystem carbon dynamics in response to global warming and provide a scientific basis for managing ecosystem productivity in the YRB,China.
基金supported by the National Science and Technology Support Program (No.2009BADA6B06-1)Anhui Major Science and Technology projects (No.08010302073)
文摘BURP domain-containing proteins have a conserved structure and are found extensively in plants.The functions of the proteins in this family are diverse,but remain unknown in Populus trichocarpa.In the present study,a complete genome of P.trichocarpa was analyzed bioinformatically.A total of 18 BURP family genes,named PtBURPs,were identified and characterized according to their physical positions on the P.trichocarpa chromosomes.A phylogenetic tree was generated from alignments of PtBURP protein sequences,while phylogenetic relationships were also examined between PtBURPs and BURP family genes in other plants,including rice,soybean,maize and sorghum.BURP genes in P.trichocarpa were classified into five classes,namely PG1β-like,BNM2-like,USP-like,RD22-like and BURP V.The multiple expectation maximization for motif elicitation(MEME) and multiple protein sequence alignments of PtBURPs were also performed.Results from the transcript level analyses of 10 PtBURP genes under different stress conditions revealed the expression patterns in poplar and led to a discussion on genome duplication and evolution,expression profiles and function of PtBURP genes.