The Tongbai Mountains is an ecologically sensi-tive region and the northern boundary of Pinus massoniana Lamb.To analyze the effect of different microenvironments on tree growth response to climate factors,we develope...The Tongbai Mountains is an ecologically sensi-tive region and the northern boundary of Pinus massoniana Lamb.To analyze the effect of different microenvironments on tree growth response to climate factors,we developed standard chronologies for earlywood width(EWW),late-wood width(LWW),and total ring width(TRW)of P.massoniana at two sampling sites on slopes with different orientations,then analyzed characteristics of the chronolo-gies and their correlations with climate variables from five stations in the region and with a regional normalized differ-ence vegetation index(NDVI).Statistical results showed that the TRW/EWW/LWW chronology consistency and charac-teristics(mean sensitivity,signal to noise ratio,expressed population signal)for trees growing on the southeastern slope were much higher than for trees on the northeastern slope.Correlations indicated that temperature in current March and August has a significant positive effect on TRW/EWW/LWW formation,and the effect on the northeastern slope was weaker than on the southeastern slope.Compared to temperature,precipitation has more complicated effects on tree growth,but the effect on the northeastern slope was also generally weaker than on the southeastern slope.Step-wise linear regression analyses showed that temperature in August was the main limiting factor at the two sampling sites.Similarly,the response of tree growth on the southeast-ern slope as determined by the NDVI is better than on the northeastern slope,and the TRW/EWW/LWW chronologies for the southeastern slope explained over 50%of the total NDVI variances in June.Overall,the results indicate that the difference in the climate response of P.massoniana at two sampling sites is clearly caused by differences in the microenvironment,and such differences should be properly considered in future studies of forest dynamics and climate reconstructions.展开更多
Plant tolerance to aluminum(Al)toxicity can be enhanced by an ectomycorrhizal(ECM)fungus through biological filtering or physical blockage.To understand the roles of ECM colonization in Al absorption with regard to Al...Plant tolerance to aluminum(Al)toxicity can be enhanced by an ectomycorrhizal(ECM)fungus through biological filtering or physical blockage.To understand the roles of ECM colonization in Al absorption with regard to Al tolerance,Pinus massoniana seedlings were inoculated with either Lactarius deliciosus(L.:Fr.)Gray isolate 2 or Pisolithus tinctorius(Pers.)Coker et Couch isolate 715 and cultivated in an acid yellow soil with or without 1.0 mM Al^(3+)irrigation for 10 weeks.Biomass production,Al bioaccumulation and transport in seedlings colonized by the two ECM fungi were compared,and the three absorption kinetics(pseudo-first order,pseudo-second order and intraparticle diffusion)models used to evaluate variances in root Al^(3+)absorption capacity.Results show that both fungi increased aboveground biomass and Al tolerance of P.massoniana seedlings,but L.deliciosus 2 was more effective than P.tinctorius 715.Lower Al absorption capacity,fewer available active sites and decreased affinity and boundary layer thickness for Al^(3+),and higher Al accumulation and translocation contributed to the increased Al tolerance in the ECM-inoculated seedlings.These results advance our understanding of the mechanisms and strategies in plant Alto lerance conferred by ECM fungi and show that inoculation with L.deliciosus will better enhance Al tolerance in P.massoniana seedlings used for forest plantation and ecosystem restoration in acidic soils,particularly in Southwest China and similar soils worldwide.展开更多
量化植物地上部和地下部元素含量对于理解和预测植物养分平衡如何响应大气氮沉降的变化至关重要。通过盆栽试验研究了氮沉降增加背景下外生菌根真菌对马尾松幼苗营养元素的影响。对马尾松幼苗进行了接种两种外生菌根真菌:(彩色豆马勃(Pi...量化植物地上部和地下部元素含量对于理解和预测植物养分平衡如何响应大气氮沉降的变化至关重要。通过盆栽试验研究了氮沉降增加背景下外生菌根真菌对马尾松幼苗营养元素的影响。对马尾松幼苗进行了接种两种外生菌根真菌:(彩色豆马勃(Pisolithus tinctorius,Pt)与厚环乳牛肝菌(Suillus grevillei,Sg))以及4种氮素浓度添加:0 kg N hm^(-2)a^(-1)(N0)、正常氮沉降30 kg N hm^(-2)a^(-1)(N30)、中度氮沉降60 kg N hm^(-2)a^(-1)(N60)、重度氮沉降90 kg N hm^(-2)a^(-1)(N90),共12个处理,测定了马尾松地上部和地下部大量元素和微量元素的含量。结果表明:施氮改变了营养元素在马尾松幼苗地上部和地下部的含量,马尾松幼苗磷(P)、钙(Ca)、铁(Fe)、锰(Mn)等元素均在N60时达到临界值,而当输入的量超过了马尾松对氮的需求时,氮沉降会使马尾松营养元素含量较最适浓度时降低,地上部碳(C)随施氮浓度的升高先升高后降低,N随施氮浓度的升高而升高,根系和叶片钾(K)、Ca、镁(Mg)均随施氮浓度的升高而降低,施氮也降低了根系C及微量元素的含量。但在同一施氮浓度下,接种外生菌根真菌(EMF)后能够提高大多数元素的含量,N90时接种厚环乳牛肝菌(Sg)和彩色豆马勃(Pt)的叶片N含量与对照相比分别提高112.6%和138.6%,根系N含量分别提高73.1%、71.6%;N60时接种Sg和Pt的植株叶片P含量比不施氮未接种对照分别提高了166.3%、132.9%,根系P含量分别提高了40.8%、38.5%。EMF能够维持植物养分平衡,从而降低高施氮量对植物的影响效果。这为未来气候变化情景中氮沉降增加下接种EMF可以调节植物元素含量,从而达到更适应环境的元素平衡来促进生长提供理论依据。展开更多
Because of global climate change, it is necessary to add forest biomass estimation to national forest resource monitoring. The biomass equations developed for forest biomass estimation should be compatible with volume...Because of global climate change, it is necessary to add forest biomass estimation to national forest resource monitoring. The biomass equations developed for forest biomass estimation should be compatible with volume equations. Based on the tree volume and aboveground biomass data of Masson pine (Pinus massoniana Lamb.) in southern China, we constructed one-, two- and three-variable aboveground biomass equations and biomass conversion functions compatible with tree volume equations by using error-in-variable simultaneous equations. The prediction precision of aboveground biomass estimates from one variable equa- tion exceeded 95%. The regressions of aboveground biomass equations were improved slightly when tree height and crown width were used together with diameter on breast height, although the contributions to regressions were statistically insignificant. For the biomass conversion function on one variable, the conversion factor decreased with increasing diameter, but for the conversion function on two variables, the conversion factor increased with increasing diameter but decreased with in- creasing tree height.展开更多
Thinning is an important activity employed in forest management. To date, studies have mainly focused on the effects of thinning on the growth of trees during the same thinning period. In this study, plantation Pinus ...Thinning is an important activity employed in forest management. To date, studies have mainly focused on the effects of thinning on the growth of trees during the same thinning period. In this study, plantation Pinus massoniana Lamb. near maturity were thinned at varying intensities and an economically important species, Cinnamomum cassia Presl., was planted beneath the thinned canopy. The aim of the study was to explore the effects of the extent of thinning on the essential oil content and its components of C. cassia in different parts of the plant, as well as the economic feasibility of the P. massoniana-C.cassia management model. Thinning significantly reduced the oil yield in the bark and branches of C. cassia, but hardly impacted the oil yield from C. cassia leaves compared with pure C. cassia forest(CK). Among the different thinning treatments, both light(T.4) and extensive(T.1)thinning reduced the oil yield of C. cassia bark and new branches. The concentrations of the main aldehydes differed in different parts of the plant and were affected by the extent of thinning. The influence on cinnamaldehyde in the bark was minor, but was much greater in the branches and leaves. Both the oil yield and content of cinnamaldehyde showed that moderate(T.3) thinning was more favorable than other thinning models. These results not only provide a potentially promising model for the transformation of low-yield artificial pure forests of P. massoniana in the future, but also offer a reference for the management of artificial mixed stands.展开更多
Oxygen sensing technology was employed to study the rapid methods for seed vigor assessment of Chinese fir (Cunninghamia lanceolata) and Masson pine (Pinus massoniana). Firstly, seeds of five lots were performed u...Oxygen sensing technology was employed to study the rapid methods for seed vigor assessment of Chinese fir (Cunninghamia lanceolata) and Masson pine (Pinus massoniana). Firstly, seeds of five lots were performed using accelerated aging (AA) into three vigor levels. Then, four oxygen sensing indices, including increased metabolism time (IMT), oxygen metabolism rate (OMR), critical oxygen pressure (COP), relative germination time (RGT) and the control indiees such as labora- tory germination indices, dehydrogenase activity (DA), and electrical conductivity (EC) were analyzed by the tests of 15 samples. The results of correlation analysis between these indices and field emergence per- formances based on two-year and two-spot data showed that RGT and OMR should be indicated as the optimal oxygen sensing indices to rap- idly and automatically evaluate seed vigor of Chinese fir and Masson pine, respectively. On the basis, one-variable linear regression equations were built to forecast their field emergence performances by the two oxygen sensing indices.展开更多
To understand the decomposition characteristics of Pinus massoniana foliar litter and the degradation of its refractory compounds in plantations under five canopy densities,a litter bag experiment over a decomposition...To understand the decomposition characteristics of Pinus massoniana foliar litter and the degradation of its refractory compounds in plantations under five canopy densities,a litter bag experiment over a decomposition time of 392 days was carried out.The results show that canopy density significantly affected decomposition rates of litter and degradation rate of lignin and cellulose.Litter decomposition rates decreased significantly with decreasing canopy density.Both lignin and cellulose degradation rates were lower with canopy densities of 0.62 and 0.74 as compared with the three other densities.Lignin and cellulose losses were more rapid in the first 118 days.Soil fauna had significant impacts on litter decomposition and the degradation of refractory compounds.Canopy density had significant effects on factors such as soil properties and soil fauna community structure,which could be conducive to the decomposition of litter and the degradation of litter recalcitrant components.Canopy density between 0.6 and 0.7 might be a favorable management practice promoting litter decomposition and beneficial for the sustainable development of P.massoniana plantations.展开更多
Forest gaps are important in forest dynamics and management, but little is known about how soil fauna influence the degradation of recalcitrant litter components in different-sized forest gaps. This investigation uses...Forest gaps are important in forest dynamics and management, but little is known about how soil fauna influence the degradation of recalcitrant litter components in different-sized forest gaps. This investigation uses litterbags with two different mesh sizes (0.04 and 3 mm) to control the meso- and microfauna entering the bags to quantify the contribution of soil fauna to the degradation of recalcitrant components (including condensed tannins, total phenol, lignin and cellulose) during litter decomposition. The experiment was conducted in seven different forest gap sizes in Pinus massoniana plantations over 1 year. One closed-canopy site (CC) and forest gap sizes of 100, 225, 400, 625, 900, 1225 and 1600 m^2 were created in a P. massoniana plantation in the Sichuan basin of China;the CC was treated as the control. Cinnamomum camphora foliage from local native trees was used in all forest gap experiments. We found the following:(1) Gap size had significant effects on the degradation rates (E) of condensed tannins and lignin and on the contributions of soil fauna;medium-sized gaps also presented high degradation rates. Soil fauna obviously contributed to the degradation of recalcitrant foliar litter components in medium-sized gaps.(2) The highest contribution to degradation (40.98%) was recorded for lignin, and the lowest contribution (0.29%) was recorded for condensed tannins. The results indicate that medium-sized gaps (900 m^2) were conducive to the degradation of recalcitrant litter components by soil fauna.展开更多
Myeloblastosis(MYB) proteins constitute one of the largest transcription factor(TF) families in plants and play crucial roles in regulating plant physiological and biochemical processes, including adaptation to divers...Myeloblastosis(MYB) proteins constitute one of the largest transcription factor(TF) families in plants and play crucial roles in regulating plant physiological and biochemical processes, including adaptation to diverse abiotic stresses. These TF families contain highly conserved MYB repeats(1 R, R2 R3, 3 R and 4 R) at the N-terminus. Roles for MYB TFs have been reported in response to such stresses as dehydration, salt, cold, and drought. The characterization of Masson pine(Pinus massoniana) MYB TFs are reported, including the analysis of MYB TFs expression in seedlings under controlled conditions and two different phosphate(Pi) deficient treatments. By searching for conserved MYB motifs in full transcriptomic RNA sequencing data for P. massoniana, 59 sequences were identified as MYB TFs. Conserved domainstructures and comparative functional and phylogenetic relationships of these MYB TFs with those in Arabidopsis were assessed using various bioinformatics tools. Based on microarray analysis, P. massoniana MYB genes exhibited different expression patterns under the two Pi deficiency conditions. Genes encoding MYB TFs that showed increased expression under critical Pi deficiency were identified, and some MYBs were differentially expressed only under conditions of severe Pi starvation. These results are useful for the functional characterization of MYB TFs that may be involved in the response to Pi deficiency and play divergent roles in plants.展开更多
Environmental heterogeneity is a constant presence in the natural world that significantly affects plant behavior at a variety of levels of complexity. In order to estimate the spatial pattern of fine root biomass in ...Environmental heterogeneity is a constant presence in the natural world that significantly affects plant behavior at a variety of levels of complexity. In order to estimate the spatial pattern of fine root biomass in the Three Gorges Reservoir Area, the spatial heterogeneity of fine root biomass in the upper layer of soils (0-10 cm) in three Mas- son pine (Pinus massoniana) stands in the Three Gorges Reservoir Area, China, was studied in 30 m x 30 m plots with geostatistical analysis. The results indicate that 1) both the live and dead fine root biomass of stand 2 were less than those of other stands, 2) the spatial variation of fine roots in the three stands was caused together by structural and ran- dom factors with moderate spatial dependence and 3) the magnitude of spatial heterogeneity of live fine roots ranked as: stand 3 〉 stand 1 〉 stand 2, while that of dead fine roots was similar in the three stands. These findings suggested that the range of spatial autocorrelation for fine root biomass varied considerably in the Three Gorges Reservoir Area, while soil properties, such as soil bulk density, organic matter and total nitrogen, may exhibit great effect on the spatial distribution of fine roots. Finally, we express our hope to be able to carry out further research on the quantitative relation- ship between the spatial heterogeneous patterns of plant and soil properties.展开更多
This study addresses the increasing demand for large-diameter production timber,and considers the time and space variability of half-sib families of Pinus massoniana.Height,diameter at breast height(DBH)and timber vol...This study addresses the increasing demand for large-diameter production timber,and considers the time and space variability of half-sib families of Pinus massoniana.Height,diameter at breast height(DBH)and timber volume of 440 open-pollinated half-sib progeny families were investigated in 14 progeny trials in different years and production regions.An evaluation of the genetic variation of all half-sib families was carried out during the sustainable rapid growth period and individual volumes were characterized as a major index.ANOVA analysis showed that there was considerable variance in the growth traits of most families in different years and on different sites.The variations caused by temporal and spatial changes of the mating system required three selection methods for analysis.The results show that there were differences among the heritabilities of different growth traits by different halfsib progenies.Average heritability values of height,DBH and volume were 0.33,0.34 and 0.36,respectively.Fortyfive superior families were selected in every progeny test,12 were selected in progeny trials by different years and five in different habitat progeny trials.Three superior families(Gui GC553A,Gui GC414A and Gui GC431A)were selected,although in different years and production regions.The genetic gains of timber volume of these selected r families ranged from 1.20 to 47.00%,which could provide a foundation for superior wood property selection and serve as material for seed improvement and extension in surrounding areas.展开更多
AIM: To study the effects of Pinus massoniana bark extract (PMBE) on cell proliferation and apoptosis of human hepatoma BEL-7402 cells and to elucidate its molecular mechanism.METHODS: BEL-7402 cells were incubated wi...AIM: To study the effects of Pinus massoniana bark extract (PMBE) on cell proliferation and apoptosis of human hepatoma BEL-7402 cells and to elucidate its molecular mechanism.METHODS: BEL-7402 cells were incubated with various concentrations (20-200 μg/mL) of PMBE for different periods of time. After 48 h, cell proliferation was determined by 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis was evaluated by morphological observation, agarose gel electrophoresis,and flow cytometry analysis. Possible molecular mechanisms were primarily explored through immunohistochemical staining.RESULTS: PMBE (20-200 μg/mL) significantly suppressed BEL-7402 cell proliferation in a time- and dose-dependent manner. After treatment of BEL-7402 cells with 160 μg/mL PMBE for 24, 48, or 72 h, a typical apoptotic 'DNA ladder'was observed using agarose gel electrophoresis. Nuclear condensation and boundary aggregation or split, apoptotic bodies were seen by fluorescence and electron microscopy.Sub-G1 curves were displayed by flow cytometry analysis.PMBE decreased the expression levels of Bcl-2 protein in a time-dependent manner after treatment of cells with 160 μg/mL PMBE.CONCLUSION: PMBE suppresses proliferation of BEL-7402 cells in a time- and dose-dependent manner and induces cell apoptosis by possibly downregulating the expression of the bcl-2 gene.展开更多
[Objectives]This study was conducted to reveal the characteristics of nutrient absorption and accumulation in Pinus massoniana plantations in Northwestern Guangxi.[Methods]Based on field investigation and indoor analy...[Objectives]This study was conducted to reveal the characteristics of nutrient absorption and accumulation in Pinus massoniana plantations in Northwestern Guangxi.[Methods]Based on field investigation and indoor analysis,the contents,accumulation and annual net accumulation of five nutrient elements(N,P,K,Ca and Mg)in a mature P.massoniana plantation(26-year-old)in Nandan County,Guangxi Province were studied.[Results]The contents of nutrient elements in different organs of the mature P.massoniana plantation were the highest in the leaves,followed by the bark,branch and root,and the lowest in the stem.In general,among the contents of the five elements in different organs,N content was the highest,followed by K or Ca,and P and Mg were the lowest.The total accumulation of nutrient elements in the 26-year-old mature P.massoniana plantation in northwestern Guangxi was 1 384.05 kg/hm^2.Among the different structural levels of the stand,the tree layer had the highest accumulation of nutrient elements,which was 1 198.41 kg/hm^2,accounting for 86.59%of the total accumulation of nutrients in the plantation,and the accumulation of nutrients in other layers from the largest to the smallest was the litter layer(91.97 kg/hm^2),herb layer(49.86 kg/hm^2)and shrub layer(43.92 kg/hm^2),accounting for 3.17%,3.60%and 6.64%of the total nutrient accumulation of the plantation,respectively.The annual net accumulation of nutrient elements in the tree layer of the mature P.massoniana plantation was 46.09 kg/(hm^2·a),and the order of the annual net accumulation of different nutrient elements followed N>K>Ca>Mg>P;and the accumulation of 1 t of dry matter needed 6.37 kg of the five nutrients.[Conclusions]This study provides a scientific basis for the rational management of P.massoniana plantations,especially forest soil management.展开更多
When pine trees are invaded by pine wilt diseases, the severely infected pine trees will die and fall down, or they will be removed when found to be damaged by the disease. It gives rise to the invasion of other speci...When pine trees are invaded by pine wilt diseases, the severely infected pine trees will die and fall down, or they will be removed when found to be damaged by the disease. It gives rise to the invasion of other species in these empty niches originally oc- cupied by pine trees, i.e., competing surrounding trees or understory shrubs will invade the empty niches during the following years. As a result, the spatial distribution and pattern of the main tree species in a pine forest will change, and a niche variety in the main population will occur. In the end, the direction of the succession and restoration of the pine forest ecosystem will be affected. In our study, a Pinus massoniana forest with the dominant shrub, Pleioblastus amarus, was invaded by pine wood nematode and was clear cut. Selecting this community as our research object, we studied the effect of the invasion of the pine wood nematode on the growth of the dominant shrub, P. amarus, in this Pinus massoniana forest. Our results show that, after the attacked pine trees were removed, the niche was occupied by Pleioblastus amarus and other shrubs, which benefited the growth ofP. amarus to its climax. Growth of P. amarus at the climax stage was greater compared with the unhealthy pine forest and the control group.展开更多
Geranylgeranyl pyrophosphate synthetase(GGPPS) has gained increasing attention as a key enzyme in terpene analysis.We designed specific primers based on plant GGPPS homologs and used reverse transcription polymerase c...Geranylgeranyl pyrophosphate synthetase(GGPPS) has gained increasing attention as a key enzyme in terpene analysis.We designed specific primers based on plant GGPPS homologs and used reverse transcription polymerase chain reaction(RT-PCR) to obtain and identify Pin GGPPS,a GGPPS gene sequence from Pinus massoniana,using bioinformatics tools.Quantitative PCR analysis of Pin GGPPS expression levels in roots,pine needles,immature stems,and semilignified stems from 6-month-old P.massoniana showed that expression levels of Pin GGPPS were highest in pine needles,followed by immature stems and semilignified stems,and lowest in roots.When we examined the correlation between Pin GGPPS gene expression levels and resin productivity in 20 adult plants for 28 successive days,Pin GGPPS expression levels presented a substantially linear distribution when plotted against their corresponding resin yields.In summary,we characterized the gene Pin GGPPS for the first time in P.massoniana,and established a correlation between Pin GGPPS gene expression levels and resin productivity,suggesting the importance of theory and production practice for P.massoniana.展开更多
Pine wilt disease(PWD)is a devastating disease affecting the growth of Pinus massoniana,often leading to withering and death.To reveal the changes involved during disease progression,we investigated the mRNA expressio...Pine wilt disease(PWD)is a devastating disease affecting the growth of Pinus massoniana,often leading to withering and death.To reveal the changes involved during disease progression,we investigated the mRNA expression profile of P.massoniana infested by Bursaphelenchus xylophilus.The infestation resulted in the downregulation of genes involved in interactions with pathogenic pathways such as disease resistance gene,CC-NBS-LRR resistancelike protein,and the gene encoding a putative nematode resistance protein.Increased infestation pressure(number of nematodes inoculated)caused a continuous decline in the gene expression of stem samples.An infestation of P.massoniana also resulted in a pathway enrichment of genes involved in phenylpropanoid metabolism and flavonoid biosynthesis,which in turn reduced the levels of total phenols and total flavonoids.A downregulation of auxin responsive family protein was observed in infested samples,which resulted in a suppression of plant growth.Thus,upon B.xylophilus infestation,a downregulation of genes associated with the recognition of pathogens,PWD resistance,and growth regulation was observed in P.massoniana,together with a decrease in the levels of phytoalexinlike secondary substances,all of which resulted in withering and ultimately death of P.massoniana.展开更多
The ecological effects of eucalypt plantations(EPs) have garnered increasing attention.To understand their effect on soil quality at a landscape scale,and to determine whether soil quality parameters differ due to d...The ecological effects of eucalypt plantations(EPs) have garnered increasing attention.To understand their effect on soil quality at a landscape scale,and to determine whether soil quality parameters differ due to different stand types,we evaluated soil characteristics in twenty-one groups of EPs,Pinus massoniana Lamb.plantations(PMPs) and natural broadleaved forests(NBFs)across Guangdong Province,China.Both the physical characteristics of soil hydrology and the properties of soil nutrients in A and B horizons were determined.Results showed that,compared to NBFs,EPs and PMPs produced a shallower litter layer,reduced canopy density,higher soil bulk density,significantly lower total porosity,non-capillary porosity,total water volume,and hygroscopic water in the A horizon(P〈0.05).Moreover,total N,available K,and soil organic carbon(SOC) in EPs and PMPs were significantly lower than in NBFs.EPs and PMPs did not differ significantly in N,P or K content,but PMPs had significantly lower SOC and boron in the A horizon than EPs.Low p H and poor capacity to buffer acidification generally occurred in all cover types.Both EPs and PMPs showed a decline in soil properties relative to NBFs,but EPs and PMPs exhibited no significant difference.These results indicate that actions are needed to ameliorate the potential negative effects on soil quality in forestry plantations.展开更多
基金This study was supported by National Key Research and Development Program of China(No.2018YFA0605601)National Natural Science Foundation of China(No.42077417 and41671042).
文摘The Tongbai Mountains is an ecologically sensi-tive region and the northern boundary of Pinus massoniana Lamb.To analyze the effect of different microenvironments on tree growth response to climate factors,we developed standard chronologies for earlywood width(EWW),late-wood width(LWW),and total ring width(TRW)of P.massoniana at two sampling sites on slopes with different orientations,then analyzed characteristics of the chronolo-gies and their correlations with climate variables from five stations in the region and with a regional normalized differ-ence vegetation index(NDVI).Statistical results showed that the TRW/EWW/LWW chronology consistency and charac-teristics(mean sensitivity,signal to noise ratio,expressed population signal)for trees growing on the southeastern slope were much higher than for trees on the northeastern slope.Correlations indicated that temperature in current March and August has a significant positive effect on TRW/EWW/LWW formation,and the effect on the northeastern slope was weaker than on the southeastern slope.Compared to temperature,precipitation has more complicated effects on tree growth,but the effect on the northeastern slope was also generally weaker than on the southeastern slope.Step-wise linear regression analyses showed that temperature in August was the main limiting factor at the two sampling sites.Similarly,the response of tree growth on the southeast-ern slope as determined by the NDVI is better than on the northeastern slope,and the TRW/EWW/LWW chronologies for the southeastern slope explained over 50%of the total NDVI variances in June.Overall,the results indicate that the difference in the climate response of P.massoniana at two sampling sites is clearly caused by differences in the microenvironment,and such differences should be properly considered in future studies of forest dynamics and climate reconstructions.
基金supported by the National Natural Science Foundation of China (31570599 and 32171753)。
文摘Plant tolerance to aluminum(Al)toxicity can be enhanced by an ectomycorrhizal(ECM)fungus through biological filtering or physical blockage.To understand the roles of ECM colonization in Al absorption with regard to Al tolerance,Pinus massoniana seedlings were inoculated with either Lactarius deliciosus(L.:Fr.)Gray isolate 2 or Pisolithus tinctorius(Pers.)Coker et Couch isolate 715 and cultivated in an acid yellow soil with or without 1.0 mM Al^(3+)irrigation for 10 weeks.Biomass production,Al bioaccumulation and transport in seedlings colonized by the two ECM fungi were compared,and the three absorption kinetics(pseudo-first order,pseudo-second order and intraparticle diffusion)models used to evaluate variances in root Al^(3+)absorption capacity.Results show that both fungi increased aboveground biomass and Al tolerance of P.massoniana seedlings,but L.deliciosus 2 was more effective than P.tinctorius 715.Lower Al absorption capacity,fewer available active sites and decreased affinity and boundary layer thickness for Al^(3+),and higher Al accumulation and translocation contributed to the increased Al tolerance in the ECM-inoculated seedlings.These results advance our understanding of the mechanisms and strategies in plant Alto lerance conferred by ECM fungi and show that inoculation with L.deliciosus will better enhance Al tolerance in P.massoniana seedlings used for forest plantation and ecosystem restoration in acidic soils,particularly in Southwest China and similar soils worldwide.
文摘量化植物地上部和地下部元素含量对于理解和预测植物养分平衡如何响应大气氮沉降的变化至关重要。通过盆栽试验研究了氮沉降增加背景下外生菌根真菌对马尾松幼苗营养元素的影响。对马尾松幼苗进行了接种两种外生菌根真菌:(彩色豆马勃(Pisolithus tinctorius,Pt)与厚环乳牛肝菌(Suillus grevillei,Sg))以及4种氮素浓度添加:0 kg N hm^(-2)a^(-1)(N0)、正常氮沉降30 kg N hm^(-2)a^(-1)(N30)、中度氮沉降60 kg N hm^(-2)a^(-1)(N60)、重度氮沉降90 kg N hm^(-2)a^(-1)(N90),共12个处理,测定了马尾松地上部和地下部大量元素和微量元素的含量。结果表明:施氮改变了营养元素在马尾松幼苗地上部和地下部的含量,马尾松幼苗磷(P)、钙(Ca)、铁(Fe)、锰(Mn)等元素均在N60时达到临界值,而当输入的量超过了马尾松对氮的需求时,氮沉降会使马尾松营养元素含量较最适浓度时降低,地上部碳(C)随施氮浓度的升高先升高后降低,N随施氮浓度的升高而升高,根系和叶片钾(K)、Ca、镁(Mg)均随施氮浓度的升高而降低,施氮也降低了根系C及微量元素的含量。但在同一施氮浓度下,接种外生菌根真菌(EMF)后能够提高大多数元素的含量,N90时接种厚环乳牛肝菌(Sg)和彩色豆马勃(Pt)的叶片N含量与对照相比分别提高112.6%和138.6%,根系N含量分别提高73.1%、71.6%;N60时接种Sg和Pt的植株叶片P含量比不施氮未接种对照分别提高了166.3%、132.9%,根系P含量分别提高了40.8%、38.5%。EMF能够维持植物养分平衡,从而降低高施氮量对植物的影响效果。这为未来气候变化情景中氮沉降增加下接种EMF可以调节植物元素含量,从而达到更适应环境的元素平衡来促进生长提供理论依据。
基金the National Biomass Modeling Program for Continuous Forest Inventory(NBMP-CFI) funded by the State Forestry Administration of China
文摘Because of global climate change, it is necessary to add forest biomass estimation to national forest resource monitoring. The biomass equations developed for forest biomass estimation should be compatible with volume equations. Based on the tree volume and aboveground biomass data of Masson pine (Pinus massoniana Lamb.) in southern China, we constructed one-, two- and three-variable aboveground biomass equations and biomass conversion functions compatible with tree volume equations by using error-in-variable simultaneous equations. The prediction precision of aboveground biomass estimates from one variable equa- tion exceeded 95%. The regressions of aboveground biomass equations were improved slightly when tree height and crown width were used together with diameter on breast height, although the contributions to regressions were statistically insignificant. For the biomass conversion function on one variable, the conversion factor decreased with increasing diameter, but for the conversion function on two variables, the conversion factor increased with increasing diameter but decreased with in- creasing tree height.
基金supported by the key technology for the management of artificial multi-layers plantation(2006–2009)the interspecific nitrogen transfer behaviors and root interaction mechanism of Eucalyptus and Dalbergia odorifera T.Chen(31460196)the key technology for the management of Strified Mixed Stands of Pinus massoniana and Cinnamomum cassia(2014–2024)
文摘Thinning is an important activity employed in forest management. To date, studies have mainly focused on the effects of thinning on the growth of trees during the same thinning period. In this study, plantation Pinus massoniana Lamb. near maturity were thinned at varying intensities and an economically important species, Cinnamomum cassia Presl., was planted beneath the thinned canopy. The aim of the study was to explore the effects of the extent of thinning on the essential oil content and its components of C. cassia in different parts of the plant, as well as the economic feasibility of the P. massoniana-C.cassia management model. Thinning significantly reduced the oil yield in the bark and branches of C. cassia, but hardly impacted the oil yield from C. cassia leaves compared with pure C. cassia forest(CK). Among the different thinning treatments, both light(T.4) and extensive(T.1)thinning reduced the oil yield of C. cassia bark and new branches. The concentrations of the main aldehydes differed in different parts of the plant and were affected by the extent of thinning. The influence on cinnamaldehyde in the bark was minor, but was much greater in the branches and leaves. Both the oil yield and content of cinnamaldehyde showed that moderate(T.3) thinning was more favorable than other thinning models. These results not only provide a potentially promising model for the transformation of low-yield artificial pure forests of P. massoniana in the future, but also offer a reference for the management of artificial mixed stands.
基金supported by National Natural Science Foundation of China (No. 30800890)
文摘Oxygen sensing technology was employed to study the rapid methods for seed vigor assessment of Chinese fir (Cunninghamia lanceolata) and Masson pine (Pinus massoniana). Firstly, seeds of five lots were performed using accelerated aging (AA) into three vigor levels. Then, four oxygen sensing indices, including increased metabolism time (IMT), oxygen metabolism rate (OMR), critical oxygen pressure (COP), relative germination time (RGT) and the control indiees such as labora- tory germination indices, dehydrogenase activity (DA), and electrical conductivity (EC) were analyzed by the tests of 15 samples. The results of correlation analysis between these indices and field emergence per- formances based on two-year and two-spot data showed that RGT and OMR should be indicated as the optimal oxygen sensing indices to rap- idly and automatically evaluate seed vigor of Chinese fir and Masson pine, respectively. On the basis, one-variable linear regression equations were built to forecast their field emergence performances by the two oxygen sensing indices.
基金supported by the National Natural Science Foundation of China(Grant Number 31370628)the National Science and Technology Support Project of China(Grant Number2011BAC09B05)the Sichuan Provincial Science and Technology Support Project(Grant Number 12ZC0017)
文摘To understand the decomposition characteristics of Pinus massoniana foliar litter and the degradation of its refractory compounds in plantations under five canopy densities,a litter bag experiment over a decomposition time of 392 days was carried out.The results show that canopy density significantly affected decomposition rates of litter and degradation rate of lignin and cellulose.Litter decomposition rates decreased significantly with decreasing canopy density.Both lignin and cellulose degradation rates were lower with canopy densities of 0.62 and 0.74 as compared with the three other densities.Lignin and cellulose losses were more rapid in the first 118 days.Soil fauna had significant impacts on litter decomposition and the degradation of refractory compounds.Canopy density had significant effects on factors such as soil properties and soil fauna community structure,which could be conducive to the decomposition of litter and the degradation of litter recalcitrant components.Canopy density between 0.6 and 0.7 might be a favorable management practice promoting litter decomposition and beneficial for the sustainable development of P.massoniana plantations.
基金supported by the National Natural Science Foundation of China(Grant Number 31370628)the National Science and Technology Support Project of China(Grant Number2011BAC09B05)the Sichuan Provincial Science and Technology Support Project(Grant Number 12ZC0017)
文摘Forest gaps are important in forest dynamics and management, but little is known about how soil fauna influence the degradation of recalcitrant litter components in different-sized forest gaps. This investigation uses litterbags with two different mesh sizes (0.04 and 3 mm) to control the meso- and microfauna entering the bags to quantify the contribution of soil fauna to the degradation of recalcitrant components (including condensed tannins, total phenol, lignin and cellulose) during litter decomposition. The experiment was conducted in seven different forest gap sizes in Pinus massoniana plantations over 1 year. One closed-canopy site (CC) and forest gap sizes of 100, 225, 400, 625, 900, 1225 and 1600 m^2 were created in a P. massoniana plantation in the Sichuan basin of China;the CC was treated as the control. Cinnamomum camphora foliage from local native trees was used in all forest gap experiments. We found the following:(1) Gap size had significant effects on the degradation rates (E) of condensed tannins and lignin and on the contributions of soil fauna;medium-sized gaps also presented high degradation rates. Soil fauna obviously contributed to the degradation of recalcitrant foliar litter components in medium-sized gaps.(2) The highest contribution to degradation (40.98%) was recorded for lignin, and the lowest contribution (0.29%) was recorded for condensed tannins. The results indicate that medium-sized gaps (900 m^2) were conducive to the degradation of recalcitrant litter components by soil fauna.
基金funded by the Natural Science Foundation of Guizhou Province,P.R.China(20161051)the National Natural Science Foundation of China(31660185)the Doctoral Fund Project of Guizhou University,P.R.China(201464)。
文摘Myeloblastosis(MYB) proteins constitute one of the largest transcription factor(TF) families in plants and play crucial roles in regulating plant physiological and biochemical processes, including adaptation to diverse abiotic stresses. These TF families contain highly conserved MYB repeats(1 R, R2 R3, 3 R and 4 R) at the N-terminus. Roles for MYB TFs have been reported in response to such stresses as dehydration, salt, cold, and drought. The characterization of Masson pine(Pinus massoniana) MYB TFs are reported, including the analysis of MYB TFs expression in seedlings under controlled conditions and two different phosphate(Pi) deficient treatments. By searching for conserved MYB motifs in full transcriptomic RNA sequencing data for P. massoniana, 59 sequences were identified as MYB TFs. Conserved domainstructures and comparative functional and phylogenetic relationships of these MYB TFs with those in Arabidopsis were assessed using various bioinformatics tools. Based on microarray analysis, P. massoniana MYB genes exhibited different expression patterns under the two Pi deficiency conditions. Genes encoding MYB TFs that showed increased expression under critical Pi deficiency were identified, and some MYBs were differentially expressed only under conditions of severe Pi starvation. These results are useful for the functional characterization of MYB TFs that may be involved in the response to Pi deficiency and play divergent roles in plants.
基金supported by the Special Fund of National Forestry Public Welfare of the State Forestry Administration (No.201104008)a Special Fund of the Research Institute of Forest Ecology, Environment and Protection of the Chinese Academy of Forestry, China (No. CAFRIFEEP201006)
文摘Environmental heterogeneity is a constant presence in the natural world that significantly affects plant behavior at a variety of levels of complexity. In order to estimate the spatial pattern of fine root biomass in the Three Gorges Reservoir Area, the spatial heterogeneity of fine root biomass in the upper layer of soils (0-10 cm) in three Mas- son pine (Pinus massoniana) stands in the Three Gorges Reservoir Area, China, was studied in 30 m x 30 m plots with geostatistical analysis. The results indicate that 1) both the live and dead fine root biomass of stand 2 were less than those of other stands, 2) the spatial variation of fine roots in the three stands was caused together by structural and ran- dom factors with moderate spatial dependence and 3) the magnitude of spatial heterogeneity of live fine roots ranked as: stand 3 〉 stand 1 〉 stand 2, while that of dead fine roots was similar in the three stands. These findings suggested that the range of spatial autocorrelation for fine root biomass varied considerably in the Three Gorges Reservoir Area, while soil properties, such as soil bulk density, organic matter and total nitrogen, may exhibit great effect on the spatial distribution of fine roots. Finally, we express our hope to be able to carry out further research on the quantitative relation- ship between the spatial heterogeneous patterns of plant and soil properties.
文摘This study addresses the increasing demand for large-diameter production timber,and considers the time and space variability of half-sib families of Pinus massoniana.Height,diameter at breast height(DBH)and timber volume of 440 open-pollinated half-sib progeny families were investigated in 14 progeny trials in different years and production regions.An evaluation of the genetic variation of all half-sib families was carried out during the sustainable rapid growth period and individual volumes were characterized as a major index.ANOVA analysis showed that there was considerable variance in the growth traits of most families in different years and on different sites.The variations caused by temporal and spatial changes of the mating system required three selection methods for analysis.The results show that there were differences among the heritabilities of different growth traits by different halfsib progenies.Average heritability values of height,DBH and volume were 0.33,0.34 and 0.36,respectively.Fortyfive superior families were selected in every progeny test,12 were selected in progeny trials by different years and five in different habitat progeny trials.Three superior families(Gui GC553A,Gui GC414A and Gui GC431A)were selected,although in different years and production regions.The genetic gains of timber volume of these selected r families ranged from 1.20 to 47.00%,which could provide a foundation for superior wood property selection and serve as material for seed improvement and extension in surrounding areas.
文摘AIM: To study the effects of Pinus massoniana bark extract (PMBE) on cell proliferation and apoptosis of human hepatoma BEL-7402 cells and to elucidate its molecular mechanism.METHODS: BEL-7402 cells were incubated with various concentrations (20-200 μg/mL) of PMBE for different periods of time. After 48 h, cell proliferation was determined by 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis was evaluated by morphological observation, agarose gel electrophoresis,and flow cytometry analysis. Possible molecular mechanisms were primarily explored through immunohistochemical staining.RESULTS: PMBE (20-200 μg/mL) significantly suppressed BEL-7402 cell proliferation in a time- and dose-dependent manner. After treatment of BEL-7402 cells with 160 μg/mL PMBE for 24, 48, or 72 h, a typical apoptotic 'DNA ladder'was observed using agarose gel electrophoresis. Nuclear condensation and boundary aggregation or split, apoptotic bodies were seen by fluorescence and electron microscopy.Sub-G1 curves were displayed by flow cytometry analysis.PMBE decreased the expression levels of Bcl-2 protein in a time-dependent manner after treatment of cells with 160 μg/mL PMBE.CONCLUSION: PMBE suppresses proliferation of BEL-7402 cells in a time- and dose-dependent manner and induces cell apoptosis by possibly downregulating the expression of the bcl-2 gene.
基金Supported by Special Fund for Innovation-driven Development in Guangxi Zhuangzu Autonomous Region(GK AA17204087-11)Natural Science Foundation of China(31560206 31760201)
文摘[Objectives]This study was conducted to reveal the characteristics of nutrient absorption and accumulation in Pinus massoniana plantations in Northwestern Guangxi.[Methods]Based on field investigation and indoor analysis,the contents,accumulation and annual net accumulation of five nutrient elements(N,P,K,Ca and Mg)in a mature P.massoniana plantation(26-year-old)in Nandan County,Guangxi Province were studied.[Results]The contents of nutrient elements in different organs of the mature P.massoniana plantation were the highest in the leaves,followed by the bark,branch and root,and the lowest in the stem.In general,among the contents of the five elements in different organs,N content was the highest,followed by K or Ca,and P and Mg were the lowest.The total accumulation of nutrient elements in the 26-year-old mature P.massoniana plantation in northwestern Guangxi was 1 384.05 kg/hm^2.Among the different structural levels of the stand,the tree layer had the highest accumulation of nutrient elements,which was 1 198.41 kg/hm^2,accounting for 86.59%of the total accumulation of nutrients in the plantation,and the accumulation of nutrients in other layers from the largest to the smallest was the litter layer(91.97 kg/hm^2),herb layer(49.86 kg/hm^2)and shrub layer(43.92 kg/hm^2),accounting for 3.17%,3.60%and 6.64%of the total nutrient accumulation of the plantation,respectively.The annual net accumulation of nutrient elements in the tree layer of the mature P.massoniana plantation was 46.09 kg/(hm^2·a),and the order of the annual net accumulation of different nutrient elements followed N>K>Ca>Mg>P;and the accumulation of 1 t of dry matter needed 6.37 kg of the five nutrients.[Conclusions]This study provides a scientific basis for the rational management of P.massoniana plantations,especially forest soil management.
基金supported by the State Key Development Program for Basic Research of China ("973" Project) (2009CB119200)the National Project of Science+1 种基金Technology for the 11th Five-Year Plan in China (Grant No. 2006BAD08A15)the "948" Project of State Forestry Administration,P. R. China (2006-4-37)
文摘When pine trees are invaded by pine wilt diseases, the severely infected pine trees will die and fall down, or they will be removed when found to be damaged by the disease. It gives rise to the invasion of other species in these empty niches originally oc- cupied by pine trees, i.e., competing surrounding trees or understory shrubs will invade the empty niches during the following years. As a result, the spatial distribution and pattern of the main tree species in a pine forest will change, and a niche variety in the main population will occur. In the end, the direction of the succession and restoration of the pine forest ecosystem will be affected. In our study, a Pinus massoniana forest with the dominant shrub, Pleioblastus amarus, was invaded by pine wood nematode and was clear cut. Selecting this community as our research object, we studied the effect of the invasion of the pine wood nematode on the growth of the dominant shrub, P. amarus, in this Pinus massoniana forest. Our results show that, after the attacked pine trees were removed, the niche was occupied by Pleioblastus amarus and other shrubs, which benefited the growth ofP. amarus to its climax. Growth of P. amarus at the climax stage was greater compared with the unhealthy pine forest and the control group.
基金supported by the Guangxi Natural Science Foundation(2014GXNSFBA118106)
文摘Geranylgeranyl pyrophosphate synthetase(GGPPS) has gained increasing attention as a key enzyme in terpene analysis.We designed specific primers based on plant GGPPS homologs and used reverse transcription polymerase chain reaction(RT-PCR) to obtain and identify Pin GGPPS,a GGPPS gene sequence from Pinus massoniana,using bioinformatics tools.Quantitative PCR analysis of Pin GGPPS expression levels in roots,pine needles,immature stems,and semilignified stems from 6-month-old P.massoniana showed that expression levels of Pin GGPPS were highest in pine needles,followed by immature stems and semilignified stems,and lowest in roots.When we examined the correlation between Pin GGPPS gene expression levels and resin productivity in 20 adult plants for 28 successive days,Pin GGPPS expression levels presented a substantially linear distribution when plotted against their corresponding resin yields.In summary,we characterized the gene Pin GGPPS for the first time in P.massoniana,and established a correlation between Pin GGPPS gene expression levels and resin productivity,suggesting the importance of theory and production practice for P.massoniana.
基金financially supported by the National Key Research and Development Program(2017YFD0600105)the National Natural Science Foundation of China(Grant No.31870641)+2 种基金the Research Foundation of Education Department of Fujian Province(No.JAT170882)Project of Financial Department of Fujian Province(Nos.K81139238 and K8911010)the Special Fund for Forestry Research in the Public Interest of China(No.201304401)
文摘Pine wilt disease(PWD)is a devastating disease affecting the growth of Pinus massoniana,often leading to withering and death.To reveal the changes involved during disease progression,we investigated the mRNA expression profile of P.massoniana infested by Bursaphelenchus xylophilus.The infestation resulted in the downregulation of genes involved in interactions with pathogenic pathways such as disease resistance gene,CC-NBS-LRR resistancelike protein,and the gene encoding a putative nematode resistance protein.Increased infestation pressure(number of nematodes inoculated)caused a continuous decline in the gene expression of stem samples.An infestation of P.massoniana also resulted in a pathway enrichment of genes involved in phenylpropanoid metabolism and flavonoid biosynthesis,which in turn reduced the levels of total phenols and total flavonoids.A downregulation of auxin responsive family protein was observed in infested samples,which resulted in a suppression of plant growth.Thus,upon B.xylophilus infestation,a downregulation of genes associated with the recognition of pathogens,PWD resistance,and growth regulation was observed in P.massoniana,together with a decrease in the levels of phytoalexinlike secondary substances,all of which resulted in withering and ultimately death of P.massoniana.
基金supported by the Science and Technology Department of Guangdong Province,China(Nos.2015B020207002 and 2014A020216032)the National Natural Science Foundation of China(No.31270675)
文摘The ecological effects of eucalypt plantations(EPs) have garnered increasing attention.To understand their effect on soil quality at a landscape scale,and to determine whether soil quality parameters differ due to different stand types,we evaluated soil characteristics in twenty-one groups of EPs,Pinus massoniana Lamb.plantations(PMPs) and natural broadleaved forests(NBFs)across Guangdong Province,China.Both the physical characteristics of soil hydrology and the properties of soil nutrients in A and B horizons were determined.Results showed that,compared to NBFs,EPs and PMPs produced a shallower litter layer,reduced canopy density,higher soil bulk density,significantly lower total porosity,non-capillary porosity,total water volume,and hygroscopic water in the A horizon(P〈0.05).Moreover,total N,available K,and soil organic carbon(SOC) in EPs and PMPs were significantly lower than in NBFs.EPs and PMPs did not differ significantly in N,P or K content,but PMPs had significantly lower SOC and boron in the A horizon than EPs.Low p H and poor capacity to buffer acidification generally occurred in all cover types.Both EPs and PMPs showed a decline in soil properties relative to NBFs,but EPs and PMPs exhibited no significant difference.These results indicate that actions are needed to ameliorate the potential negative effects on soil quality in forestry plantations.