Pyrrolizidine alkaloids(PAs)and their N-oxides(PANOs)are phytotoxins produced by various plant species and have been emerged as environmental pollutants.The sorption/desorption behaviors of PAs/PANOs in soil are cruci...Pyrrolizidine alkaloids(PAs)and their N-oxides(PANOs)are phytotoxins produced by various plant species and have been emerged as environmental pollutants.The sorption/desorption behaviors of PAs/PANOs in soil are crucial due to the horizontal transfer of these natural products from PA-producing plants to soil and subsequently absorbed by plant roots.This study firstly investigated the sorption/desorption behaviors of PAs/PANOs in tea plantation soils with distinct characteristics.Sorption amounts for seneciphylline(Sp)and seneciphylline-N-oxide(SpNO)in three acidic soils ranged from 2.9 to 5.9μg/g and 1.7 to 2.8μg/g,respectively.Desorption percentages for Sp and SpNO were from 22.2%to 30.5%and 36.1%to 43.9%.In the mixed PAs/PANOs systems,stronger sorption of PAs over PANOs was occurred in tested soils.Additionally,the Freundlich models more precisely described the sorption/desorption isotherms.Cation exchange capacity,sand content and total nitrogen were identified as major influencing factors by linear regression models.Overall,the soils exhibiting higher sorption capacities for compounds with greater hydrophobicity.PANOs were more likely to migrate within soils and be absorbed by tea plants.It contributes to the understanding of environmental fate of PAs/PANOs in tea plantations and provides basic data and clues for the development of PAs/PANOs reduction technology.展开更多
Assessing the sensitivities of ecosystem functions to climatic factors is essential to understanding the response of ecosystems to environmental change.Temperate plantation forests contribute to global greening and cl...Assessing the sensitivities of ecosystem functions to climatic factors is essential to understanding the response of ecosystems to environmental change.Temperate plantation forests contribute to global greening and climate change mitigation,yet little is known as to the sensitivity of gross primary production(GPP)and evapotranspiration(ET)of these forests to heat and drought stress.Based on near-continuous,eddy-covariance and hydrometeorological data from a young temperate plantation forest in Beijing,China(2012-2019),we used a slidingwindow-fitting technique to assess the seasonal and interannual variation in ecosystem sensitivity(i.e.,calculated slopes,S_(GPP-Ta),S_(ET-Ta),S_(GPP-EF),and S_(ET-EF))in GPP and ET to anomalies in air temperature(T_(a))and evaporative fraction(EF).The EF was used here as an indicator of drought.Seasonally,daily SGPP-Ta,SET-Ta,and SGPP-EF were greatest in summer,reaching maxima of 1.120.56 g C··m^(-2)·d^(-1)·℃^(-1),1.360.56 g H_(2)O·m^(-2)·d^(-1)·℃^(-1),and 0.370.35 g C·m^(-2)·d^(-1),respectively.Evapotranspiration was constrained by drought,especially during the spring-to-summer period,SET-EF reaching0.510.34 g H_(2)O·m^(-2)·d^(-1).Variables EF,T_(a),soil water content(SWC),vapor pressure deficit(VPD),and precipitation(PPT)were the main controls of sensitivity,with SGPP-Ta and SET-Ta increasing with Ta,VPD,and PPT(<50 mm·d^(-1))during both spring and autumn.Increased drought stress during summer caused the positive response in GPP and ET to decrease with atmospheric warming.Variable SET-EF intensified(i.e.,became more negative)with decreasing EF and increasing Ta.Interannually,annual S_(GPP-Ta)and S_(ET-Ta)were positive,S_(GPP-EF)near-neutral,and S_(ET-EF)negative.Interannual variability in S_(GPP-Ta),S_(ET-Ta),S_(ET-EF),and S_(GPP-EF)was largely due to variations in bulk surface conductance.Our study suggests that the dynamics associated with the sensitivity of ecosystems to changes in climatic factors need to be considered in the management of plantation forests under future global climate change.展开更多
[Objectives]The soil permeability and its influencing factors in typical plantations were studied to provide a scientific basis for tending and managing plantations in the Haikou forest area of Kunming City.[Methods]W...[Objectives]The soil permeability and its influencing factors in typical plantations were studied to provide a scientific basis for tending and managing plantations in the Haikou forest area of Kunming City.[Methods]With three kinds of typical forest stands,i.e.,over-mature Pinus armandii Franch.,mid-mature Eucalyptus robusta Smith,and over-mature E.robusta Smith in this region as the research objects,soil infiltration changes and the effects on soil water retention in different stands,soil layers,and gap conditions under different moisture conditions were analyzed.[Results]①Under all three moisture conditions,the over-mature P.armandii forest demonstrated higher overall infiltration rates than the other two forest stands,which showed relatively similar infiltration rates.In all three stands,the soil infiltration rate decreased as the depth of the soil increased.Significant fluctuations in soil infiltration rate were observed during the initial 0-5 min,followed by gradual stabilization or regular fluctuations after 5 min.The infiltration process generally reached saturation after approximately 20 min.②The average infiltration rate was identified as the key factor affecting soil infiltration.Comprehensive evaluation of soil permeability revealed that the over-mature P.armandii forest exhibited optimal soil permeability.③Various soil physical and chemical properties significantly affected different indexes of soil permeability under varying conditions,with soil organic carbon content and water repellency demonstrating particularly notable effects on infiltration under different conditions.[Conclusions]Soil infiltration rates gradually decreased with the deepening of the soil layer.Principal component analysis(PCA)showed that the soil permeability of the over-mature P.armandii forest was stronger than that of the other two stands under the three moisture conditions,especially in non-gap positions.All soil indexes affected soil permeability,and soil organic carbon and water repellency were the key factors affecting soil permeability.展开更多
The Andean montane forests provide a wide range of ecosystem services like water supply, carbon sequestration, and biodiversity preservation. Restoration of these forests is critical due to their degraded state and th...The Andean montane forests provide a wide range of ecosystem services like water supply, carbon sequestration, and biodiversity preservation. Restoration of these forests is critical due to their degraded state and the need to recover, maintain and enhance the ecosystem services they provide. However, we lack understanding of aboveground biomass (AGB) accumulation in restored Andean montane forests. AGB is a key indicator of ecosystem productivity and provides essential data on vegetation carbon stocks, permitting the assess successfulness of restoration efforts. In 2010 the initiative Más Bosques para Medellín was formulated in Medellín City, tropical Andes, Colombia, aiming to restore the forests located in the surrounding rural areas of the city, with interest in preserving the ecosystems services like water supply. The project established 548 ha of mixed plantations with native species. After 13 years, our study aims to developed in situ allometric equations and to evaluate AGB accumulation to assess restoration performance. We measured, harvested, and weighted 144 individuals from these arrangements to fit a general equation for the project and six specific equations for each one of the six most frequent species. The AGB had a positive correlation with diameter at breast height (D), total height (H) and specific wood density (WD). The best general equation uses D and WD as predictors (R^(2) = 0.928). The specific species equations certainly responded to the functional traits of each species. Using the latest inventory of permanent plots of the project we estimated a mean AGB accumulation of 41.91 ± 30.34 Mg ha^(–1) and a total accumulation of 22,996.05 Mg of AGB for the 548 ha. We compared these results with studies developed for natural forest in the region and other land covers. We found contrast behaviors in the AGB accumulation across our study zones. The developed equations have broad applicability across the Andes region, offering valuable insights for similar restoration initiatives. Furthermore, will facilitate the assessment of current restoration efforts and inform scientifically based decisions for future mixed plantation practices.展开更多
Tree growth is extremely vulnerable to climate change,especially in semi-arid areas.Although the response of stem radial growth(SRG)to climate change has been extensively studied,the intra-annual regulatory mechanisms...Tree growth is extremely vulnerable to climate change,especially in semi-arid areas.Although the response of stem radial growth(SRG)to climate change has been extensively studied,the intra-annual regulatory mechanisms of SRG in trees with different water use strategies and life types remain poorly understood.This study calculated the SRG of four native species in the semi-arid area of the Loess Plateau,China,including two isohydric species(Pinus tabuliformis Carrière and Populus×hopeiensis Hu&Chow)and two anisohydric species(Prunus sibirica L.and Platycladus orientalis(L.)Franco).The results revealed that the intra-annual SRG of all the four tree species exhibited a single peak,and greater SRG was found in anisohydric species.Principal component analysis and structural equation model revealed that atmospheric water,particularly relative humidity,was the main factor affecting the SRG of coniferous species(P.tabuliformis and P.orientalis),whereas the SRG was mainly affected by soil water content in broadleaf species(P.sibirica and P.×hopeiensis).These findings suggested that water use strategies and life types play important roles in SRG and environmental response of trees in semi-arid area.Considering the high climate sensitivity of wood formation in trees,our results highlight the importance of water use strategies and life types of trees in SRG prediction in the context of future climate change in arid and semi-arid areas.展开更多
Phosphorus(P)is crucial for plant growth.However,its low availability in subtropical soils necessitates that trees rely on microorganisms for effective P acquisition.The introduction of broadleaf trees has been shown ...Phosphorus(P)is crucial for plant growth.However,its low availability in subtropical soils necessitates that trees rely on microorganisms for effective P acquisition.The introduction of broadleaf trees has been shown to facilitate P acquisition in coniferous plantations by altering the rhizosphere fungal communities.Despite this,functional shifts in these communities and the expression of root phosphorus cycling genes(PCGs)remain inadequately understood.This study investigated coniferous Pinus massoniana and Cunninghamia lanceolata plantations interplanted with broadleaf species associated with arbuscular mycorrhizal(AM)or ectomycorrhizal(ECM)fungi.Rhizosphere soil and fine roots from the conifers were analyzed to examine soil bioavailable P fractions,root mycorrhizal colonization,rhizosphere fungal community composition,enzyme function predictions,and root PCGs expression.We found that citric-P in rhizospheric soil of P.massoniana increased with the introduction of Quercus gilva(an ECM-associated tree species),whereas Bray-P content in the rhizosphere of C.lanceolata decreased upon the introduction of either Q.gilva or Phoebe zhennan(an ECM-associated tree species).Moreover,the relative abundance of saprophytic fungi(e.g.,Mortierella)increased following the introduction of broadleaf trees.Specifically,the introduction of Q.gilva was associated with elevated levels of organic P mineralization genes(e.g.,phoA)and enzymes(e.g.,phytases and acid phosphatase(ACP))in conifers.In contrast,the introduction of P.zhennan increased the expression of inorganic P solubilization genes(such as qppC in P.massoniana roots and ppa in C.lanceolata roots).Key contributors to P absorption in conifer roots included Cenococcum,Rhizopogon,and Glomus.This study advances our understanding of P cycling in coniferous rhizospheres and the dynamics of coexisting mycorrhizal tree systems,yielding valuable insights into sustainable management of plantation ecosystems.展开更多
Human activities contribute to elevated nitrogen input in terrestrial ecosystems,influencing the composition of soil nutrients and microbial diversity in forest ecosystems.In this study,we built four addition treatmen...Human activities contribute to elevated nitrogen input in terrestrial ecosystems,influencing the composition of soil nutrients and microbial diversity in forest ecosystems.In this study,we built four addition treatments(0,20,40,and 80 kg ha^(−1)a^(−1)N for 6 a)at a Korean pine plantation of different soil horizons(organic(O)horizon,ranging from 0 to 10 cm,and organomineral(A)horizon,extending from 10 to 20 cm)to evaluate responses of the structure of saprophytic fungal communities.Here,80 kg ha^(−1)a^(−1)N treatment significantly decreased the community richness in soil A horizon with the Chao1 index decreasing by 12.68%.Nitrogen addition induced changes in the composition of saprophytic fungi community between the different soil horizons.The co-occurrence network and its associated topological structure were utilized to identify mycoindicators for specific fungi to both soil horizons and nitrogen addition levels.In soil O horizon,the mycoindicators included Penicillium,Trichoderma,Aspergillus,and Pseudeurotium across control,low,medium,and high nitrogen treatments.In soil A horizon,Geomyces,Cladophialophora,Penicillium,and Pseudeurotium were identified as mycoindicators.Structural equation modeling determined NH_(4)^(+)-N as the key factor driving changes in saprotrophic fungal communities.Our study aimed to screen mycoindicators that can respond to the increasing global nitrogen deposition and to assess the roles of these mycoindicators in the saprophytic fun-gal community structure within Korean pine plantations in northeast China.展开更多
An investigation on soil organic carbon, total N and P, NO3-N, available P, microbial biomass C, N and P, basal respiration and metabolic quotients （qCO2） was conducted to compare differences in soil microbial prope...An investigation on soil organic carbon, total N and P, NO3-N, available P, microbial biomass C, N and P, basal respiration and metabolic quotients （qCO2） was conducted to compare differences in soil microbial properties and nutrients between 15-year-old pure Chinese fir （Cunninghamia lanceolata） and two mixed Chinese fir plantations （mixed plantations with Alnus crernastogyne, mixed plantations with Kalopanax septemlobus） at Huitong Experimental Station of Forest Ecology （26°45′N latitude and 109°30′E longitude）, Chinese Academy of Sciences in May, 2005. Results showed that the concentrations of soil organic carbon, total N, NO3^--N, total P and available P in mixed plantations were higher than that in pure plantation. Soil microbial biomass N in two mixed plantations was averagely higher 69% and 61% than that in pure plantation at the 0-10 cm and 10-20 cm soil depth, respectively. Soil microbial biomass C, P and basal respiration in mixed plantations were higher 11%, 14% and 4% at the 0-10 cm soil depth and 6%, 3% and 3% at the 10-20 cm soil depth compared with pure plantation. However, soil microbial C： N ratio and qCO2 were averagely lower 34% and 4% in mixed plantations than pure plantation. Additionally, there was a closer relation between soil microbial biomass and soil nutrients than between basal respiration, microbial C： N ratio and qCO2 and soil nutrients. In conclusion, introduction of broad-leaved tree species into pure coniferous plantation improved soil microbial properties and soil fertility, and can be helpful to restore degraded forest soil.展开更多
[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber （Hevea brasiliensis Muell-Arg） plantations at different age stages in the western region of Hainan Island,so as to...[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber （Hevea brasiliensis Muell-Arg） plantations at different age stages in the western region of Hainan Island,so as to evaluate the ecological benefits of rubber plantations and provide basic data for studying the effect of tropical land utilization/cover change on the global carbon and nitrogen cycle. [Method]The situs was in Danzhou city,western region of Hainan Island,and the samples were four kinds of rubber plantations soil at different ages and one kind of control check （pepper,Piper nigrum L.） soil. In this research,four quadrats were set up in each sample,and the size of each was 20 cm×20 cm. Four specimens were gathered from four layers of 0-15,15-30,30-45,45-60,and the average of them was the last analysis result of each sample. Soil density was measured by cutting ring method,soil containing and hygroscopic water was detected by oven drying method,soil organic carbon （SOC） was measured by low temperature heated outside potassium dichromate oxidation-colorimetry method,and soil total nitrogen （STN） was detected by semimicro Kjeldahl method. [Result]SOC contents of different layers in rubber plantations soil at different age stages （including the CK pepper soil,the same as below） varied little,and the content of SOC in surface layer （0-15 cm） was higher,while the underlayer （45-60 cm） was lower than the average value; there was significant difference in SOC content among different kinds of soil,and the content was of 6.03-7.78 g/kg,tapping young trees （7 years） CK pepper mature age trees （30 years） prophase of young trees （2 years） tapping trees （16 years）; there was no significant difference in SOC storage among different kinds of soil,and the storage was of 61.33-74.29 t/hm2,mature age trees （30 years） tapping young trees （7 years） prophase of young trees （2 years） CK pepper tapping trees （16 years）; there was significant difference in STN content among rubber plantations soil at different age stages,the content was of 410.86-664.14 mg/kg2,CK pepper tapping young trees （7 years） prophase of young trees （2 years） mature age trees （30 years） tapping trees （16 years）,and STN content of tapping trees （16 years） soil was extremely lowest; there was significant difference in C/N ratio among different kinds of soil,the ratio was of 10.94-14.47,and the ratio of tapping trees （16 years） mature age trees （30 years） tapping young trees （7 years） CK pepper prophase of young trees （2 years）. [Conclusion]There wasn＇t unhealthy effect of rubber trees planted in tropical area on the content and storage of SOC,the content of STN and the ratio of C/N. there was no significant difference between rubber plantations and CK pepper soil,and the effects of rubber plantation on soil carbon-nitrogen was similar to that of other tropical crops （such as pepper）.展开更多
The soil respiration rates （Rh） in 6-year-old （young）, 17-year-old （middle-age）, 31-year-old （mature） Casuarina equisetifolia coastal plantations were measured using an LICOR-8100 automated soil CO2 flux syste...The soil respiration rates （Rh） in 6-year-old （young）, 17-year-old （middle-age）, 31-year-old （mature） Casuarina equisetifolia coastal plantations were measured using an LICOR-8100 automated soil CO2 flux system from May 2006 to April 2007. Results show that Rh displayed an obvious seasonal pattern across the observed years. The maximum values of Rh occurred at June and July and the minimum at December and January. Soil temperature and soil moisture as well as their interaction had significant effects on the monthly dynamics of Rh. The analysis by one-way ANOVA showed that Rh had a significantly exponential relation （p〈0.05） to soil temperature at soil depth of 5 cm, and had a linear relation （p〈0.05） to soil water content of the upper 20 cm. The result estimated by the two-factor model shows that soil temperature at soil depth of 5 cm and soil moisture at soil depth of 20 cm could explain 68.9%-91.9% of seasonal variations in Rh. The or- der of Rh rates between different stand ages was middle-age plantation〉mature plantation〉young-age plantation. With the increase of growth age of plantation, the Q10 of Rh increased. The contribution of Rh to total soil surface CO2 flux was 71.89%, 71.02% and 73.53% for the young, middle-age and mature plantation, respectively. It was estimated that the annual CO2 fluxes from Rh were 29.07, 38.964 and 30.530 t.ha^-1.a^-1 for the young, middle-age and mature plantation, respectively.展开更多
the investigation was carried out on 10-year-old plantation of Fraxinus mandshurica in Mao抏r Mountain Experimental Station of Northeast Forest University. Tree height (H), diameter at breast height (D1.3) and the inc...the investigation was carried out on 10-year-old plantation of Fraxinus mandshurica in Mao抏r Mountain Experimental Station of Northeast Forest University. Tree height (H), diameter at breast height (D1.3) and the increment of tree height in 5 years (H5), the thickness of humus layer, as well as the soil moisture were measured for the plantation and the growth indexes (H, D1.3, H5) for different site conditions were analyzed. The results showed that main site factors influencing the growth of Fraxinus mandshurica were soil moisture, gradient and location of slope in order. The growth of Fraxinus mandshurica was better on the middle- or up-slope site than on the down-slope site. Soil moisture and late frost caused by terrain are the main reasons that limit the growth of Fraxinus mandshurica plantation.展开更多
Microclimate characteristics and related environmental energy mechanisms were examined based on the long term located observations in the mature, thinned and young Cunninghamia lanceolata plantation ecosystems in...Microclimate characteristics and related environmental energy mechanisms were examined based on the long term located observations in the mature, thinned and young Cunninghamia lanceolata plantation ecosystems in western Hunan Province, China. The results show that the mature plantation ecosystem can improve the microclimate significantly by regulating the amount and spatial distribution of environmental energy, which delineates the pattern of the microclimate in forest ecosystems in the process of ecological restoration. Compared with the young plantation, the mature plantation ecosystem decreased annual mean air temperature by 0 4℃. The maximum decrease in monthly mean air temperature was 2 3℃. The mature plantation ecosystem decreased annual mean ground temperature by 1 2℃ with a maximum decrease in monthly mean ground temperature of 2 3℃. Mainly due to the dense canopy, the mature forest ecosystem regulates the distribution of radiation energy, and expenditure ratios of heat budget and principal energy components to decrease temperature or make it even.展开更多
The organic carbon contents,carbon density and carbon storage of the soil in the Pinus koraiensis plantation ecosystem were investigated in Maoershan experimental forest farm,Shangzhi County,Heilongjiang,on the west s...The organic carbon contents,carbon density and carbon storage of the soil in the Pinus koraiensis plantation ecosystem were investigated in Maoershan experimental forest farm,Shangzhi County,Heilongjiang,on the west slope of the Zhangguangcai Mountains in northeastern China for providing data to evaluation of the carbon balance in forest ecosystem of northeastern China.These soil carbon indicators were measured in three forest types,pure P.koraiensis plantation,P.koraiensis and Betula platyphylla mixed forest,and the P.koraiensis and Quercus mongolica mixed forest.The soil carbon pool consisted of four compartments,namely L layer,F layer,H layer and B layer.With variance analysis,we found that both organic carbon content and carbon density of the soil were significantly affected by forest types,soil compartments and slope positions.The highest soil carbon density（278.63 Mg·ha^-1）.was observed in the mixed forest of P.koraiensis and Q.mongolica.The B layer had the highest carbon density（212.28 Mg·ha^-1） among all the soil compartments.In terms of slope position,the highest soil carbon density（394.18 Mg·ha^-1） presented in the low slope.Besides,soil carbon content and carbon density had a marked change with the organic matter content and vertical depth of the soil in each compartment.The results of this study implied that in the temperate humid region,the mixed ecosystem of regional Pinus koraiensis plantations and natural forest had relatively high carbon storage capability.展开更多
A study was conducted to determine the characters of soil structure in different water and soil conservation forests in Keshan County,northwest of Heilongjiang Province,China.The soil bulk density,the ratio of non-cap...A study was conducted to determine the characters of soil structure in different water and soil conservation forests in Keshan County,northwest of Heilongjiang Province,China.The soil bulk density,the ratio of non-capillary porosity and capillary porosity（NCP/CP）,and the generalized soil structure index（GSSI） were measured for Fraxinus mandshurica,Larix gmelini,Pinus sylvestris var.mongolica,and Picea koraiensis plantations as well as the abandoned land（as control） adjacent to the forests in typical black soil region.Results show that at soil depth of 0–30cm,the soil bulk density of F.mandshurica forest and L.gmelini forest was lower than that of P.sylvestris var.mongolica forest and P.koraiensis forest,with the relative decrease of 8.04%–11.01%.The soil bulk density of L.gmelini forest was significantly different from that of the P.sylvestris var.mongolica forest and P.koraiensis forest.The NCP/CP values of the four types of plantations were all higher（59.75%–128.82% relatively） than that of abandoned land（p〈0.05）,indicating that the soil aeration and permeability under forest were enhanced,especially under L.gmelini forest.GSSI values of the four types of forests were also relatively higher（2.98%–4.36%） than abandoned land（p〈0.05）,indicating that those soil and water conservation forests,especially the F.mandshurica forest and P.koraiensis forest,can promote soil condition to approximate ideal soil structure.The result of this study can provide theoretical basis for scientifically evaluating the effects of vegetation restoration on soil quality in typical black soil region.展开更多
Tracheid characteristics ofPicea koraiensis from natural stand in Liangshui area and plantation in Mao'ershan area were studied. The results of variance analysis showed that the tracheid length, diameter, and thic...Tracheid characteristics ofPicea koraiensis from natural stand in Liangshui area and plantation in Mao'ershan area were studied. The results of variance analysis showed that the tracheid length, diameter, and thickness of tracheid wall were significant differences between the growth rings. All those characteristics tend to increase from heart-center to bark. In natural stand, it has positive correlation between the characteristics. In plantation, the tracheid length has positive correlation with the trachied diameter, while both the trachied length and the trachied diameter has negative correlation with the thickness of trachied wall. The tracheid length and diameter have no significant difference in growth between natural stand and plantations. The thickness of tracheid wall from the plantation is a little thicker than that from the natural stand before 15 years.展开更多
[Objective] The paper was to analyze the quality of flux observation data of rubber plantation.[Method]Based on the FSAM model,footprint and flux source area were analyzed according to the continuous flux measurement ...[Objective] The paper was to analyze the quality of flux observation data of rubber plantation.[Method]Based on the FSAM model,footprint and flux source area were analyzed according to the continuous flux measurement with the open-path eddy covariance system on the 50 m tower of Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments,Ministry of Agriculture from Jan 1 to Jun 30,2010.[Result] Under unstable stratification,source areas were smaller than those under stable conditions,and source areas in the dormant season were larger than those in the growing season at the same level.In the main wind direction 130°-270°,the upwind range of source areas was in the magnitude of 100-758 m and vertical upwind range was-251-251 m at 80% level under unstable stratification in the growing season,and they were some large than those under the unstable stratification in the dormant season.The source areas of the upwind and vertical upwind ranges were 173-1 858,-534-534 m especially under stable stratification in the growing season,and they were smaller than those under stable stratification in the dormant season.In the other wind directions of 0°-130° and 270°-360°,the ranges were similar to those of the growing season in the prevailing wind direction under the same atmospheric conditions.[Conclusion] The study would lay a foundation for the future flux calculation and analysis.展开更多
The influence of formula fertilization optimization on dry rubber yield and economic benefits of the rubber plantation in Hainan Longjiang Farm were studied by using ＂contrast＂ design method of fertilizer field expe...The influence of formula fertilization optimization on dry rubber yield and economic benefits of the rubber plantation in Hainan Longjiang Farm were studied by using ＂contrast＂ design method of fertilizer field experiments. The results showed that the actual production rate reached 4.61% and the net production rate of dry rubber reached 3.97% by application of optimized fertilization formula. Analysis of variance showed that the average dry rubber yield in optimization of formula fertil- ization area was significantly higher than that of conventional area. The results also indicated that the optimization of formula fertilization had obvious economic benefits, and each rubber tree reduced cost and increased 9.95 yuan on average after the test.展开更多
[Objective]The paper was to study the effect of continuous cropping on leaf nutrient and growth of different species of poplar plantation.[Method] The tree height,diameter at breast height（DBH）,volume of different g...[Objective]The paper was to study the effect of continuous cropping on leaf nutrient and growth of different species of poplar plantation.[Method] The tree height,diameter at breast height（DBH）,volume of different generations and species of poplar plantation in poplar production area in northern Jiangsu Province,as well as TN,TP and TK content in their leaves were determined through field investigation and indoor experiment.[Result] With the increasing generation,the changes of TN,TP and TK content in the leaves of different ages of two varieties of forest stand were also different.However,with the increasing tree ages,TN,TP and TK contents in leaves showed decrease trend.With the increasing generation,the changes of tree height of I-69 and I-72 poplar showed the similar trend.The effect of increasing generation on tree height of 7-year-old and 10-year-old poplar was relatively stable,showing decrease trend from generation to generation.The tree height of 4-year-old poplar first increased and then decreased with the increasing generation.The changes of DBH along with different generations were basically consistent with the changes of tree height.With the increasing cultivation generations,the volume of 7-year-old and 10-year-old poplar decreased with significant difference.[Conclusion ] The result provided basis for rational fertilization and management of poplar plantation,improvement of productivity of poplar plantation,and achievement of sustainable management of plantation.展开更多
Tree species composition was important for carbon storage within the same climate range.To quantify the dynamics of ecosystem carbon allocation as affected by different tree species,we measured the above-and below-gro...Tree species composition was important for carbon storage within the same climate range.To quantify the dynamics of ecosystem carbon allocation as affected by different tree species,we measured the above-and below-ground biomass accumulation in 22 years,as well as the tissue carbon concentrations of trees in Cunninghamia lanceolata plantation and Michelia macclurei plantation.Results indicated that M.macclurei plantation significantly stored more carbon（174.8 tons/hm2） than C.lanceolata plantation（154.3 tons/hm2）.Most of the carbon was found in the soil pool（57.1% in M.macclurei plantation,55.2% in C.lanceolata plantation）.Tree and soil component of M.macclurei plantation possessed significantly higher carbon storage than that of C.lanceolata plantation（p 〈 0.05）.No significant difference was found in the carbon storage of understory and forest floor.These results suggest that the broadleaved species（M.macclurei） possesses greater carbon sequestration potential than the coniferous species（C.lanceolata） in southern China.展开更多
Mixed-species plantations generally exhibit higher ecosystem multifunctionality than monospecific plantations.However,it is unclear how tree species functional composition influences species mixture effects on ecosyst...Mixed-species plantations generally exhibit higher ecosystem multifunctionality than monospecific plantations.However,it is unclear how tree species functional composition influences species mixture effects on ecosystem multifunctionality.We selected 171 monospecific and mixed-species plantations from nine regions across subtropical China,and quantified 13 key ecosystem functional properties to investigate how species mixture effects on ecosystem multifunctionality are modulated by functional diversity and identity.We found that ecosystem multifunctionality was significantly higher(p<0.05)in mixed tree plantations than in monospecific plantations except the mixed-conifer species plantations.Across all regions,ecosystem multifunctionality was significantly higher(p<0.05)in mixed conifer-broadleaf plantations than in monospecific plantations of the corresponding species,but not different between mixed and monospecific coniferous plantations.The magnitude of species mixture effects on ecosystem multifunctionality varied greatly with tree species compositions.Taking Cunninghamia lanceolata Lamb.as an example,the effects varied from a range of 2.0%–9.6%when mixed with a conifer species to 36%–87%when mixed with a broadleaf species.The functional diversity was the dominate driver shaping ecosystem multifunctionality,while functional identity,as expressed by community-weighted mean of specific leaf area,also had a positive effect on ecosystem multifunctionality through the increased below-ground nitrogen and phosphorus stocks regulated by specific leaf area of the mixing tree species.Our study highlights the important role of functional diversity in shaping ecosystem multifunctionality across region-wide environmental conditions.Mixed conifer-broadleaf tree plantations with distinct functional traits benefit the enhancement of ecosystem multifunctionality,and the magnitude of species mixture effects is modulated by the functional identity of tree species composition;those relationships deserve a special consideration in multifunctional management context of subtropical plantations.展开更多
基金supported by the earmarked fund for the Modern Agro-Industry Technology Research System (No.CARS-19)the Innovative Research Team in Chinese Academy of Agricultural Sciences (No.CAAS ASTIP-2014-TRICAAS).
文摘Pyrrolizidine alkaloids(PAs)and their N-oxides(PANOs)are phytotoxins produced by various plant species and have been emerged as environmental pollutants.The sorption/desorption behaviors of PAs/PANOs in soil are crucial due to the horizontal transfer of these natural products from PA-producing plants to soil and subsequently absorbed by plant roots.This study firstly investigated the sorption/desorption behaviors of PAs/PANOs in tea plantation soils with distinct characteristics.Sorption amounts for seneciphylline(Sp)and seneciphylline-N-oxide(SpNO)in three acidic soils ranged from 2.9 to 5.9μg/g and 1.7 to 2.8μg/g,respectively.Desorption percentages for Sp and SpNO were from 22.2%to 30.5%and 36.1%to 43.9%.In the mixed PAs/PANOs systems,stronger sorption of PAs over PANOs was occurred in tested soils.Additionally,the Freundlich models more precisely described the sorption/desorption isotherms.Cation exchange capacity,sand content and total nitrogen were identified as major influencing factors by linear regression models.Overall,the soils exhibiting higher sorption capacities for compounds with greater hydrophobicity.PANOs were more likely to migrate within soils and be absorbed by tea plants.It contributes to the understanding of environmental fate of PAs/PANOs in tea plantations and provides basic data and clues for the development of PAs/PANOs reduction technology.
基金supported by the National Key Research and Development Program of China(No.2020YFA0608100)the National Natural Science Foundation of China(NSFC,No.32071842 and 32101588)。
文摘Assessing the sensitivities of ecosystem functions to climatic factors is essential to understanding the response of ecosystems to environmental change.Temperate plantation forests contribute to global greening and climate change mitigation,yet little is known as to the sensitivity of gross primary production(GPP)and evapotranspiration(ET)of these forests to heat and drought stress.Based on near-continuous,eddy-covariance and hydrometeorological data from a young temperate plantation forest in Beijing,China(2012-2019),we used a slidingwindow-fitting technique to assess the seasonal and interannual variation in ecosystem sensitivity(i.e.,calculated slopes,S_(GPP-Ta),S_(ET-Ta),S_(GPP-EF),and S_(ET-EF))in GPP and ET to anomalies in air temperature(T_(a))and evaporative fraction(EF).The EF was used here as an indicator of drought.Seasonally,daily SGPP-Ta,SET-Ta,and SGPP-EF were greatest in summer,reaching maxima of 1.120.56 g C··m^(-2)·d^(-1)·℃^(-1),1.360.56 g H_(2)O·m^(-2)·d^(-1)·℃^(-1),and 0.370.35 g C·m^(-2)·d^(-1),respectively.Evapotranspiration was constrained by drought,especially during the spring-to-summer period,SET-EF reaching0.510.34 g H_(2)O·m^(-2)·d^(-1).Variables EF,T_(a),soil water content(SWC),vapor pressure deficit(VPD),and precipitation(PPT)were the main controls of sensitivity,with SGPP-Ta and SET-Ta increasing with Ta,VPD,and PPT(<50 mm·d^(-1))during both spring and autumn.Increased drought stress during summer caused the positive response in GPP and ET to decrease with atmospheric warming.Variable SET-EF intensified(i.e.,became more negative)with decreasing EF and increasing Ta.Interannually,annual S_(GPP-Ta)and S_(ET-Ta)were positive,S_(GPP-EF)near-neutral,and S_(ET-EF)negative.Interannual variability in S_(GPP-Ta),S_(ET-Ta),S_(ET-EF),and S_(GPP-EF)was largely due to variations in bulk surface conductance.Our study suggests that the dynamics associated with the sensitivity of ecosystems to changes in climatic factors need to be considered in the management of plantation forests under future global climate change.
文摘[Objectives]The soil permeability and its influencing factors in typical plantations were studied to provide a scientific basis for tending and managing plantations in the Haikou forest area of Kunming City.[Methods]With three kinds of typical forest stands,i.e.,over-mature Pinus armandii Franch.,mid-mature Eucalyptus robusta Smith,and over-mature E.robusta Smith in this region as the research objects,soil infiltration changes and the effects on soil water retention in different stands,soil layers,and gap conditions under different moisture conditions were analyzed.[Results]①Under all three moisture conditions,the over-mature P.armandii forest demonstrated higher overall infiltration rates than the other two forest stands,which showed relatively similar infiltration rates.In all three stands,the soil infiltration rate decreased as the depth of the soil increased.Significant fluctuations in soil infiltration rate were observed during the initial 0-5 min,followed by gradual stabilization or regular fluctuations after 5 min.The infiltration process generally reached saturation after approximately 20 min.②The average infiltration rate was identified as the key factor affecting soil infiltration.Comprehensive evaluation of soil permeability revealed that the over-mature P.armandii forest exhibited optimal soil permeability.③Various soil physical and chemical properties significantly affected different indexes of soil permeability under varying conditions,with soil organic carbon content and water repellency demonstrating particularly notable effects on infiltration under different conditions.[Conclusions]Soil infiltration rates gradually decreased with the deepening of the soil layer.Principal component analysis(PCA)showed that the soil permeability of the over-mature P.armandii forest was stronger than that of the other two stands under the three moisture conditions,especially in non-gap positions.All soil indexes affected soil permeability,and soil organic carbon and water repellency were the key factors affecting soil permeability.
基金supported by resources of the Secretary of Environment of the Medellín district,through the agreement N°001-2023 between this entity,the Faculty of Agricultural Sciences of National University of Colombia at Medellín
文摘The Andean montane forests provide a wide range of ecosystem services like water supply, carbon sequestration, and biodiversity preservation. Restoration of these forests is critical due to their degraded state and the need to recover, maintain and enhance the ecosystem services they provide. However, we lack understanding of aboveground biomass (AGB) accumulation in restored Andean montane forests. AGB is a key indicator of ecosystem productivity and provides essential data on vegetation carbon stocks, permitting the assess successfulness of restoration efforts. In 2010 the initiative Más Bosques para Medellín was formulated in Medellín City, tropical Andes, Colombia, aiming to restore the forests located in the surrounding rural areas of the city, with interest in preserving the ecosystems services like water supply. The project established 548 ha of mixed plantations with native species. After 13 years, our study aims to developed in situ allometric equations and to evaluate AGB accumulation to assess restoration performance. We measured, harvested, and weighted 144 individuals from these arrangements to fit a general equation for the project and six specific equations for each one of the six most frequent species. The AGB had a positive correlation with diameter at breast height (D), total height (H) and specific wood density (WD). The best general equation uses D and WD as predictors (R^(2) = 0.928). The specific species equations certainly responded to the functional traits of each species. Using the latest inventory of permanent plots of the project we estimated a mean AGB accumulation of 41.91 ± 30.34 Mg ha^(–1) and a total accumulation of 22,996.05 Mg of AGB for the 548 ha. We compared these results with studies developed for natural forest in the region and other land covers. We found contrast behaviors in the AGB accumulation across our study zones. The developed equations have broad applicability across the Andes region, offering valuable insights for similar restoration initiatives. Furthermore, will facilitate the assessment of current restoration efforts and inform scientifically based decisions for future mixed plantation practices.
基金financial support from the National Natural Science Foundation of China(32125028,32192431)the Science and Technology Major Project of Gansu Province,China(23ZDKA0006).
文摘Tree growth is extremely vulnerable to climate change,especially in semi-arid areas.Although the response of stem radial growth(SRG)to climate change has been extensively studied,the intra-annual regulatory mechanisms of SRG in trees with different water use strategies and life types remain poorly understood.This study calculated the SRG of four native species in the semi-arid area of the Loess Plateau,China,including two isohydric species(Pinus tabuliformis Carrière and Populus×hopeiensis Hu&Chow)and two anisohydric species(Prunus sibirica L.and Platycladus orientalis(L.)Franco).The results revealed that the intra-annual SRG of all the four tree species exhibited a single peak,and greater SRG was found in anisohydric species.Principal component analysis and structural equation model revealed that atmospheric water,particularly relative humidity,was the main factor affecting the SRG of coniferous species(P.tabuliformis and P.orientalis),whereas the SRG was mainly affected by soil water content in broadleaf species(P.sibirica and P.×hopeiensis).These findings suggested that water use strategies and life types play important roles in SRG and environmental response of trees in semi-arid area.Considering the high climate sensitivity of wood formation in trees,our results highlight the importance of water use strategies and life types of trees in SRG prediction in the context of future climate change in arid and semi-arid areas.
文摘Phosphorus(P)is crucial for plant growth.However,its low availability in subtropical soils necessitates that trees rely on microorganisms for effective P acquisition.The introduction of broadleaf trees has been shown to facilitate P acquisition in coniferous plantations by altering the rhizosphere fungal communities.Despite this,functional shifts in these communities and the expression of root phosphorus cycling genes(PCGs)remain inadequately understood.This study investigated coniferous Pinus massoniana and Cunninghamia lanceolata plantations interplanted with broadleaf species associated with arbuscular mycorrhizal(AM)or ectomycorrhizal(ECM)fungi.Rhizosphere soil and fine roots from the conifers were analyzed to examine soil bioavailable P fractions,root mycorrhizal colonization,rhizosphere fungal community composition,enzyme function predictions,and root PCGs expression.We found that citric-P in rhizospheric soil of P.massoniana increased with the introduction of Quercus gilva(an ECM-associated tree species),whereas Bray-P content in the rhizosphere of C.lanceolata decreased upon the introduction of either Q.gilva or Phoebe zhennan(an ECM-associated tree species).Moreover,the relative abundance of saprophytic fungi(e.g.,Mortierella)increased following the introduction of broadleaf trees.Specifically,the introduction of Q.gilva was associated with elevated levels of organic P mineralization genes(e.g.,phoA)and enzymes(e.g.,phytases and acid phosphatase(ACP))in conifers.In contrast,the introduction of P.zhennan increased the expression of inorganic P solubilization genes(such as qppC in P.massoniana roots and ppa in C.lanceolata roots).Key contributors to P absorption in conifer roots included Cenococcum,Rhizopogon,and Glomus.This study advances our understanding of P cycling in coniferous rhizospheres and the dynamics of coexisting mycorrhizal tree systems,yielding valuable insights into sustainable management of plantation ecosystems.
基金funded by the National Natural Science Foundation of China(grant number:31971527,32001126)Heilongjiang Provincial Key Research and Development Plan Guidance Projects(grant number:GZ20210009)Natural Science Foundation of Heilongjiang Province(grant number:TD2019C002).
文摘Human activities contribute to elevated nitrogen input in terrestrial ecosystems,influencing the composition of soil nutrients and microbial diversity in forest ecosystems.In this study,we built four addition treatments(0,20,40,and 80 kg ha^(−1)a^(−1)N for 6 a)at a Korean pine plantation of different soil horizons(organic(O)horizon,ranging from 0 to 10 cm,and organomineral(A)horizon,extending from 10 to 20 cm)to evaluate responses of the structure of saprophytic fungal communities.Here,80 kg ha^(−1)a^(−1)N treatment significantly decreased the community richness in soil A horizon with the Chao1 index decreasing by 12.68%.Nitrogen addition induced changes in the composition of saprophytic fungi community between the different soil horizons.The co-occurrence network and its associated topological structure were utilized to identify mycoindicators for specific fungi to both soil horizons and nitrogen addition levels.In soil O horizon,the mycoindicators included Penicillium,Trichoderma,Aspergillus,and Pseudeurotium across control,low,medium,and high nitrogen treatments.In soil A horizon,Geomyces,Cladophialophora,Penicillium,and Pseudeurotium were identified as mycoindicators.Structural equation modeling determined NH_(4)^(+)-N as the key factor driving changes in saprotrophic fungal communities.Our study aimed to screen mycoindicators that can respond to the increasing global nitrogen deposition and to assess the roles of these mycoindicators in the saprophytic fun-gal community structure within Korean pine plantations in northeast China.
基金This study was supported by Chinese Academy of Science Program (KZCX2-YW-405)the Knowledge Innovation Program of the Chinese Academy of Sciences
文摘An investigation on soil organic carbon, total N and P, NO3-N, available P, microbial biomass C, N and P, basal respiration and metabolic quotients （qCO2） was conducted to compare differences in soil microbial properties and nutrients between 15-year-old pure Chinese fir （Cunninghamia lanceolata） and two mixed Chinese fir plantations （mixed plantations with Alnus crernastogyne, mixed plantations with Kalopanax septemlobus） at Huitong Experimental Station of Forest Ecology （26°45′N latitude and 109°30′E longitude）, Chinese Academy of Sciences in May, 2005. Results showed that the concentrations of soil organic carbon, total N, NO3^--N, total P and available P in mixed plantations were higher than that in pure plantation. Soil microbial biomass N in two mixed plantations was averagely higher 69% and 61% than that in pure plantation at the 0-10 cm and 10-20 cm soil depth, respectively. Soil microbial biomass C, P and basal respiration in mixed plantations were higher 11%, 14% and 4% at the 0-10 cm soil depth and 6%, 3% and 3% at the 10-20 cm soil depth compared with pure plantation. However, soil microbial C： N ratio and qCO2 were averagely lower 34% and 4% in mixed plantations than pure plantation. Additionally, there was a closer relation between soil microbial biomass and soil nutrients than between basal respiration, microbial C： N ratio and qCO2 and soil nutrients. In conclusion, introduction of broad-leaved tree species into pure coniferous plantation improved soil microbial properties and soil fertility, and can be helpful to restore degraded forest soil.
基金Supported by the Project of the Basic Research Operation Cost of State Level Research Institutes "Long-term Location Investigation of Basic Data for Rubber Production " ( XJSYWFZX-2008-14 and XJSYWFZX-2007-2)the Project Natural Sciences Fund of Hainan Province (807045)~~
文摘[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber （Hevea brasiliensis Muell-Arg） plantations at different age stages in the western region of Hainan Island,so as to evaluate the ecological benefits of rubber plantations and provide basic data for studying the effect of tropical land utilization/cover change on the global carbon and nitrogen cycle. [Method]The situs was in Danzhou city,western region of Hainan Island,and the samples were four kinds of rubber plantations soil at different ages and one kind of control check （pepper,Piper nigrum L.） soil. In this research,four quadrats were set up in each sample,and the size of each was 20 cm×20 cm. Four specimens were gathered from four layers of 0-15,15-30,30-45,45-60,and the average of them was the last analysis result of each sample. Soil density was measured by cutting ring method,soil containing and hygroscopic water was detected by oven drying method,soil organic carbon （SOC） was measured by low temperature heated outside potassium dichromate oxidation-colorimetry method,and soil total nitrogen （STN） was detected by semimicro Kjeldahl method. [Result]SOC contents of different layers in rubber plantations soil at different age stages （including the CK pepper soil,the same as below） varied little,and the content of SOC in surface layer （0-15 cm） was higher,while the underlayer （45-60 cm） was lower than the average value; there was significant difference in SOC content among different kinds of soil,and the content was of 6.03-7.78 g/kg,tapping young trees （7 years） CK pepper mature age trees （30 years） prophase of young trees （2 years） tapping trees （16 years）; there was no significant difference in SOC storage among different kinds of soil,and the storage was of 61.33-74.29 t/hm2,mature age trees （30 years） tapping young trees （7 years） prophase of young trees （2 years） CK pepper tapping trees （16 years）; there was significant difference in STN content among rubber plantations soil at different age stages,the content was of 410.86-664.14 mg/kg2,CK pepper tapping young trees （7 years） prophase of young trees （2 years） mature age trees （30 years） tapping trees （16 years）,and STN content of tapping trees （16 years） soil was extremely lowest; there was significant difference in C/N ratio among different kinds of soil,the ratio was of 10.94-14.47,and the ratio of tapping trees （16 years） mature age trees （30 years） tapping young trees （7 years） CK pepper prophase of young trees （2 years）. [Conclusion]There wasn＇t unhealthy effect of rubber trees planted in tropical area on the content and storage of SOC,the content of STN and the ratio of C/N. there was no significant difference between rubber plantations and CK pepper soil,and the effects of rubber plantation on soil carbon-nitrogen was similar to that of other tropical crops （such as pepper）.
基金supported by Key Projects in the National Science & Technology Pillar Program during the EleventhFive-year Plan Period (Nos. 2006BAD03A14-01)Important Science & Technology Specific Projects of Fujian province (2006NZ0001-2)supported by the Key Laboratory of south mountain timber culti-vation, state forestry administration, P. R. China
文摘The soil respiration rates （Rh） in 6-year-old （young）, 17-year-old （middle-age）, 31-year-old （mature） Casuarina equisetifolia coastal plantations were measured using an LICOR-8100 automated soil CO2 flux system from May 2006 to April 2007. Results show that Rh displayed an obvious seasonal pattern across the observed years. The maximum values of Rh occurred at June and July and the minimum at December and January. Soil temperature and soil moisture as well as their interaction had significant effects on the monthly dynamics of Rh. The analysis by one-way ANOVA showed that Rh had a significantly exponential relation （p〈0.05） to soil temperature at soil depth of 5 cm, and had a linear relation （p〈0.05） to soil water content of the upper 20 cm. The result estimated by the two-factor model shows that soil temperature at soil depth of 5 cm and soil moisture at soil depth of 20 cm could explain 68.9%-91.9% of seasonal variations in Rh. The or- der of Rh rates between different stand ages was middle-age plantation〉mature plantation〉young-age plantation. With the increase of growth age of plantation, the Q10 of Rh increased. The contribution of Rh to total soil surface CO2 flux was 71.89%, 71.02% and 73.53% for the young, middle-age and mature plantation, respectively. It was estimated that the annual CO2 fluxes from Rh were 29.07, 38.964 and 30.530 t.ha^-1.a^-1 for the young, middle-age and mature plantation, respectively.
文摘the investigation was carried out on 10-year-old plantation of Fraxinus mandshurica in Mao抏r Mountain Experimental Station of Northeast Forest University. Tree height (H), diameter at breast height (D1.3) and the increment of tree height in 5 years (H5), the thickness of humus layer, as well as the soil moisture were measured for the plantation and the growth indexes (H, D1.3, H5) for different site conditions were analyzed. The results showed that main site factors influencing the growth of Fraxinus mandshurica were soil moisture, gradient and location of slope in order. The growth of Fraxinus mandshurica was better on the middle- or up-slope site than on the down-slope site. Soil moisture and late frost caused by terrain are the main reasons that limit the growth of Fraxinus mandshurica plantation.
文摘Microclimate characteristics and related environmental energy mechanisms were examined based on the long term located observations in the mature, thinned and young Cunninghamia lanceolata plantation ecosystems in western Hunan Province, China. The results show that the mature plantation ecosystem can improve the microclimate significantly by regulating the amount and spatial distribution of environmental energy, which delineates the pattern of the microclimate in forest ecosystems in the process of ecological restoration. Compared with the young plantation, the mature plantation ecosystem decreased annual mean air temperature by 0 4℃. The maximum decrease in monthly mean air temperature was 2 3℃. The mature plantation ecosystem decreased annual mean ground temperature by 1 2℃ with a maximum decrease in monthly mean ground temperature of 2 3℃. Mainly due to the dense canopy, the mature forest ecosystem regulates the distribution of radiation energy, and expenditure ratios of heat budget and principal energy components to decrease temperature or make it even.
基金supported by National Technology Support Project (2008BAD95B10-6)
文摘The organic carbon contents,carbon density and carbon storage of the soil in the Pinus koraiensis plantation ecosystem were investigated in Maoershan experimental forest farm,Shangzhi County,Heilongjiang,on the west slope of the Zhangguangcai Mountains in northeastern China for providing data to evaluation of the carbon balance in forest ecosystem of northeastern China.These soil carbon indicators were measured in three forest types,pure P.koraiensis plantation,P.koraiensis and Betula platyphylla mixed forest,and the P.koraiensis and Quercus mongolica mixed forest.The soil carbon pool consisted of four compartments,namely L layer,F layer,H layer and B layer.With variance analysis,we found that both organic carbon content and carbon density of the soil were significantly affected by forest types,soil compartments and slope positions.The highest soil carbon density（278.63 Mg·ha^-1）.was observed in the mixed forest of P.koraiensis and Q.mongolica.The B layer had the highest carbon density（212.28 Mg·ha^-1） among all the soil compartments.In terms of slope position,the highest soil carbon density（394.18 Mg·ha^-1） presented in the low slope.Besides,soil carbon content and carbon density had a marked change with the organic matter content and vertical depth of the soil in each compartment.The results of this study implied that in the temperate humid region,the mixed ecosystem of regional Pinus koraiensis plantations and natural forest had relatively high carbon storage capability.
基金supported by National Natural Science Foundation of China (No 30872068)the Science and Technology Key Scientific Project of Heilongjiang Province (GA06B302-3)Fund of Thesis for Post Graduated Student of NEFU(GRAM09)
文摘A study was conducted to determine the characters of soil structure in different water and soil conservation forests in Keshan County,northwest of Heilongjiang Province,China.The soil bulk density,the ratio of non-capillary porosity and capillary porosity（NCP/CP）,and the generalized soil structure index（GSSI） were measured for Fraxinus mandshurica,Larix gmelini,Pinus sylvestris var.mongolica,and Picea koraiensis plantations as well as the abandoned land（as control） adjacent to the forests in typical black soil region.Results show that at soil depth of 0–30cm,the soil bulk density of F.mandshurica forest and L.gmelini forest was lower than that of P.sylvestris var.mongolica forest and P.koraiensis forest,with the relative decrease of 8.04%–11.01%.The soil bulk density of L.gmelini forest was significantly different from that of the P.sylvestris var.mongolica forest and P.koraiensis forest.The NCP/CP values of the four types of plantations were all higher（59.75%–128.82% relatively） than that of abandoned land（p〈0.05）,indicating that the soil aeration and permeability under forest were enhanced,especially under L.gmelini forest.GSSI values of the four types of forests were also relatively higher（2.98%–4.36%） than abandoned land（p〈0.05）,indicating that those soil and water conservation forests,especially the F.mandshurica forest and P.koraiensis forest,can promote soil condition to approximate ideal soil structure.The result of this study can provide theoretical basis for scientifically evaluating the effects of vegetation restoration on soil quality in typical black soil region.
基金part of State 9th Five-Year Plan project of "Early Mensuration of Picea koraiensis (nakai)".
文摘Tracheid characteristics ofPicea koraiensis from natural stand in Liangshui area and plantation in Mao'ershan area were studied. The results of variance analysis showed that the tracheid length, diameter, and thickness of tracheid wall were significant differences between the growth rings. All those characteristics tend to increase from heart-center to bark. In natural stand, it has positive correlation between the characteristics. In plantation, the tracheid length has positive correlation with the trachied diameter, while both the trachied length and the trachied diameter has negative correlation with the thickness of trachied wall. The tracheid length and diameter have no significant difference in growth between natural stand and plantations. The thickness of tracheid wall from the plantation is a little thicker than that from the natural stand before 15 years.
基金Supported by the Fundamental Research Funds for Rubber Research Institute,CATAS (1630022011013 )Hainan Natural Science Foundation (807045)Running Costs of Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments,Ministry of Agriculture~~
文摘[Objective] The paper was to analyze the quality of flux observation data of rubber plantation.[Method]Based on the FSAM model,footprint and flux source area were analyzed according to the continuous flux measurement with the open-path eddy covariance system on the 50 m tower of Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments,Ministry of Agriculture from Jan 1 to Jun 30,2010.[Result] Under unstable stratification,source areas were smaller than those under stable conditions,and source areas in the dormant season were larger than those in the growing season at the same level.In the main wind direction 130°-270°,the upwind range of source areas was in the magnitude of 100-758 m and vertical upwind range was-251-251 m at 80% level under unstable stratification in the growing season,and they were some large than those under the unstable stratification in the dormant season.The source areas of the upwind and vertical upwind ranges were 173-1 858,-534-534 m especially under stable stratification in the growing season,and they were smaller than those under stable stratification in the dormant season.In the other wind directions of 0°-130° and 270°-360°,the ranges were similar to those of the growing season in the prevailing wind direction under the same atmospheric conditions.[Conclusion] The study would lay a foundation for the future flux calculation and analysis.
基金Supported by Key Science and Technology Project of Hainan Land Reclamation Bureau([2009]57)~~
文摘The influence of formula fertilization optimization on dry rubber yield and economic benefits of the rubber plantation in Hainan Longjiang Farm were studied by using ＂contrast＂ design method of fertilizer field experiments. The results showed that the actual production rate reached 4.61% and the net production rate of dry rubber reached 3.97% by application of optimized fertilization formula. Analysis of variance showed that the average dry rubber yield in optimization of formula fertil- ization area was significantly higher than that of conventional area. The results also indicated that the optimization of formula fertilization had obvious economic benefits, and each rubber tree reduced cost and increased 9.95 yuan on average after the test.
基金Supported by National 948 Project(2011-4-63)Special Research Fund for Welfare Act of State Forestry(200904001-3)Youth Fund of Anhui Normal University(2009xqn73)~~
文摘[Objective]The paper was to study the effect of continuous cropping on leaf nutrient and growth of different species of poplar plantation.[Method] The tree height,diameter at breast height（DBH）,volume of different generations and species of poplar plantation in poplar production area in northern Jiangsu Province,as well as TN,TP and TK content in their leaves were determined through field investigation and indoor experiment.[Result] With the increasing generation,the changes of TN,TP and TK content in the leaves of different ages of two varieties of forest stand were also different.However,with the increasing tree ages,TN,TP and TK contents in leaves showed decrease trend.With the increasing generation,the changes of tree height of I-69 and I-72 poplar showed the similar trend.The effect of increasing generation on tree height of 7-year-old and 10-year-old poplar was relatively stable,showing decrease trend from generation to generation.The tree height of 4-year-old poplar first increased and then decreased with the increasing generation.The changes of DBH along with different generations were basically consistent with the changes of tree height.With the increasing cultivation generations,the volume of 7-year-old and 10-year-old poplar decreased with significant difference.[Conclusion ] The result provided basis for rational fertilization and management of poplar plantation,improvement of productivity of poplar plantation,and achievement of sustainable management of plantation.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(No. KZCX2-YW-405)the Innovation Group Project of National Natural Science Foundation of China (No.40621061)
文摘Tree species composition was important for carbon storage within the same climate range.To quantify the dynamics of ecosystem carbon allocation as affected by different tree species,we measured the above-and below-ground biomass accumulation in 22 years,as well as the tissue carbon concentrations of trees in Cunninghamia lanceolata plantation and Michelia macclurei plantation.Results indicated that M.macclurei plantation significantly stored more carbon（174.8 tons/hm2） than C.lanceolata plantation（154.3 tons/hm2）.Most of the carbon was found in the soil pool（57.1% in M.macclurei plantation,55.2% in C.lanceolata plantation）.Tree and soil component of M.macclurei plantation possessed significantly higher carbon storage than that of C.lanceolata plantation（p 〈 0.05）.No significant difference was found in the carbon storage of understory and forest floor.These results suggest that the broadleaved species（M.macclurei） possesses greater carbon sequestration potential than the coniferous species（C.lanceolata） in southern China.
基金funded by the National Natural Science Foundation of China (No. 31930078)the National Key Research and Development Program of China (No. 2021YFD2200405)
文摘Mixed-species plantations generally exhibit higher ecosystem multifunctionality than monospecific plantations.However,it is unclear how tree species functional composition influences species mixture effects on ecosystem multifunctionality.We selected 171 monospecific and mixed-species plantations from nine regions across subtropical China,and quantified 13 key ecosystem functional properties to investigate how species mixture effects on ecosystem multifunctionality are modulated by functional diversity and identity.We found that ecosystem multifunctionality was significantly higher(p<0.05)in mixed tree plantations than in monospecific plantations except the mixed-conifer species plantations.Across all regions,ecosystem multifunctionality was significantly higher(p<0.05)in mixed conifer-broadleaf plantations than in monospecific plantations of the corresponding species,but not different between mixed and monospecific coniferous plantations.The magnitude of species mixture effects on ecosystem multifunctionality varied greatly with tree species compositions.Taking Cunninghamia lanceolata Lamb.as an example,the effects varied from a range of 2.0%–9.6%when mixed with a conifer species to 36%–87%when mixed with a broadleaf species.The functional diversity was the dominate driver shaping ecosystem multifunctionality,while functional identity,as expressed by community-weighted mean of specific leaf area,also had a positive effect on ecosystem multifunctionality through the increased below-ground nitrogen and phosphorus stocks regulated by specific leaf area of the mixing tree species.Our study highlights the important role of functional diversity in shaping ecosystem multifunctionality across region-wide environmental conditions.Mixed conifer-broadleaf tree plantations with distinct functional traits benefit the enhancement of ecosystem multifunctionality,and the magnitude of species mixture effects is modulated by the functional identity of tree species composition;those relationships deserve a special consideration in multifunctional management context of subtropical plantations.
