Despite growing attention to the role of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in forest nutrient cycling, their monthly concentration dynamics in forest ecosystems, especially in subtrop...Despite growing attention to the role of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in forest nutrient cycling, their monthly concentration dynamics in forest ecosystems, especially in subtropical forests only were little known. The goal of this study is to measure the concentrations and monthly dynamics of DOC and DON in precipitation, throughfall and stemflow for two planta- tions of Schima superba (SS) and Chinese fir (Cunninghamia lanceolata, CF) in Jianou, Fujian, China. Samples of precipitation, throughfall and stemflow were collected on a rain event base from January 2002 to December 2002. Upon collection, all water samples were analyzed for DOC, NO3 -N, NH4 -N and total dissolved N (TDN). DON was calculated by subtracting NO3 -N and NH4 -N from TDN. The results - + - + showed that the precipitation had a mean DOC concentration of 1.7 mg·L-1 and DON concentration of 0.13 mg·L-1. The mean DOC and DON concentrations in throughfall were 11.2 and 0.24 mg·L-1 in the SS and 10.3 and 0.19 mg·L-1 in the CF respectively. Stemflow DOC and DON concentrations in the CF (19.1 and 0.66 mg·L-1 respectively) were significantly higher than those in the SS (17.6 and 0.48 mg·L-1 respectively). No clear monthly variation in precipitation DOC concentration was found in our study, while DON concentration in precipita- tion tended to be higher in summer or autumn. The monthly variations of DON concentrations were very similar in throughfall and stemflow at both forests, showing an increase at the beginning of the rainy season in March. In contrast, monthly changes of the DOC concentrations in throughfall of the SS and CF were different to those in stemflow. Throughfall DOC concentrations were higher from February to April, while relatively higher DOC concentrations in stemflow were found during September-November period.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
The concentrations and seasonal dynamics of DOC in forest floors of monoculture plantations of Castanopsis kawakamii and Chinese fir (Cunninghamia lanceolata) were assessed in Sanming, Fujian, China (26°11′30...The concentrations and seasonal dynamics of DOC in forest floors of monoculture plantations of Castanopsis kawakamii and Chinese fir (Cunninghamia lanceolata) were assessed in Sanming, Fujian, China (26°11′30″N, 117°26′00″E). Forest floor samples were taken in January, April, July and October in 2002 and divided into undecomposed material (horizon Oi), partially decomposed organic material (horizon Oe), and fully decomposed organic material (horizon Oa). Upon collection. DOC concentrations of samples were analyzed by a High Temperature TOC. The results showed that the annual average DOC concentration of Chinese fir (1341.7 mg·kg^-1) in the forest floor was higher than that of Castanopsis kawakamii ( 1178.9 mg·kg^-1). Difference in DOC concentrations was observed among three horizons of the forest floor. DOC concentration of forest floor in the two forests was the highest in horizon Oe. Seasonal trends of DOC concentrations in different horizons of forest floors were similar and the maximal value occurred in autumn (or winter). The concentration and temporal change of DOC in studied forests were probably related to the variation in moisture, temperature, biological activity and quantity of organic matter in the forest floor.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
The amounts of litter produced and nutrients returned play a fundamental role in the productivity and biogeochemical and nutrient cycling of forest ecosystems.We monitored annual litterfall production, nutrient return...The amounts of litter produced and nutrients returned play a fundamental role in the productivity and biogeochemical and nutrient cycling of forest ecosystems.We monitored annual litterfall production, nutrient return,and monthly dynamics over a one-year period in Chinese fir plantations aged 10, 22, and 34 years. Our objective was to quantify litterfall and nutrient return over a complete harvest rotation of Chinese fir. Annual litterfall production increased with stand age and was recorded as(3,294.6 ± 360.4),(3,733.9 ± 211.2), and(4,876.1 ± 212.8) kg ha-1a-1in stands aged 10, 22 and 34 years, respectively. Total litter production was significantly greater in the stand aged34 years than in the stand aged 10 years(p / 0.05). With the exception of miscellaneous components, needle litterfall constituted the highest proportion(27.5–43.6 %), followed by branches/twigs(9.5–16.6 %). In all three plantations,annual total nutrient return to soil was in the order of C(1,119.95–2,709.05 kg ha-1a-1) [ N(39.32–62.04 kg ha-1a-1) [ K(15.95–22.44 kg ha-1a-1) [ P(1.30–1.63 kg ha-1a-1). C, N, K and P input to soil was significantly lower in the 10-year-old stand in comparison to the 22- and34-year-old stands(p / 0.05). Litterfall production and nutrient return(C, N and K) followed similar patterns, and C and N input to soil was significantly related to litterfall production(needle, branch and total litterfall). C, N, P and K input to soil and total litterfall production were mainly driven by needle litterfall.展开更多
We calculated a self-thinning exponent of 1.05 for tree mass using the 3/2 power equation in 93 Cunninghamia lanceolata plots.According to Weller’s allometric model,the self-thinning exponent for tree mass was calcul...We calculated a self-thinning exponent of 1.05 for tree mass using the 3/2 power equation in 93 Cunninghamia lanceolata plots.According to Weller’s allometric model,the self-thinning exponent for tree mass was calculated as 1.28 from the allometric exponents h and d.The both self-thinning exponents were significantly lower than 3/2.The self-thinning exponent of organs was estimated to be 1.42 for stems,0.93 for branches,0.96 for leaves,1.35 for roots and 1.28 for shoots,respectively.The self-thinning exponent of stem mass was not significantly different from 3/2,whereas thinning exponents of trees,branches,leaves and roots were significantly lower than 3/2.The stand leaf mass and stand branch mass were constant regardless of the stand density.The scaling relations among branch,leaf,stem,root and shoot mass(MB,ML,MS,MR and MA,respectively) showed that MB and ML scaled as the3/4 power of MS,whereas MS or MA scaled isometrically with respect to MR.展开更多
Cunninghamia lanceolata (Lamb.) Hook. is economically the most important tree species in southern China and has been cultivated in plantations on a large scale. This species is widely used in construction, furniture...Cunninghamia lanceolata (Lamb.) Hook. is economically the most important tree species in southern China and has been cultivated in plantations on a large scale. This species is widely used in construction, furniture, utensils and shipbuilding. Soil fertility of C. lanceolata stands affects soil structure, porosity and nutrient availability, which causes changes in fauna activity. During January to February 2008, an ice storm caused extensive damage to C. lanceolata stands. Despite the environmental importance of soil fauna, basic information on the distribution and diversity of soil fauna in C. lanceolata stands after ice storm damage is lacking. To assess the response of soil fauna diversity and distribution to forest gaps following the ice storm, five small gaps (each 30-40 m^2), five large gaps (each 80-100 m^2) and five canopy cover plots were selected within a 2-ha C. lanceolata stand. Soil samples were collected from 0 to 10 cm depth in March 2011 to measure soil fauna diversity and abundance. The abundance and community composition of the soil fauna varied with gap size. In canopy cover sites, the number of individuals was 2.0 and 5.2 times greater than in the small gaps and large gaps. Three taxa (Nematoda, Oribatida and lnsecta) of soil inver- tebrates occurred commonly, and Nematoda dominated the communities in all three habitat types. The Shannon-Wiener diversity index, Margalef diversity index, and Pielou evenness index were high in the small gaps, indicating that they harbored the most species, with the most even distribution, and the highest diversity. Our results indicated that gap size apparently affected abundance and community composition of the soil fauna.展开更多
[Objectives] The aim was to reveal the accumulation characteristics and differences of biomass productivity of Taiwania flousiana plantation and successive rotation plantation of Cunninghamia lanceolata .[Methods] The...[Objectives] The aim was to reveal the accumulation characteristics and differences of biomass productivity of Taiwania flousiana plantation and successive rotation plantation of Cunninghamia lanceolata .[Methods] The biomass and productivity of the 23-year-old T. flousiana plantation and successive rotation plantation of C. lanceolata were studied at Nandan Shankou Forestry Farm of Guangxi., China.[Results] There were differences in the biomass distribution of different organs of T. flousiana plantation and successive rotation plantation of C.lanceolata. The biomass for the T. flousiana plantation was distributed in the order of stem 〉 branch 〉 leaves 〉 bark, and the successive rotation plantations of C. lanceolata was stem〉 root 〉 branch 〉 bark 〉 leaves. The biomass of tree layer of 23-years-old T. flousiana plantation and successive rotation plantations were 195.21 and 136.82 t/hm^2, respectively, including 113.32 and 87.91 t/hm^2 of economic biomass (stem). The annual net productivity of tree layer of the 2 plantations were 8.49 and 5.95 t/(hm^2·a), respectively, including 5.14 and 3.82 t/(hm^2·a) of stem. Therefore, T. flousiana plantation has higher biomass accumulation ability than that of successive rotation plantations of C.lanceolata, and can be used as an excellent substitute tree species for the regeneration of C.lanceolata cutover plantation.[Conclusions]展开更多
The 23-year-old T. flousiana plantation and successive rotation plantation of C. lanceolata at Shankou Forest Farm of Nandan County, Guangxi were tested by the method of plot investigation combining with biomass m...The 23-year-old T. flousiana plantation and successive rotation plantation of C. lanceolata at Shankou Forest Farm of Nandan County, Guangxi were tested by the method of plot investigation combining with biomass measurement. Carbon storage and spatial distribution of different components in the two forests were analyzed. The results indicated that carbon content in different organs of T. flousiana ranged from 426.0 to 503.9 g/kg, and the order was bark 〉stem 〉 root 〉 branch 〉 leaf. The carbon contents in shrub, herb and litter layers were452.9 , 408.0 and 428.9 g/kg, respectively. Carbon content in the soil (0 -80 cm)was 16.59 g/kg. The carbon content in different organs of C. lanceolata ranged from 464.5 to 508.9 g/kg, and the order was bark 〉 stem 〉 branch 〉 root 〉 leaf. The carbon contents in shrub, herb and litter layers were 456.2, 416.3 and 468.1 g/kg, respectively. Carbon content in the soil (0 -80 cm)was 15.77 g/kg. Total carbon storage amounts of T. flousiana plantation and successive rotation plantation of C. lanceolata were 245.83 and 213.52 t/hm^2, respectively. The carbon storage order of different structure layers from T. flousiana plantation and successive rotation plantation of C. lanceolata was soil layer (0 -8 0 cm) 〉 vegetation layer 〉 litter layer. Annual net productivity in the arbor layers of T. flousiana plantation and successive rotation plantation of C. lanceolata plantations was 10.75 and 17.13 t/(hm^2 · a) ; annual net carbon fixation amounts were estimated as 5.05 and 3.47 t /(hm^2 · a) ; annual net absorption C02 amounts were 18.53 and 12.73 t/(hm^2 · a) respectively.展开更多
In thes paper, the variation pattffe of wood Prpebo was edied for natural Cunninghamia lanceolata. The mathematical models of property were obtained on tracbeidlength, microfibril angle, late wood percdsgn, growth rin...In thes paper, the variation pattffe of wood Prpebo was edied for natural Cunninghamia lanceolata. The mathematical models of property were obtained on tracbeidlength, microfibril angle, late wood percdsgn, growth ring width and growth ring dsisity in the radial direction. The interrelation were analynd between tracheid length and microfibril angle. The result can provide sciatilic theory basis for wood utilhaion and early prediction of wood properties .展开更多
In order to study how exogenous hormones in C.lanceolata(gymnosperm)regulate somatic embryogenesis,we measured the endogenous phytohormones of two genotypes with different somatic embryogenesis efficiency and found th...In order to study how exogenous hormones in C.lanceolata(gymnosperm)regulate somatic embryogenesis,we measured the endogenous phytohormones of two genotypes with different somatic embryogenesis efficiency and found that an increase in endogenous concentrations of IAA and ABA may be correlated to more efficient somatic embryogenesis.By applying exogenous spermidine,we found that exogenous hormones may affect somatic embryogenesis efficiency through affecting the endogenous phytohormone content.Based on these results,further studies can be conducted whereby the concentration of exogenous hormones or the levels of endogenous phytohormones by molecular methods are regulated to promote somatic embryogenesis.Our research may benefit the long-term economic output of the forestry industry and lays the foundation to studying the molecular mechanism that controls somatic embryogenesis efficiency.展开更多
Results from pot culture (with one-year old Cunninghamia lanceolata and Schima superba) are described. It was found that the biomass production and elongation of C. lanceolata was seriously inhibited at pH 2.0 rain, b...Results from pot culture (with one-year old Cunninghamia lanceolata and Schima superba) are described. It was found that the biomass production and elongation of C. lanceolata was seriously inhibited at pH 2.0 rain, but for S. superba, was not affected markedly. When pH values of experimental rain were higher than 2.0, the root growth of both species was not adversely affected. Aluminium had already accumulated to some degrees in the roots of both trees, and started to affect the root growth of C. lanceolata at pH 2.0 rain. The soil chemistry was also examined. Increased acidity of experimental rain increased the leaching of Ca and Mg. The Al/Ca mol ratio increased from 0.3 to 0.9 in top soil, and in rhizosphere to 1.5 when the pH values of simulated acid rain were 4.5 to 2.0. In this experiment, NO3- fertilization effect was discovered.展开更多
A new bislabdane-type diterpenoid lanceolactin (I), was isolated from the roots of Cunninghamia lanceolata. Its structure was elucidated on the basis of spectroscopic methods, especially 2D-NMR techniques.
The structural characteristics of the tree crowns of Cunninghamia lanceolata var. Luotian(herein, Luotian), a natural variety of C. lanceolata(Chinese-fir, herein Lanceolata) in China, were analyzed using trunk and br...The structural characteristics of the tree crowns of Cunninghamia lanceolata var. Luotian(herein, Luotian), a natural variety of C. lanceolata(Chinese-fir, herein Lanceolata) in China, were analyzed using trunk and branch measurements and biomass determinations. Samples from two typical cultivated varietal populations were collected, including twenty-six 15–23-year-old trees of Luotian from a plantation, and nine 16–23-year-old trees of Lanceolata. Our results show that Luotian and Lanceolata samples differed significantly in crown structure, morphological indices, and biomass:(1) the oldest live branches on Luotian trees were 5–6 years old and 8–11 years old on Lanceolata. The ages of the live branches were not affected by the ages of the Luotian trees, while live branch ages increased with ages of Lanceolata trees;(2) the maximumbranching order of Luotian was level two. Compared to Lanceolata, the average number of first-order lateral branches(i.e., branches emerging from the trunk) and the number of first-order lateral branch whorls per sample tree were 12.9% and 32.2% lower, respectively, in Luotian.However, the average number of branches within a single whorl was 21.8% greater in Luotian;the average number of branch whorls at crown height was 51.1% greater. Thus,the Luotian variety has thicker branches;(3) the average lateral branch angles in Luotian and Lanceolata sample trees were 105.2° and 61.4°, respectively. The branch angles in 53.0% of lateral branches on Luotian ranged from105° to 135°, but 30° to 90° in 96% of the lateral branches on Lanceolata. Within the same crown layer, the average branch angle was 1.6–2.2 times greater in Luotian, and the angle was directly proportional to crown thickness;(4) the average base diameter and branch length on Luotian were1.3 cm and 75.8 cm, respectively, and 1.6 cm and112.2 cm for Lanceolata. For individual trees, branch growth differed significantly(p < 0.01) between Luotian and Lanceolata. However, the lateral branches grew at a similar rate among Luotian trees of different ages;(5) the average height to the lowest live branch on Luotian was128.3% greater than on Lanceolata, resulting in a significant difference(p < 0.01) in crown size. Compared to the crowns on Lanceolata, the Luotian crowns were 45.3%higher and 41.1% wider, and the surface area, volume, and growth of the crown were 27.0%, 11.4%, and 2.4 times greater than for Lanceolata, respectively;and,(6) the biomass of Luotian and Lanceolata sample trees also differed significantly. The mean crown, branch, and leaf biomass for Luotian was 40.0%, 25.2%, and 54.1% of those for Lanceolata, respectively. However, the leaf biomass in each layer of the Luotian crown was higher thanthat of Lanceolata, and leaf biomass increased with crown thickness.展开更多
文摘Despite growing attention to the role of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in forest nutrient cycling, their monthly concentration dynamics in forest ecosystems, especially in subtropical forests only were little known. The goal of this study is to measure the concentrations and monthly dynamics of DOC and DON in precipitation, throughfall and stemflow for two planta- tions of Schima superba (SS) and Chinese fir (Cunninghamia lanceolata, CF) in Jianou, Fujian, China. Samples of precipitation, throughfall and stemflow were collected on a rain event base from January 2002 to December 2002. Upon collection, all water samples were analyzed for DOC, NO3 -N, NH4 -N and total dissolved N (TDN). DON was calculated by subtracting NO3 -N and NH4 -N from TDN. The results - + - + showed that the precipitation had a mean DOC concentration of 1.7 mg·L-1 and DON concentration of 0.13 mg·L-1. The mean DOC and DON concentrations in throughfall were 11.2 and 0.24 mg·L-1 in the SS and 10.3 and 0.19 mg·L-1 in the CF respectively. Stemflow DOC and DON concentrations in the CF (19.1 and 0.66 mg·L-1 respectively) were significantly higher than those in the SS (17.6 and 0.48 mg·L-1 respectively). No clear monthly variation in precipitation DOC concentration was found in our study, while DON concentration in precipita- tion tended to be higher in summer or autumn. The monthly variations of DON concentrations were very similar in throughfall and stemflow at both forests, showing an increase at the beginning of the rainy season in March. In contrast, monthly changes of the DOC concentrations in throughfall of the SS and CF were different to those in stemflow. Throughfall DOC concentrations were higher from February to April, while relatively higher DOC concentrations in stemflow were found during September-November period.
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This study was supported by the Teaching and Research Award program for MOE P.R.C. (TRAPOYT)
文摘The concentrations and seasonal dynamics of DOC in forest floors of monoculture plantations of Castanopsis kawakamii and Chinese fir (Cunninghamia lanceolata) were assessed in Sanming, Fujian, China (26°11′30″N, 117°26′00″E). Forest floor samples were taken in January, April, July and October in 2002 and divided into undecomposed material (horizon Oi), partially decomposed organic material (horizon Oe), and fully decomposed organic material (horizon Oa). Upon collection. DOC concentrations of samples were analyzed by a High Temperature TOC. The results showed that the annual average DOC concentration of Chinese fir (1341.7 mg·kg^-1) in the forest floor was higher than that of Castanopsis kawakamii ( 1178.9 mg·kg^-1). Difference in DOC concentrations was observed among three horizons of the forest floor. DOC concentration of forest floor in the two forests was the highest in horizon Oe. Seasonal trends of DOC concentrations in different horizons of forest floors were similar and the maximal value occurred in autumn (or winter). The concentration and temporal change of DOC in studied forests were probably related to the variation in moisture, temperature, biological activity and quantity of organic matter in the forest floor.
基金Foundation project: This research was supported by Chinese Academy of Science Program (N0. ZCX3-SW-418) and the Natural Science Foundation of China (N0. 30470303)
文摘到 Cunninghamialanceolata 种植园的自然第二等的阔叶的森林的变换是在副热带的中国的一个普通管理惯例。在这研究,我们比较了土壤物理化学的性质,在一天赋的微生物引起的生物资源第二等的 broad-leavedforest 和二 C。在土壤上估计森林变换的效果的 lanceolata 种植园地点在林地生态学的 Huitong 试验性的车站的微生物引起的生物资源,中国科学院。器官的碳,总氮, NH_4^+-N 和微生物引起的生物资源碳和氮多是的土壤的集中在 C 下面降低。lanceolata 种植园作为与自然离开 secondarybroad 的森林相比。在 C 的第一和第二旋转玷污微生物引起的生物资源 C。lanceolataplantations 仅仅是 53% ,那中的 46% 个分别地在自然第二等的阔叶的森林,和微生物引起的生物资源 N 里是 97% 和 79% 。到器官的 Cwas 也在种植园地点降低的土壤的微生物引起的生物资源 C 的贡献。然而,到总氮和 NH_4^+-N 的微生物引起的 N 的贡献在 C 是更大的。lanceolata 种植园地点。因此,到 C 的自然第二等的阔叶的森林的变换。lanceolata 种植园并且 C 的连续的种。lanceolataled 到在土壤的衰落微生物引起的生物资源和在副热带的中国的森林土的降级。
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 National Natural Science Foundation of China(Grant Nos.31370619 and 31100472)Doctoral Program of Higher Education of Ministry of Education of China(Grant No.20113515110009)+2 种基金Forestry Public Benefit Research Projects of National Forestry Administration(Grant No.201304303)Science and Technology Major Project of the Fujian Province(Grant No.2012NZ0001–1)Training Program Foundation for University Distinguished Young Talents of Fujian Province,P.R.China(Grant No.JA 12091)
文摘The amounts of litter produced and nutrients returned play a fundamental role in the productivity and biogeochemical and nutrient cycling of forest ecosystems.We monitored annual litterfall production, nutrient return,and monthly dynamics over a one-year period in Chinese fir plantations aged 10, 22, and 34 years. Our objective was to quantify litterfall and nutrient return over a complete harvest rotation of Chinese fir. Annual litterfall production increased with stand age and was recorded as(3,294.6 ± 360.4),(3,733.9 ± 211.2), and(4,876.1 ± 212.8) kg ha-1a-1in stands aged 10, 22 and 34 years, respectively. Total litter production was significantly greater in the stand aged34 years than in the stand aged 10 years(p / 0.05). With the exception of miscellaneous components, needle litterfall constituted the highest proportion(27.5–43.6 %), followed by branches/twigs(9.5–16.6 %). In all three plantations,annual total nutrient return to soil was in the order of C(1,119.95–2,709.05 kg ha-1a-1) [ N(39.32–62.04 kg ha-1a-1) [ K(15.95–22.44 kg ha-1a-1) [ P(1.30–1.63 kg ha-1a-1). C, N, K and P input to soil was significantly lower in the 10-year-old stand in comparison to the 22- and34-year-old stands(p / 0.05). Litterfall production and nutrient return(C, N and K) followed similar patterns, and C and N input to soil was significantly related to litterfall production(needle, branch and total litterfall). C, N, P and K input to soil and total litterfall production were mainly driven by needle litterfall.
基金supported by Foundation of Guangdong Forestry Bureau (Nos.4400-F11031,4400-F11055)
文摘We calculated a self-thinning exponent of 1.05 for tree mass using the 3/2 power equation in 93 Cunninghamia lanceolata plots.According to Weller’s allometric model,the self-thinning exponent for tree mass was calculated as 1.28 from the allometric exponents h and d.The both self-thinning exponents were significantly lower than 3/2.The self-thinning exponent of organs was estimated to be 1.42 for stems,0.93 for branches,0.96 for leaves,1.35 for roots and 1.28 for shoots,respectively.The self-thinning exponent of stem mass was not significantly different from 3/2,whereas thinning exponents of trees,branches,leaves and roots were significantly lower than 3/2.The stand leaf mass and stand branch mass were constant regardless of the stand density.The scaling relations among branch,leaf,stem,root and shoot mass(MB,ML,MS,MR and MA,respectively) showed that MB and ML scaled as the3/4 power of MS,whereas MS or MA scaled isometrically with respect to MR.
基金supported by the Shenzhen Strategic Emerging Industrial Development Funds(GCZX20120618100801416)from Shenzhen Municipal People’s Government,China
文摘Cunninghamia lanceolata (Lamb.) Hook. is economically the most important tree species in southern China and has been cultivated in plantations on a large scale. This species is widely used in construction, furniture, utensils and shipbuilding. Soil fertility of C. lanceolata stands affects soil structure, porosity and nutrient availability, which causes changes in fauna activity. During January to February 2008, an ice storm caused extensive damage to C. lanceolata stands. Despite the environmental importance of soil fauna, basic information on the distribution and diversity of soil fauna in C. lanceolata stands after ice storm damage is lacking. To assess the response of soil fauna diversity and distribution to forest gaps following the ice storm, five small gaps (each 30-40 m^2), five large gaps (each 80-100 m^2) and five canopy cover plots were selected within a 2-ha C. lanceolata stand. Soil samples were collected from 0 to 10 cm depth in March 2011 to measure soil fauna diversity and abundance. The abundance and community composition of the soil fauna varied with gap size. In canopy cover sites, the number of individuals was 2.0 and 5.2 times greater than in the small gaps and large gaps. Three taxa (Nematoda, Oribatida and lnsecta) of soil inver- tebrates occurred commonly, and Nematoda dominated the communities in all three habitat types. The Shannon-Wiener diversity index, Margalef diversity index, and Pielou evenness index were high in the small gaps, indicating that they harbored the most species, with the most even distribution, and the highest diversity. Our results indicated that gap size apparently affected abundance and community composition of the soil fauna.
基金Supported by Guangxi Key R&D Plan Project(Guike AB17292008)Major Science and Technology Project of Guangxi Forestry(Guilin Science Word[2010]No.7)Guangxi Science Research and Technology Development Plan Program(Guikeneng 159825-38)
文摘[Objectives] The aim was to reveal the accumulation characteristics and differences of biomass productivity of Taiwania flousiana plantation and successive rotation plantation of Cunninghamia lanceolata .[Methods] The biomass and productivity of the 23-year-old T. flousiana plantation and successive rotation plantation of C. lanceolata were studied at Nandan Shankou Forestry Farm of Guangxi., China.[Results] There were differences in the biomass distribution of different organs of T. flousiana plantation and successive rotation plantation of C.lanceolata. The biomass for the T. flousiana plantation was distributed in the order of stem 〉 branch 〉 leaves 〉 bark, and the successive rotation plantations of C. lanceolata was stem〉 root 〉 branch 〉 bark 〉 leaves. The biomass of tree layer of 23-years-old T. flousiana plantation and successive rotation plantations were 195.21 and 136.82 t/hm^2, respectively, including 113.32 and 87.91 t/hm^2 of economic biomass (stem). The annual net productivity of tree layer of the 2 plantations were 8.49 and 5.95 t/(hm^2·a), respectively, including 5.14 and 3.82 t/(hm^2·a) of stem. Therefore, T. flousiana plantation has higher biomass accumulation ability than that of successive rotation plantations of C.lanceolata, and can be used as an excellent substitute tree species for the regeneration of C.lanceolata cutover plantation.[Conclusions]
基金Supported by Guangxi Key R&D Plan Project(Guike AB17292008)Guangxi Science Research and Technology Development Plan Program(Guikeneng 1598025-38)Major Science and Technology Project of Guangxi Forestry(Guilin Science Word[2010]No.7)
文摘The 23-year-old T. flousiana plantation and successive rotation plantation of C. lanceolata at Shankou Forest Farm of Nandan County, Guangxi were tested by the method of plot investigation combining with biomass measurement. Carbon storage and spatial distribution of different components in the two forests were analyzed. The results indicated that carbon content in different organs of T. flousiana ranged from 426.0 to 503.9 g/kg, and the order was bark 〉stem 〉 root 〉 branch 〉 leaf. The carbon contents in shrub, herb and litter layers were452.9 , 408.0 and 428.9 g/kg, respectively. Carbon content in the soil (0 -80 cm)was 16.59 g/kg. The carbon content in different organs of C. lanceolata ranged from 464.5 to 508.9 g/kg, and the order was bark 〉 stem 〉 branch 〉 root 〉 leaf. The carbon contents in shrub, herb and litter layers were 456.2, 416.3 and 468.1 g/kg, respectively. Carbon content in the soil (0 -80 cm)was 15.77 g/kg. Total carbon storage amounts of T. flousiana plantation and successive rotation plantation of C. lanceolata were 245.83 and 213.52 t/hm^2, respectively. The carbon storage order of different structure layers from T. flousiana plantation and successive rotation plantation of C. lanceolata was soil layer (0 -8 0 cm) 〉 vegetation layer 〉 litter layer. Annual net productivity in the arbor layers of T. flousiana plantation and successive rotation plantation of C. lanceolata plantations was 10.75 and 17.13 t/(hm^2 · a) ; annual net carbon fixation amounts were estimated as 5.05 and 3.47 t /(hm^2 · a) ; annual net absorption C02 amounts were 18.53 and 12.73 t/(hm^2 · a) respectively.
文摘In thes paper, the variation pattffe of wood Prpebo was edied for natural Cunninghamia lanceolata. The mathematical models of property were obtained on tracbeidlength, microfibril angle, late wood percdsgn, growth ring width and growth ring dsisity in the radial direction. The interrelation were analynd between tracheid length and microfibril angle. The result can provide sciatilic theory basis for wood utilhaion and early prediction of wood properties .
基金This research was supported by Foundation of Jiangsu forestry bureau(LYKJ[2017]42)Key research and development plan of Jiangsu Province(BE2017376)+2 种基金the Nature Science Foundation of China(31770715)the Qinglan project of Jiangsu province,Priority Academic Program Development of Jiangsu Higher Education Institutions,Natural Science Foundation of Jiangsu Province(BK20181176)the Joint Fund of the Natural Science Foundation of China and the Karst Science Research Center of Guizhou Province(Grant No.U1812401).
文摘In order to study how exogenous hormones in C.lanceolata(gymnosperm)regulate somatic embryogenesis,we measured the endogenous phytohormones of two genotypes with different somatic embryogenesis efficiency and found that an increase in endogenous concentrations of IAA and ABA may be correlated to more efficient somatic embryogenesis.By applying exogenous spermidine,we found that exogenous hormones may affect somatic embryogenesis efficiency through affecting the endogenous phytohormone content.Based on these results,further studies can be conducted whereby the concentration of exogenous hormones or the levels of endogenous phytohormones by molecular methods are regulated to promote somatic embryogenesis.Our research may benefit the long-term economic output of the forestry industry and lays the foundation to studying the molecular mechanism that controls somatic embryogenesis efficiency.
文摘Results from pot culture (with one-year old Cunninghamia lanceolata and Schima superba) are described. It was found that the biomass production and elongation of C. lanceolata was seriously inhibited at pH 2.0 rain, but for S. superba, was not affected markedly. When pH values of experimental rain were higher than 2.0, the root growth of both species was not adversely affected. Aluminium had already accumulated to some degrees in the roots of both trees, and started to affect the root growth of C. lanceolata at pH 2.0 rain. The soil chemistry was also examined. Increased acidity of experimental rain increased the leaching of Ca and Mg. The Al/Ca mol ratio increased from 0.3 to 0.9 in top soil, and in rhizosphere to 1.5 when the pH values of simulated acid rain were 4.5 to 2.0. In this experiment, NO3- fertilization effect was discovered.
文摘A new bislabdane-type diterpenoid lanceolactin (I), was isolated from the roots of Cunninghamia lanceolata. Its structure was elucidated on the basis of spectroscopic methods, especially 2D-NMR techniques.
基金the key projects of technological innovation(No.2016ABA111)the key projects of forest tree culture(No.2016YFD0600302-4)sponsored by Hubei province government。
文摘The structural characteristics of the tree crowns of Cunninghamia lanceolata var. Luotian(herein, Luotian), a natural variety of C. lanceolata(Chinese-fir, herein Lanceolata) in China, were analyzed using trunk and branch measurements and biomass determinations. Samples from two typical cultivated varietal populations were collected, including twenty-six 15–23-year-old trees of Luotian from a plantation, and nine 16–23-year-old trees of Lanceolata. Our results show that Luotian and Lanceolata samples differed significantly in crown structure, morphological indices, and biomass:(1) the oldest live branches on Luotian trees were 5–6 years old and 8–11 years old on Lanceolata. The ages of the live branches were not affected by the ages of the Luotian trees, while live branch ages increased with ages of Lanceolata trees;(2) the maximumbranching order of Luotian was level two. Compared to Lanceolata, the average number of first-order lateral branches(i.e., branches emerging from the trunk) and the number of first-order lateral branch whorls per sample tree were 12.9% and 32.2% lower, respectively, in Luotian.However, the average number of branches within a single whorl was 21.8% greater in Luotian;the average number of branch whorls at crown height was 51.1% greater. Thus,the Luotian variety has thicker branches;(3) the average lateral branch angles in Luotian and Lanceolata sample trees were 105.2° and 61.4°, respectively. The branch angles in 53.0% of lateral branches on Luotian ranged from105° to 135°, but 30° to 90° in 96% of the lateral branches on Lanceolata. Within the same crown layer, the average branch angle was 1.6–2.2 times greater in Luotian, and the angle was directly proportional to crown thickness;(4) the average base diameter and branch length on Luotian were1.3 cm and 75.8 cm, respectively, and 1.6 cm and112.2 cm for Lanceolata. For individual trees, branch growth differed significantly(p < 0.01) between Luotian and Lanceolata. However, the lateral branches grew at a similar rate among Luotian trees of different ages;(5) the average height to the lowest live branch on Luotian was128.3% greater than on Lanceolata, resulting in a significant difference(p < 0.01) in crown size. Compared to the crowns on Lanceolata, the Luotian crowns were 45.3%higher and 41.1% wider, and the surface area, volume, and growth of the crown were 27.0%, 11.4%, and 2.4 times greater than for Lanceolata, respectively;and,(6) the biomass of Luotian and Lanceolata sample trees also differed significantly. The mean crown, branch, and leaf biomass for Luotian was 40.0%, 25.2%, and 54.1% of those for Lanceolata, respectively. However, the leaf biomass in each layer of the Luotian crown was higher thanthat of Lanceolata, and leaf biomass increased with crown thickness.