[ Objective ] The paper was to explore the correlation between inclusion contents in Casuarina spp. twigs and its resistance to Lymantria xylina. [ Method] Three types of representative Casuar/na spp. strains includin...[ Objective ] The paper was to explore the correlation between inclusion contents in Casuarina spp. twigs and its resistance to Lymantria xylina. [ Method] Three types of representative Casuar/na spp. strains including resistant strains （Zhanjiang 3, Hui 76, Hui 83, Guangdong A8-2）, moderate resistant strains （Pingtan 2, Hui 1, Long 7-18） and susceptible strains （Dongshan 2, Guangdong 501, Kang[eng） were tzst~ as materials to determine the contents of six kinds of inclusions, total phenol, tannin, flavonoids, protein, soluble sugar and polysaccharide. [ Result] The resistant strains had higher flavonaids, tannin and total phenol contents and lower soluble sugar and protein contents than the susceptible strains, while the content of polysaccharide acted randomly. The grey correla- tivity analysis showed that resistance degree, pupation rate and pupal weight had high correlation with protein and soluble sugar contents, with correlation index equal to or above 0.500 0. [ Conclusion] The study provided a theoretical basis for screening and promotion of resistant strains against L xylina.展开更多
Young leaves are conventionally used in the analysis to study the nutrient status of evergreen plants and their responses to environmental changes, but the role of old leaves remains poorly understood. We selected two...Young leaves are conventionally used in the analysis to study the nutrient status of evergreen plants and their responses to environmental changes, but the role of old leaves remains poorly understood. We selected two stand types in 31-year-old Chinese fir（Cunninghamia lanceolata） plantations with similar soil conditions but different stand densities, to test the hypothesis that nitrogen（N） concentration of old leaves and twigs is more sensitive to stand density than that of young ones. Leaves and twigs were sampled and sorted into young（one-year-old） and old（two-and three-year-old） groups. Significant differences in N concentration and carbon： nitrogen ratio between the low-density stand and high-density stand were only found in the old leaves and twigs but not in the young ones.Although the N resorption efficiency did not vary significantly with stand density, the annual N resorption rates were increased in old leaves and relatively young twigs at high stand density. These results show the potential use of old tissues in the nutrient analysis in Chinese fir plantations. Testing the generality of these results could improve the use of foliar analysis as an indicator of nutrient status and environmental changes in evergreen tree species.展开更多
Studies on litterfall and decomposition provide estimations of decomposition rates of different ecosystems.This is key information to understanding ecosystem dynamics and changes in a scenario of global warming.The ob...Studies on litterfall and decomposition provide estimations of decomposition rates of different ecosystems.This is key information to understanding ecosystem dynamics and changes in a scenario of global warming.The objective of this research was to assess litterfall production,the potential deposition of macro and micronutrients through leaf and twig fall as well as macronutrient—use efficiency in three forest ecosystems at different altitudes： a pine forest mixed with deciduous species（S1）; a Quercus spp.forest（S2）; and,a Tamaulipan thornscrub forest（S3）.Total annual litterfall deposition was 594,742 and 533 g m^（-2） for S1,S2 and S3.Leaf litter was higher （68%） than twigs（18%）,reproductive structures（8%） or miscellaneous material（6%）.Micronutrient leaf deposition was higher for Fe followed by Mn,Zn and Cu.Macronutrient leaf deposition was higher for Ca followed by K,Mg and P.Even though P deposition in leaves and twigs was lower than other macronutrients,its nutrient use efficiency was higher than Ca,Mg or K.Altitude and species composition determine litter and nutrient deposition,with higher values at mid-altitudes（550 m）.Altitude is an important factor to consider when analyzing litter production as well as nutrient deposition as shown in this study.Litter production and nutrient deposition are expected to change in a scenario of global warming.展开更多
The biochemical and physiological properties of alpine woody plants responding to elevation are associated with needles and twigs age.However,the interactions with elevation were not well studied.In this study,we inve...The biochemical and physiological properties of alpine woody plants responding to elevation are associated with needles and twigs age.However,the interactions with elevation were not well studied.In this study,we investigated age-related(current,one-year and two-year old)functional traits of Abies faxoniana in needles and twigs with elevation(2500 m,2750 m,3000 m,3250 m,and 3500 m a.s.l)at the eastern edge of the Tibetan Plateau.The macro-elements(C,N,P,K,Ca,and Mg),nonstructural carbons(soluble sugar,sucrose,and starch)and isotope composition(δ13C)were measured in needles and twigs of adult A.faxoniana trees(breast height diameter about 30 cm).There were significant age,elevation and their interaction effects on these traits(except forδ13C).Compared with twoyear-old needles and twigs,the current and one-yearold tissues possessed higher concentrations of P and K,lower Ca concentrations,as well as a lowerδ13C values and C:P and N:P ratios in needles.The current-year twigs generally had higher sucrose concentration and sucrose:starch ratio than the old ones.This study suggested that more nutrients were invested to young needles and twigs to cope with elevation for A.faxoniana than the old ones.展开更多
In order to discuss the cutting propagation effect of Rhodoleia championii, this study carried out a cutting propagation experiment with tender twigs as experi- mental materials. The results showed that selecting the ...In order to discuss the cutting propagation effect of Rhodoleia championii, this study carried out a cutting propagation experiment with tender twigs as experi- mental materials. The results showed that selecting the cuttings with 2-4 half leaves could significantly improve the rooting percentage of cuttings; the fungicide carben- dazim and rooting accelerant GGR6 at different concentrations significantJy affected the rooting percentage of cuttings; and different cutting media also significantly af- fected the rooting percentage of cuttings.展开更多
结构化连接的效率直接影响着XML查询的性能,目前对XML的结构化连接大多都是基于编码的方法.介绍了一种全新的有效支持XML结构化连接的树索引CATI(compact ancestor tree index).CATI的基本思想是,对于给定的一个祖先后代查询(A-D查询)或...结构化连接的效率直接影响着XML查询的性能,目前对XML的结构化连接大多都是基于编码的方法.介绍了一种全新的有效支持XML结构化连接的树索引CATI(compact ancestor tree index).CATI的基本思想是,对于给定的一个祖先后代查询(A-D查询)或Twig查询,遍历XML文档,找出所有的祖先A的实例,用以建立CATI的主干;对于每个A实例,找出它的直接后代D的实例链接在它的后面.因为经典的结构连接算法Stack-Tree算法效率较高且使用较广,因此应用基于CATI的结构连接算法和基于Stack-Tree的结构连接算法就A-D查询和Twig查询做了大量实验.实验结果表明,基于CATI的结构化连接在一般查询情况下性能明显优于基于Stack-Tree的结构化连接.展开更多
A new dihydrochromone derivative, named chaenomone, was isolated from the twigs of Chaenomeles sinensis (Thouin) Koehne. The structure was determined by spectroscopic methods.
基金Supported by National Science and Technology Support Program(2009BADB2B02)Key Science and Technology Program of Forest Tree Seedlings and Forestry Scientific Research Project in Fujian Province(MLK[2013]6)
文摘[ Objective ] The paper was to explore the correlation between inclusion contents in Casuarina spp. twigs and its resistance to Lymantria xylina. [ Method] Three types of representative Casuar/na spp. strains including resistant strains （Zhanjiang 3, Hui 76, Hui 83, Guangdong A8-2）, moderate resistant strains （Pingtan 2, Hui 1, Long 7-18） and susceptible strains （Dongshan 2, Guangdong 501, Kang[eng） were tzst~ as materials to determine the contents of six kinds of inclusions, total phenol, tannin, flavonoids, protein, soluble sugar and polysaccharide. [ Result] The resistant strains had higher flavonaids, tannin and total phenol contents and lower soluble sugar and protein contents than the susceptible strains, while the content of polysaccharide acted randomly. The grey correla- tivity analysis showed that resistance degree, pupation rate and pupal weight had high correlation with protein and soluble sugar contents, with correlation index equal to or above 0.500 0. [ Conclusion] The study provided a theoretical basis for screening and promotion of resistant strains against L xylina.
基金supported by the NSFC Projects of International Cooperation and Exchanges(31210103920)the National Key Research and Development Program(2016YFD0600202)+1 种基金the Gan-Po Distinguished Researcher Programthe Project of Jiangxi Provincial Department of Science and Technology(20144BBB70005)
文摘Young leaves are conventionally used in the analysis to study the nutrient status of evergreen plants and their responses to environmental changes, but the role of old leaves remains poorly understood. We selected two stand types in 31-year-old Chinese fir（Cunninghamia lanceolata） plantations with similar soil conditions but different stand densities, to test the hypothesis that nitrogen（N） concentration of old leaves and twigs is more sensitive to stand density than that of young ones. Leaves and twigs were sampled and sorted into young（one-year-old） and old（two-and three-year-old） groups. Significant differences in N concentration and carbon： nitrogen ratio between the low-density stand and high-density stand were only found in the old leaves and twigs but not in the young ones.Although the N resorption efficiency did not vary significantly with stand density, the annual N resorption rates were increased in old leaves and relatively young twigs at high stand density. These results show the potential use of old tissues in the nutrient analysis in Chinese fir plantations. Testing the generality of these results could improve the use of foliar analysis as an indicator of nutrient status and environmental changes in evergreen tree species.
基金supported by the PAICYT Grant CT259-15National Science and Technological Council(Grant250732)
文摘Studies on litterfall and decomposition provide estimations of decomposition rates of different ecosystems.This is key information to understanding ecosystem dynamics and changes in a scenario of global warming.The objective of this research was to assess litterfall production,the potential deposition of macro and micronutrients through leaf and twig fall as well as macronutrient—use efficiency in three forest ecosystems at different altitudes： a pine forest mixed with deciduous species（S1）; a Quercus spp.forest（S2）; and,a Tamaulipan thornscrub forest（S3）.Total annual litterfall deposition was 594,742 and 533 g m^（-2） for S1,S2 and S3.Leaf litter was higher （68%） than twigs（18%）,reproductive structures（8%） or miscellaneous material（6%）.Micronutrient leaf deposition was higher for Fe followed by Mn,Zn and Cu.Macronutrient leaf deposition was higher for Ca followed by K,Mg and P.Even though P deposition in leaves and twigs was lower than other macronutrients,its nutrient use efficiency was higher than Ca,Mg or K.Altitude and species composition determine litter and nutrient deposition,with higher values at mid-altitudes（550 m）.Altitude is an important factor to consider when analyzing litter production as well as nutrient deposition as shown in this study.Litter production and nutrient deposition are expected to change in a scenario of global warming.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20020401)the National Natural Science Foundation of China (NO. 31770650)
文摘The biochemical and physiological properties of alpine woody plants responding to elevation are associated with needles and twigs age.However,the interactions with elevation were not well studied.In this study,we investigated age-related(current,one-year and two-year old)functional traits of Abies faxoniana in needles and twigs with elevation(2500 m,2750 m,3000 m,3250 m,and 3500 m a.s.l)at the eastern edge of the Tibetan Plateau.The macro-elements(C,N,P,K,Ca,and Mg),nonstructural carbons(soluble sugar,sucrose,and starch)and isotope composition(δ13C)were measured in needles and twigs of adult A.faxoniana trees(breast height diameter about 30 cm).There were significant age,elevation and their interaction effects on these traits(except forδ13C).Compared with twoyear-old needles and twigs,the current and one-yearold tissues possessed higher concentrations of P and K,lower Ca concentrations,as well as a lowerδ13C values and C:P and N:P ratios in needles.The current-year twigs generally had higher sucrose concentration and sucrose:starch ratio than the old ones.This study suggested that more nutrients were invested to young needles and twigs to cope with elevation for A.faxoniana than the old ones.
基金Supported by Forestry Science and Technology Planning Project of Hunan Province(XLK201511)
文摘In order to discuss the cutting propagation effect of Rhodoleia championii, this study carried out a cutting propagation experiment with tender twigs as experi- mental materials. The results showed that selecting the cuttings with 2-4 half leaves could significantly improve the rooting percentage of cuttings; the fungicide carben- dazim and rooting accelerant GGR6 at different concentrations significantJy affected the rooting percentage of cuttings; and different cutting media also significantly af- fected the rooting percentage of cuttings.
文摘结构化连接的效率直接影响着XML查询的性能,目前对XML的结构化连接大多都是基于编码的方法.介绍了一种全新的有效支持XML结构化连接的树索引CATI(compact ancestor tree index).CATI的基本思想是,对于给定的一个祖先后代查询(A-D查询)或Twig查询,遍历XML文档,找出所有的祖先A的实例,用以建立CATI的主干;对于每个A实例,找出它的直接后代D的实例链接在它的后面.因为经典的结构连接算法Stack-Tree算法效率较高且使用较广,因此应用基于CATI的结构连接算法和基于Stack-Tree的结构连接算法就A-D查询和Twig查询做了大量实验.实验结果表明,基于CATI的结构化连接在一般查询情况下性能明显优于基于Stack-Tree的结构化连接.
文摘A new dihydrochromone derivative, named chaenomone, was isolated from the twigs of Chaenomeles sinensis (Thouin) Koehne. The structure was determined by spectroscopic methods.
