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
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
Background:Nitrogen(N)and phosphorus(P)are important elements for plant metabolism and growth.Therefore,the quantification of the scaling relationship of N to P in plant organs can help us understand many fundamental ...Background:Nitrogen(N)and phosphorus(P)are important elements for plant metabolism and growth.Therefore,the quantification of the scaling relationship of N to P in plant organs can help us understand many fundamental ecological processes.The general scaling relationships between N and P in leaves and in fine roots have been reported.As compared to leaves and fine roots,however,little information is available on the N versus P scaling relationship in the stems of woody plants,especially for twigs.In this study,a comprehensive dataset comprising 2,038 N=P paired observations for a total of 536 woody species was compiled and analyzed to determine whether a general scaling relationship exists.Results:The global mean values of twig N and P concentrations and N:P ratios were 9.33 mg⋅g^(-1),1.12 mg⋅g^(-1) and 10.16,respectively.Twig N and P concentrations and N:P ratios differed significantly within and across functional groups and biomes.Across all of the species,a uniform 0.67 scaling exponent of twig N to P was observed across different functional groups and biomes,i.e.,a 2/3-power scaling relationship was observed.However,this numerical value differed across different sites,albeit converging onto 0.67 with increasing sample sizes.Soil total phosphorus was the largest contributor to the variation in the numerical value of the scaling exponent.Conclusion:These results provide useful parameters for stoichiometric growth models,and advance our understanding of the mechanisms underlying plant nutrient dynamics.This study has potential implications in predicting responses of nutrient cycling in terrestrial ecosystem responses to changes in the environment.展开更多
Aquatic fungi play an important role in litter decomposition in aquatic ecosystems.Keeping in view the importance of aquatic fungi,diversity of these organisms was studied in two freshwater ecosystems of Gaur River an...Aquatic fungi play an important role in litter decomposition in aquatic ecosystems.Keeping in view the importance of aquatic fungi,diversity of these organisms was studied in two freshwater ecosystems of Gaur River and Khurji Nala Jabalpur Madhya Pradesh India.During the present study,34 fungal species and 6 chromista species have been recorded on decomposing substrates.Highest number of fungal genera were recorded in submerged litter samples of Tectona grandis followed by Dendroclamus strictus.The maximum percentage frequencies of various fungal species which colonize litter of different tree species were also recorded.The cluster analysis revealed that different fungal communities on various plant hosts vary significantly.展开更多
The examination of decaying twig samples fallen on the forest floor in the Andaman Islands,India yielded a new fungal species in the genus Kamalomyces(Tubeufiaceae).The new species,Kamalomyces polyseptatus is describe...The examination of decaying twig samples fallen on the forest floor in the Andaman Islands,India yielded a new fungal species in the genus Kamalomyces(Tubeufiaceae).The new species,Kamalomyces polyseptatus is described in this paper supported by photomicrographs.The novel species is characterized by superficial,scattered,globose to sub-globose,dark brown to black ascomata covered by dense black mycelium,clavate asci,vermiform,elongate,transverse septate,hyaline ascospores.The new species K.polyseptatus is easily distinguishable from other species of the genus by the presence of higher number of septa in the ascospores.A synopsis of salient features of different species of Kamalomycesis provided along with a dichotomous key to the known species of Kamalomyces.展开更多
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.
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.
基金financially supported by the National Science Fund for Excellent Young Scholars (No. 31822010)the National Key Research and Development Program of China (No. 2020YFA0608102)+3 种基金the Biodiversity Survey and Assessment Project of the Ministry of Ecology and Environment,China (No. 2019HJ2096001006)National Scientific and Technological Program on Basic Resources Investigation (No.2019FY102002)the Innovation Base Project of Gansu Province (No.20190323)the Sichuan Science and Technology Program (No.2020YFH0005)
文摘Background:Nitrogen(N)and phosphorus(P)are important elements for plant metabolism and growth.Therefore,the quantification of the scaling relationship of N to P in plant organs can help us understand many fundamental ecological processes.The general scaling relationships between N and P in leaves and in fine roots have been reported.As compared to leaves and fine roots,however,little information is available on the N versus P scaling relationship in the stems of woody plants,especially for twigs.In this study,a comprehensive dataset comprising 2,038 N=P paired observations for a total of 536 woody species was compiled and analyzed to determine whether a general scaling relationship exists.Results:The global mean values of twig N and P concentrations and N:P ratios were 9.33 mg⋅g^(-1),1.12 mg⋅g^(-1) and 10.16,respectively.Twig N and P concentrations and N:P ratios differed significantly within and across functional groups and biomes.Across all of the species,a uniform 0.67 scaling exponent of twig N to P was observed across different functional groups and biomes,i.e.,a 2/3-power scaling relationship was observed.However,this numerical value differed across different sites,albeit converging onto 0.67 with increasing sample sizes.Soil total phosphorus was the largest contributor to the variation in the numerical value of the scaling exponent.Conclusion:These results provide useful parameters for stoichiometric growth models,and advance our understanding of the mechanisms underlying plant nutrient dynamics.This study has potential implications in predicting responses of nutrient cycling in terrestrial ecosystem responses to changes in the environment.
文摘Aquatic fungi play an important role in litter decomposition in aquatic ecosystems.Keeping in view the importance of aquatic fungi,diversity of these organisms was studied in two freshwater ecosystems of Gaur River and Khurji Nala Jabalpur Madhya Pradesh India.During the present study,34 fungal species and 6 chromista species have been recorded on decomposing substrates.Highest number of fungal genera were recorded in submerged litter samples of Tectona grandis followed by Dendroclamus strictus.The maximum percentage frequencies of various fungal species which colonize litter of different tree species were also recorded.The cluster analysis revealed that different fungal communities on various plant hosts vary significantly.
基金the Science and Engineering Research Board(SERB),Ministry of Science and Technology,Govt.of India for funding the project(SERB/SB/SO/PS/18/2014 dt.19.5.2015)。
文摘The examination of decaying twig samples fallen on the forest floor in the Andaman Islands,India yielded a new fungal species in the genus Kamalomyces(Tubeufiaceae).The new species,Kamalomyces polyseptatus is described in this paper supported by photomicrographs.The novel species is characterized by superficial,scattered,globose to sub-globose,dark brown to black ascomata covered by dense black mycelium,clavate asci,vermiform,elongate,transverse septate,hyaline ascospores.The new species K.polyseptatus is easily distinguishable from other species of the genus by the presence of higher number of septa in the ascospores.A synopsis of salient features of different species of Kamalomycesis provided along with a dichotomous key to the known species of Kamalomyces.
