Diversity Of Endophytic Fungi Of Cunninghamia Lanceolata Leaves And Their Effects On Litter Decomposition

Decomposition of forest litter is one of the main links of matter cycle and energy flow in forest ecosystem.It is of great significance to maintain soil fertility and promote the normal matter cycle and nutrient balance of the whole system.In recent decades,due to artificial logging,continuous planting and improper management mode,C.lanceolata forest land degradation and forest yield decline.The study on the decomposition mechanism of litters not only has important significance for the study of carbon balance,but also provides a certain basis for the study of soil nutrient cycle,and thus provides a certain scientific basis for the study of promoting the productivity improvement of C.lanceolata forest.As for the study on the decomposition mechanism of litters,it has been found in recent years that endophytic fungi are involved in the decomposition process of litters,in order to explore the influence of endophytic fungi on the decomposition of litters,different lofting methods?OTUdoor lofting and indoor lofting?were adopted in the study,and different dominant endophytic fungi were selected to participate in the influence of different community construction on the decomposition of litters.The study on the diversity of endophytes and their subsequent participation in the decomposition process of litters is of important ecological significance,which can also provide an important basis for the accurate prediction of regional carbon balance process,as well as for the management of C.lanceolata plantation and the maintenance of soil fertility.The main results of this study are as follows:?1?In the process of senescence,the diversity and richness of endophytic fungi increased first and then decreased.At the mature stage,the diversity and richness of endophytic fungi reached the maximum value.The composition of fungal community in the same taxonomic level was similar in different leaf ages,but the proportion was different.?2?Different endophytic fungi or combination colonization affected the decomposition process of C.lanceolata litter,it is depended upon the properties of endophytic fungi.In the early stage of litters decomposition,the colonization of single fungi or combinations of endophytes of different dominance types significantly accelerated the decomposition of litters during the decomposition process.In the later stage of litter decomposition,in addition to Irpex lacteus and Colletotrichum sp.,the accelerated effect of other endophytes was almost reduced and even inhibited the decomposition process of litters.In different decomposition periods,the response of each variable of enzyme activity to the colonization of endophytic fungi with different dominance degree is not completely consistent with the mass loss rate,which mainly depends on different decomposition periods:The CO₂release rate is not strongly correlated with the mass loss rate in the early stage of decomposition,but closely correlated with the mass loss rate in the later stage;the contribution of Cx enzyme?carboxymethyl cellulase?in the early stage of decomposition to the mass loss rate was large,while that of laccase and peroxidase in the later stage of decomposition was increased.All in all,the colonization of different endophytes has a great influence on litter decomposition and corresponding microbial activities.?3?The effect of edophytes on the decomposition process of C.lanceolata litter depends on endophytic species trait.After three months,the mass loss rate of C.lanceolata litter caused by Ao+A?community including one endophyte and seven saprophytic fungi?community was the most highest among the seven groups of microbial communities.However,with the decomposition of litter,the effect caused by Ao+A community weakened,and the mass loss rate caused by Af+A community became the most highest.After three months,Af+A community had the most prominent impact on the enzyme activity of C1 enzyme?exo-1,4-?-glucanase?in the decomposition process.The community of Po+A has the most OTUstanding Cx enzyme?Carboxymethyl cellulase?,?-glucosidase??-Glucosidase?and lignin decomposition enzyme.After six months of litter decomposition,the community of Mc+B+So has the most significant effect on the cellulosic enzyme.In general,the different microbial communities assembly has significant effect on the decomposition process of litters.To sum up,the diversity and community composition of endophytic fungi in the leaves of C.lanceolata of different leaf ages are different,and the community assembly of different types of endophytic fungi have different influences on the decomposition of litters.