Preliminary Studies On Fungal Degradation And Litters Of P. Armandii Located In Erlang Mountain, Sichuan

The litter fall plays an important role among plant,litter and soil to be ligament in the ecosystem.The fertility of forest land,the growth of forest trees and the productivity of ecosystem are affected by the nutrients return.The geographical location of erlang moutain has enormous influence on east and west climate and been thinked as the climate dividing line. At present，Pinus armandii Franch has important ecological value to be edificator of forest community.This experiment mainly study the P.armandii on erlang mountain in sichuan province,elements content of N,P and K in litter needles was analyzed, related litter degradation enzyme was determined(peroxidase and cellulase,xylanase,catalase,polyphenol oxidase), the fungal strains isolated from dead needles was used to carry out the indoor degradation experiment in order to have some basic knowledge of needles degradation on P. armandii.The field observations found that during the sampling from August2012to January2013, a lot of fresh needles fell off each month, the temperature is low and humidity is high.The water content of litter needles changes with altitude and time, higher altitude, higher water content,highest in October and the rest of the month are more gentle. Litter quality analysis showed that as the altitude rises,the litter N rises,element content is consistent at all the sample plots with time,increased firstly and then reduced finally to be steady state.P changed with no obvious regular.K was significantly negatively correlated with the changes in the water content, significantly affected by water eluviation.The experiment of litter enzyme activity found that cellulase and xylanase showed low activity during the winter (November,December and January),and in September and October activity are relatively higher,with increasing altitude enzyme activity reducing.And polyphenol oxidase in each month is showed strong activity. No obvious rules about peroxidase and catalase was found in different altitudes and months, but they still remained certain activities.In a word,low enzyme activities eased the litter decomposition rate,so undecomposed layer was piled up.Three fungal strains isolated from dying litters had high homology with Rhizosphaera sp.At the same time,with another strain (Lophodermium erlangshanense) saved in our Lab,indoor decomposing experiment was carried out.And we found that all four strains have certain skills for the degradation of cellulose.Then pine needles was used as substrate to be decomposed,we had liquid fermentation indoor,by measuring enzyme activity of the EG,CBH,BGL and mass loss to get further cognition on their cellulose degradation ability.The results showed that EG and BGL was produced prior to CBH.DNS method is used to reflect the enzyme activity by comparing reducing sugars,number R.2012.9-1strain have highest degradation ability,number R2012.9-2was showed the weakest degradation ability.