| The main vegetation in the Greater Xing’an Mountains of Heilongjiang Province is larch,the biological hazards including disease,insects,rats and rabbits.Which had occurred more frequently in Dendrolimus superans,Coleophora dahurica Falkovitsh etc.This study through the reconstruction of the pest occurrence history.To provide a theoretical basis for the interference study of biological disasters on forest ecosystem carbon sinks,reveal the characteristics of forest biological disasters under the background of climate warming,evaluate the ecological benefit of natural forest protection project and formulate the appropriate strategi-es of forest biological disaster management.This article through to Shibazhan Forestry Bureau and the Songling Forestry Bureau in the Greater Xing’an Mountains of Heilongjiang Province larch tree-ring analysis.Respectively on two areas of larch biological disaster history reconstruction.Reasonable design scheme samples;Be taken back to the specimen in accordance with dry,fixed,grinding and other steps for processing;Annual ring width were measured with WinDENDRO software;Using R software instead of COFECHA procedures,to modify the correction of errors,finally eliminate due to reasons such as corrupt and broken and the correlation of main sequence are lower and singular point more sequence,to ultimately meet the requirements;Then use R software analyzing tree core tree-ring width,including round the average width of the tree,median,standard deviation,the offset,the average sensitivity and the gini coefficient,etc;Then use R software analyzing tree core tree-ring width,including round the average width of the tree,median,standard deviation,the offset,the average sensitivity and the gini coefficient,etc;Through the rwi method and Pointer Years instructions in two kinds of method,determine year two regions of interference;Year affected by the fire and meteorological factors,finally be interference by forest biological disaster year.According to the ring data obtained by cross-dating,using R’s dpl packages and pointRes packages for data analysis.Fire and meteorological factors(temperature,precipitation)do not s ignificantly affect the larch ring index,excluding confounding factors,the final decision is Shi bazhan Forestry Bureau larch biological hazards interference years were 1960,1991and 2003,S ongling Forestry Bureau larch biological disasters interference years were 1992,2003 and 2011.The results showed that the reconstruction results of larch biological disasters history consisten t with the actual situation of larch biological disasters in local.In this paper,using R software for Shibazhan Forestry Bureau in 1939～2013 and the Songling Forestry Bureau in 1960～2013 percentage of the core sample by biological disaster time series analysis,and predict the two forestry bureau from 2014 to 2023 by biological disaster changes of the core sample percentage.The research results show that Shibazhan Forestry Bureau ARIMA(0,0,1)forecast model and prediction model of Songling Forestry Bureau ARIMA(2,1,2)which can be used for two areas affected by the biological disaster sample core percentage of prediction. |
