Spatial Variability And Simulation Of Biomass Of Arbor Layer Of Broad-leaved Korean Pine Forest In Shengshan

According to the fully observed data of our 10.4 ha(400m×260m)large permanent plot of broadleaf-Korean pine forest established in Shengshan Nature Reserve,Heilongjiang Province,the moving window method and GIS were used to research the scale effect of spatial pattern of tree biomass and to explore the variation characteristics of the spatial structure of biomass under multi scale conditions,and then computer simulation of the random sampling was used for exploring the arbor biomass from the sampling intensity and the range of study area.The aim of this study is to provide data support and reference for the study of biomass cross-scale information and sampling design of forest biomass of broad-leaved Korean pine forest with similar conditions.The results showed that arbor layer biomass density of the plot at Shengshan was 154.5t/hm~2.The spatial variability of forest biomass is very strong,and the variability of the biomass of the sample is very relevant to the window scale.With the increase of the window scale,the variability of the biomass density of the sample plots showed a small trend.When the window scale is 10 m~60 m,the variation intensity is moderate.When the window scale is 70 m~90m,the weak variation intensity.There existed a minimum area of 0.49 ha in community structure of broadleaf-Korean pine forest in Shengshan Nature Reserve,and this area not only had the same biomass density as the entire plot(within 20%error range),but also could reflect the spatial variability of biomass of the broadleaf-Korean pine forest in Shengshan.It accurately reflected characteristics of the community structure,providing a theoretical basis for more accurate estimation of biomass of the broadleaf-Korean pine forest.Based on the above research,we put forward the minimum area as an index to measure the complex degree of spatial structure of forest community.The minimum size of the forest community represents the range of spatial variability,i.e.,a larger the minimum area implies a higher spatial heterogeneity.Based on the random sampling simulation of biomass in Shengshan Nature Reserve,Heilongjiang Province,we found that the accuracy of biomass estimation has relationship with area and number of the samples,and fluctuation range of biomass estimation value decreased with the increasing of area and number of samples.However,as the sample number increased,its effect on accuracy of estimation disappeared gradually.For the sampling in the entire plot,only seven 20m×20m quadrats were needed to get the result with relative error less than 20%at 95.9%probability,and sampling in the minimum area also had the same effect.It is a good guidance for the investigation of the plot size of forest biomass in broadleaf-Korean pine forest.