【摘要】 以吉林省汪清林业局金沟岭林场4块1 hm2天然云冷杉针阔混交林为研究对象,探究用传统方法及ArcGIS核密度分析方法得到的两种林分密度(以下分别简称传统林分密度与点林分密度)与半分解层凋落物现存量的空间异质性,以及林分因子对半分解层凋落物现存量空间异质性的影响.采用地统计学方法,获得点林分密度与凋落物现存量的空间格局图,同时对林分因子与凋落物现存量的相关性进行分析.结果显示:仅在样地IV,凋落物现存量与传统林分密度及点林分密度呈极显著正相关(P <0.01),与胸径呈显著正相关(P <0.05),而其他3块样地的凋落物现存量与林分因子的相关性均不显著;样地I与样地IV的两种林分密度值差异显著;样地II凋落物现存量的空间异质性更多地受到随机因素(即人为因素)的影响而表现为大面积块状分布,其余样地的空间格局均为离散型分布.本研究表明在进行空间异质性研究时,采用点林分密度要优于传统林分密度;点林分密度对凋落物现存量的影响并不一致,当点林分密度在1 700-1 900株/hm2时,二者呈显著正相关;凋落物现存量的空间异质性受到点林分密度空间异质性的影响,同时也受到其他结构因素与随机因素的影响.(图2表4参28)更多还原

【Abstract】 Four 1-hm2 plots of natural mixed spruce-fir coniferous and broadleaf forests located in the Jin’gouling Forest Farm of Jilin Province were investigated to explore the spatial heterogeneity of stand density calculated using the traditional method(traditional stand density) and ArcGIS kernel density analysis method(point stand density) and of the standing crop in the semi-decomposition litter layer. The influence of stand factors on the spatial heterogeneity of the standing crop in the semidecomposition litter layer was also studied. The geostatistical method was used to obtain the spatial pattern of point stand density and the standing crop in the semi-decomposition litter layer, and the correlation between above-ground factors and standing crop was analyzed using statistics. The standing crop showed a very significant positive correlation with traditional stand density and point stand density(P < 0.01), and a significant positive correlation with diameter at breast height in plot IV(P < 0.05), but no significant correlations with above-ground factors in the other plots. There existed significant differences between the two stand density values of plot I and plot IV; the spatial heterogeneity of the standing crop in plot II was more affected by random factors(anthropogenic factors) and showed a massive clustered distribution. The spatial pattern of the standing crop in the other three plots presented a discrete distribution. The point stand density was more appropriate than the traditional stand density for studying spatial heterogeneity. The effect of stand density on the standing crop in the semi-decomposition litter layer varied. When the point stand density was 1 700-1 900 stem/hm2, there was a significant positive correlation between point stand density and standing crop. The spatial heterogeneity of the standing crop in the semi-decomposition litter layer was affected by that of point stand density and also by other structural factors and random factors.更多还原