北京市西山地区栓皮栎林空间结构特征研究

Spatial Structure Characteristics of Quercus Variabilis Forests in Xishan Mountain Area of Beijing City

以地面三维激光扫描仪作为林分资源调查的技术手段,采用"多站式"扫描方法来获取栓皮栎林标准地内林木树种、树高、胸径、胸高断面积等测树因子,利用混交度、大小比数、角尺度3个指标分析了北京市西山林区栓皮栎林样地的空间结构特征。研究结果表明:(1)栓皮栎林乔木层共包括15个树种,其中,栓皮栎种群在密度和断面积累积量方面占有明显优势,是乔木层的建群种和优势种;(2)栓皮栎林整个林分混交度较低,平均混交度0.306,各树种混交度以栓皮栎、栾树为最低,其它伴生树种以中度、强度和极强度为主;(3)栓皮栎、元宝枫、刺槐、辽东栎种群在空间结构单元中以优势木、亚优势木和中庸木为主,分别占种群总株数的64%,68%,64%和59%,其它树种优势度不明显;(4)栓皮栎林林分平均角尺度为0.528,说明该林分水平分布格局为聚集分布,但聚集程度较低。

This study investigated quantitative forest stand parameters at the plot-level such as the tree height,diameter,basal area,and other parameters with terrestrial laser scanning and ＂multi-stop＂ scanning method,then the spatial structural characteristics of one plot-level stand of Quercus variabilis forests in Xishan Mountain of Beijing City were described by using mingling degree,neighborhood comparison and uniform angle index.The result showed that there were fifteen populations in arbor layer of Quercus variabilis forests,among which,Quercus variabilis had the obvious advantage in population density and basal area,being the dominant and constructive species of the tree layer.The average mingling degree of the whole stand was 0.306,suggesting the low mingling degree of the stand.The dominant species such as Quercus variabilis and Koelreuteria paniculata population were mainly none or less-mixed,while the accompanying species generally presented moderate,intensity and high intensity.In the spatial structural units,Quercus variabilis,Acer truncatum,Robinia pseudoacacia and Quercus liaotungensis Koidz were mainly of dominant,sub-dominant,and intermediate trees,accounting for 64%,68%,64% and 59% of the total plants of the populations respectively,while the advantage of other populations was not obvious.The uniform angle index value of Quercus variabilis forests was 0.528,indicating that the spatial pattern of the stands was of aggregative distribution,but the aggregation degree was not high and the aggregation scale was not large.