作 者 ：张笑菁,赵秀海*,康峰峰,王娟,贺自书,马钦彦,卢文敏,药占文
期 刊 ：生态学报 2010年 30卷 18期 页码：4821~4827
Keywords:Pinus tabulaeformis, spatial pattern, sampling scale, diameter class,
摘 要 ：油松（Pinus tabulaeformis）耐低温、干旱和贫瘠，是我国北方温性针叶林中分布最广的森林群落，也是我国北方广大地区最主要的造林树种之一。太岳林区在山西省素称“油松之乡”，麻池背的油松天然林从封禁以来，在其生长过程中未受到干扰破坏，形成了独特的油松天然林生态系统顶级群落。2007年7月，在太岳林区灵空山林场的麻池背，设置了一块面积为4hm2的油松天然林样地，逐一测量并记录了样地内所有胸径大于1cm乔木树种的胸径（DBH），树高，冠幅（南北，东西）和枝下高，并对其挂牌标记，鉴定种名，确定坐标位置。用扩散系数C，平均拥挤度m*和聚块性指数m*/m及Morisita指数Iδ 对样地内林木的空间格局进行了判断, 主要研究了油松林木空间格局随取样尺度、林木径级变化的动态以及油松上层木，下层木和枯立木的空间格局，另外还分析了主要伴生树种辽东栎（Quercus liaotungensis）以及其他所有阔叶树种的空间格局。研究结果表明：样地内胸径大于1cm的乔木树种共35种，3561株，油松2583株，占总个体数的72.50%，其中活立木2482株，枯立木101株；辽东栎319株，占总个体数的9.07%，为油松的主要伴生树种；其余各树种的个体数占总个体数的比例均不到4%。林分中构成中上层林的树种是油松，树高10m以上的乔木树种中，油松以外的其他树种只占了3.99%；10m以下的乔木树种和灌木组成了下层林木。油松的径级分布呈峰型，中径级个体多，主要集中在28—36cm，小径级与大径级则相对较少。在5m×5m，10m×10m，20m×20m三个尺度下，油松林木均为集群格局，且尺度变化对聚集程度影响不明显；同时对不同径级油松林木分布格局研究显示，除最大径级（d＞44cm）外，其余各径级基本都为集群格局，而最大径级为随机格局，表明随着生长发育，油松林木空间格局由集群格局逐渐向随机格局转变；油松上层木、下层木和枯立木均为集群格局；主要伴生树种辽东栎以及其他所有阔叶树种皆为集群格局。
Abstract:Pinus tabulaeformis is the dominant species in the most widely distributed temperate coniferous forest community in northern China. The species is resistant to low temperatures, dry conditions and poor soil nutrient status. It is also one of the most important tree species for afforestation in large parts of northern China. Taiyue Forest Area is famous for its Pinus tabulaeformis in Shanxi Province, where it is known as the “township of Pinus tabulaeformis”. Since the closing of the hillsides to facilitate afforestation without disturbance for a long time the forest in Ma Chibei area formed a unique natural Pinus tabulaeformis climax community. In order to study the community spatial distribution pattern, a 400m2 (20m×20m) plot of natural Pinus tabulaeformis was established in the Ma Chibei area on the Ling Kongshan Forest Farm of the Taiyue Forest Area in July 2007. All trees in the plot with a diameter at breast height (DBH) of 1cm or more were tagged, mapped, measured and identified as to their species. The measurements included the DBH, total tree height, two crown diameters (East-Westerly and North-Southerly direction) and height to the lowest live branch. The spatial distribution pattern of the trees in the plot was evaluated using four indices: the Coefficient of Dispersion (C), the Index of Mean Crowding (m*), the Index of Patchiness (m*/m) and Morisita’s Index (Iδ), The study focused on the sensitivity of the spatial pattern of Pinus tabulaeformis by changing the sampling scale and diameter range, and on the spatial pattern of the dominant, the overtopped and the dead standing trees of Pinus tabulaeformis. In addition, the spatial patterns of Quercus liaotungensis and other broad-leaved trees were evaluated using the four indexes. A total of 3561 trees with a DBH ≥ 1cm were recorded in the plot, which includes 35 species, of which 2583 individuals or 72.50 percent were Pinus tabulaeformis (2482 live and 101 dead standing); 319 were Quercus liaotungensis, the main associated tree species of Pinus tabulaeformis. The other 33 tree species together made up 18.4 percent of the total number, none of them was represented by more than 4 percent. In the structure composition of storey，Pinus tabulaeformis lies in upper-middle level, all other trees except Pinus tabulaeformis only account for 4 percent of the total number of the trees with a height ≥ 10m；Lower level storey is made of trees less than 10m and shrubs. The DBH distribution of Pinus tabulaeformis in the plot is unimodal and shows a maximum frquency in the diameter range 28—36cm. Pinus tabulaeformis shows a clumped spatial distribution at three different sampling scales (5m×5m,10m×10m, 20 m×20m). The change of scale had no obvious effect on the degree of spatial aggregation. However, the biggest Pinus tabulaeformis (d＞44cm) were randomly distributed. Thus, during the development of Pinus tabulaeformis, the spatial pattern gradually changed from clumped to random. The dominant, the overtopped and the dead standing trees of Pinus tabulaeformis as well as Quercus liaotungensis and other broad-leaved trees all showed a clumped distribution.
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