为了研究林下可燃物含水率的空间异质性状况,在东北林业大学老爷岭生态站附近对落叶松林下地表可燃物按试验地的坡位分3个方向进行取样.其中:沿坡上至坡下定为垂直方向,与之垂直的方向定为水平方向,垂直方向和水平方向的夹角平分线方向定为斜向.对每个方向凋落物层和腐殖质层分层取样,并计算含水率,利用常规统计和地统计学中的半方差分析处理数据.研究结果表明,可燃物含水率相对变异较大的是斜向样带,变异系数为0.46.除水平方向的凋落物层可燃物外,其他样带可燃物含水率都有明显的空间相关性,斜向凋落物层基台值最大(1.632),总体上看,凋落物层可燃物含水率的异质性程度比腐殖质层高.可燃物含水率在3个方向半方差与距离相关性高,具有明显的各向异性.其中,凋落物层各向异性十分明显,腐殖质层各向异性变异复杂近不明显.通过模拟取样估测样地总体含水率,结果表明:控制取样间隔距离可以提高取样精度,在取样间隔距离为2～8m、取样强度在7个以上时,标准误差已经减少至10％以下；随机取样需要更大的取样强度且误差较大,不具优越性.%Traditional statistics and semivariance analysis of geostatistics were applied to study the differences in spatial heterogeneity of moisture content of land surface dead fuel of 2-layer samples (liner and humus layers) in 3 transects (slantwise, vertical, and horizontal) in a larch stand in Laoyeling Ecological Station in Maoershan Experimental Forest Farm, Shangzhi City. Results show that the relative variation in moisture content in the slantwise transect is the largest, with a variation coefficient of 0.46. The spatial variability of moisture content of land surface fuel is remarkable, and the moisture content of the litter layer is less than that of the humus layer. Variation analysis reflects that, except for the upper horizontal transect, the other two transects has obvious spatial correlation, and the sill for the slantwise transect is the largest (1.632), and the heterogeneity degree in the litter layer is higher than that in the humus layer. The anisotropies of the transects of different directions are obvious. The anisotropy of the litter layer is very distinct, and that of the humus layer is complicated. The influence of sampling technique on moisture content estimation under heterogeneity conditions was also assessed. The results indicate that adjusting sampling interval distance can improve the precision and decrease the amount of sampling. The standard error could reduce to 10% when the sampling interval distance ranged from 2 m to 8 m and the sampling intensity was over 7. However, random sampling has no advantages.
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