坡位对油松人工林地上生物量分配格局的影响

摘要

油松是华北地区重要的造林树种,研究油松人工林地上部分生物量的空间分配格局对北方地区人工林培育具有重要意义.以河北省平泉县34年生油松人工林为调查对象,通过比较不同坡位的林木生长量、地上生物量及土壤养分含量的差异,研究坡位对土壤养分分配及林木生长状况的影响.结果表明:胸径和树高均随坡位由上到下的变化而增加;就单株乔木各器官而言,不同坡位林木枝、干的生物量分配表现为上坡＜中坡＜下坡,而叶的生物量则是随着坡位由上而下逐渐减小;油松人工林分的乔木层、凋落物层、草本层分别占地上部分生物量的92.2％～95.1％,3.5％～6.3％,1.2％～1.5％;各土层的土壤有机质含量在不同坡位上均表现为下坡＞中坡＞上坡.%Pinus tabulaeformis is one of important tree species in north China and is necessary to study its above-ground biomass distribution pattern of the plantations. By taking 34-year-old forest plantations of Pinus tabulaeformis in Pingquan county, Hebei province as the object, the effect of slope position on soil nutrient distribution and tree growth conditions were studied through comparing the differences of forest increment, above-ground biomass, soil nutrient content. The results show that the DBH and height increased as the slope position changed from the up-slope to middle-slope to down-slope; as far as all organs of a single tree are concerned, the biomasses of branches and stems on different slope positions ranked by magnitude as followings: biomass on the up-slope, biomass on the middle-slope and biomass on the down-slope; while the biomass of leaves decreased from upslope to middle-slope to down-slope; the arbor-layer biomass, litter layers biomass, shrub biomass occupied 92.2%~95.1%, 3.5%~6.3%, 1.2%~1.5% of total stand, respectively; the soil organic matter contents in different layer ordered from high to low as following: in the bottom soil > middle > upper.