华北落叶松人工幼林林分密度与生物量的关系

Relations of stand density and the biomass of the artificial young Larix principis-rupprechtii forest

华北落叶松(larixprincipis-rupprechtii Mayr.)是燕山山地的主要树种,生态和经济效益显著。以河北木兰林管局境内13a生华北落叶松人工幼林为研究对象,用样方调查的方法对立地条件相同密度分别为1800、2400和3000株/hm2的3种林分生物量进行研究,结果表明:林分总生物量随密度的增大而增大,低、中、高3种密度林分总生物量分别为21180.6、26724.6和31352.4kg/hm2;乔木层生物量最大,占总生物量的98.9%,草本层次之,占0.7%,灌木层最少,仅占0.4%;林木平均木生物量随密度的增大略微减少,密度由低到高其平均木生物量依次为11537.5、11077.3和10357.8g/株;各密度林分乔木层各器官生物量均存在W干>W枝>W根>W叶>W皮的分布规律;3种密度的林分生物量结构特征基本相同,3000株/hm2的林分结构合理,更能达到丰产的目的。

Larix principis-rupprechtii Mayr. is the main species in the Yanshan Mountain area,and it has prominent effect in ecology and economy. The paper used the 13 year-old young plantations of Prince Rupprecht＇ s Larch in the area of Mulan Forestry Bureau of Hebei. The method of sampling was used for the stand biomass research among the three densities as 1 800,2 400,3 000 trees/hm^2 ,but in the same conditions.The result indicated： The total stand biomass increased with the increasing density.The stand total biomass with the three densities of low, middle,high,are 21 180.6,26 724.6,31 352.4 kg/hm^2 .The tree layer biomass is the largest, 98.9% on the total biomass, then Herb layer, just 0.7%, while the shrub layer is the lowest, only 0.4%. The average wood biomass of stands decreased slightly with the increasing density. The average wood biomass of stands are 11 537.5,11 077.3 and 10 357.8 g/tree in turn with the density from low to high. The organ biomasses of tree layer with every densities, has the distributing rule of Wtnmk 〉 Wbranch 〉 Wroot 〉 Wleave 〉 Wskin. The stands biomass of the three densities has the same structure character basically. The stands structure of 3 000 trees/hm^2 is reasonable, and it also can meet the purpose of fertility.