大兴安岭南部温带山杨天然次生林不同生长阶段生物量及碳储量

Biomass and carbon storage of the secondary forest (Populus davidiana) at different stand growing stages in southern Daxinganling temperature zone

基于内蒙古赛罕乌拉森林生态系统定位研究站山杨(Populus davidiana Dode)天然次生林幼龄林、中龄林、近熟林、成熟林及过熟林生物量调查,探讨了不同龄组山杨天然次生林单株木、林分、林下植被和枯落物的生物量及群落碳储量的时空变化规律。结果表明:随林龄的增大,山杨天然次生林木和各器官生物量总体呈增加趋势,树干所占比例增加,中龄林增加尤为明显;林下植被层、枯落物层生物量随林龄增大呈增加趋势。群落总碳储量的空间分布序列是:乔木层>枯落物层>林下植被层。幼龄林、中龄林、近熟林、成熟林和过熟林群落的碳储量分别为27.146 6、53.545 1、60.889 8、77.915 8、79.135 3t.hm-2,乔木层碳储量分别为22.206 5、47.215 7、52.056 3、68.445 3、68.773 1 t.hm-2,枯落物层和林下植被层碳储量平均值分别为5.814 4、2.172 7 t.hm-2。乔木层、枯落物层和林下植被层碳储量占总量的平均率分别为86.05%、10.39%和3.57%。研究认为山杨天然次生林群落碳储量随林龄增加的变化规律明显,碳汇潜力巨大;中龄林为碳储量增长迅速期,且持续较长一段时间,是林分管理的关键阶段;自然稀疏有利于促进林木生长,林分碳储量并未随林分密度下降而减小。

This paper mainly discussed（1） temporal-spatial pattern of community biomass and carbon storage in different stand structures,（e.g.single tree,the stand,the understory vegetation） and（2） different age group of aspen secondary forest（Populus davidiana）,based on investigating the biomass of different age group of aspen secondary forest,including juvenile,half-mature,near-mature,mature and over mature forest stand patterns.The results showed that the forest and all biomasses increase among different age group of Populus secondary forest stands,especially in half-mature forest.The biomass of understory vegetation and litter layer also showed the upper trend with increasing of different age group.The order of total community carbon storage in different plantation layers showed differently： tree canopylitter layerunderstory vegetation.The total carbon storages in juvenile,half-mature,near-mature,mature and over mature forest are 27.146 6,53.545 1,60.889 8,77.915 8,79.135 3 t.hm-2 respectively.The carbon storages in tree layer are 22.206 5,47.215 7,52.056 3,68.445 3,68.773 1 t.hm-2 respectively.The average carbon storages in litter layer and understory vegetation are 5.814 4,and 2.172 7 t.hm-2.The carbon storages in tree layer,litter layer and understory vegetation are 86.05%,10.39%,and 3.57% respectively.The result demonstrated that the carbon storage in aspen secondary forest changed with different age group,and it showed a great potential for carbon sink.The carbon storages in half-mature forest grow rapidly,and last long time.It is a critical stage for forest management and stand dynamics.Natural thinning is useful for trees grow,the carbon storage did not decrease with decreasing stand density due to the natural thinning.