扩鞭繁殖毛竹林碳氮贮量的动态变化特征

Dynamic Changes in Carbon and Nitrogen Storage of Phyllostachys edulis Forest with Rhizome Expansion

为探讨不同成林时间扩鞭繁殖毛竹林的碳、氮贮量变化特征,以撂荒地和14年生杉木林为对照,对不同成林时间扩鞭繁殖毛竹林的碳、氮变化动态进行了研究。结果表明,林地的碳、氮贮量均显著高于撂荒地;而14年生杉木林转化为毛竹林后,碳贮量短暂下降后快速上升,成林10年毛竹林的碳贮量达到最大,其后随着"林龄"的增长呈下降的趋势。成林时间超过10年的毛竹林的氮贮量显著高于14年生的杉木林,而成林5年毛竹林的氮贮量低于杉木林。几种类型林分系统的碳、氮贮量均为土壤层>乔木层>凋落物层>林下植被层,且乔木层碳、氮贮量比例越大,土壤层碳氮贮量比例越低。毛竹林凋落物碳、氮贮量高于撂荒地,低于杉木林;但毛竹林凋落物层碳氮贮量随着成林时间的延长而降低,毛竹林较低的凋落物碳氮贮量可能会影响毛竹林的持续固碳能力。因此,平衡乔木层和土壤层的碳氮贮量是森林实现科学经营的关键。

The purpose was to comprehend the dynamic changes in carbon and nitrogen storage of Phyllostachys edulis forest with rhizome expansion, the changes in carbon and nitrogen storage of P. edulis forest in Yong＇an City, Fujian Province were studied with abandoned land and 14-year-old Chinese fir （Cunninghamia lanceolata） forest as control. The results showed that the carbon and nitrogen storage of forest was higher significantly than that of abandoned land. The carbon storage of P. edulis forest deceased firstly and then increased quickly when Chinese fir transformed into moso bamboo. The carbon storage reached the maximum when moso bamboo forest was i0 years old, and then decreased with age increasing. The change trend of carbon storage was difference from that of nitrogen storage. The nitrogen storage of moso bamboo forest with more than 10-year-old was higher significantly than that of 14-year-old Chinese fir, and the nitrogen storage of moso bamboo forest at the age of 5 were lower significantly than that of Chinese fir. The carbon and nitrogen storages of all forest types were in the order： soil layer 〉 tree layer 〉 litter-fall layer 〉 vegetation layer under canopy. Meanwhile, the carbon and nitrogen storages in soil layer decreased while those in tree layer increased. The carbon and nitrogen storages in litter-fall of moso bamboo were higher than those in abandoned land, and lower than those in Chinese fir forest. Meanwhile, the carbon and nitrogen storages in litter-fall of moso bamboo forest decreased with stand age increasing. The low carbon and nitrogen storages in litter-fall of moso bamboo forest may decline continued carbon sequestration capacity. So, it was important to balance the carbon and nitrogen storages between tree laver and soil laver.