论文部分内容阅读
毛竹混交林具有较高的生产力和较好的生态功能,可能与混合凋落物的养分归还特征有关。本研究采用凋落物分解袋法对不同混合比例毛竹凋落叶分解特征进行了为期1年的研究,共设置5个处理,分别为Ⅰ(毛竹纯叶)、Ⅱ(毛竹、楠木叶比例为8:2);Ⅲ(毛竹、杉木叶比例8:2)、Ⅳ(毛竹、楠木叶比例5:5)和Ⅴ(毛竹、杉木叶比例5:5)。结果表明,不同处理凋落物分解速率符合Olson指数分解模型,R2均高于0.92。5个处理分解系数的排列顺序为Ⅱ>Ⅰ>Ⅲ>Ⅴ>Ⅳ,分别为0.68、0.66、0.58、0.55和0.49。处理Ⅰ和Ⅱ的分解速度显著高于其他处理,说明并非所有类型毛竹混合凋落叶均会促进凋落物分解,只有合适的比例和树种会促进凋落物分解。其中,竹阔混合凋落叶的分解速度高于竹针混合凋落叶的分解速度,竹阔混交可能更有利于竹林持续生产力的维持。N、P、K3种元素养分释放模式不同,N元素表现为净富集与净释放交替出现;P元素在经过4个月的快速富集后,4—5个月有短暂的净释放过程,其后呈富集状态;K元素浓度先升高后降低,在放置的前3个月净释放,随后呈富集状态。竹林凋落叶的养分含量对凋落物养分归还有重要影响,尤其是C/N和P可能作为竹林凋落物分解的指示者。
Moso-bamboo mixed forest has higher productivity and better ecological function, which may be related to the nutrient return characteristics of mixed litter. In this study, litter decomposition bag method was used to study the decomposition characteristics of litter with different mixed proportion for one year. Five treatments were set up, namely Ⅰ (pure bamboo leaves), Ⅱ (Phyllostachys praecox, 2); Ⅲ (Phyllostachys, fir ratio 8: 2), Ⅳ (Phyllostachys Phoebe, Phoebe bark ratio 5: 5) and Ⅴ (Phyllostachys praecox, Cunninghamia lanceolata ratio 5: 5). The results showed that the decomposition rates of litter under different treatments were in accordance with the Olson index decomposition model, and R2 was higher than 0.92. The decomposition order of the treatments was Ⅱ> Ⅰ> Ⅲ> Ⅴ> Ⅳ, which were 0.68,0.66,0.58,0.55 and 0.49. The decomposition rates of treatments I and II were significantly higher than those of other treatments, indicating that not all litter mixed litter will promote the decomposition of litter, and only the proper proportion and species will promote litter decomposition. Among them, the decomposition rate of mixed withered leaves of bamboo and broad leaves was higher than that of mixed litter of bamboo needles, and mixed bamboo and broadleaf could be more conducive to the sustainable productivity of bamboo forests. N, P and K showed different nutrient release patterns. N showed a net enrichment and a net release alternated. After 4 months of fast enrichment, P showed a brief net release from 4-5 months, Followed by enrichment; K element concentration first increased and then decreased, the net release in the first 3 months of placement, followed by enrichment. The nutrient content of litter on bamboo leaves has an important effect on litter nutrient return, especially C / N and P may be used as indicator of litter decomposition in bamboo forest.