【摘要】 [目的]开展凋落叶分解速率研究,探讨凋落叶分解速率与初始质量的关系,为甘肃省兴隆山森林生态系统物质循环研究提供依据。[方法]采用凋落物分解袋法,以兴隆山青杄、山杨和白桦3种主要树种的凋落叶为研究对象,进行凋落叶分解速率及凋落叶初始质量的研究,明确凋落叶分解速率与初始质量的关系。[结果]青杄中龄林针叶分解速率为0.16,95%分解期为19.08a;青杄近熟林针叶分解速率为0.13,95%分解期为23.70a;山杨和白桦凋落叶分解速率均为0.11,95%分解期分别为28.57a和27.27a;山杨和白桦凋落叶分解速率明显要小于青杄针叶,这很可能是凋落叶分解主场效应和分解袋孔径较小所致。凋落叶分解速率与氮含量呈显著线性正相关,与木质素含量、碳/氮值、木质素/氮值和钾含量呈显著线性负相关,特别是与木质素含量、氮含量和木质素/氮值,相关系数均达0.700 0以上;钾含量、木质素含量、木质素/氮、碳/磷和纤维素含量是影响兴隆山森林凋落叶分解速率的重要指标。[结论]木质素/氮值是影响凋落叶分解速率的关键质量指标,凋落叶初始木质素/氮值越高,分解速率越低。更多还原

【Abstract】 [Objective]To study the decomposition rate of litter leaf and investigate the relationship between litter decomposition rate and their initial quality in order to provide a scientific basis for forest ecosystem material circulation research in Xinglong Mountain of Gansu Province.[Methods]A field litterbag experiment was conducted in Xinglong Mountain from 2013 to 2016.Litter leaf of three main tree species including Picea wilsonii,Populus davidiana and Betula platyphylla was taken as the research object.Samples of litterbags were retrieved at May,August and November in every year.The litter decomposition rate and their initial quality were studyed.The relationship between litter decomposition rate and their initial quality were clarified.[Results]The leaf decomposition rate of P.wilsonii in middle aged forest was 0.16,and the 95% decomposition period was 19.08 a.The leaf decomposition rate of P.wilsonii in pre-mature forest was 0.13,and the 95% decomposition period was 23.70 a.The decomposition rate of litter leaf for P.davidianaand B.platyphylla was 0.11,and the 95% decomposition period was 28.57 a and 27.27 a,respectively.The decomposition rate of litter leaves of P.davidianaand B.platyphylla was significantly lower than that of the needle leaf of P.wilsonii,which was probably due to the home-field advantage of litter decomposition and smaller aperture of decomposition bags.The litter decomposition rate was positively correlated with N content,but negatively correlated with lignin content,C/N value,lignin/N and K conten.Especially,for lignin content,N content and lignin/N values,the correlation coefficients were above 0.7 000.K content,content of lignin,lignin/N,C/P and cellulose content were key indicators affecting the decomposition rate of forest litter in Xinglong Mountain.[Conclusion]Lignin/N is a key quality indicator affecting litter decomposition rate.The higher the initial lignin/N value of litter leaves,the lower the decomposition rate.更多还原