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[目的]毛竹(Phyllostachys edulis)叶片分解与竹林碳循环和养分周转关系密切,通过室内模拟氮沉降和温度升高试验,为预测未来气候变暖和氮沉降条件对凋落竹叶分解的调控提供参考,为科学管理毛竹林提供科学依据。[方法]以毛竹原状叶片及粉状叶片(粉碎过2 mm)为研究对象,布设3因素2水平试验,即施氮(添加氮5 mg·g-1)和不加氮对照,12℃和28℃培养温度,原状和粉状叶片,恒温箱中培养78 d,采用密闭碱液吸收法定期测定CO2释放量,并计算分解速率。[结果]表明:施氮处理、培养温度和叶片形态及其交互作用对凋落竹叶分解速率的影响因培养阶段不同而存在差异,总体上表现为培养前期(0—23 d)和培养中期(24—48 d)的分解速率高于培养后期(49—78 d)。从均值来看,施氮处理抑制原状叶片在12℃培养下的分解速率,而对两种形态叶片在28℃培养条件的分解速率影响不显著;施氮处理可增加原状凋落竹叶分解速率的温度敏感性(Q10),但对粉状凋落竹叶分解速率的Q10值影响不显著,且原状凋落竹叶分解速率的Q10值高于粉状凋落叶。凋落竹叶C/N在培养后期显著升高,且氮添加显著促进粉状竹叶C/N增加。[结论]氮沉降对毛竹凋落叶分解的影响效应与培养温度和叶片形态有关。凋落物分解的影响因素众多,凋落物分解对全球环境变化的响应不仅应该深入研究其化学和生物学机制,还要关注物理过程及其调控潜能。
[Objective] The leaf decomposition of Phyllostachys edulis was closely related to the carbon cycling and nutrient turnover in bamboo forest. Through indoor simulation of nitrogen deposition and temperature increase test, it could provide reference for the prediction of future climate warming and nitrogen deposition on the regulation of litter decomposition. Provide a scientific basis for scientific management of bamboo grove. [Method] The 3-factor-2 level test was conducted on original leaves and powdery leaves (crushed by 2 mm) of Moso bamboo. Nitrogen application (5 mg · g-1 added nitrogen) and no nitrogen control, 12 ℃ and 28 ℃ culture temperature, the original shape and powder leaves, incubator for 78 days, using sealed lye absorption regular determination of CO2 emissions, and calculate the decomposition rate. [Result] The results showed that the effects of nitrogen application, culture temperature, leaf morphology and their interaction on the decomposition rate of litter leaves were different due to different stages of culture. Overall, there were differences between pre-culture (0-23 d) and mid-culture 24-48 d) was higher than the late stage of cultivation (49-78 d). From the average, nitrogen treatment inhibited the decomposition rate of original leaves at 12 ℃, but had no significant effect on the decomposition rate of the two kinds of leaves at 28 ℃. Nitrogen treatment increased the decomposition rate of original litter leaves Q10, but had no significant effect on the Q10 value of decomposition rate of powdery litter leaves, and the Q10 value of litter decomposition rate was higher than that of powder litter leaves. Litter leaf C / N increased significantly at the late stage of culture, and nitrogen addition significantly promoted the increase of C / N of the powdery bamboo leaves. [Conclusion] The effect of nitrogen deposition on the decomposition of litter leaves was related to the culture temperature and leaf morphology. Litter decomposition has many influencing factors. The response of litter decomposition to global environmental change should not only study its chemical and biological mechanisms in depth, but also pay attention to the physical process and its regulation potential.