滇中高原华山松林凋落叶枝分解特征对氮的响应  

Responses of leaf litter and twig decomposition characteristics in Pinus armandii forest to nitrogen in central Yunnan Plateau

作　　者：肖文贤 王克勤[1] 宋娅丽[1] 安文雄 郑兴蕊 潘禹 XIAO Wenxian;WANG Keqin;SONG Yali;AN Wenxiong;ZHENG Xingrui;PAN Yu(College of Ecology and Environment,Southwest Forestry University,Kunming,unnan 650224,China)

机构地区：[1]西南林业大学生态与环境学院,云南昆明650224

出　　处：《西北农林科技大学学报（自然科学版）》2023年第4期73-83,共11页Journal of Northwest A&F University(Natural Science Edition)

基　　金：云南省教育厅科学研究基金项目(2022J0510);云南省高校优势特色重点学科(生态学)建设项目(050005113111);国家林草局林业科技创新平台运行玉溪森林生态系统国家定位观测研究站项目(2020132078);云南玉溪森林生态系统国家长期科研基地项目(2020132550);国家自然科学基金项目(42067005);云南省基础研究计划项目(202001AT070136)。

摘　　要：【目的】研究施氮对滇中高原华山松林凋落叶、枝分解特征的影响,为预测未来高海拔区域森林凋落物分解对持续氮增加的响应与适应提供理论依据。【方法】2019年1月-2020年1月,采用尼龙网袋法,以滇中高原华山松林为对象,开展施氮处理下凋落叶、枝原位分解试验,设置对照(N 0 g/(m^(2)·a),CK)、低氮(N 10 g/(m^(2)·a),LN)、中氮(N 20 g/(m^(2)·a),MN)和高氮(N 25 g/(m^(2)·a),HN)4种处理,分析不同处理华山松林凋落叶、枝质量残留率及木质素和纤维素残留率,在此基础上探讨了华山松林凋落叶、枝质量残留率与木质素、纤维素残留率的关系。【结果】(1)随着分解时间的延长,各处理华山松林凋落叶、枝质量残留率均呈下降趋势。分解1年后,凋落叶质量残留率低于凋落枝,可知凋落叶分解速率快于凋落枝;与CK相比,LN、MN处理凋落叶、枝质量残留率均明显降低,而HN处理则明显提高。(2)与CK的凋落叶分解50%和95%所需的时间(1.764和7.623年)相比,LN处理分别减少了0.018和0.077年,MN处理分别减少了0.009和0.039年,而HN处理分别增加了0.336和1.455年;与CK的凋落枝分解50%和95%所需的时间(4.030和17.417年)相比,LN处理分别减少了0.179和0.774年,MN处理分别减少了0.092和0.396年,而HN处理分别增加了0.171和0.739年。(3)随着分解时间的延长,各处理凋落叶、枝木质素残留率均先降低后升高,纤维素残留率总体呈下降趋势。分解1年时,与CK相比,LN、MN处理促进了木质素和纤维素的分解,而HN处理则抑制其分解。相关性分析结果表明,华山松林凋落叶、枝质量残留率均与其纤维素残留率之间呈极显著正相关关系。【结论】施氮对华山松林凋落叶、枝的分解有不同程度影响,影响大小与木质素和纤维素分解对施氮的响应有关。【Objective】This study investigated the effect of nitrogen(N)application on leaf litter and twig decomposition characteristics of Pinus armandii forest in central Yunnan Plateau to provide data for exploring future variation trend of nutrient cycling in different forest ecosystems influenced atmospheric N deposition.【Method】During January 2019-January 2020,using litterbag method,the Pinus armandii forests in central Yunnan Plateau were selected to set in situ leaf litter and twig decomposition experiment with four N treatment levels of control(N 0 g/(m2·a),CK),low nitrogen(N 10 g/(m^(2)·a),LN),medium nitrogen(N 20 g/(m^(2)·a),MN)and high nitrogen(N 25 g/(m^(2)·a),HN).Leaf litter and twig mass remaining rates and lignin and cellulose remaining rates of Pinus armandii forest under different treatments were analyzed.On this basis,the relationship between leaf litter and twig litter mass remaining rates and lignin and cellulose remaining rates of Pinus armandii forest was discussed.【Result】(1)With the extension of decomposition time,mass remaining rates of leaf litter and twig litter of Pinus armandii decreased in each treatment.After one year,the mass remaining rate of leaf litter was lower than that of twig litter,indicating that leaf litter decomposition was faster than that of twig litter.Compared with CK,leaf litter and twig litter mass remaining rates in LN and MN treatments decreased significantly,while those in HN treatment increased significantly.(2)Compared to the time needed for 50%and 95%mass losses of leaf litter decomposition of CK(1.764 and 7.623 years),the LN treatment decreased it by 0.018 and 0.077 years,the MN treatment decreased it by 0.009 and 0.039 years,while the HN treatment increased it by 0.336 and 1.455 years.Compared to the time needed for 50% and 95% mass losses of twig litter decomposition of CK(4.030 and 17.417 years),the LN treatment decreased it by 0.179 and 0.774 years,the MN treatment decreased it by 0.092 and 0.396 years,while the HN treatment increased it by 0.171 a

关 键 词：华山松林 森林凋落物 凋落物分解 滇中高原 

分 类 号：S714.[农业科学—林学]