林分类型和分解位置对亚热带人工林凋落叶养分动态的影响  

Effects of stand type and decomposition position on leaf litter nutrient dynamics in subtropical plantations of China

作　　者：吴盼盼 张艳 江灵昕 李睿[1,2,3] 毛瑢 WU Panpan;ZHANG Yan;JIANG Lingxin;LI Rui;MAO Rong(Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed,College of Forestry,Jiangxi Agricultural University,Nanchang 330045,China;Matoushan Observation and Research Station of Forest Ecosystem,Fuzhou 335300,Jiangxi,China;Jiangxi Provincial Key Laboratory of Soil Erosion and Prevention,Jiangxi Academy of Water Science and Engineering,Nanchang 330029,China)

机构地区：[1]江西农业大学林学院,国家林业和草原局鄱阳湖流域森林生态系统保护与修复重点实验室,南昌330045 [2]江西马头山森林生态系统定位监测研究站,江西抚州335300 [3]江西省水利科学院,江西省土壤侵蚀与防治重点实验室,南昌330029

出　　处：《生态学杂志》2024年第9期2632-2640,共9页Chinese Journal of Ecology

基　　金：江西省“科技+水利”联合计划项目(2022KSG01010);国家自然科学基金项目(32060295);江西省“双千计划”项目(jxsq2018106044)资助。

摘　　要：凋落物分解释放的养分是土壤养分的主要来源,因此凋落物养分动态变化对于森林土壤肥力和林分生产力的维持具有重要的意义。然而,以往关于森林凋落物养分释放的研究均集中在地表分解的凋落物,基本忽略了空中分解的凋落物,而且所关注的养分元素均为氮、磷等大量营养元素,很少涉及钙、镁等中量营养元素。本研究以马尾松(Pinus massoniana)、湿地松(Pinus elliottii)、枫香(Liquidambar formosana)和木荷(Schima superba)4种亚热带地区常见造林树种的凋落叶作为对象,采用分解袋法调查了凋落叶在不同林分类型(马尾松、湿地松、枫香和木荷人工林)和分解位置(空中和地表)的氮、磷、钙和镁动态变化特征。结果表明,在360天的分解期内,凋落叶氮在所有人工林中均表现出先富集、后释放的格局;凋落叶磷在马尾松和湿地松人工林中呈现出先富集、后释放的模式,而在枫香和木荷人工林均出现净释放趋势;在所有人工林中,凋落叶钙和镁均呈现出净释放现象。在空中分解的枫香和木荷凋落叶养分残留量均高于地表分解的凋落叶,但马尾松和湿地松凋落叶养分残留量随着分解位置的变化没有一致性的变化趋势。本研究表明,林分类型和分解位置是凋落物养分释放的重要影响因素,而且凋落物分解过程中大量和中量营养元素的释放格局存在较大的差异。这为理解亚热带人工林养分循环过程和制定合理的养分管理措施提供数据支撑。Nutrient release from decomposing litter is a main source of soil nutrients.Consequently,litter nutrient dynamics are of great importance to maintain soil fertility and stand productivity in forests.However,most previous studies have focused on nutrient dynamics of litter decomposing on forest floor,but ignored nutrient dynamics of lit⁃ter decomposing in the air.Moreover,little is known about the dynamics of litter medium nutrient elements such as calcium and magnesium in forests compared with the macronutrients such as nitrogen and phosphorus.In this study,we selected leaf litter of four common afforestation species(Pinus massoniana,Pinus elliottii,Liquidambar formo⁃sana,and Schima superba)in subtropical regions and used the litterbag method to investigate the effects of stand type(P.massoniana,P.elliottii,L.formosana,and S.superba plantations)and decomposition position(in the air and on the forest floor)on litter nitrogen,phosphorus,calcium,and magnesium dynamics.The results showed that,across the four plantations,leaf litter nitrogen exhibited an initial immobilization and subsequently a net re⁃lease during 360⁃day decomposition.However,litter phosphorus remaining during decomposition initially increased and then decreased in P.massoniana and P.elliottii plantations,but showed a net decline in the L.formosana and S.superba plantations.In addition,litter calcium and magnesium showed a gradual net release during 360⁃day decomposition in the four plantations.Litter nitrogen,phosphorus,calcium,and magnesium remaining of L.formo⁃sana and S.superba was greater in the air than on the forest floor,whereas P.massoniana and P.elliottii litter nitro⁃gen,phosphorus,calcium,and magnesium remaining did not exhibit a consistent changing pattern between in the air and on the forest floor during decomposition.These findings suggest that stand type and decomposition position are important determinants of litter nutrient release and highlight that the release patterns of litter macronutrients and medium nutrients d

关 键 词：凋落物分解 空中分解 养分固持 养分归还 亚热带森林 

分 类 号：S718.5[农业科学—林学]