林层高度对不同品质凋落物分解动态的影响  

Effects of forest canopy height on decomposition dynamics of litter with varying qualities

作　　者：解婷婷 徐定兰 易伶俐 方平福 钟曲颖 侯志琪 杨清培[1] 宋庆妮[1] 刘骏[1] Xie Tingting;Xu Dinglan;Yi Lingli;Fang Pingfu;Zhong Quying;Hou Zhiqi;Yang Qingpei;Song Qingni;Liu Jun(College of Forestry,Jiangxi Agricultural University,Nanchang 330045,China;Administration of Jiangxi Guanshan National Nature Reserve,Yichun,Jiangxi 336300,China)

机构地区：[1]江西农业大学林学院,南昌330045 [2]江西官山国家级自然保护区管理局,江西宜春336300

出　　处：《植物科学学报》2024年第6期757-765,共9页Plant Science Journal

基　　金：国家自然科学基金项目(42067050);江西省研究生创新专项资金项目(YC2023-S383)。

摘　　要：凋落叶分解和养分释放是森林生态系统中养分循环的重要环节。为探讨凋落物在不同林层高度下的分解动态以及养分释放差异,本研究以杉木(Cunninghamia lanceolata(Lamb.)Hook)、甜槠(Castanopsis eyrei(Champ.ex Benth.)Tutcher)、拟赤杨(Alniphyllum fortunei(Hemsl.)Penk)3种不同品质凋落物叶片为实验材料,采取凋落物分解袋法,开展为期1年的凋落物在空中5 m(H5)、0.5 m(H0.5)和地面(H0)3个林层高度上的分解实验。结果显示:(1)在1年分解期内,3种品质凋落物在空中的分解比地面质量残留率低14.13%~21.22%;(2)随着分解时间的增加,3个林层高度上的差异分别出现在拟赤杨的分解前期,甜槠和杉木的分解后期;(3)无论在地面还是空中,高品质凋落物均比相同位置低品质凋落物的分解速度快;(4)随着时间的增加,3种品质凋落叶在3个林层高度下的养分残留率最终表现为拟赤杨<甜槠<杉木,凋落叶分解时的养分化学计量比受叶片自身初始化学性质的影响较大,受林层高度的影响较小。Leaf litter decomposition and nutrient release play important roles in nutrient cycling within forest ecosystems.This study investigated the decomposition dynamics and nutrient release of litter at varying forest heights.Leaf litter from three species:Cunninghamia lanceolata(Lamb.)Hook,Castanopsis eyrei(Champ.ex Benth.)Tutcher,and Alniphyllum fortunei(Hemsl.)Penk,which representing a gradient from low to high litter quality,was examined using a litterbag approach.A year-long decomposition experiment was conducted at three vertical forest heights:5 m(H5),0.5 m(H0.5),and ground(H0).Results showed that:(1)Over the one-year decomposition period,litter decomposition rates in the air(H5 and H0.5)were 14.13%–21.22%slower than those on the ground(H0).(2)Height-related differences in decomposition rates emerged during different phases of decomposition,with A.fortunei showing pronounced early-stage differences and Castanopsis eyrei and Cunninghamia lanceolata exhibiting late-stage differences.(3)Highquality litter consistently decomposed faster than low-quality litter across all heights,regardless of whether it was on the ground or in the air.(4)After one year,nutrient retention rates across all heights followed the trend:A.fortunei<Castanopsis eyrei<Cunninghamia lanceolata.The nutrient stoichiometric ratios during decomposition were primarily affected by the initial chemical composition of the litter rather than the vertical differences in forest height.

关 键 词：空中凋落物 林层高度 垂直位置 残留率 

分 类 号：Q948[生物学—植物学]