亚热带不同植被恢复阶段林地凋落物层现存量和养分特征  

Stock and nutrient characteristics of litter layer at different vegetation restoration stages in subtropical region,China

作　　者：陈金磊 张仕吉[1] 李雷达[1] 辜翔[1] 刘兆丹 王留芳 方晰[1,2,3] CHEN Jinlei;ZHANG Shiji;LI Leida;GU Xiang;LIU Zhaodan;WANG Liufang;FANG Xi(School of Life Science and Technology,Central South University of Forestry and Technology,Changsha 410004,China;National Engineering Laboratory of South China Forestry Ecology Applicable Technologies,Changsha 410004,China;Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province,Huitong 438107,China)

机构地区：[1]中南林业科技大学生命科学与技术学院,长沙410004 [2]南方林业生态应用技术国家工程实验室,长沙410004 [3]湖南会同杉木林生态系统国家野外科学观测研究站,会同438107

出　　处：《生态学报》2020年第12期4073-4086,共14页Acta Ecologica Sinica

基　　金：国家林业公益性行业科研专项(201504411);国家自然科学基金项目(30771720,31170426);湖南省研究生科研创新项目(CX20190597)。

摘　　要：为揭示亚热带森林植被自然恢复过程中,凋落物层现存量及其养分元素储存能力的演变,采用空间代替时间的方法,在位于亚热带丘陵区的长沙县选取地域相邻、生境条件基本一致的檵木+南烛+杜鹃灌草丛(Loropetalum chinense+Vaccinium bracteatum+Rhododendron simsii scrub-grass-land,LVR)、檵木+杉木+白栎灌木林(L.chinense+Cunninghamia lanceolata+Quercus fabri shrubbery,LCQ)、马尾松+柯+檵木针阔混交林(Pinus massoniana+Lithocarpus glaber+L.chinense coniferous-broad leaved mixed forest,PLL)、柯+红淡比+青冈常绿阔叶林(L.glaber+Cleyera japonica+Cyclobalanopsis glauca evergreen broad-leaved forest,LAG)作为一个恢复序列,设置固定样地,采集未分解层(U层)、半分解层(S层)、已分解层(D层)凋落物样品,测定凋落物层现存量和主要养分元素含量、储量及其释放率,分析植物多样性指数与凋落物层现存量、养分元素含量的相关性。结果表明:1)凋落物层及各分解层凋落物现存量随着植被恢复而增加;同一恢复阶段D层凋落物现存量最高,占凋落物层现存量的41.59%—51.02%,不同分解层凋落物现存量的差异随着植被恢复而增大;各恢复阶段凋落物分解率为0.44—0.61,周转期为1.65—2.28 a。2)凋落物层及各分解层凋落物主要养分元素含量均表现为:N>Ca>Mg>K>P,随着植被恢复呈现出不同的变化特征,其中N、P含量总体上呈增加趋势,K含量LAG(除U层外)最高,PLL最低,Ca含量LCQ最高,PLL最低,Mg含量LAG(除U层外)最高,LVR最低;同一恢复阶段N、P(除PLL、LAG外)、K、Ca、Mg含量随着凋落物的分解而下降。3)不同恢复阶段凋落物层主要养分元素的储量依次为:N>Ca>Mg>K>P;凋落物层及各分解层凋落物主要养分元素总储量及各种养分元素的储量总体上随着植被恢复而增加;同一恢复阶段随着凋落物的分解,N、P储量增加,而K、Ca、Mg储量变化不大;随着植被恢复,凋落物层养分元素储存能�This paper aims to investigate the evolution of litter stocks and its nutrient storage capacity along the natural restoration of subtropical forest vegetation.We used the space-for-time substitution method by selecting four adjacent vegetation communities with almost same habitat conditions in Changsha County,Hunan Province,China.The four communities are comprised of Loropetalum chinense+Vaccinium bracteatum+Rhododendron simsii scrub-grass-land(LVR),L.chinense+Cunninghamia lanceolata+Quercus fabri shrubbery(LCQ),Pinus massoniana+Lithocarpus glaber+L.chinense coniferous-broad leaved mixed forest(PLL),and L.glaber+Cleyera japonica+Cyclobalanopsis glauca evergreen broad-leaved forest(LAG)to represent the secondary forest successional sequence in this region.Permanent plots were established in each vegetation community.Litter samples were collected up into un-decomposed layer litter(U),semidecomposed layer litter(S)and decomposed layers(D).The standing crop of litter,the main nutrient elements content,reserves and release rates were measured.The correlation between plant diversity and litters stock,contents of main nutrients was analyzed.The results showed that:1)the stocks of litter layers and its different decomposed layers increased with the vegetation restoration.The stocks in the D layer were the highest,accounted for 41.59%—51.02% of stocks of litter layer at the same restoration stage.The difference between different decomposition layers increased with the vegetation restoration.The decomposition rates of litters were from 0.44 to 0.61 at different restoration stages,and the cycle time were 1.65 to 2.28 a.2)The contents of main nutrients in litters layer and its different decomposed layers were in the order of N>Ca>Mg>K>P,and presented different variations with vegetation restoration.With vegetation restoration,content of N and P increased on the whole,but K content was the highest in LAG(except U layer)and the lowest in PLL.Ca content was the highest in LCQ and the lowest in PLL,as well as Mg content was th

关 键 词：湘中丘陵区 植被恢复 凋落物层 养分元素 释放率 

分 类 号：S714[农业科学—林学]