滨海沙地3种林分类型的凋落物及其分解动态变化  

Dynamic changes of litterfall and its decomposition of three forest types in coastal sandy land

作　　者：谭芳韵 韩俊学 张艺帆 谢伟东[1] 梁嘉玲 卢立国 曹雨虹 TAN Fang-yun;HAN Jun-xue;ZHANG Yi-fan;XIE Wei-dong;LIANG Jia-ling;LU Li-guo;CAO Yu-hong(College of Forestry,Guangxi University,Nanning 530004,China;Guangxi Zhuang Autonomous Region State-owned Yachang Forest Farm,Baise,Guangxi 533099,China)

机构地区：[1]广西大学林学院,南宁530004 [2]广西壮族自治区国有雅长林场,广西百色533099

出　　处：《西南农业学报》2023年第7期1513-1521,共9页Southwest China Journal of Agricultural Sciences

基　　金：国家自然科学基金项目(31260093,31560061);广西创新驱动发展重大专项(AA17204058);广西自然科学基金项目(2013GXNSFAA019057)。

摘　　要：【目的】探究滨海沙地天然林和人工林的凋落物量及其分解动态,为滨海防护林体系的保护与重建提供参考依据。【方法】采用时间动态分析法,在南亚热带滨海沙地区域选取高山榕/假苹婆天然林(FS)、红鳞蒲桃天然林(SH)、马占相思人工林(AM)为研究对象,使用收集网和分解袋法,测定各林分的凋落物量、残留量及凋落物碳(C)、氮(N)、磷(P)初始含量,分析各林分凋落物总量和叶、枝、花果及杂物组分占比、凋落物总量的月动态变化情况及分解速率,通过Olson模型和相关性分析分别研究凋落物周转期和分解率与凋落物初始养分的相关性。【结果】3种林分类型的年凋落量为8645.74~23404.07 kg/hm2,排序为FS>SH>AM;凋落叶量占林分凋落物总量的比重最大,为84.24%~94.98%,AM的凋落叶量与FS和SH间存在显著差异(P<0.05,下同),凋落物总量及各组分凋落量均表现为2种天然林高于人工林。3种林分年凋落物量的月动态变化均呈现3峰型,峰值分别出现在5月、8月和10月或11月,总体在5月达到全年凋落量最高峰但具体波动幅度存在差异。在时间序列上,FS和SH的凋落物分解速率变化趋势均表现为先快后慢,AM表现为慢—快—慢;试验结束时,各林分的干物质残留量排序为AM(66.30%)>SH(46.90%)>FS(23.90%)。3种林分凋落物分解符合Olson模型,预测分解的半衰期为0.423~1.472 a,分解周转期为AM(6.360 a)>SH(4.016 a)>FS(1.827 a)。凋落物分解速率与初始C含量呈极显著负相关(P<0.01),与C/N呈显著负相关。【结论】滨海沙地FS和SH 2种天然林分的年凋落物量大、分解率快和周转期短,具有较高改善滨海沙地土壤结构和维持土壤肥力的能力。在滨海沙地的植被恢复和防护林体系建设中,应优先从当地的天然林分中选择建群树种和伴生树种构建近自然的混交林或复层林,增加林分的生物多样性和凋落物组成的复杂性,提高林分对土�【Objective】The present study focused on the litterfall accumulation and decomposition dynamics of natural and artificial forests in coastal sandy land,and provided theoretical references for the protection and reconstruction of coastal shelterbelt systems.【Method】According to the time dynamic analysis method,two natural forests of Ficus altissima/Sterculia lanceolate natural forests(FS)and Syzygium hancei natural forests(SH),and Acacia mangium plantation pure forest(AM)were selected in the southern subtropical coastal sandy area.The collection net and decomposition bag were used to determine the amount of litterfall accumulation,the residual amount and the initial content of litterfall C,N and P,and to analyze the monthly dynamic change,decomposition rate and the proportion of leaves,branches,flowers+fruits and scraps in each stand.The Olson model and correlation analysis were used to analyze the turnover period and the correlation between decomposition rate and initial nutrients of litterfall.【Result】In the study,the annual litterfall of the three forest types was between 8645.74-23404.07 kg/hm~2,and the order was FS SH AM.Leaf litter was the dominant component in the total litterfall and contributed about 84.24%to 94.98%.There was a significant difference between the foliage litter amount of AM and FS and SH(P0.05,the same as below).The total litter and the litter of each component were higher in two natural forests than in artificial forests.The monthly dynamics of annual volume in the three kinds of forests showed three peaks,appearing in May,August and October or November,respectively,and reached the highest annual litter amount in May as a whole,but the specific fluctuation amplitude was different.The decomposition rate of litters showed that FS and SH were both fast at first and then slow,and AM was slow-fast-slow.At the end of the experiment,the order of dry matter residue was AM(66.30%)SH(46.90%)FS(23.90%).Litter decomposition conformed to Olson model,and the predicted half-life of decomposit

关 键 词：滨海沙地 林分类型 凋落物 分解过程 动态变化 

分 类 号：S714[农业科学—林学]