不同强度间伐对杉木人工林凋落物分解速率的影响  

Effects of Different Intensity Thinning on Litter Decomposition in Chinese Fir Plantations

作　　者：肖文娅 刁娇娇[1] 费菲[1] 关庆伟[1] XIAO Wenya;DIAO Jiaojiao;FEI Fei;GUAN Qingwei(College of Biology and Environment;Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University,Nanjing 210037, China)

机构地区：[1]南京林业大学生物与环境学院//南京林业大学南方现代林业协同创新中心,江苏南京210037

出　　处：《生态环境学报》2016年第8期1291-1299,共9页Ecology and Environmental Sciences

基　　金：国家林业公益性行业科研专项“提高城市森林固碳能力的关键技术研究与示范”(201104075);江苏省普通高校研究生科研创新计划项目(KYLX16_0832);江苏高校优势学科建设工程资助项目(PAPD)

摘　　要：为了明晰凋落物分解对间伐强度的响应,本文以南京市溧水区林场间伐7年后的25年生杉木Cunninghamia lanceolata(Lamb.)Hook.人工林为研究对象,研究了不同间伐强度下凋落物的分解速率和化学组成的变化,并分析其与部分环境因子之间的关系,以期为不同间伐强度对凋落物分解特征影响机制的初步探究奠定基础,为人工针叶林的可持续发展提供科学依据。结果显示,(1)间伐显著改变了杉木人工林凋落物的分解速率;与对照地相比,中度间伐下分解最快,失重率为31.98%;弱度间伐次之,为30.94%;强度间伐则会减缓杉木凋落物的分解,失重率仅达到27.03%。(2)经1年分解,对照地和3种间伐强度下凋落物均表现出N的净积累,中度间伐强度对凋落物中N的影响显著,w(C)/w(N)和w(木质素)/w(N)的年动态变化趋势相似,其中w(C)/w(N)是反映分解速率的理想指标。(3)间伐主要通过影响凋落物层温度、蔗糖酶和纤维素酶的活性来改变凋落物的分解速率。本研究结果表明,适度间伐能够改变凋落物层温度和酶活性,加速杉木人工林凋落物的分解,减缓过分积累,促进土壤养分的输入;过度间伐会抑制凋落物分解,阻滞养分的回归与利用。该研究对进一步揭示间伐对森林系统中物质及养分循环的影响机制有一定意义,可为制定合理有效的营林措施,促进针叶人工林养分循环提供一定的科学依据。In order to understand the response of litter decomposition on thinning intensity, we study the dynamic changes of litterdecomposition rate and chemical composition, and analyze their relationships with a part of environmental factors in a Chinese firplantation in Lishui District, Nanjing. The purpose is to lay the foundation for the study of different thinning intensities on litterdecomposition mechanism characteristics, and provide scientific basis for the sustainable development of artificial coniferous forests.The results are as follows: (1) Litter decomposition rate has been significantly affected by thinning. Compare with control check,litter decomposes fastest in medium-intensity-thinning (mass loss: 31.98%) and faster in light-intensity-thinning (mass loss: 30.94%),but it shows a decrease in high intensity thinning (mass loss: 27.03%). (2) During one year decomposition,it has showed a netaccumulation of w(N) and similar trends of w(C)/w(N) and w(lignin)/w(N) in all plots. Among them, medium intensity thinning has asignificantly influence on nitrogen content. In addition, w(C)/w(N) is an ideal indicator to reflect litter decomposition rates. (3)Through change the temperature and activities of cellulase and invertase in litter layer, thinning can influence litter decompositionrate. Our results suggest that moderate thinning can change the litter layer temperature and enzyme activities, accelerating thedecomposition of litter in a Chinese fir plantation, thus, reduce excessive litter accumulation, improving soil nutrient input. However,excessive thinning will inhibit the litter decomposition, nutrient utilization and return block. This study is meaningful of furtherexploring the mechanism of material and nutrients’ cycle affected by thinning. It can provide some scientific basis for developingreasonable and effective measures to promote the forest, promoting conifer plantation nutrient cycle.

关 键 词：杉木人工林 间伐强度 凋落物 化学成分 分解速率 

分 类 号：S718.55[农业科学—林学]