不同密度华北落叶松叶凋落物年际分解动态研究  

nter-annual Dynamics of Leaf Litter Decomposition in Control-density Larix principis-rupprechtiiPlantations

作　　者：江萍[1,2] 刘勇[1] 

机构地区：[1]北京林业大学省部共建森林培育与保护教育部重点实验室,北京100083 [2]石河子大学林学系,新疆石河子832000

出　　处：《林业资源管理》2013年第1期38-44,共7页Forest Resources Management

基　　金：高等学校博士学科点专项科研基金(20090014110011);国家自然基金(30972353);北京市教育委员会学科建设与研究生教育建设项目"北京市生态公益林质量升级关键技术研究";产学研联合培养研究生基地项目(CXYBL2008-2010)

摘　　要：不同林分密度下叶凋落物基质物质、养分动态及分解速率研究对人工林密度管理具有重要的实践意义。2009—2011年应用分解网袋法对不同林分密度等级下叶凋落物3年间的分解速率、养分动态及化学成分的变化进行测定分析,结果表明:1)凋落物叶失重率年际变化为倒"V"型变化;高密度林分Ⅰ失重率在第3年与其它林分密度存在极显著差异,说明密度对凋落物分解的影响有时间效应。2)分解速率所体现出的林分密度调控效应与失重率及木质素与氮的比值在试验的3年内均保持负相关的变化规律,故木质素/氮、失重率可作为凋落物分解速率的预测指标;可用灰分含量作为周转时间的指示指标。3)N,K的养分动态为释放—固定循环模式;P为平衡波动—固定模式,Mg为持续固定模式,Ca表现出单一的释放—固定变化模式。It is of vital importance to study the density effects on leaf litter substrate quality and their roles on decomposition rate in managed Larix principis-rupprechtii plantations. In 2000, the thinning experiment was done in four different densities. Decomposition rate, nutrient dynamics and chemical components of leaf litter were explored by litter bag method during 2009 to 2011. The results showed that ： （ 1 ） Mass loss rate of inter-annual dynamics were shaped like inversed ＂V＂. Highest-density stand I, induced by regulated thinning,showed obviously significance between other three-densities＇ stands （[[, m and 1V ）. It indicates that density has specific temporal effect on litter decomposition. （2）The density effect reflected by decompo- sition rates was consistent with ratio of lignin content to nitrogen and mass loss rate;therefore the ratio and mass loss rate could be used as predictors of leaf litter decomposition. Additionally,ash mass could be consid- ered as a predictor of tumover period. （3）In the whole observation of 3 years ,return pattern of N and K exhibi- ted two-recycled accumulation-release mode ;P followed balanced fluctuation- accumulation mode;Mg indica- ted the continuous increased mode. However, return pattern of Ca was one-recycled release-accumulation mode. The paper was aimed at offering a theoretical basis for forest thinning management.

关 键 词：年际动态 凋落物基质质量 抚育间伐 分解模型 

分 类 号：S791.22[农业科学—林木遗传育种]