南亚热带7种林分凋落叶养分含量的年动态变化

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1、第45卷第4期林业科学Vo1．45．No．42009年4月SCIENTL～SILVAESINICAEApr．，2009南亚热带7种林分凋落叶养分含量的年动态变化*卢立华蔡道雄贾宏炎何日明(中国林业科学研究院热带林业实验中心凭祥532600)摘要：2006—05—20o7—04对广西凭祥市7种主要林分凋落叶的N，P，K，Ca及Mg含量进行分析。结果表明：林分凋落叶的N，P，K，Ca及Mg含量全年月份动态变化趋势较为一致；在林木生长旺盛的高温雨季4—9月，林分凋落叶的N及P养分含量较高，而K的含量较低；在林木生长缓慢或

2、休眠的干旱低温季10月至翌年3月，凋落叶N及P养分的含量较低，而K的含量较高，说明林分凋落叶的N与P含量与林木生长量成正相关，而K与生长量成负相关；Ca随月份的变化较小，但不同林分之间的差异较大；Mg随月份的变化较大；西南桦凋落叶N含量最高(14．44g·kg)，火力楠最低(5．11g·kg)；次生林河落叶P含量最高(1．20g·kg)，马尾松最低(仅0．53g。kg)；K也以次生林最高(5．16g·kgI1)，马尾松最低(1．71g·kgI1)；Ca以杉木最高(达l1．10g·kg)，马尾松最低(仅3．76g·k

3、g)；Mg以次生林最高(3．03g-kgI1)，马尾松最低(1．18g·kg)；7种林分凋落叶的N，P，K，Ca与Mg的最高与最低含量比值都超过2。关键词：南亚热带；林分凋落叶；养分含量中图分类号：$718．554．2文献标识码：A文章编号：1001—7488(2009)04—0001—06AnnualVariationsofNutrientConcentrationoftheFoliageLittersFromSevenStandsintheSouthernSubtropicalAreaLuLihuaCaiDao

4、xiongJiaHongyanHeRiming(TheExperimentalCenterTropicalForestry，CAFPingxiang532600)Abstract：Tostudythemonthlydynamicsofforestleaflitterfall，theleaflittersof7forestsinPingxiangofGuangxiwerecollectedandtheirchemicalcomponents(N，P，K，CaandMg)weredeterminedduringthep

5、eriodfromMayof2006toAprilof2007．Theresultsindicatedthatthemonthlyvariationsofleaflitter’snutrientcontentsofN，P，K，CaandMginleaflittersfromsevenstandshadcommontrends．ThecontentsofNandPintheleaflitterfallwerehigh，whilethecontentofKwaslowintherainseason(fromAprilt

6、oSeptember)whenthetemperaturewashighandtreesgrewvigorously．Bycontrastinthedryseason(fromOctobertonextMarch)whenthetemperaturewaslowandtreesgrewslowlyorwasindormancy，theconcentrationofKwashigh．andthecontentsofNandPwerelowintheleaflitterfal1．ItsuggestedthatNandP

7、concentrationsinthe1eaflitterfal1werepositivelyrelatedtogrowthoftree，whereastheconcentrationofKinfoliagelitterwasnegativelyrelatedwiththetree’sgrowth．ThecontentofCawasstablealltheyearwithinaforest，howeveritvariedsignificantlyfromonestandtoanother．Themonthlyvar

8、iationofMginleaflitterfallfluctuatedsignificantly．Theleaflitterfall’snutrientcontentsofdifierentforestsvariedgreatly．ThehighestcontentofN(14．44g‘kg)occurredinBetulaalnoidesplantati