摘要
采用田间定位试验的方法,研究了追施氮肥对2年生桉树各器官生物量积累及养分浓度与贮量的影响.结果表明:与对照相比,追施氮肥使桉树生物量增加24.2%,其中树枝增幅最高,为38.2%,树叶最少.追施氮肥显著促进了桉树对养分的吸收,其增幅顺序为P>K>N>Mg>Ca>Si;叶片中N、P、Mg、Si含量最高,K在树干中的贮量最大,树枝部位的养分浓度与贮量增加最为显著.桉树N、P、K养分以内循环为主,叶片凋落前分别有73.8%、79.1%和72.9%的N、P、K养分被转移到植株体内,其外循环量仅为全树贮量的14.8%、7.7%和8.6%;Ca、Mg、Si养分则以外循环方式为主,其中Ca最明显,树叶中89.2%的Ca随叶片凋落,其外循环通量占全树Ca总贮量的25.9%.
A field experiment was conducted to study the effects of nitrogen（N） topdressing on the biomass accumulation and nutrient concentration and storage in different organs of two-year-old eucalyptus.Comparing with the control,N topdressing increased the eucalyptus biomass by 24.2 %.Branch had the highest increment（38.2%）,while leaf had the lowest one.The nutrient uptake under N topdressing was improved significantly,with the order of PKNMgCaSi.Leaf had the highest contents of N,P,Mg,and Si;trunk had the highest storage of K;while branch had the most significant increase of nutrient concentration and storage.The N,P,and K were recycled mainly through internal flux,with 73.8% of N,79.1% of P,and 72.9% of K in leaf transferred back to the plant before leaf fallen,and the external flux of these three nutrients only occupied 14.8%,7.7%,and 8.6% of their total storage in the tree,respectively.The Ca,Mg and Si were the external flux elements,especially for Ca.89.2% of Ca in leaf was cycled in external flux,accounting for 25.9% of its total storage in the tree.
出处
《应用生态学报》
CAS
CSCD
北大核心
2010年第8期1933-1939,共7页
Chinese Journal of Applied Ecology
基金
中国科学院知识创新工程重要方向项目(KZCX2-YW-405)
国家"十一五"科技支撑计划项目(2008BADA7B08)
教育部重点实验室开放基金项目(ERCERR08014)资助
关键词
桉树
追施氮肥
生物量
养分浓度
养分贮量
Eucalyptus
nitrogen topdressing
biomass
nutrient concentration
nutrient storage.
