秦岭中幼林龄华北落叶松针叶与土壤的碳氮磷生态化学计量特征  

Carbon,nitrogen,and phosphorus stoichiometric characteristics of soil and leaves from young and middle aged Larix principis-rupprechtii growing in a Qinling Mountain plantation

作　　者：牛瑞龙 高星[1] 徐福利[2,3] 王渭玲[1] 王玲玲[1] 孙鹏跃 白小芳[3] 

机构地区：[1]西北农林科技大学生命科学学院,杨凌712100 [2]西北农林科技大学资源环境学院,杨凌712100 [3]中国科学院水利部水土保持研究所,杨凌712100

出　　处：《生态学报》2016年第22期7384-7392,共9页Acta Ecologica Sinica

基　　金：国家重点基础研究发展计划"973计划"资助项目(2012CB416902)

摘　　要：为探究华北落叶松人工林物质循环规律与养分元素的分配格局,将华北落叶松针叶和土壤结合起来,以秦岭地区7年(7a)、12年(12a)、22年(22a)生华北落叶松人工林为研究对象,综合探究中幼林龄华北落叶松针叶和土壤的C、N、P含量及C∶N∶P化学计量特征。结果表明,不同林龄间土壤C和P含量的差异显著,7a和12a的C和P含量显著高于22a的,N含量差异不显著,随土层深度的增加,土壤C、N、P均呈下降趋势;22a土壤的C∶P和N∶P显著高于7a和12a,说明随着林龄增加,P限制了人工林正常的生长发育,C∶N在林龄之间的差异不显著;不同林龄针叶C差异不显著,N和P差异显著,N和P含量在中龄林中最高;22a针叶的C∶N和C∶P均表现为显著下降,3种林龄华北落叶松针叶的N∶P在6.8—9.3之间,说明幼、中林龄华北落叶松主要受N的限制;华北落叶松针叶和土壤的C、C∶N之间呈显著的正相关,P、C∶P之间呈显著的负相关,N、N∶P之间相关性不显著。中林龄华北落叶松人工林土壤P元素含量低,主要是通过养分的再吸收来满足植株的生长需求,而非通过吸收土壤养分。Ecological stoichiometry theory is an important tool that can be used to explore the law of substance cycling and the distribution patterns of nutrient elements. Carbon（ C）,nitrogen（ N）,and phosphorus（ P） play an important role in regulating plant growth and various physiological functions. In recent years,some studies have reported that Larix principisrupprechtii,which was introduced into Shaanxi Province in 1958,grew well during its initial stage,but as its age increased,the growth potential fell and soil fertility decreased. There has been a global trend towards forest ecosystem restoration and reconstruction. Therefore, we chose to study the Larix principis-rupprechtii plantation in the Qinling Mountains that contained trees with three different stand ages. These were 7 years old（ 7a）,12 years old（ 12a）,and 22 years old（22a）. The contents and mass ratios of the C,N,and P elements in the soil and leaves were investigated. The results showed that an increase in soil depth led to a decrease in soil C,N,and P contents for each growth stage. The soil C and P contents were different for the three stand ages. The soil C and P contents of 7a and 12 a were significantly higher than those for 22 a. In contrast,there was no significant difference in soil N between the stand ages. The soil C ∶ P and N∶ P mass ratios for 22 a were significantly higher than those for 7a and 12 a,which indicated that P limited the development of Larix principis-rupprechtii as the stand age increased. There were no significant differences between soil C ∶ N mass ratios for different stand ages. There were large significant differences in leaf N and P among the stand ages,but leaf C showed a different trend. The leaf N and P contents were highest during middle age. The leaf C ∶ N and C ∶ P mass ratios represent plant C assimilation ability to a certain extent. Therefore,these indexes could reflect nutrient utilization efficiency and the growth rate of plants. In this study,the leaf C ∶ N and C ∶ P mass ra

关 键 词：生态化学计量 秦岭 华北落叶松 针叶 土壤 

分 类 号：S791.22[农业科学—林木遗传育种]