| 摘要: |
| 【目的】探究祁连圆柏针叶和林下土壤C、N、P含量及其生态化学计量特征，解决祁连圆柏与土壤之间的养分循环和供应等问题，为青海省植被保护与修复提供依据。【方法】以祁连圆柏天然次生林为研究对象，在青海省不同地区（祁连县、德令哈市、乌兰县、都兰县、兴海县、泽库县）以及不同海拔（2 900~3 519 m）采集祁连圆柏针叶和林下土壤样品，综合探究针叶和林下土壤C、N、P含量及其生态化学计量特征，以及祁连圆柏生态化学计量内稳性之间的差异，并采用冗余分析研究环境因子对其的影响。【结果】①不同地区、不同海拔间祁连圆柏针叶和林下土壤C、N、P含量及其生态化学计量均存在明显的差异，其中泽库县和海拔3 000 m地区祁连圆柏针叶及林下土壤总氮（TN）、全磷（TP）含量均相对较高，祁连圆柏生长速率快。②祁连圆柏针叶全碳（TC）、C∶N、C∶P和N∶P为绝对稳态型，针叶TN和TP含量均为稳态型。③祁连圆柏针叶和林下土壤C、N、P含量及生态化学计量受平均气温、海拔、年均降水量、pH等环境因子的综合影响，环境因子对祁连圆柏针叶和林下土壤C、N、P含量及其生态化学计量差异的累计解释率分别为73.34%和57.10%。【结论】祁连圆柏内稳性较强，具有良好的生态适应性，其中泽库县和海拔3 000 m处较适合祁连圆柏生存，可进一步作为青海省天然林保护修复以及种苗培育的重点区域。整体来看，祁连圆柏生长主要受N元素的限制，可采取叶面喷施氮肥、引入固氮植物或者适当降低土壤pH值等措施以促进其生长。 |
| 关键词: 祁连圆柏 生态化学计量 养分揗环 |
| DOI： |
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| 基金项目:国家林业和草原局研究计划“青海柏树生态系统有机碳空间特征研究”（LC-2-12） |
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| Ecological stoichiometry and influencing factors of C,N and P in Juniperus przewalskii needles and soil in Qinghai |
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HOU Xiaowei,WEN Miaoxia,WANG Hai,et al
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| Abstract: |
| 【Objective】This study explored C,N and P contents and stoichiometry of Juniperus przewalskii needles and understory soil to solve nutrient circulation and supply problems between Juniperus przewalskii and understory soil,so as to provide basis for vegetation protection and restoration in Qinghai Province.【Method】The natural secondary forest of Juniperus przewalskii in Qinghai was selected to collect needles and understory soil samples from different regions (Qilian County,Delingha,Wulan County,Dulan County,Xinghai County and Zeku County) and altitudes (2 900-3 519 m).The differences in C,N and P contents,stoichiometry and internal stability were explored and redundancy analysis was used to study the influence of environmental factors.【Result】① There were significant differences in C,N and P contents and stoichiometry of Juniperus przewalskii needles and understory soil among different regions and altitudes.Total N (TN) and total P (TP) contents of needles and understory soil were higher in Zeku County and at the altitude of 3 000 m,indicating faster growth of Juniperus przewalskii.② Total C (TC) content and ratios of C∶N,C∶P and N∶P of Juniperus przewalskii needles were absolutely stable,and contents of TN and TP were stable.③ C,N and P contents and stoichiometry of Juniperus przewalskii needles and understory soil were associated with unique environmental factors,such as temperature,altitude,precipitation and pH.The accumulative explanation rates of environmental factors on differences of needles and understory soil were 73.34% and 57.10%,respectively.【Conclusion】Juniperus przewalskii had strong internal stability and ecological adaptability.Zeku County and the altitude of 3 000 m were more suitable for Juniperus przewalskii,which can be further used as key areas for natural forest protection and seedling cultivation in Qinghai.The growth of Juniperus przewalskii was mainly limited by N element.Nitrogen fertilizer spraying,nitrogen-fixing plants introduction and lower soil pH can improve the growth of Juniperus przewalskii. |
| Key words: Juniperus przewalskii ecological stoichiometry nutrient circulation |
