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码上扫一扫！ |
| 祁连山东部不同海拔白桦天然林土壤养分化学计量特征及其影响因素 |
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马小东, 王作枭, 鲁雅雯, 李川, 贺康宁
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北京林业大学 水土保持学院,北京 100083
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| 摘要: |
| 【目的】探究祁连山东部不同海拔白桦天然林土壤养分含量及其化学计量特征和影响因素，为该地区白桦天然林养分管理提供理论依据。【方法】在青海省祁连山东部北川河流域白桦天然林分布较为密集的区域划分4个海拔等级(>2 600～≤2 700，>2 700～≤2 800,>2 800～≤2 900,>2 900～≤3 050 m)，并设置20 m×20 m的样地16个，调查样地的林分密度（SD）、胸径（DBH）、树高（H）、郁闭度（CD）、灌草丰富度（SGR）、凋落物厚度（LD）和坡度（S），使用土钻和环刀采集0~20，20~40和40~60 cm土层土壤，分别测定土壤质量含水量（SWC）、土壤体积质量（SBD）、饱和导水率（SHC）、pH以及土壤有机碳（SOC）、全氮（TN）、全磷（TP）和碱解氮（AN）、速效磷（AP）、速效钾（AK）含量，分析土壤养分及其化学计量比与环境因素的相关性，采用冗余分析探究了环境因素对土壤养分及其化学计量比的影响。【结果】（1）随着海拔的升高，0～60 cm土层土壤SOC、TN、AN、AK含量以及C∶N、C∶P和N∶P呈先升高后降低的趋势，TP、AP含量呈先降低后升高的趋势，AN∶AK变化不明显，而AN∶AP、AK∶AP呈先下降后升高再下降趋势。（2）在同一海拔下，随着土层深度的增加，土壤SOC、TN、TP、AN、AK含量以及C∶P、N∶P、AN∶AP、AK∶AP均呈递减趋势，C∶N呈先升高后下降的趋势，而AP含量和AN∶AK无明显的变化规律。（3）土壤C∶P、N∶P平均值均高于全国土壤平均水平。（4）冗余分析发现，SHC、SD、SWC、LD、pH和SGR对土壤碳氮磷及其化学计量比有显著或极显著影响，其解释量分别为33.7%，13.5%，6.5%，4.9%，3.0%和2.9%；SHC、pH、LD、SWC对土壤速效养分及其化学计量比有显著或极显著的影响，其解释量分别为28.2%，9.9%，5.4%，3.8%。【结论】环境因素对祁连山东部不同海拔白桦天然林土壤养分及其化学计量比有明显影响，其中SHC、SWC、pH和LD是主要的影响因素；研究区土壤C、N有效性较好，P有效性较差，建议后期在白桦天然林管理过程中适当补充磷肥。 |
| 关键词: 白桦天然林 环境因素 土壤生态化学计量特征 土壤养分 祁连山东部 |
| DOI：10.13207/j.cnki.jnwafu.2025.08.010 |
| 分类号: |
| 基金项目:青海省科技厅项目“低效退化天然白桦林林分结构调整和功能提升技术研究与示范”（2022-SF-160） |
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| Characteristics of soil nutrient stoichiometry and its influencing factors in natural forests of Betula platyphylla at different altitudes in the eastern Qilian Mountains |
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MA Xiaodong, WANG Zuoxiao, LU Yawen, LI Chuan, HE Kangning
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School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China
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| Abstract: |
| 【Objective】This research aimed to investigate the soil nutrient content and its stoichiometric characteristics and influencing factors of Betula platyphylla natural forests at different altitudes in the eastern Qilian Mountains,in order to provide a theoretical basis for the nutrient management of B.platyphylla natural forests in this region.【Method】Four altitude classes (>2 600-≤2 700，>2 700-≤2 800,>2 800-≤2 900,>2 900-≤3 050 m) were determined by dividing the area of denser distribution of B.platyphylla natural forests in the Beichuan River Basin in the eastern Qilian Mountains of Qinghai Province,and 16 sample plots of 20 m×20 m were set up.The stand density (SD),diameter at breast height (DBH),height (H),canopy density (CD),shrub-grass richness (SGR),litter depth (LD) and slope (S) of the sample plots were investigated.Soil was collected from the 0-20,20-40 and 40-60 cm soil layers with a soil auger and a ring cutter,and soil water content (SWC),soil bulk density (SBD),saturated hydraulic conductivity (SHC),pH,and soil organic carbon (SOC),total nitrogen (TN),total phosphorus (TP),and alkali hydrolyzed nitrogen (AN),available phosphorus (AP),and available potassium (AK) were measured.The correlation of soil nutrients and their stoichiometric ratios with environmental factors was analysed,and redundancy analysis was used to investigate the effects of environmental factors on soil nutrients and their stoichiometric ratios.【Result】(1) With the increase of elevation,SOC,TN,AN,AK,C∶N,C∶P and N∶P of the soil from 0-60 cm soil layers showed a tendency of increasing and then decreasing,and TP and AP showed a tendency of decreasing and then increasing.No significant difference was observed in AN∶AK,while AN∶AP and AK∶AP showed a tendency of decreasing and then increasing and then decreasing.(2) At the same elevation,with the increase of soil depth,SOC,TN,TP,AN,AK,C∶P,N∶P,AN∶AP,AK∶AP showed a decreasing trend,C∶N showed a tendency to increase and then decrease,and no obvious changing pattern was observed in AP and AN∶AK.(3) The averages of soil C∶P and N∶P were higher than national soil averages.(4) Redundancy analysis revealed that the environmental factors with significant or highly significant effects on soil C,N,P and their stoichiometric ratios were SHC,SD,SWC,LD,pH and SGR,with explanations of 33.7%,13.5%,6.5%,4.9%,3.0%,and 2.9%,respectively,and those with significant or highly significant effects on AN,AK,AP and their stoichiometric ratios were SHC,pH,LD,and SWC,with explanations of 28.2%,9.9%,5.4%,and 3.8%,respectively.【Conclusion】Environmental factors significantly affected soil nutrients and their stoichiometric ratios in natural forests of B.platyphylla at different elevations in the eastern Qilian Mountains,with SHC,SWC,pH,and LD being the main influencing factors.C and N effectiveness in the study area was relatively high and P effectiveness was relatively low.It is recommended to supplement phosphorus fertilizer appropriately during the management of B.platyphylla natural forest in the later stage. |
| Key words: Betula platyphylla natural forests environmental factor soil ecological stoichiometry soil nutrients the eastern Qilian Mountains |
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