| 高寒草地灌丛化对土壤团聚体稳定性及其铁铝氧化物分异的研究 |
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| 引用本文： | 陈红,马文明,周青平,杨智,刘超文,刘金秋,杜中曼.高寒草地灌丛化对土壤团聚体稳定性及其铁铝氧化物分异的研究[J].草业学报,2020,29(9):73-84. |
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| 作者姓名： | 陈红 马文明 周青平 杨智 刘超文 刘金秋 杜中曼 |
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| 作者单位： | 西南民族大学青藏高原研究院,四川 成都 610041 |
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| 基金项目： | 国家自然科学基金(31600378),西南民族大学中央高校基本科研业务费专项资金(2020NQN06)和西南民族大学研究生创新型科研项目(CX2019SZ88)资助 |
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| 摘 要： | 团聚体对有机碳的物理保护是土壤碳固存的重要机制。本研究以青藏高原东缘灌丛化草地和未灌丛化草地为研究对象,采用Cambardella与Elliott湿筛法和沉降虹吸法分离和提取团聚体,测定了灌丛化草地和未灌丛化草地中土壤团聚体含量,分析了团聚体稳定性、不同形态铁铝氧化物的分异及铁铝氧化物与团聚体稳定性的关系。结果显示:灌丛化显著降低了<0.053 mm微团聚体含量(P<0.05),对团聚体稳定性没有显著影响(P>0.05);灌丛化显著增加了>0.25 mm大团聚体内游离态铝的含量(Ald的含量增加了14.09%)(P<0.05)和<0.25 mm微团聚体内游离态铁铝的含量(Fed、Ald的含量分别增加了9.75%和15.31%)(P<0.05),显著降低了<0.25 mm微团聚体内络合态铁铝的含量(Fep、Alp的含量分别降低了31.03%和9.41%)(P<0.05)。通过增强回归树分析,游离态铁铝氧化物对团聚体稳定性的作用最强,络合态铝氧化物对团聚体稳定性作用最弱。表明灌丛化有助于增强团聚体的稳定,促进土壤有机碳的固存。
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| 关 键 词： | 青藏高寒草地 灌丛化 团聚体稳定性 铁铝氧化物 增强回归树 |
| 收稿时间： | 2020-02-20 |
| 修稿时间： | 2020-04-14 |
Shrub encroachment effects on the stability of soil aggregates and the differentiation of Fe and Al oxides in Qinghai-Tibet alpine grassland |
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| CHEN Hong,MA Wen-ming,ZHOU Qing-ping,YANG Zhi,LIU Chao-wen,LIU Jin-qiu,DU Zhong-man.Shrub encroachment effects on the stability of soil aggregates and the differentiation of Fe and Al oxides in Qinghai-Tibet alpine grassland[J].Acta Prataculturae Sinica,2020,29(9):73-84. |
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| Authors: | CHEN Hong MA Wen-ming ZHOU Qing-ping YANG Zhi LIU Chao-wen LIU Jin-qiu DU Zhong-man |
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| Institution: | Qinghai-Tibet Plateau Research Institute, Southwest Minzu University, Chengdu 610041, China |
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| Abstract: | The physical protection of soil aggregates is an important mechanism of soil carbon sequestration. In this study, shrub-grassland and shrubless-grassland in East margin of Qinghai-Tibet Plateau were investigated. We used wet sieving proposed by Cambardella and Elliott and a settling siphon to separate soil aggregates, which were then measured. Data obtained included: Soil aggregate stability, differentiation of different forms of Fe and Al oxides, and the relationship between Fe and Al oxides and soil aggregate stability. It was found that: Shrub encroachment significantly reduced (P<0.05) the proportion of microaggregates (<0.053 mm), but had no significant effect on soil aggregate stability (P>0.05). Shrub encroachment significantly increased the content of dithionthite-citrate-bicarbonate extractable Al oxides in macroaggregates (>0.25 mm), which was increased by 14.09% (P<0.05). Shrub encroachment also significantly increased the content of dithionthite-citrate-bicarbonate extractable Fe and Al oxides in microaggregates (<0.25 mm), which was increased by 9.75% and 15.31%, respectively (P<0.05). However, shrub encroachment significantly reduced the content of complex Fe and Al oxides in microaggregates (<0.25 mm), the content of sodium pyrophosphate extractable Fe and Al oxides decreased by 31.03% and 9.41%, respectively (P<0.05). Boosted regression tree analysis indicated that the free Fe and Al oxides had the strongest effect on soil aggregate stability, while the complex Al oxides had the weakest effect.The results indicate that shrub encroachment is helpful to enhance soil aggregate stability and promote the sequestration of soil organic carbon. |
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| Keywords: | Qinghai-Tibet alpine grassland shrub encroachment aggregate stability Fe and Al oxides boosted regression tree |
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