人工油松林表层土壤团聚体活性有机碳含量对短期氮添加的响应

发布时间：2018-03-09 17:01

本文选题：氮沉降　切入点：土壤团聚体　出处：《生态学报》2017年20期 　论文类型：期刊论文

【摘要】：大气氮沉降正在显著影响着森林生态系统的土壤碳循环过程。目前关于大气氮沉降如何影响土壤不同粒级团聚体内活性有机碳含量还不是十分清楚,制约人们对森林土壤碳循环的认识和有关碳循环模型的发展。通过近2年的林地梯度氮添加(0、3、6、9 g Nm~(-2)a~(-1))实验,研究了短期氮添加对人工油松林表层土壤团聚体中不同活性有机碳含量的影响。结果表明:短期氮添加对表层土壤(0—10 cm)水稳性团聚体分布无显著影响;随着氮添加水平增加,大、微团聚体有机碳含量,大、微团聚体中活性和高活性有机碳含量呈先升高后降低的变化规律,并在N6处理(6 g Nm~(-2)a~(-1))下上述各指标达到最大;同一处理下土壤大、微团聚体活性有机碳含量都表现为高活性有机碳中活性有机碳低活性有机碳;相比CK处理,N6处理大团聚体低、中、高活性有机碳含量分别增加115.06%、178.73%和79.61%,微团聚体低、中、高活性有机碳含量增加32.84%、166.79%和62.05%。大、微团聚体中活性有机碳含量增幅最大,表明团聚体中活性有机碳对氮添加响应最为明显。研究发现,短期氮添加主要通过影响表层大、微团聚体中的中活性有机碳进而影响土壤表层有机碳含量。主成分分析表明,N添加改变了土壤理化性质,进而导致根系生物量增加并促进凋落物分解,是表层土壤团聚体活性有机碳变化的主要原因。
[Abstract]:Atmospheric nitrogen deposition is significantly affecting the soil carbon cycle in forest ecosystems. It is not clear how atmospheric nitrogen deposition affects the content of active organic carbon in soil aggregates at different grain levels. The understanding of forest soil carbon cycle and the development of relevant carbon cycle models were restricted. The effects of short-term nitrogen supplementation on the content of different active organic carbon in surface soil aggregates of artificial Pinus tabulaeformis forest were studied. The results showed that short-term nitrogen supplementation had no significant effect on the distribution of water-stable aggregates in surface soil. The content of active and high active organic carbon in microaggregate increased first and then decreased, and the above indexes reached the maximum under N6 treatment (6 g), and the soil was large under the same treatment, the content of organic carbon in microaggregate was large, and the content of high active organic carbon in microaggregate was higher than that in the same treatment, and the content of organic carbon in microaggregate increased first and then decreased, and the above indexes reached the maximum under N6 treatment. The content of active organic carbon in microaggregate was lower than that in CK treatment, and the content of high active organic carbon increased by 115.06% and 79.61%, respectively, and the content of microaggregate was lower than that of CK treatment, and the content of high active organic carbon increased by 115.06% and 79.61%, respectively. The content of high active organic carbon increased 32.84% 166.79% and 62.05% respectively. The content of active organic carbon in microaggregate increased the most, indicating that the response of active organic carbon to nitrogen addition was the most obvious. The results of principal component analysis showed that the addition of N changed the physical and chemical properties of soil, which resulted in the increase of root biomass and the decomposition of litter. It is the main reason for the change of active organic carbon in surface soil aggregate.
【作者单位】：西北农林科技大学水土保持研究所;中国科学院水利部水土保持研究所;
【基金】：国家自然科学基金资助项目(41371508) 中国科学院重点部署项目(KFZD-SW-306-2)
【分类号】：S714.2

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