氮沉降和土壤线虫对落叶松人工林土壤有机碳矿化的影响

发布时间：2018-05-02 00:54

本文选题：有机氮沉降 + 土壤有机碳矿化　；参考：《生态学杂志》2017年08期

【摘要】：大气氮沉降不仅含有无机态氮,还含有大量有机态氮,然而目前大部分研究主要关注无机态氮沉降对土壤有机碳(SOC)矿化的影响,对于有机态氮沉降的影响关注甚少。为更全面地了解大气氮沉降对SOC矿化的影响,我们在温带落叶松(Larix gmelinii)人工林长期氮沉降试验样地中采集了对照(CK)、无机氮(IN)、有机氮(ON)及无机氮有机氮混施(IN∶ON=7∶3;MN)4种不同氮沉降处理的表层土壤(0~10 cm),然后进行室内恒温(25℃)培养62 d,测定SOC矿化速率。同时,为了研究氮沉降背景下土壤线虫在SOC矿化中的作用,我们将每个氮沉降处理的土壤分为2组,分别添加或不添加线虫抑制剂。结果显示:与CK处理相比,IN、ON及MN处理均显著降低了SOC矿化速率,其SOC累积矿化量分别降低了15.7%、23.9%和34.3%,表明无机有机氮混施处理对SOC矿化的抑制作用大于无机氮沉降和有机氮沉降。因此,单一形态的氮沉降模拟研究可能低估了大气氮沉降对SOC矿化的抑制作用。另外,添加线虫抑制剂促进了SOC矿化,且添加线虫抑制剂在IN、ON和MN处理中对SOC累积矿化量影响的效应值较CK处理分别增加了0.08%、42.40%和29.0%,该结果表明,土壤线虫对SOC矿化的影响与氮沉降形态有关。相关性分析结果显示,SOC累积矿化量与土壤C∶N、有效磷含量及真菌∶细菌呈显著正相关,与土壤硝态氮含量和革兰氏阳性细菌∶革兰氏阴性细菌比呈显著负相关。因此,在全球变化背景下,氮沉降的增加有利于降低温带森林生态系统土壤碳释放。
[Abstract]:Atmospheric nitrogen deposition not only contains inorganic nitrogen, but also contains a large amount of organic nitrogen. However, most researches focus on the effect of inorganic nitrogen deposition on soil organic carbon soc mineralization, but little on organic nitrogen deposition. In order to understand the effect of atmospheric nitrogen deposition on SOC mineralization, In the long-term nitrogen deposition test plot of Larix gmelinii (Larix gmelinii) plantation in temperate zone, we collected the surface soil of CK, INP, ON) and inorganic nitrogen and organic nitrogen mixed with 4 different nitrogen deposition treatments, I. e., 010 cm ~ (10) cm ~ (-1) and 0.10 cm ~ (10) cm ~ (-1), respectively. The mineralization rate of SOC was measured for 62 days. At the same time, in order to study the role of soil nematode in SOC mineralization in the background of nitrogen deposition, each soil treated with nitrogen deposition was divided into two groups, with or without nematode inhibitor. The results showed that the mineralization rate of SOC was significantly decreased in the treatment of Inchon and MN, and the cumulative mineralization of SOC was decreased by 15.723. 9% and 34. 3%, respectively. The results showed that the inhibition effect of mixed application of inorganic organic nitrogen on the mineralization of SOC was greater than that on the deposition of inorganic nitrogen and organic nitrogen. Therefore, the simulation study of nitrogen deposition in a single form may underestimate the inhibition of atmospheric nitrogen deposition on SOC mineralization. In addition, the addition of nematode inhibitor promoted the mineralization of SOC, and the effect value of adding nematode inhibitor on the cumulative mineralization of SOC increased by 0.08% and 29.0%, respectively, compared with CK treatment. The effect of soil nematode on SOC mineralization is related to nitrogen deposition. The results of correlation analysis showed that the accumulation of SOC mineralization was positively correlated with soil C: n, available phosphorus content and fungi: bacteria, and negatively correlated with soil nitrate content and Gram-positive bacteria: Gram-negative bacteria ratio. Therefore, under the background of global change, the increase of nitrogen deposition is beneficial to reduce soil carbon release from temperate forest ecosystem.
【作者单位】：中国科学院森林生态与管理重点实验室(沈阳应用生态研究所);中国科学院大学;中国科学院会同森林生态实验站;
【基金】：国家重点研发计划项目(2016YFA0600801)资助
【分类号】：S714.2

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