Main controls on the denitrification rates during cropland revegetation in the southwest China Karst Critical Zone Observatory
Main controls on the denitrification rates during cropland revegetation in the southwest China Karst Critical Zone Observatory
复制标题
西南喀斯特关键带观测站农田植被恢复反硝化率的主要控制
DOI：
10.1016/j.agee.2020.107228
复制
发表时间：
2021-03
期刊：
影响因子：
--
通讯作者：
Qiubing Wang
中科院分区：
文献类型：
--
作者：
D;an Li;Xinyu Zhang;Jennifer A.J. Dungait;Sophie M. Green;Xuefa Wen;Timothy A. Quine;Qiubing Wang
中国西南亚热带喀斯特生态系统因集约化农业而严重退化，其植被重建依赖于土壤养分循环等功能的持续和恢复。反硝化是一种通过硝化和反硝化微生物进行的氮（N）去除过程。我们仍然没有一个全面的了解反硝化作用，是什么驱动它在退化喀斯特生态系统的农田植被重建。我们使用的时空时序方法，建立一个恢复梯度（坡耕地，废弃的坡耕地，次生林和原生林）在中国西南岩溶临界带观测站。通过对培养土壤中硝化菌和硝化菌的数量进行定量分析，并测定了潜在反硝化速率（PDR）和基础反硝化速率（BDR），研究了不同恢复阶段土壤的反硝化活性。植被恢复过程中，植被恢复率呈上升趋势，坡耕地植被恢复率最低（p< 0.05）。PDR和BDR都与细菌丰度呈正相关（即，亚硝酸盐还原酶，nirK，和nirS），但与硝化菌丰度呈负相关（即，氨氧化、AOA和AOB）。BDR/PDR的比例为84%，在坡地农田，但只有1%的原始森林，这表明，氮循环是低效的（“漏”），积极管理的农田土壤，但在森林土壤中是“紧”。AOB和nirSabundances解释了大部分的PDR在坡耕地和废弃的坡耕地，而土壤磷（P）含量解释了大部分的变化在BDR和PDR的土地，在森林植被恢复的后期阶段。随着植被恢复的进行，PDR的逐步增加直接受土壤有效磷和全磷含量的控制。速效磷也与碳（C）和氮含量的增加，间接影响BDR通过增加丰度的nirKandnirS。我们的结论是，农田植被恢复有助于促进“紧”的N-循环在贫困的喀斯特土壤，我们建议，明智的P施肥对坡地农田将减少退化生态系统的反硝化活性。
The revegetation of karst ecosystems in subtropical southwest China that became severely degraded because of intensive agriculture relies on the persistence and recovery of soil functions such as nutrient cycling. Denitrification is a nitrogen (N) removal process that is carried out by nitrifying and denitrifying microorganisms. We still do not have a comprehensive understanding of denitrification and what drives it during revegetation of cropland in degraded karst ecosystems. We used the space-for-time chronosequence method to establish a restoration gradient (sloping cropland, abandoned sloping cropland, and secondary and primary forest) within the Karst Critical Zone Observatory in southwest China. We quantified the abundances of the nitrifier and denitrifier microbial communities and measured the potential denitrification rates (PDR) and basal denitrification rates (BDR) in incubated soils to investigate the denitrification activity in soils at different stages of restoration. The PDR increased through the cropland revegetation phases, and the BDR was lowest in the abandoned sloping cropland (p< 0.05). Both the PDR and BDR were positively correlated with the denitrifier abundances (i.e., nitrite reductase,nirK,andnirS), but were negatively correlated with nitrifier abundances (i.e., ammonia oxidation, AOA, and AOB). The BDR/PDR ratio was 84 % in the sloping cropland but was only 1% in the primary forest, which suggests that the N cycling was inefficient (‘leaky’) in actively managed farmland soils but was ‘tight’ in forest soils. The AOB andnirSabundances explained most of the PDR in the sloping cropland and abandoned sloping cropland, while the soil phosphorus (P) contents explained most of the variation in BDR and PDR in land that was forested in later phases of revegetation. Progressive increases in the PDR as the revegetation progressed was directly controlled by the soil available P and total P contents. Available P was also associated with increases in the carbon (C) and N contents, which influenced the BDR indirectly through increased abundances ofnirKandnirS. We conclude that revegetation of cropland helped to facilitate ‘tight’ N-cycling in poor karst soils, and we suggest that judicious P fertilization on sloping cropland would reduce the denitrification activity in degraded ecosystems.
登录
查看更多内容
西南岩溶地区次生演替过程中氮磷限制的变化
影响因子：
4.9
作者：
Pan, Fujing;Li, Dejun;Chen, Hongsong;Wang, Kelin
通讯作者：
Wang, Kelin
影响因子：
4.2
作者：
Gu Yun-fu;Yingyan Wang;Q. Xiang;Xiumei Yu;K. Zhao;Xiao-ping Zhang;K. Lindström;Hu Yufu;
通讯作者：
Gu Yun-fu;Yingyan Wang;Q. Xiang;Xiumei Yu;K. Zhao;Xiao-ping Zhang;K. Lindström;Hu Yufu;
影响因子：
6.6
作者：
Kachenchart, Boonlue;Jones, Davey L.;Limsakul, Atsamon
通讯作者：
Limsakul, Atsamon
影响因子：
9.7
作者：
T. Robson;S. Lavorel;J. Clément;X. Roux
通讯作者：
T. Robson;S. Lavorel;J. Clément;X. Roux
影响因子：
4.8
作者：
Blaud, Aimeric;van der Zaan, Bas;Banwart, Steve
通讯作者：
Banwart, Steve