Linking Nitrous Oxide and Nitric Oxide Fluxes to Microbial Communities in Tropical Forest Soils and Oil Palm Plantations in Malaysia in Laboratory Incubations
Linking Nitrous Oxide and Nitric Oxide Fluxes to Microbial Communities in Tropical Forest Soils and Oil Palm Plantations in Malaysia in Laboratory Incubations
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DOI：
10.3389/ffgc.2020.00004
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发表时间：
2020-01-30
影响因子：
3.2
通讯作者：
Skiba, Ute M.
中科院分区：
文献类型：
--
作者：
Drewer, Julia;Zhao, Jun;Skiba, Ute M.
目前对与矿物土壤上从森林到油棕榈的土地利用变化相关的温室气体（GHG）通量的理解不足以提供可靠的排放率估计或GHG缓解战略建议。油棕榈的单一种植在东南亚扩大，大部分取代了热带森林。现有的有限数据表明，土地用途转换与可能加剧的温室气体负担有关，包括一氧化二氮（N2 O）和一氧化氮（NO）的排放，但潜在的生物机制尚不清楚。本研究以马来西亚婆罗洲沙巴不同土地利用方式的热带土壤为研究对象，在实验室培养条件下，研究了热带土壤N2 O和NO的排放潜力。在类似的控制条件下，记录森林和油棕土壤表现出高和类似的潜力N2 O和NO排放量增加土壤水分，而排放量可以忽略不计的河岸储备土壤中的水分条件。采伐林土壤和油棕（OP）人工林的土壤N2 O和NO排放速率相似，在35和22天的培养期内，平均通量分别为11.5和1.6 ng N g（-1）h（-1）（OP）和15.6和6.0 ng N g（-1）h（-1）（采伐林）。相反，河岸储备土壤没有响应再润湿和施氮和通量可以忽略不计。此外，N2 O通量平均约10倍高于NO通量。森林土壤也有可能排放大量的N2 O和NO，这一事实对热带地区的土地利用变化情景具有重要影响，特别是因为一些情景表明，由于生物质燃烧、氮肥使用量增加和化石燃料消耗，热带地区的大气氮沉降可能急剧增加。相关基因转录本的定量表明，变形菌nirS和AniA-nirK（β变形菌分支的奈瑟氏菌）含有的硝化菌可能会持续贡献N2 O的排放，而硝化菌（氨氧化古菌在这项研究中）是有条件的活性产生N2 O。因此，这项研究提供了一些证据，N2 O和NO排放与微生物的遗传多样性群体，这可能是重要的，在调制温室气体排放在不同的土地利用和现场条件下。
Current understanding of greenhouse gas (GHG) fluxes associated with land-use change from forest to oil palm on mineral soil is not sufficient to provide reliable estimates of emission rates or advice on GHG mitigation strategies. Monocultures of oil palm have expanded in Southeast Asia, mostly replacing tropical forests. The limited data available have indicated that the land-use conversion is associated with a potentially aggravated GHG burden, including nitrous oxide (N2O) and nitric oxide (NO) emissions, with unclear underlying biological mechanisms. In this study, we investigated N2O and NO emission potentials of tropical soils with different land-uses from Sabah, Malaysian Borneo, under laboratory incubation. Under similar controlled conditions, logged forest and oil palm soils showed high and similar potentials of N2O and NO emissions following increase in soil moisture, while the emissions were negligible in a riparian reserve soil irrespective of moisture conditions. Soil N2O and NO emission rates from logged forest soils and oil palm (OP) plantations were of similar magnitude, with average fluxes over the 35 and 22 day incubation periods, respectively, of 11.5 and 1.6 ng N g(-1) h(-1) (OP) and 15.6 and 6.0 ng N g(-1) h(-1) (logged forest). Contrarily, the riparian reserve soil did not respond to rewetting and nitrogen application and fluxes were negligible. Furthermore, N2O fluxes were on average about 10 times higher than NO fluxes. The fact that forest soils also have the potential to emit large amounts of N2O and NO, has important implications for land-use change scenarios in the tropics, especially as some scenarios suggest atmospheric N deposition is likely to drastically increase in tropical regions due to biomass burning, increased N-fertilizer use and fossil fuel consumption. Quantification of related gene transcripts implied that Proteobacterial nirS and AniA-nirK (betaproteobacterial clade of Neisseria) containing denitrifiers might continuously contribute to the N2O emissions, while the nitrifiers (ammonia oxidizing archaea in this study) are conditionally active to produce N2O. This study therefore provides some evidence for N2O and NO emissions associated with phylogenetically diverse groups of microorganisms, which might be of importance in modulating the GHG emissions under different land-uses and field conditions.