Effects of nitrate and sulfate on greenhouse gas emission potentials from microform-derived peats of a boreal peatland: A 13C tracer study
Effects of nitrate and sulfate on greenhouse gas emission potentials from microform-derived peats of a boreal peatland: A 13C tracer study
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DOI：
10.1016/j.soilbio.2016.06.018
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发表时间：
2016-09
影响因子：
9.7
通讯作者：
Ivana Lozanovska;Y. Kuzyakov;J. Krohn;S. Parvin;M. Dorodnikov
中科院分区：
文献类型：
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作者：
Ivana Lozanovska;Y. Kuzyakov;J. Krohn;S. Parvin;M. Dorodnikov
不断增加的自然和人为的硝酸盐（NO3−）和硫酸盐（SO 42 −）沉积到泥炭地可能会改变CH 4氧化，CO2和N2 O的产生，从而影响全球温室气体（GHG）的平衡。在控制这些地球化学过程的环境因素中，泥炭地微地貌的影响知之甚少。从芬兰东部一个北方贫营养沼泽的不同微地貌位置采集泥炭样品，在与NO3-和SO 42-孵育前后测量CO2、CH 4和N2 O通量。通过对土壤中添加13 CH 4，研究了CH 4的氧化、微生物利用和向土壤有机质（SOM）转化过程。我们假设NO3-和SO 42-的加入会1）刺激CO2和N2 O的产生（营养效应），但2）由于加速其他更有利的能量过程而减少CH 4氧化（例如脱氮），微生物生物量（MB）在50 cm以下为9- 1000 g/m3，在50 cm以下为1000 g/m3，在50 cm以下为1000 g/m3。比表土高15倍。甲基溴控制着温室气体的动态，并与特定的深度环境条件有关，而不是与氧气供应有关。事实上，生产的CO2和N2 O，和氧化电位的CH 4显示没有明确的联系与自然建立的通气带泥炭地的微形态。添加NO3-和SO 42-后，与对照相比，CO2的产生量减少了20-65%，其中空心表土的CO2排放量减少幅度最大。反过来，CH 4氧化被抑制了20-94%与NO3−添加在50厘米的草坪和NO3−和SO 42 −在50厘米的空心。在50 cm处的洼地和草坪中，NO3−处理使N2 O的产生增加了180-240倍。总之，人类引起的NO3-和SO 42-的沉积可能会抑制CO2排放和CH 4氧化的北方贫营养沼泽，特别是在沉积增加的条件下。最后，无机化合物的沉积是非常重要的生态系统C和N平衡的估计要考虑。
Increasing natural and anthropogenic deposition of nitrate (NO3−) and sulfate (SO42−) to peatlands may modify CH4oxidation, CO2and N2O production, thereby affecting the balance of greenhouse gases (GHG) globally. Among environmental factors controlling these biogeochemical processes, effects of peatland microrelief are poorly understood. Fluxes of CO2, CH4and N2O were measured before and after incubation with NO3−and SO42−for peat samples collected from various microrelief positions of a boreal oligotrophic mire in Eastern Finland. Soil was spiked with13CH4to understand the processes of CH4oxidation, its microbial utilization and incorporation into soil organic matter (SOM). We hypothesized that the addition of NO3−and SO42−would 1) stimulate CO2and N2O production (nutritional effect), but 2) decrease CH4oxidation due to acceleration of other more energetically favorable processes (e.g. denitrification), and 3) these patterns should follow the naturally established aerobic zone of a microform type and decrease with depth.Microbial biomass (MB) at 50 cm below all microforms was 9–15 folds higher than in the topsoil. MB controlled the GHG dynamics and was related to specific depth-dependent environmental conditions, rather than oxygen availability. Indeed, production of CO2and N2O, and oxidation potentials of CH4revealed no clear linkage with the naturally established aeration zone of the peatland’s microforms. Following NO3−and SO42−addition, production of CO2decreased by 20–65% compared to the control, with the greatest reduction in CO2emission occurring in the topsoil of hollows. In turn, CH4oxidation was suppressed by 20–94% with NO3−addition at 50 cm in lawns and with both NO3−and SO42−at 50 cm in hollows. The N2O production was increased up to 180–240 times under NO3−treatment at 50 cm in hollows and lawns. In conclusion, human-induced deposition of NO3−and SO42−may suppress CO2emissions from and CH4oxidation by boreal oligotrophic mires especially under the conditions of deposition increase. Finally, the deposition of inorganic compounds is strongly important to be considered in the estimation of ecosystem C and N balances.