Temporal changes in abundance and composition of ammonia-oxidizing bacterial and archaeal communities in a drained peat soil in relation to N2O emissions
Temporal changes in abundance and composition of ammonia-oxidizing bacterial and archaeal communities in a drained peat soil in relation to N2O emissions
复制标题
DOI：
10.1007/s11368-011-0413-9
复制
发表时间：
2011-08
影响因子：
3.6
通讯作者：
Janet Andert;Ella Wessén;G. Börjesson;S. Hallin
中科院分区：
文献类型：
--
作者：
Janet Andert;Ella Wessén;G. Börjesson;S. Hallin
目的北方泥炭土约占陆地环境的 3%，当排水时，它们会成为温室气体一氧化二氮 (N2O) 的来源。氨氧化可直接或通过促进反硝化导致 N2O 排放，但我们对泥炭土壤中氨氧化细菌 (AOB) 和古细菌 (AOA) 的生态知之甚少。我们的目的是确定排水和森林泥炭土中这些群落的丰度和组成随 N2O 排放和氨氧化活动的变化。材料和方法在 9 个月的时间内，在上部 0.5 米的三个不同深度对泥炭进行了采样，其中包括两次夏季采样和两次冬季采样。通过细菌和古细菌基因的 T-RFLP 和定量实时 PCR 确定群落组成和丰度。使用氯酸盐抑制技术测量潜在的氨氧化速率，并使用室测定原位 N2O 排放。结果与讨论土壤参数显示出很小的空间和时间异质性，这可能解释了为什么氨氧化剂的丰度、组成或活性没有与深度相关的影响。与大多数陆地环境相比，AOB 在数量上优于 AOA。尽管 AOB 显示出比 AOA 更显着的季节性特征，但两组在采样期间的群落组成都发生了变化。仅在 AOB 中观察到丰度随时间变化，从 5 月到 3 月数量有所减少。这种差异并未通过活性或 N2O 排放量反映出来。 结论 泥炭土中的高铵浓度可能有利于 AOB 而不是 AOA，我们假设它们比 AOA 更活跃，因此对气候和环境变化做出反应。然而，除了氨氧化之外，其他过程可能是该地点 N2O 排放的原因。
PurposeBoreal peat soils comprise about 3% of the terrestrial environments, and when drained, they become sources of the greenhouse gas nitrous oxide (N2O). Ammonia oxidation can result in N2O emissions, either directly or by fuelling denitrification, but we know little about the ecology of ammonia-oxidizing bacteria (AOB) and archaea (AOA) in peat soils. Our aim was to determine temporal alterations in abundance and composition of these communities in a drained and forested peat soil in relation to N2O emissions and ammonia oxidation activity.Materials and methodsThe peat was sampled at three different depths in the upper 0.5 m over a period of 9 months covering two summer and two winter samplings. Community composition and abundance were determined by T-RFLP and quantitative real-time PCR of the bacterial and archaealamoAgenes. Potential ammonia oxidation rates were measured using the chlorate inhibition technique, and in situ N2O emission was determined using chambers.Results and discussionThe soil parameters displayed little spatial and temporal heterogeneity, which probably explained why there were no depth-related effects on the abundance, composition, or activity of the ammonia oxidizers. In contrast to most terrestrial environments, the AOB dominated numerically over the AOA. Both groups changed in community composition between sampling occasions, although the AOB showed more significant seasonal signatures than the AOA. Temporal changes in abundance were only observed for the AOB, with a decrease in numbers from May to March. Such differences were not reflected by the activity or N2O emissions.ConclusionsThe high ammonium concentrations in the peat soil likely favored the AOB over the AOA, and we hypothesize that they were more active than the AOA and therefore responded to climatic and environmental changes. However, other processes rather than ammonia oxidation were likely responsible for N2O emissions at the site.