• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文OA文献 >Effects of long-term CO2 enrichment on soil-atmosphere CH4 fluxes and the spatial micro-distribution of methanotrophic bacteria
【2h】

Effects of long-term CO2 enrichment on soil-atmosphere CH4 fluxes and the spatial micro-distribution of methanotrophic bacteria

机译：长期CO2浓度升高对土壤-大气CH4通量及甲烷营养细菌的空间微分布的影响

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Background: Effects of elevated atmospheric CO2 concentrations on plant growth and associated C cycling have intensively been studied, but less is known about effects on the fluxes of radiatively active trace gases other than CO2. Net soil-atmosphere CH4 fluxes are determined by the balance of soil microbially-driven methane (CH4) oxidation and methanogenesis, and both might change under elevated CO2.\udMethods and Results: Here, we studied CH4 dynamics in a permanent grassland exposed to elevated CO2 for 14 years. Soil-atmosphere fluxes of CH4 were measured using large static chambers, over a period of four years. The ecosystem was a net sink for atmospheric CH4 for most of the time except summer to fall when net CH4 emissions occurred. We did not detect any elevated CO2 effects on CH4 fluxes, but emissions were difficult to quantify due to their discontinuous nature, most likely because of ebullition from the saturated zone. Potential methanotrophic activity, determined by incubation of fresh sieved soil under standardized conditions, also did not reveal any effect of the CO2 treatment. Finally, we determined the spatial micro-distribution of methanotrophic activity at less than 5× atmospheric (10 ppm) and elevated (10000 ppm) CH4 concentrations, using a novel auto-radiographic technique. These analyses indicated that domains of net CH4 assimilation were distributed throughout the analyzed top 15 cm of soils, with no dependence on CH4 concentration or CO2 treatment.\udConclusions: Our investigations suggest that elevated CO2 exerts no or only minor effects on CH4 fluxes in the type of ecosystem we studied, at least as long as soil moisture differences are small or absent as was the case here. The autoradiographic analyses further indicate that the spatial niche of CH4 oxidation does not shift in response to CO2 enrichment or CH4 concentration, and that the same type of methanotrophs may oxidize CH4 from atmospheric and soil-internal sources.
机译：背景：已深入研究了大气中二氧化碳浓度升高对植物生长和相关碳循环的影响，但对除二氧化碳以外的辐射活性微量气体通量的影响知之甚少。土壤-大气中CH4的净通量取决于土壤微生物驱动的甲烷（CH4）氧化和甲烷生成的平衡，并且在CO2升高的情况下都可能发生变化。\ ud方法和结果：在这里，我们研究了暴露于高海拔草地的永久性草地中CH4的动态变化。二氧化碳排放14年。 CH4的土壤-大气通量是使用大型静室测量的，历时四年。在大部分时间里，生态系统都是大气中CH4的净汇，除了夏天时会发生CH4净排放的秋天。我们没有发现任何升高的CO2对CH4通量的影响，但是由于其不连续性，很难对排放进行量化，这很可能是由于饱和区的沸腾引起的。通过在标准条件下孵育新鲜过筛的土壤确定的潜在甲烷营养活性也未显示出CO2处理的任何效果。最后，我们使用一种新颖的放射自显影技术确定了在小于5倍的大气（10 ppm）和升高的（10000 ppm）CH4浓度下甲烷营养活动的空间微分布。这些分析表明，净CH4同化作用域分布在整个被分析的前15 cm的土壤中，与CH4浓度或CO2处理无关。\ ud结论：我们的研究表明，升高的CO2对CH4通量中的CH4通量没有影响或仅有很小的影响。我们研究的生态系统类型至少要像这里的情况一样小或不存在土壤水分差异。放射自显影分析进一步表明，CH4氧化的空间生态位不会响应于CO2富集或CH4浓度变化，并且相同类型的甲烷营养生物可能会氧化来自大气和土壤内部来源的CH4。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号