Regional Integration of CH4 Emission Studies (RICHES)

该项目研究了酸雨污染（全球日益严重的问题）如何影响湿地中强大的温室气体甲烷（CH4）的排放，而湿地是这种气体的最大来源。我们将通过对过去20年发表的许多甲烷排放研究以及这些地区的污染数据进行区域整合来解决这一重要问题。最近在湿地模拟酸雨硫污染的实验表明，这些相互作用对全球范围内CH4的排放有重要影响，并可能抵消湿地CH4源的甲烷增长，否则，全球变暖将导致甲烷增长。这些评估是基于数量有限的实验研究的结果。这类研究的不足之处在于，它们可能只能复制污染加剧时期初期的条件，而不能复制长期的生态系统反应。其他污染物也有影响，如活性氮（硝酸盐和氨），可能有重要的影响，但如果没有长期（如十年）的实验，很难量化。我们的方法将把大量监测湿地甲烷排放的研究，跨越现有的污染梯度，作为一个区域/全球实验，更准确地代表污染的长期影响。

This project investigates how pollution, in the form of acid rain (globally a growing problem), can influence the emission of the powerful greenhouse gas methane (CH4) from wetlands, the largest individual source of this gas. We will tackle this important question by performing a regional integration of the many CH4 emission studies that have been published in the past 2 decades together with data on pollution in these areas. Recent experiments where acid rain sulphur pollution has been simulated in wetlands have shown that these interactions can have an important effect on the emission of CH4 at the global scale and may be offsetting the growth of methane from the wetland CH4 source that should otherwise be occurring through global warming. These assessments are based on the findings of a limited number of experimental studies. The draw back from such studies is that they may replicate conditions only at the beginning of a period of increased pollution rather than the long-term ecosystem response. There are also effects of other pollutants such as reactive nitrogen (nitrate and ammonia) that may have important effects but are difficult to quantify without long-term (e.g. decade long) experiments. Our approach will treat the numerous studies that have monitored CH4 emission from a wide range of wetlands, spanning existing pollution gradients, as a regional/global experiment where the long-term impacts of pollution are more accurately represented.