Abstract：
Methane is a powerful greenhouse gas, more potent than carbon dioxide, and emitted from a variety of natural sources including wetlands, permafrost, mammalian guts and termites. As increases in global temperatures continue to break records, quantifying the magnitudes of key methane sources has never been more pertinent. Over the last 40 years, the contribution of termites to the global methane budget has been subject to much debate. The most recent estimates of termite emissions range between 9 and 15 Tg CH4 year-1, approximately 4% of emissions from natural sources (excluding wetlands). However, we argue that the current approach for estimating termite contributions to the global methane budget is flawed. Key parameters, namely termite methane emissions from soil, deadwood, living tree stems, epigeal mounds and arboreal nests, are largely ignored in global estimates. This omission occurs because data are lacking and research objectives, crucially, neglect variation in termite ecology. Furthermore, inconsistencies in data collection methods prohibit the pooling of data required to compute global estimates. Here, we summarise the advances made over the last 40 years and illustrate how different aspects of termite ecology can influence the termite contribution to global methane emissions. Additionally, we highlight technological advances that may help researchers investigate termite methane emissions on a larger scale. Finally, we consider dynamic feedback mechanisms of climate warming and land-use change on termite methane emissions. We conclude that ultimately the global contribution of termites to atmospheric methane remains unknown and thus present an alternative framework for estimating their emissions. To significantly improve estimates, we outline outstanding questions to guide future research efforts.
摘要：
甲烷是一种强大的温室气体，比二氧化碳更有效，从包括湿地在内的各种自然来源排放，永久冻土,哺乳动物的内脏和白蚁.随着全球气温的上升不断打破记录，量化关键甲烷源的大小从未如此相关。在过去的40年里,白蚁对全球甲烷预算的贡献一直存在争议。白蚁排放量的最新估计在9至15TgCH4year-1之间，约占自然排放源（不包括湿地）的4％。然而,我们认为，目前估计白蚁对全球甲烷预算的贡献的方法是有缺陷的。关键参数,即土壤中的白蚁甲烷排放，Deadwood,活的树干，表皮土丘和树栖巢，在全球估计中很大程度上被忽视了。出现这种遗漏是因为缺乏数据和研究目标，至关重要的是,白蚁生态中的忽视变异。此外，数据收集方法的不一致阻碍了计算全球估计所需的数据的汇集。这里,我们总结了过去40年取得的进展，并说明了白蚁生态的不同方面如何影响白蚁对全球甲烷排放的贡献。此外,我们强调了技术进步，这些进步可能有助于研究人员更大规模地调查白蚁甲烷排放。最后,我们考虑了气候变暖和土地利用变化对白蚁甲烷排放的动态反馈机制。我们得出的结论是，最终白蚁对大气甲烷的全球贡献仍然未知，因此提出了估算其排放量的替代框架。为了显著改善估计，我们概述了悬而未决的问题，以指导未来的研究工作。
