Global methane emission estimates from ultraviolet irradiation of terrestrial plant foliage
Global methane emission estimates from ultraviolet irradiation of terrestrial plant foliage
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DOI：
10.1111/j.1469-8137.2010.03259.x
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发表时间：
2010-01-01
期刊：
影响因子：
9.4
通讯作者：
McLeod, Andy R.
中科院分区：
文献类型：
--
作者：
Bloom, A. Anthony;Lee-Taylor, Julia;McLeod, Andy R.
几项研究报告了植被叶子的原位甲烷（CH4）排放，但关于其作为全球来源的重要性仍存在相当大的争议。在这里，我们报告了一项研究，评估了叶面果胶中紫外线 (UV) 辐射驱动的 CH4 排放作为全球 CH4 来源的作用。我们将果胶中光谱加权的 CH4 产量与全球紫外线照射气候学模型、卫星衍生的叶面积指数 (LAI) 和气温数据相结合，以估计植被叶子中潜在的全球 CH4 排放量。我们的结果表明，紫外线照射果胶中的全球叶面 CH4 排放量可以解释0.2-1.0 Tg yr-1，其中 60% 来自热带纬度，相当于 CH4 总来源的 < 0.2%。我们的估计比之前对全球叶面 CH4 排放的估计低一到两个数量级。最近的研究表明，果胶并不是紫外线驱动的 CH4 排放的唯一分子来源，其他环境压力也可能产生 CH4。因此，需要对此类 CH4 生成机制进行进一步评估，以确认树叶对全球 CH4 预算的贡献。
Several studies have reported in situ methane (CH4) emissions from vegetation foliage, but there remains considerable debate about its significance as a global source. Here, we report a study that evaluates the role of ultraviolet (UV) radiation-driven CH4 emissions from foliar pectin as a global CH4 source.We combine a relationship for spectrally weighted CH4 production from pectin with a global UV irradiation climatology model, satellite-derived leaf area index (LAI) and air temperature data to estimate the potential global CH4 emissions from vegetation foliage.Our results suggest that global foliar CH4 emissions from UV-irradiated pectin could account for 0.2-1.0 Tg yr-1, of which 60% is from tropical latitudes, corresponding to < 0.2% of total CH4 sources.Our estimate is one to two orders of magnitude lower than previous estimates of global foliar CH4 emissions. Recent studies have reported that pectin is not the only molecular source of UV-driven CH4 emissions and that other environmental stresses may also generate CH4. Consequently, further evaluation of such mechanisms of CH4 generation is needed to confirm the contribution of foliage to the global CH4 budget.