刊登于去年Nature上的研究显示，陆地植物可能是温室气体甲烷的来源之一，这表明植物有可能造成全球甲烷增加。这个具有富有争议性的结果，引起了一群荷兰科学家团体针对这个理论进行重新分析研究。
在一篇发表于New Phytologist的文章中，Tom Dueck和他的同事发表了他们的研究结果，结论是植物释放的甲烷量几乎可以忽略不计，而且对于全球气候的改变没有任何影响。
这个研究团体结合了专家及他们设计的新实验设备。植物在这种含有大气二氧化碳的装置中生长，但是其中的碳为同位素碳13。
这项设计使得植物释放出来的碳可以更容易地侦测到。因此，如果植物释放出甲烷，其中就会含有同位素碳13，而且在空气中较轻的碳分子背景下能被探测出来。
一共有6种植物在这种富含碳13的环境中生长，而含有碳13的甲烷的释放也通过声光激光技术测量。这种技术非常灵敏，即使是蚂蚁呼吸产生的二氧化碳都能测出。在这样的先进技术下，测量到的甲烷值也是接近测量极限，在统计上而言是接近0的。这是首次提出的相反测试结果。
考虑到植物数量对结果的影响，科学家又模拟了大量植物生长的情况，结果还是发现产生的甲烷可忽略不计。因此专家认为没有必要再评估植物减轻甲烷量潜力的必要了，但是对于全球甲烷总量，还是需要进一步分析。
（编译/姜欣慧） (资料来源 : biocompare)
英文原文链接：
http://news.biocompare.com/newsstory.asp?id=180447
原始出处：
No evidence for substantial aerobic methane emission by terrestrial plants: a 13C-labelling approach
Tom A. Dueck 11Plant Research International, PO Box 16, 6700 AA, Wageningen, the Netherlands; , Ries de Visser 22IsoLife, PO Box 349, 6700 AH, Wageningen, the Netherlands; , Hendrik Poorter 33Plant Ecophysiology, Utrecht University, PO Box 800.84, 3508 TB, Utrecht, the Netherlands; , Stefan Persijn 44Molecular & Laser Physics, Radboud University, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands; , Antonie Gorissen 22IsoLife, PO Box 349, 6700 AH, Wageningen, the Netherlands; , Willem de Visser 11Plant Research International, PO Box 16, 6700 AA, Wageningen, the Netherlands; , Ad Schapendonk 55Plant Dynamics, Englaan 8, 6703 EW, Wageningen, the Netherlands, Jan Verhagen 11Plant Research International, PO Box 16, 6700 AA, Wageningen, the Netherlands; , Jan Snel 11Plant Research International, PO Box 16, 6700 AA, Wageningen, the Netherlands; , Frans J. M. Harren 44Molecular & Laser Physics, Radboud University, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands; , Anthony K. Y. Ngai 44Molecular & Laser Physics, Radboud University, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands; , Francel Verstappen 11Plant Research International, PO Box 16, 6700 AA, Wageningen, the Netherlands; , Harro Bouwmeester 11Plant Research International, PO Box 16, 6700 AA, Wageningen, the Netherlands; , Laurentius A. C. J. Voesenek 33Plant Ecophysiology, Utrecht University, PO Box 800.84, 3508 TB, Utrecht, the Netherlands; and Adrie van der Werf 11Plant Research International, PO Box 16, 6700 AA, Wageningen, the Netherlands;
1Plant Research International, PO Box 16, 6700 AA, Wageningen, the Netherlands; 2IsoLife, PO Box 349, 6700 AH, Wageningen, the Netherlands; 3Plant Ecophysiology, Utrecht University, PO Box 800.84, 3508 TB, Utrecht, the Netherlands; 4Molecular & Laser Physics, Radboud University, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands; 5Plant Dynamics, Englaan 8, 6703 EW, Wageningen, the Netherlands
Author for correspondence:Tom A. Dueck
Tel: +31 317475918
Fax: +31 317423110
Email: tom.dueck@wur.nl
Key words : 13C-labelling, climate change, methane emission.
New Phytologist (2007) doi: 10.1111/j.1469-8137.2007.02103.x
No claim to original Dutch government works. Journal compilation © New Phytologist (2007)
Summary
• The results of a single publication stating that terrestrial plants emit methane has sparked a discussion in several scientific journals, but an independent test has not yet been performed.
• Here it is shown, with the use of the stable isotope 13C and a laser-based measuring technique, that there is no evidence for substantial aerobic methane emission by terrestrial plants, maximally 0.3% (0.4 ng g1 h1) of the previously published values.
• Data presented here indicate that the contribution of terrestrial plants to global methane emission is very small at best.
• Therefore, a revision of carbon sequestration accounting practices based on the earlier reported contribution of methane from terrestrial vegetation is redundant.
Fig. 1 Methane spectra. (a) Spectra calculated from the Hitran database (http://cfa-www.harvard.edu/Hitran/). The arrow indicates the 13C-methane peak used for the measurements. (b) Measured photoacoustic spectrum of laboratory air.
Fig. 2 Long-term steady-state methane emissions by vegetation. (a) Measured 13C-methane emissions (mean ± SE) by a mixture of 13C-enriched plants in the ESPAS (Experimental Soil Plant Atmosphere System) growth chamber under controlled steady-state conditions. Plant biomass increased from 289 (day 0) to 374 (day 6) g dry weight during the experiment (n = 3), and the emissions are given at the median of the time for accumulated emission. (b) Measured (solid line) and predicted (dashed lines) accumulation of methane by 13C-enriched plants in the ESPAS growth chamber. Measured methane concentrations (solid line, closed squares), and methane concentrations predicted from our continuous-flow experiment (Table 3; 21 ng g1 h1, dashed line, open triangles), or from Keppler et al. (2006: ‘sunlight’, 374 ng g1 h1, dot-dashed line, closed diamond; ‘no sun’, 119 ng g1 h1, dotted line, open squares).
