Possible emissions of N_2O from plants in coniferous-deciduous mixed forests

针阔混交林植物N_2O排放的研究(英文)

Aboveground vertical profiles of N2O concentrations were measured with in two natural coniferous-deciduous mixed forests of 1998 and 1999 in Changbai M ountain. Significant high N2O concentrations were found in six profiles out of t welve profiles. The results showed that high concentrations were 3.03% to 64.9% higher than the "normal concentrations" in these six profiles. Differences betwe en the high concentrations and the "normal concentrations" were statistically si gnificant. The simultaneous occurrence of high concentrations at/nearby the cano py height and normal concentrations at the trunk space height indicated an efflu x of N2O from foliage to atmosphere. This study afforded evidence supporting tha t plant per se, besides forest soil, was an important source of atmospheric N2O in a forest ecosystem.

本研究测定了长白山两种阔叶红松林地表以上空气的N2O浓度垂直梯度分布。在进行的 十二次观测中，有六次观测发现了不同高度处的空气N2O浓度间存在显著差异。这些观测结 果中，高N2O浓度比正常浓度高3.03%到64.9%（差异显著或极显著）；并且，林冠及其附近 处的高N2O浓度与树干高度处正常N2O浓度的同时存在这一现象表明了树冠向大气排放N2O。 本文为证明在森林生态系统中，除土壤外，植物自身在自然状态下也是一个重要的N2O排放 源提供了证据。