Molecular composition of soil dissolved organic matter in recently-burned and long-unburned boreal forests
Molecular composition of soil dissolved organic matter in recently-burned and long-unburned boreal forests
复制标题
最近燃烧和长期未燃烧的北方森林土壤溶解有机物的分子组成
DOI：
10.1071/wf19085
复制
发表时间：
2020
影响因子：
3.1
通讯作者：
Pumpanen Jukka
中科院分区：
文献类型：
--
作者：
Ide Jun'ichiro;Ohashi Mizue;Koster Kajar;Berninger Frank;Miura Ikumi;Makita Naoki;Yamase Keitaro;Palviainen Marjo;Pumpanen Jukka
森林火灾可以改变土壤溶解有机质的质量，从而对森林生态系统的生态地球化学循环产生重大影响。然而，很少有资料是关于火灾对北方森林土壤中DOM的化学组成的影响。为了澄清这些影响，土壤DOM的分子组成进行了比较，最近烧毁和长期未烧毁的北方森林（6年和156年，分别自上次火灾）在芬兰拉普兰。超高分辨率傅立叶变换离子回旋共振质谱分析表明，最近烧毁和长期未烧毁的森林之间的物种，平均分子量或分子化合物的数量没有显着差异。然而，具有稠合芳香结构的化合物的数量在最近被烧毁的森林中往往更大，而两个森林之间不共享的蛋白质和碳水化合物的数量显着较小。木质素类分子占两种林分总分子种类的绝大部分。我们的研究结果表明，火不仅产生了几种溶解的黑碳，但也引起燃烧的植物残留物，这提供了不同的木质素样分子在最近燃烧的森林土壤，并导致分子物种的数量是在长期未燃烧的森林土壤相媲美。
Forest fires can change the quality of dissolved organic matter (DOM) in soils, and consequently have a great influence on biogeochemical cycles in forest ecosystems. However, little information is available regarding the effects of fire on the chemical composition of DOM in boreal forest soils. To clarify these effects, the molecular composition of soil DOM was compared between recently-burned and long-unburned boreal forests (6 and 156 years since the last fire, respectively) in Finnish Lapland. Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry revealed that there were no significant differences in species, average molecular weight or the number of molecular compounds detected between the recently-burned and long-unburned forests. However, the number of compounds with condensed aromatic structures tended to be larger in the recently-burned forest, whereas the numbers of proteins and carbohydrates not shared between the two forests were significantly smaller. Lignin-like molecules accounted for most of the total molecular species in both forests. Our results suggest that fire not only generated several species of dissolved black carbon, but also caused burned plant residues, which supplied diverse lignin-like molecules in the recently-burned forest soils and led to the number of molecular species being comparable to that in the long-unburned forest soils.