论文部分内容阅读
泥炭藓是雨养泥炭沼泽中的优势植物和主要造炭植物。多酚类化合物通常被视为是一种植物防御性化合物的次生代谢产物。泥炭藓含有独特的多酚,可抑制微生物活性,减缓泥炭残体分解。在自然生态系统中生物活性氮不断增加的背景下,泥炭藓残体成为检测大气氮沉降对泥炭残体多酚含量潜在影响的理想基质。本研究选择长期大气氮沉降梯度上的11处欧洲雨养泥炭地,测试了泥炭藓泥炭样本的总氮含量和可溶性多酚浓度。试验结果表明,由于外源性有效氮的增加,导致泥炭藓残体中氮浓度持续增长,残体中多酚含量降低。这种负相关关系与有关泥炭藓中多酚与蛋白质生物合成争夺相同前体的报道相一致。由于有效氮的抑制分解作用,导致多酚含量下降,加快泥炭残体的分解,因此长期氮富集所导致的泥炭藓残体化学特征变化将对全球碳平衡产生重要影响。
Peat moss is the dominant plant and major charcoal in rain-fed peat swamps. Polyphenols are often regarded as secondary metabolites of plant defensive compounds. Peat moss contains unique polyphenols, which inhibit microbial activity and slow the decomposition of peat residues. In the context of increasing bioactive nitrogen in natural ecosystems, peat moss remnants are ideal substrates for detecting the potential impact of atmospheric nitrogen deposition on the peat residue polyphenol content. In this study, we selected eleven European rain-fed peatlands on long-term atmospheric nitrogen deposition gradient to test the total nitrogen content and soluble polyphenol concentration in peat moss peat samples. The results showed that due to the increase of exogenous available nitrogen, the concentration of nitrogen in peat moss continued to increase and the content of polyphenols in the residue decreased. This negative correlation is consistent with reports that polyphenols and protein biosynthesis in the peat moss compete for the same precursor. Long-term enrichment of peat moss residues caused by long-term nitrogen enrichment will have a significant impact on the global carbon balance due to the inhibition of available nitrogen, resulting in the decrease of polyphenol content and the decomposition of peat residues.