Legume presence reduces the decomposition rate of non-legume roots
Legume presence reduces the decomposition rate of non-legume roots
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DOI：
10.1016/j.soilbio.2015.11.026
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发表时间：
2016-03
影响因子：
9.7
通讯作者：
S. Saar;M. Semchenko;Janna M. Barel;G. B. Deyn
中科院分区：
文献类型：
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作者：
S. Saar;M. Semchenko;Janna M. Barel;G. B. Deyn
活的植物可以通过释放根系分泌物的启动效应来提高凋落物的分解速度，根系分泌物为腐养微生物提供能量，从而使它们能够更快地降解凋落物。然而，这种效应的强度预计取决于凋落物的性质。为了测试生长植物的存在是否会影响不同性状死根的分解速率，我们以7种植物（3种草、3种豆科植物、1种牧草）的死根作为凋落物，在有或没有生长的白三叶（Trifolium repens）植物的土壤中培养8周后，量化凋落物质量损失。我们期望在ofT的存在下根分解会更快。特别是对碳氮比高的根。我们发现。补偿减缓了禾草和草本根的分解（负启动），而对豆科植物根的分解没有显著影响。我们的研究结果表明，在有活植物存在的情况下，根系分解可以被减缓，这种效果取决于分解根系的性质，氮和磷含量较低的凋落根明显减少，而相对营养丰富的豆科植物的凋落根则没有明显减少。豆科植物对非豆科凋落物分解的负启动效应可能与土壤微生物对基质的优先利用有关。
Living plants can enhance litter decomposition rates via a priming effect by releasing root exudates which provide energy to saprotrophic microbes and thereby enable them to degrade litter faster. The strength of this effect, however, is expected to be dependent on the litter properties. To test whether the presence of a growing plant affects the decomposition rate of dead roots with different traits, we used dead roots of seven species (3 grasses, 3 legumes, 1 forb) as litter and quantified litter mass loss after eight weeks of incubation in soil with or without a growing white clover (Trifolium repens) plant. We expected root decomposition to be faster in the presence ofT. repens, especially for roots with high C:N ratio. We found that the presence ofT. repensslowed down the decomposition of grass and forb roots (negative priming), while it did not significantly affect the decomposition of legume roots. Our results show that root decomposition can be slowed down in the presence of a living plant and that this effect depends on the properties of the decomposing roots, with a pronounced reduction in root litter poor in N and P, but not in the relatively nutrient-rich legume root litters. Negative priming effect of legume plants on non-legume litter decomposition may have resulted from preferential substrate utilisation by soil microbes.