Root litter decomposition is suppressed in species mixtures and in the presence of living roots
Root litter decomposition is suppressed in species mixtures and in the presence of living roots
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DOI：
10.1111/1365-2745.14207
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发表时间：
2023-10-13
影响因子：
5.5
通讯作者：
De Vries，Franciska T.
中科院分区：
文献类型：
--
作者：
Heredia-Acuna，Cristina;Semchenko，Marina;De Vries，Franciska T.
植物物种多样性和身份可以显着修改凋落物分解，但其潜在的机制仍然难以捉摸，特别是根凋落物。在这里，我们的目的是解开植物物种多样性改变根凋落物分解的机制。我们假设：（1）混合群落中物种间的相互作用导致凋落物比单一群落中的凋落物分解快;（2）有活体植物存在时，凋落物分解加速，特别是当凋落物和活植物的特性相匹配时（Home Field Advantage）建立了四种常见草地物种的单一栽培和混合栽培，以获得个体凋落物和“天然”根凋落物混合物。使用来自单一栽培物的凋落物产生“人工”混合凋落物，基于qPCR测量，以与天然凋落物混合物中的物种组成相同的比例混合。这六种类型的根凋落物在四种单一栽培、四种混合物和未种植的土壤中进行培养。根凋落物的特性和活根的存在对根分解有很大影响，但对多样性影响不大。混合种属凋落物的分解速度低于基于单种属凋落物分解的预期速度。此外，存在的活根抑制分解独立的凋落物和活植物的身份之间的匹配。分解之间没有显着差异的“天然”和“人工”根凋落物混合物，表明在物种混合物中的根-根相互作用并不影响根化学质量。抑制分解存在的活根表明，与活根和根凋落物控制根凋落物分解微生物群落之间的相互作用。由于我们没有发现支持家庭场优势或种间根系相互作用在修改分解中的重要性，混合物种凋落物的抑制分解似乎主要是由化学而不是生物相互作用驱动的。
Plant species diversity and identity can significantly modify litter decomposition, but the underlying mechanisms remain elusive, particularly for root litter. Here, we aimed to disentangle the mechanisms by which plant species diversity alters root litter decomposition. We hypothesised that (1) interactions between species in mixed communities result in litter that decomposes faster than litter produced in monocultures; (2) litter decomposition is accelerated in the presence of living plants, especially when the litter and living plant identities are matched (known as home‐field advantage).Monocultures and a mixture of four common grassland species were established to obtain individual litter and a ‘natural’ root litter mixture. An ‘artificial’ mixed litter was created using litter from monocultures, mixed in the same proportions as the species composition in the natural litter mixtures based on qPCR measurements. These six root litter types were incubated in four monocultures, a four‐species mixture and an unplanted soil.Root decomposition was strongly affected by root litter identity and the presence, but not diversity, of living roots. Mixed‐species litter decomposed slower than expected based on the decomposition of single‐species litters. In addition, the presence of living roots suppressed decomposition independent of the match between litter and living plant identities. Decomposition was not significantly different between the ‘natural’ and ‘artificial’ root litter mixtures, indicating that root‐root interactions in species mixtures did not affect root chemical quality.Synthesis. Suppressed decomposition in the presence of living roots indicates that interactions between microbial communities associated with living roots and root litter control root litter decomposition. As we found no support for the importance of home‐field advantage or interspecific root interactions in modifying decomposition, suppressed decomposition of mixed‐species litter seems to be primarily driven by chemical rather than biotic interactions.