Litter decomposition affected by bamboo expansion is modulated by litter-mixing and microbial composition
Litter decomposition affected by bamboo expansion is modulated by litter-mixing and microbial composition
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竹子膨胀影响的凋落物分解受到凋落物混合和微生物组成的调节
DOI：
10.1111/1365-2435.13911
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发表时间：
2021
影响因子：
5.2
通讯作者：
Liu Shirong
中科院分区：
文献类型：
--
作者：
Luan Junwei;Li Siyu;Dong Wei;Liu Yanchun;Wang Yi;Liu Shirong
凋落物分解是驱动碳(C)和养分循环的关键生态系统过程，这一过程可能受到植物入侵或扩张引起的植物群落组成变化的影响。然而，植物群落组成变化引起的凋落叶组成变化（如凋落叶混合效应）和土壤微生物群落的变化对分解的影响尚不清楚。本研究通过布置432个凋落物袋（50 μm筛网），在3个地区的竹林扩展和未竹林扩展的立地对竹竹和竹竹两种树种（混合或单独）的凋落叶进行分解，评估竹林扩展对凋落叶分解、微生物群落结构和功能的影响。竹材膨化降低了微生物碳氮比（C / N）和营养胁迫指标（cy/pre），这很可能是由于凋落物氮释放加速导致氮有效性提高所致。竹木凋落物的N损失量（28.1±3.03%）是乔木凋落物（13.2±3.1%）的两倍多，竹木混合凋落物的分解使凋落物N损失量从15.3±3.1%增加到25.9±3.1%（增加69%）。然而，凋落物类型和凋落物处理对C损失的影响并不一致。凋落物的非加性混合效应是由于微生物养分利用效率的提高，这可以通过凋落物处理和cy/pre对分解的交互作用来说明。此外，在忽略凋落物处理的情况下，森林类型对凋落物的分解和cy/pre有交互影响，当两个站点具有相当的cy/pre时，竹林扩展的腐烂率和凋落物N损失将高于非扩展站点，但现实情况是竹林扩展往往具有更低的cy/pre。这些结果表明，在引入的凋落物和当地微生物群落的养分利用效率之间存在权衡，以推动分解。研究结果表明，竹材膨胀对凋落物分解的影响是由凋落物混合和微生物组成共同调节的，这为预测植物群落组成变化引起的土壤C和养分循环变化提供了新的思路。在本文的支持信息中可以找到一个免费的简单语言摘要。
Litter decomposition is a key ecosystem process that drives carbon (C) and nutrient cycling, which could be affected by shifts in plant community composition caused by plant invasion or expansion. However, how changes in leaf litter composition (e.g. litter‐mixing effect) and soil microbial community induced by shift in plant community composition affect decomposition remains elusive.Here, by deploying 432 litterbags (50‐μm mesh screen), we treated leaf litter of bambooPhyllostachys edulisand tree species (in a mixture or alone) and decomposed them in forest sites expanded or not expanded by bamboo at three regions, to assess the effects of bamboo expansion on decomposition, microbial community structure and function.Bamboo expansion reduced microbial C to nitrogen (N) ratio and nutritional stress indicator (cy/pre), which was very likely ascribed to elevated N availability as a result of accelerated litter N release. The N loss of bamboo litter (28.1 ± 3.03%) was more than double of tree species litter (13.2 ± 3.1%), and decomposing litter of bamboo and tree species in a mixture increased litter N loss from 15.3 ± 3.1% to 25.9 ± 3.1% (by 69%). However, no consistent effect of litter type and litter treatment on C loss was observed. The non‐additive litter‐mixing effect is attributable to increased microbial nutrient use efficiency, which is illustrated by the interactive effect between litter treatment and cy/pre on decomposition. Moreover, the forest type interactively affected decomposition with cy/pre as ignoring litter treatment, where higher decay rate and litter N loss at bamboo expanded than non‐expanded sites would be expected when both sites having comparable cy/pre, but the reality is that bamboo expansion tends to have lower cy/pre. These results imply a trade‐off between introduced litter and nutrient use efficiency of local microbial community to drive decomposition.Our results demonstrate that litter decomposition affected by bamboo expansion was jointly modulated by litter‐mixing and microbial composition, which sheds new insights on predicting changes in soil C and nutrient cycling induced by shifts in plant community composition.A free plain language summary can be found within the Supporting Information of this article.