题目：Influences of plant traits on the retention and redistribution of bioavailable nitrogen within the plant-soil system
期刊：
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作者：Junsheng Huang, Meifeng Deng, Zhou Jia, Sen Yang, Lu Yang, Shengnan Pan, Pengfei Chang, Chao Liu, Lingli Liu
通讯作者：Lingli Liu
地址：State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China
Highlights
·速生植物更有效地获取和保留生物有效氮。
·较高的植物氮滞留与较高的根系生长速率(RGR)相关。
·根系生长速率越高的植物对土壤中氮的清除能力越强。
·矿物相关有机质对氮的保留与根系生长速率呈正相关。
Abstract
土地转换对稻田土壤碳矿化的影响已受到越来越多的关注，但土壤微多样性和化学多样性在这一过程中的耦合作用尚不清楚。为了解决这一问题，本研究以稻田（PF）为研究对象，以菜地（VF）、稻菜轮作（RV）和撂荒地（AL）为研究对象。分析了土壤矿化特征与微生物群落、代谢生理和可溶性有机质（DOM）化学多样性的关系。转化后，AL和RV土壤矿化增强，分别是PF的217.49%和183.02%，而VF无明显变化，但厌氧环境转变为好氧环境，土壤真菌丰富度/多样性增加。这是因为土壤矿化直接受DOM数量和微生物代谢活性碳的调控，间接受DOM化学多样性和微生物群落的调控。AL具有最大的DOC含量、最大的亲水物质（如羧基、碳水化合物和氨基）和丰富的富营养类群（如放线菌门和变形菌门）。VF无显著变化主要与土壤中浓缩的芳香烃和寡营养微生物增多、DOC减少有关，导致土壤顽固性碳的微生物代谢占主导地位。RV也存在顽固的碳代谢。而RV具有较高的生物利用度和适宜的DOM，表现出适度的土壤矿化。综上所述，研究结果从微观化学多样性的角度提供了土地转换对土壤矿化影响的分子视角，凸显了养分供应和微生物代谢策略的重要性。
Fig. 1. Biplot of plant traits resulting from the PCA. The orange points stand for legume species, the springgreen stand for forb species, and the darkgreen stand for grass species. RAD, root area density (cm2 kg−1); RD, root diameter (mm); RGR, root growth rate (g m−2 day−1); RL, root lifespan (day); RLD, root length density (m kg−1); RTD, root tissue density (mg mm−3); SGR, shoot growth rate (g m−2 day−1); SLA, specific leaf area (mm2 mg−1); SRL, specific root length (cm mg−1).
Fig. 2. Box plot of the 15N tracer retention by the (a) plant-soil systems, (b) shoots, (c) roots, (d) particulate organic matter (POM), and (e) mineral associated organic matter (MAOM). The 15N retention was given as percent of the 15N retained by a given component to total added 15N. The span of the box in the violin is the first to third quartile, the horizontal line inside the boxes is the median of samples, and black dots represent outliers.
Table 1. The 15N tracer allocation (%) in shoots, roots, particulate organic matter (POM), and mineral associated organic matter (MAOM), given as the relative 15N retention by a given component with respect to total 15N retention.
Data are expressed as means ± SE (n = 5). Different letters indicate significant differences among species.
Fig. 3. The relative importance metrics of plant functional traits as predictors of the 15N tracer retention (a-c), and its relationship with root growth rate and root lifespan (d-f). The error bars show 95 % confidence intervals. The red stars indicate the coefficient of the factor in multiple linear regression is significant. Note that the P value and R2 (marginal) in (e) were drawn from linear mixed model with species as a random effect (see methods). The orange points stand for legume species, the springgreen stand for forb species, and the darkgreen stand for grass species. Different point shapes stand for different species (see Fig. 1). * P < 0.05; *** P < 0.001.
Fig. 4. Relationships between the 15N tracer retention by plants (a) and plant-soil systems (b) and rhizosphere priming effects. The orange points stand for legume species, the springgreen stand for forb species, and the darkgreen stand for grass species. Different point shapes stand for different species (see Fig. 1). RPE_POM, rhizosphere priming effects on native particulate organic matter decomposition; RPE_MAOM, rhizosphere priming effects on native mineral-associated organic matter decomposition.
Fig. 5. The relative ability of plant N scavenging and its drivers. (a) The relative N scavenging ability of plants for each species, determined as the ratio of the 15N tracer retention by plants to rhizosphere priming effects. Bars are means ± SE (n = 5 except for M. ruthenica with n = 3). Different letters indicate significant differences among means. (b) The relative importance metrics of plant functional traits as predictors of the relative N scavenging ability of plants. The error bars show 95 % confidence intervals. The red stars indicate the coefficient of the factor in multiple linear regression is significant (P < 0.05). The relationships of the relative N scavenging ability of plants with plant C:N (c), and root growth rate (d). The orange points stand for legume species, the springgreen stand for forb species, and the darkgreen stand for grass species. Different point shapes stand for different species (see Fig. 1).
