Plant diversity enhances production and downward transport of biodegradable dissolved organic matter
Plant diversity enhances production and downward transport of biodegradable dissolved organic matter
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DOI：
10.1111/1365-2745.13556
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发表时间：
2020-11
影响因子：
5.5
通讯作者：
M. Lange;Vanessa-Nina Roth;N. Eisenhauer;C. Roscher;T. Dittmar;C. Fischer‐Bedtke;Odette González Macé;A. Hildebrandt;A. Milcu;L. Mommer;N. Oram;Janneke M. Ravenek;S. Scheu;B. Schmid;Tanja Strecker;Cameron Wagg;A. Weigelt;G. Gleixner
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文献类型：
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作者：
M. Lange;Vanessa-Nina Roth;N. Eisenhauer;C. Roscher;T. Dittmar;C. Fischer‐Bedtke;Odette González Macé;A. Hildebrandt;A. Milcu;L. Mommer;N. Oram;Janneke M. Ravenek;S. Scheu;B. Schmid;Tanja Strecker;Cameron Wagg;A. Weigelt;G. Gleixner
植物多样性是地下生态系统功能的重要驱动力，如根系生长，土壤有机质（SOM）储存和微生物代谢，主要通过影响植物根系和土壤之间的相互作用。溶解有机质（DOM）作为土壤有机质中最具移动的形式，在众多的土壤过程中起着至关重要的作用。因此，DOM可能是植物多样性对土壤过程影响的重要介质。然而，植物多样性与DOM之间的关系还没有研究到目前为止。在德国耶拿进行的草地生物多样性长期试验中，采用6年62个植物群落的连续土壤水采样，研究了植物多样性对DOM浓度影响的机制。此外，我们研究了植物多样性对DOM分子特性的影响。虽然DOM浓度在一年中变化很大，夏季和秋季浓度最高，但我们发现DOM浓度随着季节的变化而不断增加。植物多样性对DOM浓度的正效应主要是通过增加表层土壤中的微生物活性和新固碳来介导的。土壤微生物活性对DOM浓度的影响因季节而异，冬、春两季为DOM的消耗期，夏秋两季为DOM的产生期。此外，我们发现增加的内容小，易于分解的DOM分子达到更深的土壤层与高植物多样性。合成.我们的研究结果表明，植物多样性以多种方式增强了DOM的持续向下传输。一方面，植物多样性越高，土壤DOM含量越高，另一方面，土壤DOM降解越少。这项研究首次表明，较高的植物多样性增强了溶解分子的向下运输，这可能刺激深层土壤的发育，从而提高土壤肥力。
Plant diversity is an important driver of below‐ground ecosystem functions, such as root growth, soil organic matter (SOM) storage and microbial metabolism, mainly by influencing the interactions between plant roots and soil. Dissolved organic matter (DOM), as the most mobile form of SOM, plays a crucial role for a multitude of soil processes that are central for ecosystem functioning. Thus, DOM is likely to be an important mediator of plant diversity effects on soil processes. However, the relationships between plant diversity and DOM have not been studied so far. We investigated the mechanisms underlying plant diversity effects on concentrations of DOM using continuous soil water sampling across 6 years and 62 plant communities in a long‐term grassland biodiversity experiment in Jena, Germany. Furthermore, we investigated plant diversity effects on the molecular properties of DOM in a subset of the samples. Although DOM concentrations were highly variable over the course of the year with highest concentrations in summer and autumn, we found that DOM concentrations consistently increased with plant diversity across seasons. The positive plant diversity effect on DOM concentrations was mainly mediated by increased microbial activity and newly sequestered carbon in topsoil. However, the effect of soil microbial activity on DOM concentrations differed between seasons, indicating DOM consumption in winter and spring, and DOM production in summer and autumn. Furthermore, we found increased contents of small and easily decomposable DOM molecules reaching deeper soil layers with high plant diversity. Synthesis. Our findings suggest that plant diversity enhances the continuous downward transport of DOM in multiple ways. On the one hand, higher plant diversity results in higher DOM concentrations, on the other hand, this DOM is less degraded. This study indicates, for the first time, that higher plant diversity enhances the downward transport of dissolved molecules that likely stimulate soil development in deeper layers and therefore increase soil fertility.