{"title":"Soil water status dominates growth and nitrogen acquisition strategy of Carex thunbergii in response to nitrogen and water additions","authors":"Wuqiong Hu, Dafeng Hui, Chaohe Huangfu","doi":"10.1007/s11368-024-03848-0","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Purpose</h3><p>Subtropical lake riparian ecosystems experience seasonal water table fluctuations and increased nitrogen (N) deposition with changing N composition. However, the interplay of soil water content (SWC), N deposition chemical composition, and their interaction on plant growth through regulating N acquisition remains poorly understood.</p><h3 data-test=\"abstract-sub-heading\">Methods</h3><p>In this controlled experiment with a sedge species <i>Carex thunbergii</i>, we investigated two treatment factors: (1) SWC at 100%, 60%, and 30% of field capacity, combined with (2) N treatments with NH<sub>4</sub><sup>+</sup>:NO<sub>3</sub><sup>−</sup> ratios of 1:3, 2:2, and 3:1. Treatment verifications were conducted using <sup>15</sup>N isotope tracer (<sup>15</sup>NH<sub>4</sub>NO<sub>3 </sub>and NH<sub>4</sub><sup>15</sup>NO<sub>3</sub>) technology.</p><h3 data-test=\"abstract-sub-heading\">Results</h3><p>Results showed a notable trend of reduced biomass of <i>C. thunbergii</i> with increasing NH<sub>4</sub><sup>+</sup>: NO<sub>3</sub><sup>−</sup> ratio, especially under high SWC conditions. This negative effect of a high NH<sub>4</sub><sup>+</sup>: NO<sub>3</sub><sup>−</sup> ratio on plant biomass accumulation also aligned with reduced N use efficiency (NUE). Conversely, <i>C. thunbergii</i> exhibited accelerated N uptake with increasing SWC, with the most pronounced response observed in the treatment of NH<sub>4</sub><sup>+</sup>: NO<sub>3</sub><sup>−</sup> ratio of 3:1. Principal component analyses provided evidence for SWC-dominated functional coordination between plant below- and aboveground parts in mediating plant N acquisition, while correlation analyses revealed that NUE mainly contributed to belowground productivity of <i>C. thunbergii</i>.</p><h3 data-test=\"abstract-sub-heading\">Conclusions</h3><p>Our findings suggest that manipulating water table (as a proxy of SWC) and managing soil NH<sub>4</sub><sup>+</sup>: NO<sub>3</sub><sup>−</sup> ratios could optimize the productivity of this sedge species in riparian ecosystem. The coordination of leaf-root trait highlights the necessity to integrate above- and belowground traits for a comprehensive understanding of plant N acquisition strategies. Understanding plant N acquisition and use efficiency may help us better predict the potential impacts of future climate change components on ecosystem functions.</p>","PeriodicalId":17139,"journal":{"name":"Journal of Soils and Sediments","volume":"46 1","pages":""},"PeriodicalIF":3.0000,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Soils and Sediments","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1007/s11368-024-03848-0","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose
Subtropical lake riparian ecosystems experience seasonal water table fluctuations and increased nitrogen (N) deposition with changing N composition. However, the interplay of soil water content (SWC), N deposition chemical composition, and their interaction on plant growth through regulating N acquisition remains poorly understood.
Methods
In this controlled experiment with a sedge species Carex thunbergii, we investigated two treatment factors: (1) SWC at 100%, 60%, and 30% of field capacity, combined with (2) N treatments with NH4+:NO3− ratios of 1:3, 2:2, and 3:1. Treatment verifications were conducted using 15N isotope tracer (15NH4NO3 and NH415NO3) technology.
Results
Results showed a notable trend of reduced biomass of C. thunbergii with increasing NH4+: NO3− ratio, especially under high SWC conditions. This negative effect of a high NH4+: NO3− ratio on plant biomass accumulation also aligned with reduced N use efficiency (NUE). Conversely, C. thunbergii exhibited accelerated N uptake with increasing SWC, with the most pronounced response observed in the treatment of NH4+: NO3− ratio of 3:1. Principal component analyses provided evidence for SWC-dominated functional coordination between plant below- and aboveground parts in mediating plant N acquisition, while correlation analyses revealed that NUE mainly contributed to belowground productivity of C. thunbergii.
Conclusions
Our findings suggest that manipulating water table (as a proxy of SWC) and managing soil NH4+: NO3− ratios could optimize the productivity of this sedge species in riparian ecosystem. The coordination of leaf-root trait highlights the necessity to integrate above- and belowground traits for a comprehensive understanding of plant N acquisition strategies. Understanding plant N acquisition and use efficiency may help us better predict the potential impacts of future climate change components on ecosystem functions.
期刊介绍：
The Journal of Soils and Sediments (JSS) is devoted to soils and sediments; it deals with contaminated, intact and disturbed soils and sediments. JSS explores both the common aspects and the differences between these two environmental compartments. Inter-linkages at the catchment scale and with the Earth’s system (inter-compartment) are an important topic in JSS. The range of research coverage includes the effects of disturbances and contamination; research, strategies and technologies for prediction, prevention, and protection; identification and characterization; treatment, remediation and reuse; risk assessment and management; creation and implementation of quality standards; international regulation and legislation.
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