Characterization of phosphorus availability in response to radial oxygen losses in the rhizosphere of Vallisneria spiralis
Characterization of phosphorus availability in response to radial oxygen losses in the rhizosphere of Vallisneria spiralis
复制标题
苦草根际径向氧损失响应磷有效性的表征
DOI：
10.1016/j.chemosphere.2018.05.180
复制
发表时间：
2018
期刊：
影响因子：
8.8
通讯作者：
Xie XC
中科院分区：
文献类型：
--
作者：
Han Chao;Wang Zhaode;Yang Shika;Ke Fan;Xu Di;Ren Jinghua;Xie Xianchuan;Wang ZD;Xie XC
沉水植物的径向氧损失（ROL）会引起氧化还原条件和相关磷（P）有效性的变化，这一观点已使用传统的破坏性技术在更大的空间尺度上得到间接证实。然而，由于缺乏令人满意的位点测绘技术，有关微生态位的关键信息在很大程度上被忽视了。在这项研究中，我们在两个植被期的苦草 (V. spiralis) 根际部署了一种最近开发的混合传感器，以从固定观察点提供氧 (O2) 和磷的时空共同分布的二维成像。总体而言，O2 和 P 的图像显示出整个根际亚毫米尺度的高度时空异质性。 P 动员的明显减少与 youngV 周围 2 毫米厚区域内 O2 的急剧增加很好地对应。 spiralisroot，表明 ROL 和 P 可用性之间存在显着的耦合关系。令人惊讶的是，尽管 ROL 沿老 V 线存在显着的日间变化。 螺旋根，根际大部分区域的磷利用率全天没有波动；然而，ROL 通过改变根际外层的氧化还原梯度显着增加了磷的固定化。这项研究清楚地证明了 V 的 ROL 是如何连续的。 spiraliscan 在调节根际磷的有效性方面发挥着重要作用。这一说法背后的前提是发现这种连续的 ROL 如何导致在根沉积物中形成三种独特的氧化还原景观（好氧层、缺氧层或厌氧层）。
The viewpoint that radial oxygen loss (ROL) of submerged macrophytes induces changes in redox conditions and the associated phosphorus (P) availability has been indirectly confirmed at larger spatial scales using conventional, destructive techniques. However, critical information about microniches has largely been overlooked due to the lack of satisfactoryin situmapping technologies. In this study, we deployed a recently developed hybrid sensor in the rhizosphere ofVallisneria spiralis(V. spiralis) during two vegetation periods to provide 2-D imaging of the spatiotemporal co-distribution of oxygen (O2) and P from a fixed observation point. Overall, the images of O2and P showed a high degree of spatiotemporal heterogeneity throughout the rhizosphere at the sub-mm scale. A clear decrease in the P mobilization corresponded well to the steep O2enhancement within a 2-mm-thick zone around youngerV. spiralisroot, indicating a significant coupling relationship between ROL and P availability. Surprisingly, despite significant diurnal shifts in ROL along the olderV. spiralisroots, P availability did not fluctuate in a substantial part of the rhizosphere throughout the day; however, ROL increased the P immobilization significantly by changing the redox gradients at the outer rhizosphere. This study clearly demonstrates how continuous ROL ofV. spiraliscan play a major role in regulating P availability within the rhizosphere. The premise behind this statement is the discovery of how this continuous ROL can lead to the formation of three distinctive redox landscapes in the rooting sediment (oxic, suboxic, or anaerobic layers).