当前位置: X-MOL 学术J. Great Lakes Res. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Complex patterns of phosphorus delivery in the Lake of the Woods watershed
Journal of Great Lakes Research ( IF 2.4 ) Pub Date : 2022-06-23 , DOI: 10.1016/j.jglr.2022.06.002
Kelly A. Macgillivray , Wesley J. Greenwood , Andrew M. Paterson , Shaun A. Watmough , Andrew J. Williams , M. Catherine Eimers

Lake of the Woods (LoW) is a large, transboundary lake that continues to experience harmful algal blooms despite large declines in phosphorus (P) inputs from point sources. Tributary runoff is considered the largest source of P to the lake; however, there are few monitoring data within the Canadian portion of the basin (∼60% of total area), to guide management. To address this gap, we monitored five rivers of contrasting land use within the lower Rainy River region, an acknowledged “hot spot” of P delivery in the basin. Total P (TP) concentrations were consistently high at all five rivers (volume-weighted range: 19–215 μg/l) despite differences in agriculture across sites (7–27%), suggesting ‘natural’ background P levels are high in this landscape. Furthermore, TP concentrations were strongly correlated with total suspended sediment and geogenic metals, iron (Fe) and aluminum, and TP was especially high during events (>400 μg/l) indicating erosion is an important source of P delivery. However, equally high TP and Fe during periods of slow, stagnant flow in the summer and under winter ice suggest erosion is not the only source of P. Instead, we suggest redox release of P from streambed sediment is also important. This observation is significant, because internal P release within the tributaries, especially during the summer could ‘seed’ downstream algal blooms. The strong sensitivity of TP to both high and low flow conditions indicates that frequent, all-season, multi-year measurements are needed to understand the mechanisms of P delivery in this basin.



中文翻译:

伍兹湖流域磷输送的复杂模式

伍兹湖 (LoW) 是一个大型跨界湖泊,尽管来自点源的磷 (P) 输入量大幅下降,但仍继续出现有害藻华。支流径流被认为是湖泊磷的最大来源;然而,流域的加拿大部分(约占总面积的 60%)的监测数据很少,无法指导管理。为了解决这一差距,我们监测了雨河下游地区土地利用对比鲜明的五条河流,这是该流域公认的磷输送“热点”。尽管不同地点的农业存在差异 (7–27%),但所有 5 条河流的总磷 (TP) 浓度始终很高(体积加权范围:19–215 微克/升),表明该地区的“自然”背景磷水平较高景观。此外,TP 浓度与总悬浮沉积物和地质成因金属、铁 (Fe) 和铝密切相关,并且 TP 在事件期间特别高 (>400 μg/l),表明侵蚀是 P 输送的重要来源。然而,在夏季和冬季冰下缓慢、停滞的流动期间,同样高的 TP 和 Fe 表明侵蚀不是 P 的唯一来源。相反,我们认为从河床沉积物中氧化还原释放 P 也很重要。这一观察结果很重要,因为内部 P 在支流中释放,尤其是在夏季,可能会“播种”下游藻类大量繁殖。TP 对高流量和低流量条件的高度敏感性表明需要频繁、全季节、多年的测量来了解该盆地的 P 输送机制。TP 在事件期间特别高 (>400 μg/l),表明侵蚀是 P 输送的重要来源。然而,在夏季和冬季冰下缓慢、停滞的流动期间,同样高的 TP 和 Fe 表明侵蚀不是 P 的唯一来源。相反,我们认为从河床沉积物中氧化还原释放 P 也很重要。这一观察结果很重要,因为内部 P 在支流中释放,尤其是在夏季,可能会“播种”下游藻类大量繁殖。TP 对高流量和低流量条件的高度敏感性表明需要频繁、全季节、多年的测量来了解该盆地的 P 输送机制。TP 在事件期间特别高 (>400 μg/l),表明侵蚀是 P 输送的重要来源。然而,在夏季和冬季冰下缓慢、停滞的流动期间,同样高的 TP 和 Fe 表明侵蚀不是 P 的唯一来源。相反,我们认为从河床沉积物中氧化还原释放 P 也很重要。这一观察结果很重要,因为内部 P 在支流中释放,尤其是在夏季,可能会“播种”下游藻类大量繁殖。TP 对高流量和低流量条件的高度敏感性表明需要频繁、全季节、多年的测量来了解该盆地的 P 输送机制。夏季和冬季冰下的停滞流动表明侵蚀不是 P 的唯一来源。相反,我们认为河床沉积物中 P 的氧化还原释放也很重要。这一观察结果很重要,因为内部 P 在支流中释放,尤其是在夏季,可能会“播种”下游藻类大量繁殖。TP 对高流量和低流量条件的高度敏感性表明需要频繁、全季节、多年的测量来了解该盆地的 P 输送机制。夏季和冬季冰下的停滞流动表明侵蚀不是 P 的唯一来源。相反,我们认为河床沉积物中 P 的氧化还原释放也很重要。这一观察结果很重要,因为内部 P 在支流中释放,尤其是在夏季,可能会“播种”下游藻类大量繁殖。TP 对高流量和低流量条件的高度敏感性表明需要频繁、全季节、多年的测量来了解该盆地的 P 输送机制。

更新日期:2022-06-23
down
wechat
bug