Summer 2022 Resources and Publications

Imbalance of global nutrient cycles exacerbated by the greater retention of phosphorus over nitrogen in lakes
Wu, Zhen,  Jincheng Li, Yanxin Sun, Josep Peñuelas, Jilin Huang, Jordi Sardans, Qingsong Jiang, Jacques C. Finlay, Gregory L. Britten, Michael J. Follows, Wei Gao, Boqiang Qin, Jinren Ni, Shouliang Huo and Yong Liu
Nature Geoscience 15   2022

Imbalanced anthropogenic inputs of nitrogen (N) and phosphorus (P) have significantly increased the ratio between N and P globally, degrading ecosystem productivity and environmental quality. Lakes represent a large global nutrient sink, modifying the flow of N and P in the environment. It remains unknown, however, the relative retention of these two nutrients in global lakes and their role in the imbalance of the nutrient cycles.

Overwinter survival of Corbicula fluminea in a central Minnesota lake
Megan M. Weber and Daniel Cibulka
PLOS One     July 2022

Although Corbicula fluminea has been one of the more prolific freshwater invasive species in the world, previous studies have suggested a low probability for overwinter survival in northern latitudes without an artificially created thermal refuge. The discovery of live Cfluminea in a central Minnesota lake absent any known thermal refuge in 2020 presented an opportunity to further evaluate the overwinter survival and population structure of Cfluminea at the presumed edge of their potential range.

The Entropic Braiding Index (eBI): a robust metric to account for the diversity of channel scales in multi-thread rivers
Tejedor, Alejandro, Jon Schwenk, Maarten Kleinhans, Ajay B Limaye, Lawrence Vulis, Paul Carling, Holger Kantz and Efi Foufoula-Georgiou
ESSOAr  May 2022

The Braiding Index (BI), defined as the average count of intercepted channels per cross-section, is a widely used metric for characterizing multi-thread river systems. However, it does not account for the diversity of channels (e.g., in terms of discharge) within different cross-sections, omitting important information related to system complexity. Here we present a modification of BI (the Entropic Braiding Index, eBI) which augments the information content in BI by using Shannon Entropy to encode the diversity of channels in each cross section.

Impacts of Emergent Vegetation on Hyporheic Exchange
Qingjun Judy Yang and Shih-Hsun Huang
Earth and Space Science     April 2022

Hyporheic exchange, or the exchange of water and solutes between surface and subsurface water at the sediment-water interface, regulates water quality and biogeochemical cycles in aquatic ecosystems. Vegetation, which is ubiquitous in nature, is known to impact hyporheic exchange, yet how vegetation impacts hyporheic exchange remains to be characterized. Here, we show that at the same spatially and temporally averaged flow velocity, vegetation increases the rate of hyporheic exchange by a factor of four. By tracking the movement of fluorescent dye in a flume with index-matched sediment and translucent vegetation dowels, we demonstrate that vegetation-induced hyporheic exchange at the sediment-water interface can be characterized by an effective hyporheic exchange velocity.