Skip to main content
U.S. flag

An official website of the United States government

The ecology of river ice

August 17, 2021

Many of the world's rivers are ice-covered during winter months but increasing evidence indicates that the extent of river ice will shift substantially as winters warm. However, our knowledge of rivers during winter lags far behind that of the growing season, limiting our understanding of how ice loss will affect rivers. Physical, chemical, and biological processes change from headwaters to large rivers; thus, we expect ice processes and resulting effects on the ecology of rivers could also vary with river size, as a result of the associated changes in geomorphology, temperature regimes, and connectivity. To conceptualize these relationships, we review typically disparate literature on ice processes and winter ecology and compare what is known in the smallest and largest rivers. In doing so, we show that our ability to link ice with ecology across river networks is made difficult by a primary focus on ice processes in larger rivers and a lack of study of ecosystem processes during winter. To address some of these gaps, we provide new scenarios of river ice loss and analyses of how the annual importance of winter gross primary productivity (GPP) varies with river size. We show projected ice loss varied with large-scale watershed characteristics such as north-south orientation and that the importance of winter to annual GPP was greatest in the smallest rivers. Finally, we highlight information needed to fill knowledge gaps on winter across river networks and improve our understanding of how rivers may change as climate and ice regimes shift.

Publication Year 2021
Title The ecology of river ice
DOI 10.1029/2021JG006275
Authors Audrey Thellman, Kathi Jo Jankowski, Brian Hayden, Xiao Yang, Wayana Dolan, Adrianne P Smits, Antoin M O'Sullivan
Publication Type Article
Publication Subtype Journal Article
Series Title JGR Biogeosciences
Index ID 70223770
Record Source USGS Publications Warehouse
USGS Organization Upper Midwest Environmental Sciences Center