Winter conditions are rapidly changing in temperate ecosystems, particularly for those that experience periods of snow and ice cover. Relatively little is known of winter ecology in these systems, due to a historical research focus on summer ‘growing seasons’. We executed the first global quantitative synthesis on under-ice lake ecology, including 36 abiotic and biotic variables from 42 research groups and 101 lakes, examining seasonal differences and connections as well as how seasonal differences vary with geophysical factors. Plankton were more abundant under ice than expected; mean winter values were 43.2% of summer values for chlorophyll a, 15.8% of summer phytoplankton biovolume and 25.3% of summer zooplankton density. Dissolved nitrogen concentrations were typically higher during winter, and these differences were exaggerated in smaller lakes. Lake size also influenced winter-summer patterns for dissolved organic carbon (DOC), with higher winter DOC in smaller lakes. At coarse levels of taxonomic aggregation, phytoplankton and zooplankton community composition showed few systematic differences between seasons, although literature suggests that seasonal differences are frequently lake-specific, species-specific, or occur at the level of functional group. Within the subset of lakes that had longer time series, winter influenced the subsequent summer for some nutrient variables and zooplankton biomass.
Bibliographical noteFunding Information:
Funding was provided by the National Science Foundation (NSF DEB #1431428; NSF DEB #1136637) and Washington State University. M. Timofeyev and E. Silow were partially supported by Russian Science Foundation project No 14-14-00400 and Ministry of education and science of Russia GosZasanie project No 1354–2014/51. We are grateful to Marianne Moore, Deniz Özkundakci, Chris Polashenski and Paula Kankaala for discussions that greatly improved this work. We also gratefully acknowledge the following individuals for contributing to this project: John Anderson, Jill Baron, Rick Bourbonniere, Sandra Brovold, Lluis Camarero, Sudeep Chandra, Jim Cotner, Laura Forsstöm, Guillaume Grosbois, Chris Harrod, Klaus D. Joehnk, T.Y. Kim, Daniel Langenhaun, Reet Laugaste, Suzanne McGowan, Virginia Panizzo, Giampaolo Rossetti, R.E.H. Smith, Sarah Spaulding, Helen Tammert, Steve Thackeray, Kyle Zimmer, Priit Zingel and two anonymous reviewers. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government.
© 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.
- Aquatic ecosystem
- data synthesis
- time series
- winter ecology