University of Oulu

Leffler, AJ, Beard, KH, Kelsey, KC, Choi, RT, Schmutz, JA, Welker, JM. Delayed herbivory by migratory geese increases summer‐long CO2 uptake in coastal western Alaska. Glob Change Biol. 2019; 25: 277– 289.

Delayed herbivory by migratory geese increases summer‐long CO2 uptake in coastal western Alaska

Saved in:
Author: Leffler, A. Joshua1; Beard, Karen H.2; Kelsey, Katharine C.3;
Organizations: 1Department of Natural Resource Management, South Dakota State University, Brookings, South Dakota
2Department of Wildland Resources, Utah State University and the Ecology Center, Logan, Utah
3Department of Biological Sciences, University of Alaska ‐ Anchorage, Anchorage, Alaska
4U.S. Geological Survey Alaska Science Center, Anchorage, Alaska
5UArctic, Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
Format: article
Version: accepted version
Access: embargoed
Persistent link:
Language: English
Published: John Wiley & Sons, 2019
Publish Date: 2019-10-08


The advancement of spring and the differential ability of organisms to respond to changes in plant phenology may lead to “phenological mismatches” as a result of climate change. One potential for considerable mismatch is between migratory birds and food availability in northern breeding ranges, and these mismatches may have consequences for ecosystem function. We conducted a three‐year experiment to examine the consequences for CO2 exchange of advanced spring green‐up and altered timing of grazing by migratory Pacific black brant in a coastal wetland in western Alaska. Experimental treatments represent the variation in green‐up and timing of peak grazing intensity that currently exists in the system. Delayed grazing resulted in greater net ecosystem exchange (NEE) and gross primary productivity (GPP), while early grazing reduced CO2 uptake with the potential of causing net ecosystem carbon (C) loss in late spring and early summer. Conversely, advancing the growing season only influenced ecosystem respiration (ER), resulting in a small increase in ER with no concomitant impact on GPP or NEE. The experimental treatment that represents the most likely future, with green‐up advancing more rapidly than arrival of migratory geese, results in NEE changing by 1.2 µmol m−2 s−1 toward a greater CO2 sink in spring and summer. Increased sink strength, however, may be mitigated by early arrival of migratory geese, which would reduce CO2 uptake. Importantly, while the direct effect of climate warming on phenology of green‐up has a minimal influence on NEE, the indirect effect of climate warming manifest through changes in the timing of peak grazing can have a significant impact on C balance in northern coastal wetlands. Furthermore, processes influencing the timing of goose migration in the winter range can significantly influence ecosystem function in summer habitats.

see all

Series: Global change biology
ISSN: 1354-1013
ISSN-E: 1365-2486
ISSN-L: 1354-1013
Volume: 25
Issue: 1
DOI: 10.1111/gcb.14473
Type of Publication: A1 Journal article – refereed
Field of Science: 1181 Ecology, evolutionary biology
Funding: This work was supported by the National Science Foundation (ARC1304523, ARC1304879, & DGE1633756).
Copyright information: © 2018 John Wiley & Sons Ltd.