Circumpolar assessment of ecological mismatch between avian herbivores and plant phenology Completed

The timing of breeding is constrained in Arctic ecosystems and small temporal differences in when individuals breed can have large effects on fitness. Arctic ecosystems are generally warming more rapidly than other ecosystems which, for migratory species, can cause an imbalance, or mismatch, between when they have evolved to breed versus when it is optimal to breed environmentally. Geese are abundant herbivores summering in tundra ecosystems, and whose presence has important feedbacks on ecosystem processes. Some goose populations have already exhibited signs that spring vegetation phenology is occurring earlier than individuals are able to breed, with a consequent effect on their reproductive fitness. The magnitude of this ecological “mismatch”, and the corresponding response of geese to the mismatch, thus has implications to both the populations and to tundra landscapes. We propose a large, circumpolar meta-analysis that strives to understand the ecological conditions that contribute to establishing a mismatch, as well as its magnitude and impact. For instance, what is the degree of concordance of green up on migratory staging areas with green up on breeding areas, and how influential is this concordance on the magnitude or impact of mismatch? A suite of multi-decade breeding biology studies from Alaska, Canada, Europe, and Russia will provide population data on geese, while corresponding spatiotemporal vegetation phenology data will be quantified by analysis of NDVI (normalized difference vegetation index) derived from satellite remote sensing. Results of these co-analyses will help establish a foundation for hypothesizing how climate warming will influence the distribution, abundance, and ecosystem feedbacks of avian herbivores in tundra communities of the circumpolar north.