Arctic climate shifts drive rapid ecosystem responses across the West Greenland landscape

Abstract

Prediction of high latitude response to climate change is hampered by poor understanding of the role of nonlinear changes in ecosystem forcing and response. While the effects of nonlinear climate change are often delayed or dampened by internal ecosystem dynamics, recent warming events in the Arctic have driven rapid environmental response, raising questions of how terrestrial and freshwater systems in this region may shift in response to abrupt climate change. We quantified environmental responses to recent abrupt climate change in West Greenland using long-term monitoring and paleoecological reconstructions. Using >40 years of weather data, we found that after 1994, mean June air temperatures shifted 2.2°C higher and mean winter precipitation doubled from 21 to 40 mm; since 2006, mean July air temperatures shifted 1.1°C higher. Nonlinear environmental responses occurred with or shortly after these abrupt climate shifts, including increasing ice sheet discharge, increasing dust, advancing plant phenology, and in lakes, earlier ice out and greater diversity of algal functional traits. Our analyses reveal rapid environmental responses to nonlinear climate shifts, underscoring the highly responsive nature of Arctic ecosystems to abrupt transitions.

Global lake responses to climate change

“…Changes in winter conditions and precipitation have a range of consequences. For example, altering the duration, timing and condition of lake ice will affect biogeochemical cycling, community composition, algal biomass 150 , food web dynamics and gas emissions 151,152 , with similar consequences from permafrost thaw 153 . Precipitation and snowmelt are among the major factors that affect nutrient and dissolved organic matter avail ability in lakes.…”

Centennial clonal stability of asexualDaphniain Greenland lakes despite climate variability

“…In the Illulissat area of West Greenland, clonal richness of Daphnia pulex populations was between 4 and 5 genotypes [29,30]. The lakes along Kangerlussuaq in SW Greenland are particularly well-studied in relationship to recent climate change, with evidence for a dramatic increase in environmental forcing of these sensitive habitats [31]. In the context of the present study, the Kangerlussuaq area is a natural experimental site, in that direct anthropogenic impacts are limited or absent.…”

“…Kangerlussuaq, in contrast to most Arctic regions, was cooling throughout much of the 20 th century. However, since 1996 the area has undergone pronounced climate change, including rapid warming (> 2 °C) over the last 15 years, partly in relation to changes in the Greenland Blocking Index [31].…”

“…It is possible that these seasonal environmental changes and the vertical O 2 gradients exert greater physiological stress in Daphnia than the stress associated with regional warming. Of course, this genetic stasis may not continue should environmental change in SW Greenland stay at a similar rate[31].…”

The case for research integration, from genomics to remote sensing, to understand biodiversity change and functional dynamics in the world's lakes

“…Another recent example of translational complementary, demonstrated by Saros et al (2019) involved the modeling of satellite-derived ice-out dates as a function of weather station air temperature data, so that the resulting model could be used to reconstruct longer time series of ice-out. Along with a diversity of other evidence, these modeled data allowed resolution of nonlinear climate impacts in Greenland.…”