Early snowmelt effects on Arctic tundra plants and soils: a summary of findings from a three-year field experiment at Imnavait Creek, Alaska
Abstract
In addition to warming temperatures, Arctic ecosystems are responding to climate change with earlier snowmelt. To examine the effects of early snowmelt on Arctic tundra plants and soils, we experimentally advanced the timing of snowmelt in combination with an open-top chamber warming treatment and evaluated the responses of plant phenology, decomposers, and nutrient cycling processes. During the three years of our study (2010-2012), we advanced snowmelt by 4, 15, and 10 days, respectively. We observed advanced plant phenology during leaf-out; however, this did not translate into greater plant production. We saw mixed evidence on whether plant senescence was also advanced, with spectral measurements indicating changes that were possibly linked to mosses, but marked vascular plant individuals showing no clear effects. Finally, a key focus of the study was belowground responses, including plant roots, decomposers, and soil nutrients, for which we worked to improve techniques for monitoring, especially in microlysimetry of soil nitrogen dynamics. Despite intensive monitoring, we saw limited responses in these belowground functions, with effects primarily seen on the first sampling date of the season or restricted to particular years or soil depths. Taken together, our findings indicate that while early leaf-out can be cued by a 1-2 week advancement of snowmelt, particularly if air temperatures are warm, broader ecosystem response requires a greater change in soil conditions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.B13D..04D
- Keywords:
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- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0439 Ecosystems;
- structure and dynamics;
- BIOGEOSCIENCES;
- 0475 Permafrost;
- cryosphere;
- and high-latitude processes;
- BIOGEOSCIENCES