Diminishing Snowpack and Greenhouse Gas Fluxes: Investigating CO₂ Dynamics in Subalpine Ecosystems

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Presenter Information(s)

Emma Tunks

Abstract or Description

Climate change is expected to reduce the depth and duration of snowpack in many mountain ecosystems. This change has implications for the greenhouse gas budgets that are partly controlled by snowpack. Snow can act as an insulating blanket in cold temperatures, which can keep the ground temperature from falling much below freezing even when air temperatures can drop much lower. The loss of snowpack and resulting changes on soil temperature will likely impact carbon cycling in subalpine ecosystems. However, a current gap in our knowledge is how the changes in the timing of snow cover will affect land-atmosphere fluxes of carbon dioxide in and out of subalpine ecosystems. Our study addresses this question through a field experiment including removing snow from plots to simulate both postponed snow cover and a season without lasting snow and measuring the fluxes of CO₂ throughout the season. We hypothesize that summer season CO₂ flux to the atmosphere will decrease in the snow removal plots because without snow, the colder temperatures will limit the amount of soil and root respiration. Our results suggest that the postponed snow cover reduces CO₂ flux to less than 3 µmols m^-2 s^-1 compared to the control and removal plots which both saw over 4 µmols m^-2 s^-1. This research is important because it will help us better understand how climate change will impact alpine ecosystems, and will help determine if subalpine ecosystems will contribute to positive and negative feedbacks within the carbon-climate system.

Mentor

Katharine Kelsey