Quantification of annual soil CO2 emission in unburned and burned black spruce forest of interior Alaska
Abstract
Estimation of annual soil CO2 emission is not simple due to the winter contribution. Further, change in the snow-covered period and frequency in measuring winter CO2 efflux leads to inadequately estimate the annual carbon budget. It is not easy to quantify the annual soil carbon emission in response to recently drastic changes of climate and environment in sub-Arctic and Arctic. Here, we report the research findings on the evaluation of winter carbon emission with 30-minute interval soil CO2 efflux-measurement in unburned and burned black spruce forest of interior Alaska from August 1 2015 to September 30 2016. 'Warm' and 'cold' seasons are defined by snow-free and snow-covered period monitored by the time-lapsed camera and growing and non-growing seasons by the soil temperature of 0 °C, respectively. Also, annual soil CO2 emission estimated from August 1 2015 to July 31 2016 and September 1 2015 to August 31 2016, respectively. As the results, The annual budgets of 'warm' and 'cold' seasons soil CO2 emissions in unburned and burned black spruce soils were 258.8 and 162.2 gC m-2 period-1 during August 1 2015 to July 31 2016, and were 268.2 and 165.2 gC m-2 period-1 during September 1 2015 and August 31 2016, respectively. There are not significant differences of soil CO2 effluxes between August 1 2015 to July 31 2016 and September 1 2015 and August 31 2016, based on a one-way ANOVA at the 95 % confidence level (p < 0.05). Cold season CO2 emissions in unburned and burned black spruce soils were 111.5 and 34.2 gC m-2 period-1 by the snow depth, and were 103.8 and 35.6 gC m-2 period-1 by the soil temperature, respectively. Cold season CO2 emissions in unburned black spruce soils contributed to 38.7 to 43.1 % of annual CO2 emission; on the other hand, cold season CO2 emissions contributed to 20.7 to 21.9 % of annual CO2 emission in burned black spruce soils. Higher winter carbon contribution to the annual budget in unburned black spruce forest may be due to much warm winter 2015/16. On the other hand, it is not distinct to discriminate winter carbon emission from burned black spruce forest soil to be higher or not due to changes in soil organic matter and soil microbial community by 2004 wildfire.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.B31E2495K
- Keywords:
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- 0428 Carbon cycling;
- BIOGEOSCIENCESDE: 0475 Permafrost;
- cryosphere;
- and high-latitude processes;
- BIOGEOSCIENCESDE: 0702 Permafrost;
- CRYOSPHEREDE: 1615 Biogeochemical cycles;
- processes;
- and modeling;
- GLOBAL CHANGE