Nongrowing Season CO2 Emissions Determine the Distinct Carbon Budgets of Two Alpine Wetlands on the Northeastern Qinghai-Tibet Plateau

NWIPB OpenIR

	Nongrowing Season CO2 Emissions Determine the Distinct Carbon Budgets of Two Alpine Wetlands on the Northeastern Qinghai-Tibet Plateau
	Song, CG; Luo, FL; Zhang, LL; Yi, LB; Wang, CY; Yang, YS; Li, JX; Chen, KL; Wang, WY; Li, YN; Zhang, FW
	2021
发表期刊	ATMOSPHERE
卷号	12 期号:12
摘要	Alpine wetlands sequester large amounts of soil carbon, so it is vital to gain a full understanding of their land-atmospheric CO2 exchanges and how they contribute to regional carbon neutrality; such an understanding is currently lacking for the Qinghai-Tibet Plateau (QTP), which is undergoing unprecedented climate warming. We analyzed two-year (2018-2019) continuous CO2 flux data, measured by eddy covariance techniques, to quantify the carbon budgets of two alpine wetlands (Luanhaizi peatland (LHZ) and Xiaobohu swamp (XBH)) on the northeastern QTP. At an 8-day scale, boosted regression tree model-based analysis showed that variations in growing season CO2 fluxes were predominantly determined by atmospheric water vapor, having a relative contribution of more than 65%. Variations in nongrowing season CO2 fluxes were mainly controlled by site (categorical variable) and topsoil temperature (T-s), with cumulative relative contributions of 81.8%. At a monthly scale, structural equation models revealed that net ecosystem CO2 exchange (NEE) at both sites was regulated more by gross primary productivity (GPP), than by ecosystem respiration (RES), which were both in turn directly controlled by atmospheric water vapor. The general linear model showed that variations in nongrowing season CO2 fluxes were significantly (p < 0.001) driven by the main effect of site and T-s. Annually, LHZ acted as a net carbon source, and NEE, GPP, and RES were 41.5 +/- 17.8, 631.5 +/- 19.4, and 673.0 +/- 37.2 g C/(m(2) year), respectively. XBH behaved as a net carbon sink, and NEE, GPP, and RES were -40.9 +/- 7.5, 595.1 +/- 15.4, and 554.2 +/- 7.9 g C/(m(2) year), respectively. These distinctly different carbon budgets were primarily caused by the nongrowing season RES being approximately twice as large at LHZ (p < 0.001), rather than by other equivalent growing season CO2 fluxes (p > 0.10). Overall, variations in growing season CO2 fluxes were mainly controlled by atmospheric water vapor, while those of the nongrowing season were jointly determined by site attributes and soil temperatures. Our results highlight the different carbon functions of alpine peatland and alpine swampland, and show that nongrowing season CO2 emissions should be taken into full consideration when upscaling regional carbon budgets. Current and predicted marked winter warming will directly stimulate increased CO2 emissions from alpine wetlands, which will positively feedback to climate change.
收录类别	SCIE
文献类型	期刊论文
条目标识符	http://210.75.249.4/handle/363003/61337
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	Song, CG,Luo, FL,Zhang, LL,et al. Nongrowing Season CO2 Emissions Determine the Distinct Carbon Budgets of Two Alpine Wetlands on the Northeastern Qinghai-Tibet Plateau[J]. ATMOSPHERE,2021,12(12).
APA	Song, CG.,Luo, FL.,Zhang, LL.,Yi, LB.,Wang, CY.,...&Zhang, FW.(2021).Nongrowing Season CO2 Emissions Determine the Distinct Carbon Budgets of Two Alpine Wetlands on the Northeastern Qinghai-Tibet Plateau.ATMOSPHERE,12(12).
MLA	Song, CG,et al."Nongrowing Season CO2 Emissions Determine the Distinct Carbon Budgets of Two Alpine Wetlands on the Northeastern Qinghai-Tibet Plateau".ATMOSPHERE 12.12(2021).