Abstract

Climate warming in high latitudes impacts CO2 sequestration of northern peatlands through the changes in both production and decomposition processes. The response of the net CO2 fluxes between ecosystems and the atmosphere to the climate change and weather anomalies can vary across the forest and non-forest peatlands. To better understand the differences in CO2 dynamics at forest and non-forest boreal peatlands induced by changes in environmental conditions the estimates of interannual variability of the net ecosystem exchange (NEE), total ecosystem respiration (TER) and gross primary production (GPP) was obtained at two widespread peatland ecosystems – paludified spruce forest and adjacent ombrotrophic bog in the southern taiga of west Russia using 6-year of paired eddy covariance flux measurements. The period of measurements (2015–2020) was characterized by both positive and negative annual and growing season air temperature and precipitation anomalies. Flux measurements showed that in spite of the lower growing season TER (332…339 gC∙m−2) and GPP (442…464 gC∙m−2) rates the bog had a lower NEE (−132…−108) than the forest excepting the warmest and the wettest year of the period and was a sink of atmospheric CO2 in the selected years while the forest was a CO2 sink or source between years depending on the environmental conditions. Growing season NEE at the forest site was between −142 and 28 gC∙m−2, TER between 1135 and 1366 gC∙m−2 and GPP between 1207 and 1462 gC∙m−2. Annual NEE at the forest was between −62 and 145 gC∙m−2, TER between 1429 and 1652 gC∙m−2 and GPP between 1345 and 1566 gC∙m−2 respectively. Anomalously warm winter with sparse and thin snow cover lead to the increased GPP as well as lower NEE in early spring at forest and to the increased spring TER at the bog. Also, the shifting of the compensation point to the earlier dates at the forest and to the later dates at the bog following the warmest winter of the period was detected. This study suggest that the warming in winter can increase CO2 uptake of the paludified spruce forests of southern taiga in non-growing season.

Highlights

  • CO2 net ecosystem exchange (NEE) between peatlands and the atmosphere is an important process of the 30 global carbon cycle controlling the terrestrial carbon stocks and influence the climate system (Gorham, 1991; Aurela et al, 2002; Wieder and Vitt, 2006)

  • 575 Six years of the paired eddy covariance CO2 flux measurements in 2015-2020 period showed that paludified spruce forest and adjacent ombrotrophic bog in southern taiga of west Russia have a different daily, growing season and annual NEE, total ecosystem respiration (TER) and gross primary production (GPP) as well as different response of the CO2 fluxes to changes in environmental conditions

  • In spite of the higher daily, growing season and annual TER and GPP rates at paludified forest (PF) site, ombrotrophic bog (OB) was a stronger sink of the atmospheric CO2 excepting the warmest and the 580 wettest year of the period (2020) when the growing season was followed by anomalously warm winter with sparse snow cover

Read more

Summary

Introduction

CO2 net ecosystem exchange (NEE) between peatlands and the atmosphere is an important process of the 30 global carbon cycle controlling the terrestrial carbon stocks and influence the climate system (Gorham, 1991; Aurela et al, 2002; Wieder and Vitt, 2006). With regard to the strong dependence of NEE on the environmental parameters variability, regional and site-specific features of the peatlands as well as its significant potential feedbacks to the climate system in response to the global warming (IPCC, 2014; Helbig et al, 2020; Loisel et al, 2021) the experimental estimates of the interannual variability of the ecosystem CO2 fluxes at different peatlands located in the same landscape are very useful to assess 70 the diversity of the possible effects of the weather anomalies and climate change on the ecosystem carbon dioxide exchange between the northern peatlands and the atmosphere (Lavoie et al, 2005; Ueyama et al, 2014; Park et al, 2021). The aim of the study was to analyze the interannual variability of NEE, TER and GPP at the ombrotrophic bog and paludified spruce forest located in the same landscape and to establish the response of CO2 fluxes on 90 interannual variability of environmental conditions using 6-years of paired eddy covariance flux measurements

Objectives
Methods
Results
Discussion
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call