Carbon fluxes and environmental controls across different alpine grassland types on the Tibetan Plateau

Yuyang Wang, Jingfeng Xiao, Yaoming Ma, Yiqi Luo, Zeyong Hu, Fu Li, Yingnian Li, Lianglei Gu, Zhaoguo Li, Ling Yuan

Research output: Contribution to journalArticlepeer-review

Abstract

The magnitude and spatial patterns of carbon fluxes in alpine grasslands determine the regional terrestrial carbon balance of the Tibetan Plateau. However, the patterns and controlling factors of carbon fluxes on the plateau remain unclear, hampering the understanding of the carbon cycle of these vulnerable ecosystems. In this study, we compared the spatial variations of carbon fluxes of ten alpine ecosystems with diverse grassland types and explored their environmental controls across these different ecosystems. Our results show that the mean annual net ecosystem exchange (NEE) of carbon dioxide (CO2) varied from -284 to 31 g C m−2 across sites. The alpine meadow ecosystems in the northeast and east of the plateau were strong CO2 sinks (∼x223C 200 g C m−2 y−1), while the western alpine grasslands were weak CO2 sinks or even sources. During the growing season, soil temperature generally played the dominant role in regulating the daily variations of the carbon fluxes for the alpine meadow ecosystems in the cold and humid northeastern areas, while soil moisture was the main controlling factor for the alpine grassland ecosystems in the dry western areas. Annual gross primary productivity (GPP), ecosystem respiration (Re) and the carbon sink capacity linearly increased with the increasing longitude but linearly decreased with elevation. The spatial pattern of annual NEE was primarily controlled by surface soil moisture, and higher soil water content (SWC) led to greater carbon sink capacity. SWC, vapor pressure deficit (VPD) also had favorable effects on the annual GPP and Re. The spatial variations of carbon fluxes resulted primarily from the longitudinal or altitudinal variations of the dominant environmental factors. This study provides guidance for the assessment of carbon fluxes on the Tibetan Plateau.

Original languageEnglish (US)
Article number108694
JournalAgricultural and Forest Meteorology
Volume311
DOIs
StatePublished - Dec 15 2021

Keywords

  • Alpine meadow
  • Alpine steppe
  • Carbon sink
  • Eddy covariance
  • Environmental drivers
  • Spatial pattern
  • Tibetan Plateau

ASJC Scopus subject areas

  • Global and Planetary Change
  • Forestry
  • Agronomy and Crop Science
  • Atmospheric Science

Fingerprint

Dive into the research topics of 'Carbon fluxes and environmental controls across different alpine grassland types on the Tibetan Plateau'. Together they form a unique fingerprint.

Cite this