Using eddy covariance observations to determine the carbon sequestration characteristics of subalpine forests in the Qinghai–Tibet Plateau
-
Published:2024-08-06
Issue:15
Volume:21
Page:3509-3522
-
ISSN:1726-4189
-
Container-title:Biogeosciences
-
language:en
-
Short-container-title:Biogeosciences
Author:
Zhu NiuORCID, Wang Jinniu, Luo DongliangORCID, Wang Xufeng, Shen Cheng, Wu Ning
Abstract
Abstract. Subalpine forests are a crucial component of the carbon cycling system in the Qinghai–Tibet Plateau (QTP). However, there are currently significant data gaps in the QTP, and it is essential to enhance continuous monitoring of forest carbon absorption processes in the future. This study investigates 2 years' carbon exchange dynamics of a subalpine forest on the QTP using an eddy covariance method. We first characterized the seasonal carbon dynamics of the subalpine forest, revealing the higher carbon dioxide (CO2) exchange rates in summer and autumn and lower rates in winter and spring, and found that autumn is the peak period for carbon sequestration in this subalpine forest, with the maximum measured value of CO2 absorption reaching 10.70 µmol m−2 s−1. Subsequently, we examined the environmental factors influencing the carbon sequestration function. Principal component analysis (PCA) shows that photosynthetically active radiation (PAR) was the major environmental factor driving the net ecosystem exchange (NEE) of CO2, significantly influencing forest carbon absorption, and the increase in relative humidity decreases the rate of carbon fixation. In addition, we explored NEE and its influencing factors at the regional scale and found that air temperature promotes carbon dioxide absorption (negative NEE values), while the average annual precipitation shows a minor effect on NEE. At the annual scale, the subalpine forest functions as a strong carbon sink, with an average NEE of −332 to −351 g C m−2 (from November 2020 to October 2022). Despite the challenges of climate change, forests remain robust carbon sinks with the highest carbon sequestration capacity in the QTP, with an average annual CO2 absorption rate of 368 g C m−2. This study provides valuable insights into the carbon cycling mechanism in subalpine ecosystems and the global carbon balance.
Funder
National Natural Science Foundation of China State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences West Light Foundation, Chinese Academy of Sciences
Publisher
Copernicus GmbH
Reference69 articles.
1. Acosta-Hernández, A. C., Padilla-Martínez, J. R., Hernández-Díaz, J. C., Prieto-Ruiz, J. A., Goche-Telles, J. R., Nájera-Luna, J. A., and Pompa-García, M.: Influence of Climate on Carbon Sequestration in Conifers Growing under Contrasting Hydro-Climatic Conditions, Forests, 11, 1134, https://doi.org/10.3390/f11111134, 2020. 2. Ataka, M., Kominami, Y., Sato, K., and Yoshimura, K.: Microbial Biomass Drives Seasonal Hysteresis in Litter Heterotrophic Respiration in Relation to Temperature in a Warm-Temperate Forest, J. Geophys. Res.-Biogeo., 125, e2020JG005729, https://doi.org/10.1029/2020JG005729, 2020. 3. Banbury Morgan, R., Herrmann, V., Kunert, N., Bond-Lamberty, B., Muller-Landau, H. C., and Anderson-Teixeira, K. J.: Global patterns of forest autotrophic carbon fluxes, Glob. Change Biol., 27, 2840–2855, https://doi.org/10.1111/gcb.15574, 2021. 4. Baumgartner, S., Barthel, M., Drake, T. W., Bauters, M., Makelele, I. A., Mugula, J. K., Summerauer, L., Gallarotti, N., Cizungu Ntaboba, L., Van Oost, K., Boeckx, P., Doetterl, S., Werner, R. A., and Six, J.: Seasonality, drivers, and isotopic composition of soil CO2 fluxes from tropical forests of the Congo Basin, Biogeosciences, 17, 6207–6218, https://doi.org/10.5194/bg-17-6207-2020, 2020. 5. Cai, W., He, N., Li, M., Xu, L., Wang, L., Zhu, J., Zeng, N., Yan, P., Si, G., and Zhang, X.: Carbon sequestration of Chinese forests from 2010 to 2060: Spatiotemporal dynamics and its regulatory strategies, Science Bull., 67, 836–843, https://doi.org/10.1016/j.scib.2021.12.012, 2022.
|
|