Impact of meteorological variability on diurnal and seasonal net ecosystem productivity in a desert riparian forest ecosystem

Dexiong Teng; Xuewei Gong; Xuemin He; Jingzhe Wang; Guanghui Lv; Jinlong Wang; Xiaodong Yang

doi:10.3389/fpls.2024.1332192

Impact of meteorological variability on diurnal and seasonal net ecosystem productivity in a desert riparian forest ecosystem

Front Plant Sci. 2024 Apr 18:15:1332192. doi: 10.3389/fpls.2024.1332192. eCollection 2024.

Authors

Dexiong Teng¹, Xuewei Gong¹, Xuemin He^{2

3}, Jingzhe Wang⁴, Guanghui Lv^{2

3}, Jinlong Wang^{2

3}, Xiaodong Yang⁵

Affiliations

¹ CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
² College of Ecology and Environment, Xinjiang University, Urumqi, China.
³ Xinjiang Jinghe Observation and Research Station of Temperate Desert Ecosystem, Ministry of Education, Urumqi, China.
⁴ School of Artificial Intelligence, Shenzhen Polytechnic University, Shenzhen, China.
⁵ Department of Geography & Spatial Information Technology, Ningbo University, Ningbo, China.

Abstract

The desert riparian forests are susceptible to meteorological changes and contribute significantly to the net ecosystem productivity (NEP) variations of arid ecosystems. However, the responsive patterns of their NEP variations to the meteorological variabilities remain inadequately comprehended. To address this gap, we utilized seven years of eddy covariance flux measurements in a representative desert riparian forest to investigate the NEP variations and its response to changing meteorological factors across diverse temporal scales. The results revealed significant periodic variations in half-hourly NEP, with dominant cycles spanning from five hours to one year, with a principal oscillation period of one day. Key meteorological factors including global solar radiation (Rg), relative humidity (RH), air temperature (Ta), soil temperature (Ts), and vapor pressure deficit (VPD) exhibited synchronization with NEP on daily scales. This synchronization, coupled with the observed one-day periodic NEP variations, provides robust evidence supporting the existence of a circadian rhythm in the ecosystem carbon exchange of desert riparian forest regulated by meteorological conditions. Seasonal patterns were significant in the impact of Rg phase, Ta diurnal amplitude, and VPD diurnal amplitude on NEP diurnal amplitude and phase. The NEP diurnal amplitude significantly, directly, and positively affected daily NEP in both the dormant and growing seasons, whereas its phase yielded significant negative effects (P< 0.05). The averages, amplitudes, and phases of diurnal meteorological conditions controlled the daily NEP by regulating NEP diurnal amplitude and phase. These findings provide evidence that the variability in circadian rhythms, caused by the increase in diurnal Ta and VPD, significantly impact the daily NEP at an ecosystem scale. This study enriches our comprehension of the meteorological mechanisms governing diurnal and seasonal carbon uptake dynamics within desert riparian forests, providing fresh insights into the direct and indirect roles of climate change in shaping patterns of ecosystem carbon exchange.

Keywords: arid ecosystem; carbon flux; circadian regulation; eddy covariance; structure equation model.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was financially supported by the China Postdoctoral Science Foundation (2023M733672), the Postdoctoral Research Startup Foundation for Postdoc of Liaoning Province of China (2022-BS-022), Key R&D Program of Liaoning Province (2023JH2/101800043), the Guangdong Basic and Applied Basic Research Foundation (2023A1515011273), the Basic Research Program of Shenzhen (20220811173316001), and Specific Innovation Program of the department of Education of Guangdong Province (2023KTSCX315).