Effects of the lunar cycle on ecosystem and heterotrophic respiration in a boreal Sphagnum-dominated peatland

ABSTRACT

The growth of Sphagnum is influenced by the lunar cycle, which suggests a corresponding carbon (C) accumulation rhythm in peatlands. However, this rhythm can only occur if C accumulation from Sphagnum growth is not offset by its total losses through respiration and other processes. To address the uncertainty, through correlation-regression analysis we examine the influence of the lunar cycle on recent measurements of ecosystem (ER) and heterotrophic (Rh) respiration conducted by Järveoja and colleagues on the oligotrophic peatland of Degerö Stormyr. We found that ER and Rh accelerated near the full moon and slowed down near the new moon. The response of the hourly ER to the lunar cycle is significant from 22:00 to 8:00 and is not significant beyond this range. This response was concentrated in the initial and finished phases of the season, but during the middle of the season it disappeared. This behavior could potentially be caused by the high sensitivity of the Sphagnum cover to moonlight, as well as the sensitivity to the lunar cycle of only the nocturnal component ER. During most of the day, the lunar cycle had a significant effect on hourly Rh, with the highest impact observed between 5:00 and 10:00 and at 20:00. The greatest impact occurs during those hours when ER declines, and possibly Sphagnum photosynthetic productivity peaks. The findings suggest a circalunar rhythm of C accumulation in peatlands due to the opposite trends between C accumulation during Sphagnum growth and C losses with respiration during the lunar cycle.

KEYWORDS:

• Peatlands
• heterotrophic respiration
• ecosystem respiration
• Sphagnum
• lunar cycle
• carbon cycle

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

The conception and design of the study were developed by VLM. Data preparation and analysis were performed by VLM. The first draft of the manuscript was written by VLM, with contribution from EVL. VLM and EVL contributed to the revised manuscript. VLM and EVL read and approved the final manuscript.

Data availability statement

The datasets analysed during the current study are available in the Figshare digital repository, https://doi.org/10.6084/m9.figshare.12730949.v1.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/07420528.2024.2365825.

Additional information

Funding

The study was supported by the research project [FMEN-2022-0018] of the Karelian Research Centre RAS (Department of Multidisciplinary Scientific Research).