Kelp dissolved organic carbon release is seasonal and annually enhanced during senescence

Kelp dissolved organic carbon release is seasonal and annually enhanced during senescence

© 2024 Phycological Society of America.

Bibliographische Detailangaben
Veröffentlicht in:Journal of phycology. - 1966. - 60(2024), 4 vom: 20. Aug., Seite 980-1000
1. Verfasser: Carlson, Andrew Kalani (VerfasserIn)
Weitere Verfasser: Yoshimura, Takeshi, Kudo, Isao
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2024
Zugriff auf das übergeordnete Werk:Journal of phycology
Schlagworte:Journal Article Research Support, Non-U.S. Gov't dissolved organic carbon kelp light macroalgae seasonal variability Carbon 7440-44-0
Beschreibung
Zusammenfassung:© 2024 Phycological Society of America.
Macroalgae influence local and global biogeochemical cycles through their production of dissolved organic carbon (DOC). Yet, data remain scarce and annualized estimates are typically based on high growth periods without considering seasonal variability. Although the mechanisms of active exudation and passive leakage need clarifying, ecophysiological stress is known to enhance DOC release. Therefore, DOC leakage from seasonally senescent macroalgae may be overlooked. This study focuses on the annual kelp Saccharina japonica var. religiosa (class Phaeophyceae) from Oshoro Bay, Hokkaido, Japan. Three years (2020-2022) of seasonal data were collected and analyzed, with least squares mean DOC release rates established for kelp (n = 88) across 16 incubation experiments (t ≥ 4 d, DOC samples ≥1 · d-1) under different photosynthetically active radiation (PAR) treatments (200, 400, 1200, or 1500 μmol photons · m-2 · s-1). Differences in PAR, dry weight biomass (g DW), sea surface temperature, or salinity could not explain DOC release-rate variability, which was high between individual kelp. Instead, there were significant intra-annual differences, with mean DOC release rates (mg C · g-1 DW · d-1 ± standard error between n kelp) higher during the autumn "late decay" period (0.71 ± 0.10, n = 27) compared to the winter "early growth" period (0.14 ± 0.025, n = 10) and summer "early decay" period (0.25 ± 0.050, n = 24). This relationship between seasonal senescence and macroalgal DOC release is further evidence that long-term, place-based studies of DOC dynamics are essential and that global extrapolations are premature
Beschreibung:Date Completed 26.08.2024
Date Revised 24.10.2024
published: Print-Electronic
Citation Status MEDLINE
ISSN:1529-8817
DOI:10.1111/jpy.13483