熱帯海草藻場におけるブルーカーボン蓄積・フラックスの景観・サイトスケールの空間変動

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:熱帯海草藻場の炭素動態における空間的異質性の定量手法と、地形設定が炭素蓄積を説明しないという知見を提供する。

🏢実務担当者:ブルーカーボンクレジット創出を検討する企業は、単一地点の測定値ではなく空間的・時間的変動を考慮したMRV設計が必要であることを示唆する。

🏛政策担当者:ブルーカーボン認証制度の設計において、面積当たり一律の炭素蓄積係数ではなく、空間階層構造を反映したサンプリング・モデル枠組みの必要性を示す。

Seagrass meadows are emerging natural climate solutions for climate change mitigation through their high potential for organic carbon sequestration and storage, also known as blue carbon. However, the variability in current blue carbon stock and flux estimates is high, particularly at landscape scale. This knowledge gap highlights the need for evaluating blue carbon at spatial scales that are both locally robust and globally relevant. We quantified the magnitude of variability in blue carbon stocks and fluxes in tropical intertidal seagrass meadows at the site and landscape scales. We sampled within and across six intertidal seagrass meadows representing three geomorphic settings, including reef-associated settings dominated by Cymodocea spp., estuaries Halophila spp. and lagoons dominated by Thalassia spp., across Singapore. Within and across these sites, we measured soil organic carbon (C org ) stocks and greenhouse gas fluxes using the static chamber method. Tropical intertidal seagrass meadows stored 27.5±19.9 Mg C org ha −1 (mean ± SD) in the top 0–25 cm of soil, which varied significantly within sites (min–max: 5.1–78.9 Mg C org ha −1 , n =42). Plot-level mean fluxes averaged 27.5±25.3 mgm-2h-1 of CO 2 (min–max: −18.6 to 82.4, n =56) and 0.5±18.2 µgm-2h-1 of CH 4 (min–max: −66.4 to 57.5, n =56). Mixed-effects models indicated that geomorphic setting did not explain variation in 0–25 cm stocks or in CO 2 and CH 4 fluxes. Sensitivity analyses for 0–100 cm stocks showed a marginal geomorphology effect for measured-only totals ( p =0.074) that was not present after extrapolation to 100 cm ( p =0.816). In multivariate driver models, CO 2 flux was negatively associated with water temperature ( p =0.011) and showed an overall geomorphology effect ( p =0.027), while CH 4 drivers were not resolved (all p ≥0.158. Plot-level modelling further showed that CO 2 decreased with increasing 0–25 cm C org stock ( p =0.044), whereas CH 4 showed no association with C org stocks ( p =0.469). Overall, these results highlight strong spatial heterogeneity in tropical intertidal seagrass carbon dynamics and underscore the need for spatially and temporally explicit sampling and modelling frameworks that reflect nested spatial structure.

• openalex https://doi.org/10.5194/bg-23-6599-2026first seen 2026-09-23 05:03:58