新しい衛星マッピングで熱帯樹木の喪失を17%過小評価していたことが判明(New Satellite Mapping Reveals Tropical Tree Cover Losses Underestimated by 17%)

ad

2025-07-07 中国科学院(CAS)

新しい衛星マッピングで熱帯樹木の喪失を17%過小評価していたことが判明(New Satellite Mapping Reveals Tropical Tree Cover Losses Underestimated by 17%)
Pan-tropical high-resolution tree cover map. (Image by AIR)

新たな研究により、世界の森林モニタリングでは熱帯地域の樹木被覆の17.31%、約3億9590万ヘクタールが見落とされていたことが明らかになった。中国科学院・空間情報研究所の王立教授らの国際研究チームは、5メートル未満の高解像度衛星画像と自動アルゴリズムを用いて2015~2022年の熱帯域を解析し、総計6105万ヘクタールの樹木喪失を記録。樹木損失の36.07%は農地や都市部など非森林地域に集中し、従来の10メートル解像度データでは捉えきれなかった。伐採や農地転換など人為的要因が56.03%を占める一方、増加分は降水増による43.98%に過ぎない。研究チームは、散在する樹木の喪失が気候緩和や生態系の回復に深刻な影響を及ぼすと警告し、政策決定者に対し、非森林樹木も保全対象に含めるよう呼びかけている。

<関連情報>

これまで発見されていなかった樹木をマッピングすることで、見過ごされていた全熱帯の樹木被覆の変化が明らかになった Mapping previously undetected trees reveals overlooked changes in pan-tropical tree cover

Shidong Liu,Jie Zhang,Li Wang,Philippe Ciais,Jianjun Zhang,Josep Penuelas,Biswajit Nath,Iskid Jacquet,Xia Wu,Shengping Ding,Wang Li,Ni Huang,Wanjuan Song,WenJian Ni & Zheng Niu
Nature Communications  Published:01 July 2025
DOI:https://doi.org/10.1038/s41467-025-60662-z

Abstract

Detecting tree cover is crucial for sustainable land management and climate mitigation. Here we develop an automatic detection algorithm using high-resolution satellite data (<5 m) to map pan-tropical tree cover (2015–2022), enabling identification and change analysis for previously undetected tree cover (PUTC). Our findings reveal that neglecting PUTC represents 17.31 ± 1.78% of the total pan-tropical tree cover. Tree cover net decreased by 61.05 ± 2.36 Mha in both forested areas (63.93%) and non-forested areas (36.07%) between 2015 and 2022. Intense changes in tree cover are primarily observed in regions with PUTC, where the World Cover dataset with a resolution of 10 m often fails to accurately detect tree cover. We also conduct a sensitivity analysis to quantify the contributions f climate factors and anthropogenic impacts (including human activities and land use cover change) to tree cover dynamics. Our findings indicate that 43.98% of tree cover gain is linked to increased precipitation, while 56.03% of tree cover loss is associated with anthropogenic impacts. These findings highlight the need to include undetected tree cover in strategies combating degradation, climate change, and promoting sustainability. Fine-scale mapping can improve biogeochemical cycles modeling and vegetation-climate interactions, improving global change understanding.

1904環境影響評価
ad
ad
Follow
ad
タイトルとURLをコピーしました