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西非撒哈拉和萨赫勒地区的树木数量出乎意料
Martin Brandt1,2, Compton J Tucker3, Ankit Kariryaa4,5
1Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark. mabr@ign.ku.dk.
Nature
|October 15, 2020
概括
森林以外的旱地树木对生物多样性和生态系统服务至关重要. 这项研究绘制了西非18亿棵树的地图,
科学领域:
- 生态学
- 遥感技术
- 环境科学
背景情况:
- 森林以外的树木对生物多样性和生态系统服务至关重要,但没有充分记录.
- 干旱地区的孤立树木扮演着重要的角色,
- 了解TOF分布是解决荒漠化,气候变化和贫困的关键.
研究的目的:
- 绘制西非130万平方公里的树冠大小和树木密度.
- 分析从超干旱到亚湿区的降雨梯度上的树木分布.
- 通过量化树木的存在,
主要方法:
- 使用次米分辨率卫星图像进行全面的地面覆盖.
- 应用深度学习算法来检测和绘制大于3平方米的单个树冠.
- 在不同气候区的树木密度和树冠覆盖量.
主要成果:
- 检测到超过18亿个单独的树木, 平均树冠大小为12平方米.
- 观察到树冠覆盖率从超干旱地区的0.1%增加到亚湿地区的13.3%.
- 在沙漠地区发现了令人惊的高树密度,
结论:
- 孤立的树木在干旱地区比以前更为普遍, 发挥着重要的生态作用.
- 这些发现为全球TOF监测提供了可扩展的方法.
- 这项研究强调了TOF在减轻环境退化和支持生计方面的潜力.
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