Quantitative analysis of the links between forest structure and land surface albedo on a global scale

Open access
Date
2020-09-01Type
- Journal Article
Citations
Cited 15 times in
Web of Science
Cited 16 times in
Scopus
ETH Bibliography
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Abstract
Forests are critical in regulating climate by altering the Earth's surface albedo. Therefore, there is an urgent need to enhance our knowledge about the effects of forest structure on albedo. Here, we present a global assessment of the links between forest structure and albedo at a 1-km spatial resolution using generalized additive models (GAMs). We used remotely sensed data to obtain variables representing forest structure, including forest density, leaf area index, and tree cover, during the peak growing season in 2005 with pure forest pixels that cover ~7% of the Earth's surface. Furthermore, we estimated black-sky albedo at a solar zenith angle of 38° using the most recent collection of the moderate resolution imaging spectroradiometer (MODIS; version 6) at shortwave, near-infrared, and visible spectral regions. In addition, for the first time, we mapped the magnitude of the relationship between forest structure and albedo at each pixel with a 0.5-degree spatial resolution. Our results suggested that forest structure may modulate albedo in most of the sub-biomes. The response of shortwave albedo was always positive to the leaf area index and negative to the tree cover (except for deciduous broadleaf forests in mediterranean and temperate regions), while the response to forest density varied across space in 2005. The spatial map affirmed that the links between forest structure and albedo vary over geographical locations. In sum, our study emphasized the importance of forest structure in the surface albedo regulation. This paper provides the first spatially explicit evidence of the magnitude of relationships between forest structure and albedo on a global scale. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000416241Publication status
publishedExternal links
Journal / series
Remote Sensing of EnvironmentVolume
Pages / Article No.
Publisher
ElsevierSubject
Albedo; Forest structure; Forest density; Tree cover; Leaf area indexOrganisational unit
09625 - Crowther, Thomas Ward / Crowther, Thomas Ward
Related publications and datasets
Is referenced by: https://doi.org/10.3929/ethz-b-000450969
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Show all metadata
Citations
Cited 15 times in
Web of Science
Cited 16 times in
Scopus
ETH Bibliography
yes
Altmetrics