DOI: 10.1016/j.jag.2016.07.001
Scopus记录号: 2-s2.0-84997840804
论文题名: Multidecadal analysis of forest growth and albedo in boreal Finland
作者: Lukeš P ; , Stenberg P ; , Mõttus M ; , Manninen T ; , Rautiainen M
刊名: International Journal of Applied Earth Observation and Geoinformation
ISSN: 15698432
出版年: 2016
卷: 52 起始页码: 296
结束页码: 305
语种: 英语
英文关键词: Albedo
; fAPAR
; Forest structure
; LAI
; NDVI
; Seasonal trends
; Time series
Scopus关键词: albedo
; boreal forest
; growth rate
; leaf area index
; NDVI
; seasonal variation
; time series
; Finland
英文摘要: It is well known that forests serve as carbon sinks. However, the balancing effect of afforestation and increased forest density on global warming due to carbon storage may be lost by low albedo (thus high absorption) of the forests. In the last 30 years, there has been a steady increase in the growing stock of Finnish forests by nearly a quarter while the area of the forests has remained virtually unchanged. Such increase in forest density together with the availability of detailed forest inventories provided by the Multi-Source National Forest Inventory (MS-NFI) in high spatial resolution makes Finland an ideal candidate for exploring the effects of increased forest density on satellite derived estimates of bio-geochemical products e.g. albedo (directional-hemispherical reflectance, DHR), fraction of photosynthetically active radiation absorbed by canopies (fAPAR), leaf area index (LAI) and normalized difference vegetation index (NDVI) in both current and long-term perspective. In this study, we first used MODIS-based vegetation satellite products for Finnish forests to study their seasonal patterns and interrelations. Next, the peak growing season observations are linked to the MS-NFI database to yield the generic relationships between forest density and the satellite-derived vegetation indicators. Finally, long-term GIMMS3g datasets between 1982 and 2011 (2008 for DHR) are analyzed and interpreted using forest inventory data. The vegetation peak growing season NIR DHR and VIS DHR showed weak to moderate negative correlation with fAPAR, whereas there was no correlation between NIR DHR and fAPAR. Next, we show that the spectral albedos in the near-infrared region (NIR DHR) showed weak negative correlation with forest biomass, basal area or canopy cover whereas, as expected, the spectral albedo in the visible region (VIS DHR) correlated negatively with these measures of forest density. Interestingly, the increase in forest density (biomass per ha) of Finnish forests during the last 30 years was not accompanied by trends in the indicators of vegetation ‘greenness’ and photosynthetic productivity (fAPAR, LAI and NDVI) or in forest albedo (DHR). Even though there were small increases in both DHR, fAPAR, LAI and NDVI and from the start to the end of the study period (1982–2011), the pattern and magnitude of change in these variables did not follow the development of forest biomass in the different NFI inventories. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/80022
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Forest Sciences, University of Helsinki, PO BOX 27, Helsinki, Finland; Global Change Research Institute, Academy of Sciences of the Czech Republic, Bělidla 4a, Brno, Czech Republic; Department of Geosciences and Geography, University of Helsinki, P.O. Box 68, Helsinki, Finland; Finnish Meteorological Institute, P.O. Box 503, Helsinki, Finland; Aalto University, School of Engineering, Department of Built Environment, P.O. Box 15800, Aalto, Finland; Aalto University, School of Electrical Engineering, Department of Radio Science and Engineering, P.O. Box 13000, Aalto, Finland
Recommended Citation:
Lukeš P,, Stenberg P,, Mõttus M,et al. Multidecadal analysis of forest growth and albedo in boreal Finland[J]. International Journal of Applied Earth Observation and Geoinformation,2016-01-01,52