DOI: 10.1016/j.foreco.2012.12.017
Scopus记录号: 2-s2.0-84872518425
论文题名: An assessment of ground reference methods for estimating LAI of boreal forests
作者: Majasalmi T. ; Rautiainen M. ; Stenberg P. ; Lukeš P.
刊名: Forest Ecology and Management
ISSN: 0378-1127
出版年: 2013
卷: 292 起始页码: 10
结束页码: 18
语种: 英语
英文关键词: Allometric models
; Foliage mass
; LAI-2000
; Shoot-level clumping correction
; Specific leaf area
Scopus关键词: Allometric method
; Allometric models
; Allometrics
; Best fit
; Boreal forests
; Canopy gap fractions
; Canopy radiation
; Coniferous forests
; Correction method
; Energy exchanges
; Finland
; Foliage biomass
; Foliage mass
; LAI-2000
; Land surface
; Leaf area
; Leaf Area Index
; Light transmittance
; Net primary production
; Norway spruce
; Optical methods
; Plant canopies
; Reference method
; Regression model
; Scots pine
; Silver birch
; Specific leaf area
; Stem diameter
; Tree species
; Estimation
; Plants (botany)
; Regression analysis
; Forestry
; allometry
; coniferous forest
; deciduous forest
; diameter
; ecological modeling
; energy flux
; foliage
; leaf area index
; net primary production
; optical method
; phytomass
; shoot
; transmittance
; Estimation
; Foliar Analysis
; Mathematical Models
; Regression Analysis
; Species Identification
; Finland
; Picea abies
; Pinus sylvestris
英文摘要: The amount of green leaf area, quantified by the leaf area index (LAI), is one of the key factors determining ecosystem net primary production and energy exchange between land surfaces and the atmosphere. LAI can be measured indirectly using optical methods that are based on the tight relationship between LAI and canopy light transmittance, or through allometric regression models. Until now there has been very little research to compare LAI estimated by the two different approaches. In this study we compare optically-based estimates of LAI to estimates produced using local foliage biomass models for three boreal tree species. Our study is based on 661 Scots pine, Norway spruce and Silver birch stands in the southern boreal zone in Finland. Routine stand inventory and LAI-2000 Plant Canopy Analyzer measurements were performed in all stands. We used three allometric foliage mass models to calculate foliage masses for each stand. The foliage mass estimates were then converted to LAI using specific leaf area (SLA) values. A theoretical stem diameter distribution was also used together with the only diameter-dependent foliage mass models. Optical LAI was corrected for shoot-level clumping (i.e., the clumping of needles into shoots). Finally, we estimated LAI from measured canopy gap fractions by inverting a canopy radiation model. Allometric foliage mass models produced significantly different foliage mass estimates (and the LAI estimates based on them). Among the allometric methods, however, the most sophisticated in terms of input tree variables agreed fairly well with each other and also with the clumping-corrected optical methods. The results indicate a need for caution when using foliage biomass or LAI estimates calculated using different models, especially if the estimates are to be used as an input for other models. The simple shoot-level clumping correction of optical LAI showed the best fit with allometric LAI. Our results support the use of a simple shoot-level clumping correction instead of more complicated correction methods in optical LAI estimation in coniferous forests. © 2012 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/66736
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Forest Sciences, University of Helsinki, P.O. Box 27, Helsinki FI-00014, Finland
Recommended Citation:
Majasalmi T.,Rautiainen M.,Stenberg P.,et al. An assessment of ground reference methods for estimating LAI of boreal forests[J]. Forest Ecology and Management,2013-01-01,292