scholarly journals A New Optical Instrument for Measuring Leaf area Index Based on a Canopy Gap Size Distribution Theory

1995 ◽  
Author(s):  
J M Chen
Keyword(s):  
Leaf Area Index ◽  
Size Distribution ◽  
Leaf Area ◽  
Distribution Theory ◽  
Canopy Gap ◽  
Gap Size ◽  
Optical Instrument ◽  
Area Index

A new method to estimate clumping index integrating gap fraction averaging with the analysis of gap size distribution

2019 ◽  
Vol 49 (5) ◽  
pp. 471-479 ◽  
Author(s):  
Francesco Chianucci ◽  
Jie Zou ◽  
Peng Leng ◽  
Yinguo Zhuang ◽  
Carlotta Ferrara
Keyword(s):  
Leaf Area Index ◽  
Size Distribution ◽  
Leaf Area ◽  
New Method ◽  
Gap Size ◽  
Area Index ◽  
Canopy Density ◽  
Gap Fraction ◽  
Direct Measurements ◽  
Clumping Index

Estimates of clumping index (Ω) are required to improve the indirect estimation of leaf area index (L) from optical field-based instruments such as digital hemispherical photography (DHP). A widely used method allows estimation of Ω from DHP using simple gap fraction averaging formulas (LX). This method is simple and effective but has the disadvantage of being sensitive to the spatial scale (i.e., the azimuth segment size in DHP) used for averaging and canopy density. In this study, we propose a new method to estimate Ω (LXG) based on ordered weighted gap fraction averaging (OWA) formulas, which addresses the disadvantages of LX and also accounts for gap size distribution. The new method was tested in 11 broadleaved forest stands in Italy; Ω estimated from LXG was compared with other commonly used clumping correction methods (LX, CC, and CLX). Results showed that LXG yielded more accurate Ω estimates, which were also more correlated with the values obtained from the gap size distribution methods (CC and CLX) than Ω obtained from LX. Leaf area index estimates, adjusted by LXG, are only 5%–6% lower than direct measurements obtained from litter traps, while other commonly used clumping correction methods yielded more underestimation.

Use of airborne lidar for estimating canopy gap fraction and leaf area index of tropical montane forests

2015 ◽  
Vol 36 (10) ◽  
pp. 2569-2583 ◽  
Author(s):  
Janne Heiskanen ◽  
Lauri Korhonen ◽  
Jesse Hietanen ◽  
Petri K.E. Pellikka
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Canopy Gap ◽  
Airborne Lidar ◽  
Montane Forests ◽  
Area Index ◽  
Tropical Montane Forests ◽  
Gap Fraction

Estimating Crop Leaf Area Index at Different Spatial Scales Based on Statistical Distribution Theory

2014 ◽  
Vol 12 (3) ◽  
pp. 599-608
Author(s):  
Jihua Wang ◽  
Yingying Dong ◽  
Haikuan Feng ◽  
Guijun Yang ◽  
Xingang Xu
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Spatial Scales ◽  
Distribution Theory ◽  
Statistical Distribution ◽  
Area Index

An improved theoretical model of canopy gap probability for Leaf Area Index estimation in woody ecosystems

2015 ◽  
Vol 358 ◽  
pp. 303-320 ◽  
Author(s):  
William Woodgate ◽  
Mathias Disney ◽  
John D. Armston ◽  
Simon D. Jones ◽  
Lola Suarez ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Canopy Gap ◽  
Area Index ◽  
Gap Probability ◽  
Index Estimation
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