scholarly journals New estimates of leaf angle distribution from terrestrial LiDAR: Comparison with measured and modelled estimates from nine broadleaf tree species

2019 ◽  
Vol 264 ◽  
pp. 322-333 ◽  
Author(s):  
Matheus Boni Vicari ◽  
Jan Pisek ◽  
Mathias Disney
Keyword(s):  
Tree Species ◽  
Leaf Angle ◽  
Angle Distribution ◽  
Terrestrial Lidar ◽  
Broadleaf Tree ◽  
Leaf Angle Distribution

scholarly journals Leaf Segmentation Based on k-Means Algorithm to Obtain Leaf Angle Distribution Using Terrestrial LiDAR

2019 ◽  
Vol 11 (21) ◽  
pp. 2536 ◽  
Author(s):  
Kuangting Kuo ◽  
Kenta Itakura ◽  
Fumiki Hosoi
Keyword(s):  
Canopy Structure ◽  
Field Measurements ◽  
Leaf Angle ◽  
Angle Distribution ◽  
Angle Estimation ◽  
Terrestrial Lidar ◽  
Common Solution ◽  
Segmentation Approach ◽  
Leaf Angle Distribution ◽  
Leaf Segmentation

It is critical to take the variability of leaf angle distribution into account in a remote sensing analysis of a canopy system. Due to the physical limitations of field measurements, it is difficult to obtain leaf angles quickly and accurately, especially with a complicated canopy structure. An application of terrestrial LiDAR (Light Detection and Ranging) is a common solution for the purposes of leaf angle estimation, and it allows for the measurement and reconstruction of 3D canopy models with an arbitrary volume of leaves. However, in most cases, the leaf angle is estimated incorrectly due to inaccurate leaf segmentation. Therefore, the objective of this study was an emphasis on the development of efficient segmentation algorithms for accurate leaf angle estimation. Our study demonstrates a leaf segmentation approach based on a k-means algorithm coupled with an octree structure and the subsequent application of plane-fitting to estimate the leaf angle. Furthermore, the accuracy of the segmentation and leaf angle estimation was verified. The results showed average segmentation accuracies of 95% and 90% and absolute angular errors of 3° and 6° in the leaves sampled from mochi and Japanese camellia trees, respectively. It is our conclusion that our method of leaf angle estimation has high potential and is expected to make a significant contribution to future plant and forest research.

scholarly journals EXTRACTION OF LEAF ANGLE DISTRIBUTION FROM AN INDIVIDUAL BROADLEAF TREE USING TERRESTRIAL LASER SCANNING DATA

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 957-962
Author(s):  
Y. Chen ◽  
Z. Liu ◽  
W. Zhang ◽  
C. Qiao ◽  
H. Gu
Keyword(s):  
Field Measurement ◽  
Point Cloud ◽  
Structural Parameters ◽  
Leaf Angle ◽  
Structural Parameter ◽  
Angle Distribution ◽  
Area Index ◽  
Broadleaf Tree ◽  
Leaf Angle Distribution ◽  
Leaf Segmentation

<p><strong>Abstract.</strong> The angular distribution of leaves is a key vegetation structural parameter for evaluating the reflection and transmission of solar radiation through vegetation canopies. Accurate extraction of Leaf Angle Distribution (LAD) is of great importance in estimating other vegetation structural parameters such as the canopy clumping and leaf area index. However, field measurement of LAD is time-consuming, labour-intensive and subjective. In most studies, LAD is assumed to follow the spherical distribution assumption within canopy which may lead to considerable errors. To address this issue, we proposed a new approach for leaf segmentation and LAD measurement of individual broadleaf tree based on the TLS point cloud data. Based on the point density, point continuity and the distribution of intensity in the point cloud, this approach provides a fast and accurate leaf segmentation and LAD extraction strategy. Results of this TLS-based LAD method compared well with that extracted by the field measurement and the MDI-based method. This strategy shows its potential and applicability in accurate LAD measurement and LAI estimation.</p>

scholarly journals The leaf angle distribution of natural plant populations: assessing the canopy with a novel software tool

Plant Methods ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 11 ◽  
Author(s):  
Mark Müller-Linow ◽  
Francisco Pinto-Espinosa ◽  
Hanno Scharr ◽  
Uwe Rascher
Keyword(s):  
Software Tool ◽  
Leaf Angle ◽  
Angle Distribution ◽  
Plant Populations ◽  
Natural Plant ◽  
Leaf Angle Distribution

Estimating Leaf Angle Distribution From Smartphone Photographs

2019 ◽  
Vol 16 (8) ◽  
pp. 1190-1194 ◽  
Author(s):  
Jianbo Qi ◽  
Donghui Xie ◽  
Linyuan Li ◽  
Wuming Zhang ◽  
Xihan Mu ◽  
...  
Keyword(s):  
Leaf Angle ◽  
Angle Distribution ◽  
Leaf Angle Distribution

scholarly journals Estimating Crown Structure Parameters of Moso Bamboo: Leaf Area and Leaf Angle Distribution

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 686 ◽  
Author(s):  
Xuhan Wu ◽  
Weiliang Fan ◽  
Huaqiang Du ◽  
Hongli Ge ◽  
Feilong Huang ◽  
...  
Keyword(s):  
Leaf Area ◽  
Tree Height ◽  
Moso Bamboo ◽  
Leaf Angle ◽  
Angle Distribution ◽  
Angle Measurements ◽  
Crown Structure ◽  
Leaf Angle Distribution ◽  
Carbon Balances ◽  
Two Parameters

Both leaf area (LA) and leaf angle distribution are the most important eco-physiological measures of tree crowns. However, there are limited published investigations on the two parameters of Moso bamboo (Phyllostachys edulis (Carrière) J. Houz., abbreviated as MB). The aim of this study was to develop allometric equations for predicting crown LA of MB by taking the diameter at breast height (DBH) and tree height (H) as predictors and to investigate the leaf angle distribution of a MB crown based on direct leaf angle measurements. Data were destructively sampled from 29 MB crowns including DBH, H, biomass and the area of sampled leaves, biomass of total crown leaves, and leaf angles. The results indicate that (1) the specific leaf area (SLA) of a MB crown decreases from the bottom to the top; (2) the vertical LA distribution of MB crowns follow a “Muffin top” shape; (3) the LA of MB crowns show large variations, from 7.42 to 74.38 m2; (4) both DBH and H are good predictors in allometry-based LA estimations for a MB crown; (5) linear, exponential, and logarithmic regressions show similar capabilities for the LA estimations; (6) leaf angle distributions from the top to the bottom of a MB crown can be considered as invariant; and (7) the leaf angle distribution of a MB crown is close to the planophile case. The results provide an important tool to estimate the LA of MB on the standing scale based on DBH or H measurements, provide useful prior knowledge for extracting leaf area indexes of MB canopies from remote sensing-based observations, and, therefore, will potentially serve as a crucial reference for calculating carbon balances and other ecological studies of MB forests.

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