Measuring Leaf Angle Distribution Using Terrestrial Laser Scanning in a European Beech Forest

2018 ◽  
Author(s):  
Jing Liu ◽  
Andrew K. Skidmore ◽  
Tiejun Wang ◽  
Xi Zhu ◽  
Joe Premier ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
European Beech ◽  
Beech Forest ◽  
Leaf Angle ◽  
Angle Distribution ◽  
Leaf Angle Distribution

Variation of leaf angle distribution quantified by terrestrial LiDAR in natural European beech forest

2019 ◽  
Vol 148 ◽  
pp. 208-220 ◽  
Author(s):  
Jing Liu ◽  
Andrew K. Skidmore ◽  
Tiejun Wang ◽  
Xi Zhu ◽  
Joe Premier ◽  
...  
Keyword(s):  
European Beech ◽  
Beech Forest ◽  
Leaf Angle ◽  
Angle Distribution ◽  
Terrestrial Lidar ◽  
Leaf Angle Distribution

scholarly journals Retrieving Corn Canopy Leaf Area Index from Multitemporal Landsat Imagery and Terrestrial LiDAR Data

2019 ◽  
Vol 11 (5) ◽  
pp. 572 ◽  
Author(s):  
Wei Su ◽  
Jianxi Huang ◽  
Desheng Liu ◽  
Mingzheng Zhang
Keyword(s):  
Laser Scanning ◽  
Landsat Imagery ◽  
Terrestrial Laser Scanning ◽  
Distribution Functions ◽  
Leaf Angle ◽  
Angle Distribution ◽  
Area Index ◽  
Leaf Angle Distribution ◽  
Modis Lai

Leaf angle is a critical structural parameter for retrieving canopy leaf area index (LAI) using the PROSAIL model. However, the traditional method using default leaf angle distribution in the PROSAIL model does not capture the phenological dynamics of canopy growth. This study presents a LAI retrieval method for corn canopies using PROSAIL model with leaf angle distribution functions referred from terrestrial laser scanning points at four phenological stages during the growing season. Specifically, four inferred maximum-probability leaf angles were used in the Campbell ellipsoid leaf angle distribution function of PROSAIL. A Lookup table (LUT) is generated by running the PROSAIL model with inferred leaf angles, and the cost function is minimized to retrieve LAI. The results show that the leaf angle distribution functions are different for the corn plants at different phenological growing stages, and the incorporation of derived specific corn leaf angle distribution functions distribute the improvement of LAI retrieval using the PROSAIL model. This validation is done using in-situ LAI measurements and MODIS LAI in Baoding City, Hebei Province, China, and compared with the LAI retrieved using default leaf angle distribution function at the same time. The root-mean-square error (RMSE) between the retrieved LAI on 4 September 2014, using the modified PROSAIL model and the in-situ measured LAI was 0.31 m2/m2, with a strong and significant correlation (R2 = 0.82, residual range = 0 to 0.6 m2/m2, p < 0.001). Comparatively, the accuracy of LAI retrieved results using default leaf angle distribution is lower, the RMSE of which is 0.56 with R2 = 0.76 and residual range = 0 to 1.0 m2/m2, p < 0.001. This validation reveals that the introduction of inferred leaf angle distributions from TLS data points can improve the LAI retrieval accuracy using the PROSAIL model. Moreover, the comparations of LAI retrieval results on 10 July, 26 July, 19 August and 4 September with default and inferred corn leaf angle distribution functions are all compared with MODIS LAI products in the whole study area. This validation reveals that improvement exists in a wide spatial range and temporal range. All the comparisons demonstrate the potential of the modified PROSAIL model for retrieving corn canopy LAI from Landsat imagery by inferring leaf orientation from terrestrial laser scanning data.

scholarly journals Influencing Factors in Estimation of Leaf Angle Distribution of an Individual Tree from Terrestrial Laser Scanning Data

2021 ◽  
Vol 13 (6) ◽  
pp. 1159
Author(s):  
Hailan Jiang ◽  
Ronghai Hu ◽  
Guangjian Yan ◽  
Shiyu Cheng ◽  
Fan Li ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Point Clouds ◽  
Leaf Angle ◽  
Normal Vector ◽  
Angle Distribution ◽  
Point Density ◽  
Lad Estimation ◽  
Leaf Angle Distribution ◽  
Occlusion Effect

Leaf angle distribution (LAD) is an important attribute of forest canopy architecture and affects the solar radiation regime within the canopy. Terrestrial laser scanning (TLS) has been increasingly used in LAD estimation. The point clouds data suffer from the occlusion effect, which leads to incomplete scanning and depends on measurement strategies such as the number of scans and scanner location. Evaluating these factors is important to understand how to improve LAD, which is still lacking. Here, we introduce an easy way of estimating the LAD using open source software. Importantly, the influence of the occlusion effect on the LAD was evaluated by combining the proposed complete point clouds (CPCs) with the simulated data of 3D tree models of Aspen, Pin Oak and White Oak. We analyzed the effects of the point density, the number of scans and the scanner height on the LAD and G-function. Results show that: (1) the CPC can be used to evaluate the TLS-based normal vector reconstruction accuracy without an occlusion effect; (2) the accuracy is slightly affected by the normal vector reconstruction method and is greatly affected by the point density and the occlusion effect. The higher the point density (with a number of points per unit leaf area of 0.2 cm−2 to 27 cm−2 tested), the better the result is; (3) the performance is more sensitive to the scanner location than the number of scans. Increasing the scanner height improves LAD estimation, which has not been seriously considered in previous studies. It is worth noting that relatively tall trees suffer from a more severe occlusion effect, which deserves further attention in further study.

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.

scholarly journals Evaluation of six leaf angle distribution functions in the Castillo® coffee variety

2017 ◽  
Vol 35 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Carlos Andrés Unigarro M. ◽  
Álvaro Jaramillo R. ◽  
Claudia Patricia Flórez R.
Keyword(s):  
Coffea Arabica ◽  
Regression Coefficient ◽  
Statistical Tests ◽  
Beta Function ◽  
Distribution Functions ◽  
Leaf Angle ◽  
Angle Distribution ◽  
Leaf Angle Distribution ◽  
Two Parameters ◽  
Coffea Arabica L

The study was conducted at the "Estación Central Naranjal Ce-nicafé" (National Coffee Research Center, Chinchina, Caldas, Colombia) on Coffea arábica L. variety Castillo® to find the leaf angle distribution function that best described the tilt of the angles present in the canopy. Leaf angles were recorded for 1,559 leaves located in the upper, middle and lower profiles of the canopy. The observed leaf angle distribution was compared with the Beta, ellipsoidal and four de Wit distribution functions. The fit between comparisons was determined by the Pearson X2 test and its significance, the regression coefficient statistically equal to one and the RMSE. Likewise, the leaf angle distribution recorded in the field per profile and their combination was described based on three angle classes (1stclass: 0°-30°; 2nd class: 30°-60°; and 3rd class: 60°-90°) according to the Goudriaan criterion. Generally, the leaf angle distribution present in the canopy of Castillo® coffee variety is adequately described by the Beta function with two parameters and the ellipsoidal function based on the adjustment provided by the statistical tests.

ORIENTATION OF SORBUS AUCUPARIA LEAVES BY THE RESULTS OF FIELD SURVEYS IN THE TERRITORY OF THE LENINGRAD REGION

2021 ◽  
Author(s):  
I. V. Matelenok ◽  
◽  
F. A. Alekseev ◽  
E. A. Evdokimova ◽  
◽  
...  
Keyword(s):  
Forest Canopy ◽  
Integral Function ◽  
Leaf Angle ◽  
Distribution Data ◽  
Leningrad Region ◽  
Angle Distribution ◽  
Office Work ◽  
Sorbus Aucuparia ◽  
Inclination Angles ◽  
Leaf Angle Distribution

Methods for retrieving leaf inclination angles in a forest canopy are considered. To acquire data on the orientation of Sorbus aucuparia leaves, a technique based on leveled camera digital photography well suited for conducting surveys in a boreal forest was used. In the course of field and office work, leaf angle distribution data for the specified species in the Priozersky district of the Leningrad region was obtained and analyzed. Values of the Ross-Nielson integral function were estimated.

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