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.

scholarly journals Simulations of Leaf BSDF Effects on Lidar Waveforms

2020 ◽  
Vol 12 (18) ◽  
pp. 2909
Author(s):  
Benjamin D. Roth ◽  
Adam A. Goodenough ◽  
Scott D. Brown ◽  
Jan A. van Aardt ◽  
M. Grady Saunders ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Radiative Transfer ◽  
Forest Canopy ◽  
Near Infrared ◽  
Difficult Problem ◽  
Leaf Angle ◽  
Lidar Data ◽  
Angle Distribution ◽  
Visible Wavelengths ◽  
Leaf Angle Distribution

Establishing linkages between light detection and ranging (lidar) data, produced from interrogating forest canopies, to the highly complex forest structures, composition, and traits that such forests contain, remains an extremely difficult problem. Radiative transfer models have been developed to help solve this problem and test new sensor platforms in a virtual environment. Many forest canopy studies include the major assumption of isotropic (Lambertian) reflecting and transmitting leaves or non-transmitting leaves. Here, we study when these assumptions may be valid and evaluate their associated impacts/effects on the lidar waveform, as well as its dependence on wavelength, lidar footprint, view angle, and leaf angle distribution (LAD), by using the Digital Imaging and Remote Sensing Image Generation (DIRSIG) remote sensing radiative transfer simulation model. The largest effects of Lambertian assumptions on the waveform are observed at visible wavelengths, small footprints, and oblique interrogation angles relative to the mean leaf angle. For example, a 77% increase in return signal was observed with a configuration of a 550 nm wavelength, 10 cm footprint, and 45° interrogation angle to planophile leaves. These effects are attributed to (i) the bidirectional scattering distribution function (BSDF) becoming almost purely specular in the visible, (ii) small footprints having fewer leaf angles to integrate over, and (iii) oblique angles causing diminished backscatter due to forward scattering. Non-transmitting leaf assumptions have the greatest error for large footprints at near-infrared (NIR) wavelengths. Regardless of leaf angle distribution, all simulations with non-transmitting leaves with a 5 m footprint and 1064 nm wavelength saw around a 15% reduction in return signal. We attribute the signal reduction to the increased multiscatter contribution for larger fields of view, and increased transmission at NIR wavelengths. Armed with the knowledge from this study, researchers will be able to select appropriate sensor configurations to account for or limit BSDF effects in forest lidar data.

scholarly journals Leaf angle distribution in Johnsongrass, leaf thickness in sorghum and Johnsongrass, and association with response to Colletotrichum sublineola

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ezekiel Ahn ◽  
Gary Odvody ◽  
Louis K. Prom ◽  
Clint Magill
Keyword(s):  
Protective Role ◽  
Leaf Thickness ◽  
Leaf Angle ◽  
Distribution Data ◽  
Post Inoculation ◽  
Pathogenicity Test ◽  
Angle Distribution ◽  
Basal Leaf ◽  
Leaf Angle Distribution

AbstractBasal leaf angle distribution was surveyed in twenty-one Johnsongrass cultivars near the end of the vegetative stage. The angles increased from the top to the bottom leaves, and compared to cultivated grain sorghums, the average angle was larger in Johnsongrass. When basal leaf angle distribution data were correlated with pathogenicity test data from excised-leaf assays for three isolates of Colletotrichum sublineola, the results showed a weak positive correlation between basal leaf angle and pathogenicity level in Johnsongrass. In order to investigate a protective role of leaf thickness to C. sublineola, leaf thickness was measured in three sorghum cultivars and one Johnsongrass cultivar at the 8-leaf-stage. Leaf thickness near the apex, near the base, and half-way between the two points were measured in the top four leaves of each plant. Thickness of leaf blade and midrib were recorded separately. Using an excised-leaf-assay, the three points were inoculated with C. sublineola, and pathogenicity level was recorded 4-days-post-inoculation. Results showed strong negative correlations between leaf midrib thickness and pathogenicity level in sorghum and Johnsongrass but not in leaf blades.

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.

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

Extension of the Optical Diffraction Analysis Technique for Estimating Forest Canopy Geometry.

1979 ◽  
Vol 27 (5) ◽  
pp. 575 ◽  
Author(s):  
DS Kimes ◽  
JA Smith ◽  
JK Berry
Keyword(s):  
Diffraction Analysis ◽  
Pinus Contorta ◽  
Forest Canopy ◽  
Optical Diffraction ◽  
Angle Distribution ◽  
Coordinate Transformations ◽  
Frequency Distributions ◽  
Analysis Technique ◽  
Inclination Angles

Optical diffraction analysis of in situ ground photographs has previously been used to estimate foliage angle distributions in grassland canopies. These canopies are typically characterized by a single component-leaves-and the foliage is highly linear in nature. In this paper, the diffraction technique is extended to a multicomponent forest canopy containing needles and branches. Additional convolution and coordinate transformations are used to estimate the branch and needle angle frequency distributions for top, middle, and base sections of two lodgepole pine (Pinus contorta) trees. The resulting distributions show that the branch inclination angles tend to increase as one proceeds to the tree tops. The needle inclination angle distribution was relatively constant for all layers, and it is believed that this distribution is characteristic of a large class of needle-bearing species.

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.

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