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Journal articles on the topic 'Tree crown'

Author: Grafiati

Published: 4 June 2021

Last updated: 26 July 2025

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1

Clatterbuck, Wayne K., Tyler M. L. Brannon, and Edward C. Yost. "Branch Elongation, Bud Durability, and Wind-Generated Crown Movement Associated with Crown Abrasion in Deciduous Trees." Forests 15, no. 2 (2024): 247. http://dx.doi.org/10.3390/f15020247.

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Trees that grow in close proximity to other trees are subject to crown and branch abrasion, causing mechanical injury. The loss of branch tips and buds through abrasion can affect the architecture and growth of tree crowns. This research quantifies the impacts of crown abrasion between neighboring trees of several deciduous species and how crown abrasion may influence stand dynamics. Tree interactions were evaluated during the dormant and growing seasons to determine how wind-generated movement affects crowns under foliated and un-foliated conditions. Branch elongation was measured in tree cro

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2

Tahar, K. N., M. A. Asmadin, S. A. H. Sulaiman, N. Khalid, A. N. Idris, and M. H. Razali. "Individual Tree Crown Detection Using UAV Orthomosaic." Engineering, Technology & Applied Science Research 11, no. 2 (2021): 7047–53. http://dx.doi.org/10.48084/etasr.4093.

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Unmanned Aerial Vehicles (UAVs) are increasingly used in forestry as they are economical and flexible. This study aims to present the advantages of the drone photogrammetry method in collecting individual tree crowns, as individual tree crown detection could deliver essential ecological and economic information. The referred accuracy for individual tree crown extraction is 79.2%. Only crowns that were clearly visible were selected and manually delineated on the image because the distribution of the true crown size is significantly different from the segmented crowns. The aim of this study is t

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3

Zeide, Boris, and Peter Pfeifer. "A Method for Estimation of Fractal Dimension of Tree Crowns." Forest Science 37, no. 5 (1991): 1253–65. http://dx.doi.org/10.1093/forestscience/37.5.1253.

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Abstract A method is proposed for estimating fractal dimension of tree crowns from measurements of foliage mass and crown volume. Because fractal dimensions for each of the ten investigated species were greater than two, crown surface and volume depend on the unit of measurement. The power relationship between foliage mass and crown volume reflects self-similarity of tree crowns. In all studied cases, fractal dimensions of dominant trees were greater than those of intermediate trees of the same species. Fractal dimension can be used as an indicator of tolerance, crown class, and foliage distri

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4

Power, Hugues, Valerie LeMay, Frank Berninger, Derek Sattler, and Daniel Kneeshaw. "Differences in crown characteristics between black (Picea mariana) and white spruce (Picea glauca)." Canadian Journal of Forest Research 42, no. 9 (2012): 1733–43. http://dx.doi.org/10.1139/x2012-106.

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Black spruce ( Picea mariana (Mill.) Britton, Sterns & Poggenb.) and white spruce ( Picea glauca (Moench) Voss) are phylogenetically proximal species that differ in productivity. Crown characteristics of these two species have not been extensively studied, in spite of the importance of these two species to the Canadian boreal forest and the importance of tree crowns for understanding and modelling tree growth. In this paper, we characterize and compare the crown lengths, crown profiles (i.e., radii), shapes, and surface areas of these two species using 65 white spruce and 57 black spruce t

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Boivin, Frédéric, Alain Paquette, Pierre Racine, and Christian Messier. "A fast and reliable method for the delineation of tree crown outlines for the computation of crown openness values and other crown parameters." Canadian Journal of Forest Research 41, no. 9 (2011): 1827–35. http://dx.doi.org/10.1139/x11-107.

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Numerous crown parameters (e.g., leaf area index, diameter, height, volume) can be obtained via the analysis of tree crown photographs. In all cases, parameter values are functions of the position of the crown outline. However, no standardized method to delineate crowns exists. To explore the effect of different outlines on tree crown descriptors, in this case crown openness (CO), and facilitate the adoption of a standard method free of user bias, we developed the program Crown Delineator that automatically delineates any outline around tree crowns following predetermined sensibility settings.

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6

Shamim, Ahmed, and Pretzsch Hans. "TLidar-based crown shape indicates tree ring pattern in Norway spruce (Picea abies (L.) H. Karst) trees across competition gradients. A modeling and methodological approach." Ecological indicators 2023, no. 148 (2023): 110116. https://doi.org/10.5281/zenodo.7716499.

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Tree crowns and growth rings are physiologically and functionally connected through supporting and resource sharing. Management interventions may strongly influence tree growth by altering this linkage. However, conventional approaches have limited ability to characterize crown shape precisely, thus hindering our understanding of the relationship between crown shape and tree ring patterns. We, thus, aimed to test three hypotheses: (HI) Crown shape (regularity vs. irregularity) and ring patterns (regularity or irregularity) are significantly correlated and (HII) vary across density gradients; i

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7

Liu, Yao, Haotian You, Xu Tang, Qixu You, Yuanwei Huang, and Jianjun Chen. "Study on Individual Tree Segmentation of Different Tree Species Using Different Segmentation Algorithms Based on 3D UAV Data." Forests 14, no. 7 (2023): 1327. http://dx.doi.org/10.3390/f14071327.

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Individual structural parameters of trees, such as forest stand tree height and biomass, serve as the foundation for monitoring of dynamic changes in forest resources. Individual tree structural parameters are closely related to individual tree crown segmentation. Although three-dimensional (3D) data have been successfully used to determine individual tree crown segmentation, this phenomenon is influenced by various factors, such as the (i) source of 3D data, (ii) the segmentation algorithm, and (iii) the tree species. To further quantify the effect of various factors on individual tree crown

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8

Kaźmierczak, Katarzyna. "The current growth increment of pine tree stands comprising three different age classes." Forest Research Papers 74, no. 2 (2013): 93–100. http://dx.doi.org/10.2478/frp-2013-0009.

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Abstract The study presents the results of an analysis of the pine tree growth increments (height increment, dbh increment, basal area increment and volume increment) for a 5-year period. The study involved Scots pine trees of Kraft’s class 1, 2 and 3 (dominant stand) in stands of different age classes (II, III, V) growing in fresh mixed coniferous (BMśw) and fresh coniferous (Bśw) forest habitats. The multivariate analysis of variance was performed to assess the statistical significance of age and dominance of trees within a stand on their increment. The dominance position was classified for

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9

Antos, Joseph A., Roberta Parish, and Gordon D. Nigh. "Effects of neighbours on crown length of Abies lasiocarpa and Picea engelmannii in two old-growth stands in British Columbia." Canadian Journal of Forest Research 40, no. 4 (2010): 638–47. http://dx.doi.org/10.1139/x10-011.

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Crown length is a key aspect of vertical structure in multi-aged, multistrata, mixed-species forests. Crown length, defined as the distance from the tree top to the lowest live branch whorl, was determined for 3169 mapped trees ≥4.0 cm in diameter, in four 0.25 ha plots in each of two old-growth Abies lasiocarpa (Hook.) Nutt. – Picea engelmannii Parry ex Engelm. stands. We randomly selected half the trees to build models and half for validation. Crown length was modelled as a function of tree height, incorporating modifiers to account for neighbouring trees. The inclusion radius and height thr

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10

Karna, Yogendra K., Trent D. Penman, Cristina Aponte, and Lauren T. Bennett. "Assessing Legacy Effects of Wildfires on the Crown Structure of Fire-Tolerant Eucalypt Trees Using Airborne LiDAR Data." Remote Sensing 11, no. 20 (2019): 2433. http://dx.doi.org/10.3390/rs11202433.

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The fire-tolerant eucalypt forests of south eastern Australia are assumed to fully recover from even the most intense fires; however, surprisingly, very few studies have quantitatively assessed that recovery. The accurate assessment of horizontal and vertical attributes of tree crowns after fire is essential to understand the fire’s legacy effects on tree growth and on forest structure. In this study, we quantitatively assessed individual tree crowns 8.5 years after a 2009 wildfire that burnt extensive areas of eucalypt forest in temperate Australia. We used airborne LiDAR data validated with

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11

Menshutina, Tatyana Vladimirovna, and Marina Gennadievna Kostenko. "Peculiarities of growth and development of apple tree varieties depending on the formation of the crown under aid conditions of the northern Pre-Caspian region." Agrarian Scientific Journal, no. 9 (October 1, 2024): 35–41. https://doi.org/10.28983/asj.y2024i9pp35-41.

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In the conditions of the sharply continental climate of the Northern Pre-Caspian region, various methods of forming the crowns of apple trees are being studied to create highly productive intensive plantations in the arid zone. The article presents the results of a study on the influence of various methods of crown formation on the main economic and biological indicators of apple tree varieties in the semi-desert zone of the Northern Pre-Caspian region. The purpose of the research is to determine optimal crown designs that maximally take into account the biological characteristics of varieties

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12

Escoto-Rodríguez, Martín, José M. Facelli, and Jennifer R. Watling. "Do wide crowns in arid woodland trees reflect hydraulic limitation and reduction of self-shading?" Functional Plant Biology 41, no. 12 (2014): 1221. http://dx.doi.org/10.1071/fp14022.

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In arid regions many tree species develop broad crowns. A number of hypotheses involve trade-offs between growth in height and horizontal spreading, but there is no explanation for the switch from vertical to horizontal growth during development. Using Acacia papyrocarpa Benth as a model, we measured tree height and crown shape across different sites and topographic positions. We also measured δ13C of phyllodes from crown tops and lateral spreading branches. Trees were significantly taller at the base of a hill, where water availability is typically greater, than on the adjacent steep hillslop

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13

Gillespie, Andrew R., and Harold W. Hocker Jr. "The influence of competition on individual white pine thinning response." Canadian Journal of Forest Research 16, no. 6 (1986): 1355–59. http://dx.doi.org/10.1139/x86-239.

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A model predicting white pine (Pinusstrobus L.) diameter growth after thinning included competition, initial diameter, and crown class as independent variables. Model coefficients indicated a decrease in percent 8-year diameter growth with increasing crown suppression, crown competition, or tree size class. Variables selected were superior to age, percent live crown, and prethinning growth. Equations predicting basal area and volume growth were similar in form to diameter growth. Height growth, however, was more closely correlated with crown characteristics and unaffected by competition. Annua

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14

Miller, Gary W. "Effect of Crown Growing Space on the Development of Young Hardwood Crop Trees." Northern Journal of Applied Forestry 17, no. 1 (2000): 25–35. http://dx.doi.org/10.1093/njaf/17.1.25.

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Abstract Crown release of individual crop trees can be used to increase the growth and competitiveness of selected trees in young hardwood stands. Forest managers need information on the response of individual trees to such thinnings to prescribe stand treatments that meet specific management objectives. Codominant northern red oak (Quercus rubra L.), chestnut oak (Quercus prinus L.), black cherry (Prunus serotina Ehrh.), and yellow-poplar (Liriodendron tulipifera L.) crop trees in stands 12 to 16 yr old were given a crown-touching release by cutting all adjacent trees that touched the crown o

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15

Kaźmierczak, Katarzyna. "The current growth increment of pine tree stands comprising three different age classes." Forest Resaerch Papers 74 (2) (March 1, 2013): 93–100. https://doi.org/10.2478/frp-2013-0009.

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The study presents the results of an analysis of the pine tree growth increments (height increment, dbh increment, basal area increment and volume increment) for a 5-year period. The study involved Scots pine trees of Kraft’s class 1, 2 and 3 (dominant stand) in stands of different age classes (II, III, V) growing in fresh mixed coniferous (BMśw) and fresh coniferous (Bśw) forest habitats. The multivariate analysis of variance was performed to assess the statistical significance of age and dominance of trees within a stand on their increment. The dominance position was classified for eac

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16

Zeide, Boris, and Charles A. Gresham. "Fractal dimensions of tree crowns in three loblolly pine plantations of coastal South Carolina." Canadian Journal of Forest Research 21, no. 8 (1991): 1208–12. http://dx.doi.org/10.1139/x91-169.

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Because crown structure is closely associated with many aspects of tree growth, fractal dimension of the crown is likely to be a useful indicator of tree form as well as growth. This paper investigates the relationship between the fractal dimension of crowns and two growth-regulating factors, site quality and thinning intensity. The two-surface method allows one to calculate fractal dimension from the regression of foliage area (or mass) on the area (or volume) of the convex hull that envelopes the crown. The hull's volume can be computed from the length and width of a crown using an equation

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17

Osada, Noriyuki. "Branching, biomass distribution, and light capture efficiency in a pioneer tree, Rhus trichocarpa, in a secondary forest." Canadian Journal of Botany 83, no. 12 (2005): 1590–98. http://dx.doi.org/10.1139/b05-133.

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Crown architecture and biomass distribution patterns were investigated in relation to branching and tree size in a pioneer species, Rhus trichocarpa Miq. (Anacardiaceae), in a Japanese secondary forest. Crown architecture changed with tree size and with branching. Crown depth and area were greater in taller trees. In addition, branched trees had crowns of greater depth, and crown area increased more rapidly with increasing height in branched trees as compared with unbranched trees. In contrast, biomass distribution to nonphotosynthetic and photosynthetic organs changed only with tree size and

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18

McCaskill, George. "The Hungry Bob Fire & Fire Surrogate Study: A 20-Year Evaluation of the Treatment Effects." Forests 10, no. 1 (2018): 15. http://dx.doi.org/10.3390/f10010015.

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The Hungry Bob fuels reduction project was part of a 12-site National Fire and Fire Surrogate (FFS) network of experiments conducted across the United States from the late 1990s through the early 2000s to determine the regional differences in applying alternative fuel-reduction treatments to forests. The Hungry Bob project focused on restoration treatments applied in low elevation, dry second-growth ponderosa pine (Pinus ponderosa subsp. ponderosa (Douglas ex C. Lawson) and Douglas-fir (Pseudotsuga menziesii subsp. glauca (Beissn.) Franco forests of northeastern Oregon. Treatments included a s

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19

Cohn, Gregory M., Russell A. Parsons, Emily K. Heyerdahl, Daniel G. Gavin, and Aquila Flower. "Simulated western spruce budworm defoliation reduces torching and crowning potential: a sensitivity analysis using a physics-based fire model." International Journal of Wildland Fire 23, no. 5 (2014): 709. http://dx.doi.org/10.1071/wf13074.

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The widespread, native defoliator western spruce budworm (Choristoneura occidentalis Freeman) reduces canopy fuels, which might affect the potential for surface fires to torch (ignite the crowns of individual trees) or crown (spread between tree crowns). However, the effects of defoliation on fire behaviour are poorly understood. We used a physics-based fire model to examine the effects of defoliation and three aspects of how the phenomenon is represented in the model (the spatial distribution of defoliation within tree crowns, potential branchwood drying and model resolution). Our simulations

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20

Shokirov, Shukhrat, and Géza Király. "Analysis of multitemporal aerial images for fenyőfő Forest change detection." Landscape & Environment 10, no. 2 (2016): 89–100. http://dx.doi.org/10.21120/le/10/2/4.

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This study evaluated the use of 40 cm spatial resolution aerial images for individual tree crown delineation, forest type classification, health estimation and clear-cut area detection in Fenyőfő forest reserves in 2012 and 2015 years. Region growing algorithm was used for segmentation of individual tree crowns. Forest type (coniferous/deciduous trees) were distinguished based on the orthomosaic images and segments. Research also investigated the height of individual trees, clear-cut areas and cut crowns between 2012 and 2015 years using Canopy Height Models. Results of the research were exami

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Buba, Toma. "Impacts of Different Tree Species of Different Sizes on Spatial Distribution of Herbaceous Plants in the Nigerian Guinea Savannah Ecological Zone." Scientifica 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/106930.

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This study was aimed at finding the impacts of different tree species and individual trees of different sizes on species richness, diversity, and composition of the herbaceous layer. All the three tree species have greatly increased species richness and diversity both within and outside their crown zones compared with the open grassland. Both species richness and diversity were found to be higher under all the three tree species than outside their crowns, which was in turn higher than the open field.Daniella oliverihas the highest species richness and diversity both within and outside its crow

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22

Biging, Greg S., and Lee C. Wensel. "Estimation of crown form for six conifer species of northern California." Canadian Journal of Forest Research 20, no. 8 (1990): 1137–42. http://dx.doi.org/10.1139/x90-151.

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Geometric models are presented for the prediction of crown volume and width at any height in the crown of six conifer species in the Sierra Nevada. Crown volume is defined as the geometric space occupied by the crown and is allometrically related to the diameter, height, and crown ratio of individual trees. Crown diameter is derived from crown volume, tree height, and crown ratio. The crown volumes and associated measures can be used to compute indices of individual tree competition such as those used in the CACTOS (California Conifer Timber Output Simulator) system or to compute other measure

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23

Gan, Yi, Quan Wang, and Atsuhiro Iio. "Tree Crown Detection and Delineation in a Temperate Deciduous Forest from UAV RGB Imagery Using Deep Learning Approaches: Effects of Spatial Resolution and Species Characteristics." Remote Sensing 15, no. 3 (2023): 778. http://dx.doi.org/10.3390/rs15030778.

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The automatic detection of tree crowns and estimation of crown areas from remotely sensed information offer a quick approach for grasping the dynamics of forest ecosystems and are of great significance for both biodiversity and ecosystem conservation. Among various types of remote sensing data, unmanned aerial vehicle (UAV)-acquired RGB imagery has been increasingly used for tree crown detection and crown area estimation; the method has efficient advantages and relies heavily on deep learning models. However, the approach has not been thoroughly investigated in deciduous forests with complex c

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24

Lintunen, Anna, Risto Sievänen, Pekka Kaitaniemi, and Jari Perttunen. "Models of 3D crown structure for Scots pine (Pinus sylvestris) and silver birch (Betula pendula) grown in mixed forest." Canadian Journal of Forest Research 41, no. 9 (2011): 1779–94. http://dx.doi.org/10.1139/x11-092.

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The interplay between plant structure and functioning determines vital plant characteristics, such as the efficiency of light capture by the foliage, and thus continuous efforts have attempted to include plant architecture in plant growth models. We constructed two crown structure models enabling the generation of 3D trees using simple tree measurements as input for Scots pine ( Pinus sylvestris L.) and silver birch ( Betula pendula Roth.), boreal species growing in mixed stands. The data for the models were obtained from sample-based digitizing of 3D crown architecture accompanied by characte

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Pouliot, D. A., D. J. King, and D. G. Pitt. "Development and evaluation of an automated tree detectiondelineation algorithm for monitoring regenerating coniferous forests." Canadian Journal of Forest Research 35, no. 10 (2005): 2332–45. http://dx.doi.org/10.1139/x05-145.

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An algorithm is presented for automated detectiondelineation of coniferous tree regeneration that combines strategies of several existing algorithms, including image processing to isolate conifer crowns, optimal image scale determination, initial crown detection, and crown boundary segmentation and refinement. The algorithm is evaluated using 6-cm pixel airborne imagery in operational regeneration conditions typically encountered in the boreal forest 510 years after harvest. Detection omission and commission errors as well as an accuracy index combining both error types were assessed on a tr

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26

Televinova, Maria, and Irina Antonova. "The features of the biennial shoot systems of Ulmus glabra Huds. characteristic of the crown in the virginal age state." BIO Web of Conferences 38 (2021): 00128. http://dx.doi.org/10.1051/bioconf/20213800128.

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The morphological features of crowns were studied on the material of individuals of U. glabra of seed regeneration in the gaps of decaying three-hundred-year-old oak forests. We collected data on all crown shoots of five trees of young virginal age (from 10 to 18 years). The principal component method was used twice: first on the model tree to characterize features of the shoots biennial systems under the study, then to reveal ontogenetic and structural features of the crown organization of five virginal trees. Using the method of shoots biennial systems extraction allowed us to form a set of

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27

Stajic, Branko, Ksenija Vukic, Zivan Janjatovic, and Marko Kazimirovic. "Growing space efficiency of European ash (Fraxinus excelsior L.) in the region of Majdanpecka domena." Bulletin of the Faculty of Forestry, no. 115 (2017): 99–126. http://dx.doi.org/10.2298/gsf1715099s.

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This paper reports on the size and completeness of tree crowns and their effectiveness for the production of wood volumes in the case of a pure 35-years European ash stand. Starting from the interaction between the elements of the crowns structure and elements of the tree and stand growth the economical use of growing space was perceived and the optimal stand state was also defined, what were the main objectives of this paper. The trees with slender crowns, despite their better ratio of the surface area/volume of the crown, produced lower wood volume (undeveloped crowns). On the other hand, wh

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Octarina, Nur Ayu, Rico Andrian, and Rahmat Safei. "Classification of crown density and foliage transparency scale for broadleaf tree using VGG-16." Journal of Soft Computing Exploration 4, no. 4 (2023): 222–32. http://dx.doi.org/10.52465/joscex.v4i4.251.

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Crown density and foliage transparency are important parameters for tree crown conditions. Previously, observers carried out crown density and foliage transparency assessments manually, which could be a less efficient process.This research aims to use the VGG-16 deep learning architecture to classify the density and transparency of broadleaves tree crowns. In this study, broadleaves tree crown datasets were collected for four types of broadleaves tree: cacao (theobroma cacao), durian (durio zibethinus), rubber (havea brasiliensis), candlenut (aleurites moluccana); then the data is labeled base

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Suchocka, Marzena, Tatiana Swoczyna, Joanna Kosno-Jończy, and Hazem M. Kalaji. "Impact of heavy pruning on development and photosynthesis of Tilia cordata Mill. trees." PLOS ONE 16, no. 8 (2021): e0256465. http://dx.doi.org/10.1371/journal.pone.0256465.

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Tree pruning is carried out to reduce conflict with infrastructure, buildings, and any other human activity. However, heavy pruning may result in a diminished tree crown capacity for sugar production and exposure to fungal infection. This risk leads to a decrease in tree stability or vigour. In this work, we analysed the effect of heavy pruning of roadside trees on the photosynthetic performance process compared to neighbouring unpruned trees. Four years of tree crown growth was studied by terrestrial imaging. Tree vitality (Roloff’s classification) and risk (Visual Tree Assessment) were evalu

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Schneider, Robert, Rafael Calama, and Olivier Martin-Ducup. "Understanding Tree-to-Tree Variations in Stone Pine (Pinus pinea L.) Cone Production Using Terrestrial Laser Scanner." Remote Sensing 12, no. 1 (2020): 173. http://dx.doi.org/10.3390/rs12010173.

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Kernels found in stone pinecones are of great economic value, often surpassing timber income for most forest owners. Visually evaluating cone production on standing trees is challenging since the cones are located in the sun-exposed part of the crown, and covered by two vegetative shoots. Very few studies were carried out in evaluating how new remote sensing technologies such as terrestrial laser scanners (TLS) can be used in assessing cone production, or in trying to explain the tree-to-tree variability within a given stand. Using data from 129 trees in 26 plots located in the Spanish Norther

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Dahir, Srud Zubair, and Tariq Salih. "Individual Tree Parameters Models for Melia Azedarach (Chinaberry) Tree Grown in Erbil." Science Journal of University of Zakho 10, no. 4 (2022): 181–87. http://dx.doi.org/10.25271/sjuoz.2022.10.4.960.

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The crown width of a tree is very important parameter. It is responsible for tree survival and for producing the food for the whole tree. They produce oxygen, filter out dust and other airborne pollutants from the air, purification of the water, generate shadow and determine the scenic beauty of trees and forests. The tree crowns have a significant effect on the microclimate. But measuring of the crown width is a difficult task that needs much money, time and effort. Thus this study aimed at developing of mathematical relationship between the crown width and breast height diameter for Chinaber

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Wan Mohd Jaafar, Wan, Iain Woodhouse, Carlos Silva, et al. "Improving Individual Tree Crown Delineation and Attributes Estimation of Tropical Forests Using Airborne LiDAR Data." Forests 9, no. 12 (2018): 759. http://dx.doi.org/10.3390/f9120759.

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Individual tree crown (ITC) segmentation is an approach to isolate individual tree from the background vegetation and delineate precisely the crown boundaries for forest management and inventory purposes. ITC detection and delineation have been commonly generated from canopy height model (CHM) derived from light detection and ranging (LiDAR) data. Existing ITC segmentation methods, however, are limited in their efficiency for characterizing closed canopies, especially in tropical forests, due to the overlapping structure and irregular shape of tree crowns. Furthermore, the potential of 3-dimen

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Aryal, Bimal, James Steenberg, and Peter Duinker. "The Effects of Residential Street Tree Spacing and Crown Interactions on Crown Dimensions and Canopy Cover." Arboriculture & Urban Forestry 47, no. 5 (2021): 183–95. http://dx.doi.org/10.48044/jauf.2021.017.

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Urban trees provide people with a range of ecosystem services. Trees planted along streets have been a large focus of urban forest research and practice, and municipalities invest significant resources in their survival. However, the optimal spacing of street trees is not addressed in the scientific literature, and existing municipal street tree spacing standards are highly variable and poorly enforced. In this study, we examine variability in crown shape and size for street trees to test for possible interaction effects at closer spacings. We measured variability in crown diameters both paral

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Grznárová, A., M. Mokroš, P. Surový, M. Slavík, M. Pondelík, and J. Merganič. "THE CROWN DIAMETER ESTIMATION FROM FIXED WING TYPE OF UAV IMAGERY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W13 (June 4, 2019): 337–41. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w13-337-2019.

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<p><strong>Abstract.</strong> The forest inventory is an important instrument for sustainable forest management. Canopy Height Model (CHM) and Digital Surface Model (DSM) created from high-resolution UAV (unmanned aerial vehicle) imagery provide possibility to determine tree crown diameters for the whole stand at fast. The goal of this paper is to identify the influence of tree species on the accuracy of estimation of crown diameter from high-resolution UAV imagery. In Plot 1 with coniferous tree species we identified 21 trees from total of 22 trees that leads to a detection

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Ashton, P. Mark S., Lydia P. Olander, Graeme P. Berlyn, Rajesh Thadani, and Ian R. Cameron. "Changes in leaf structure in relation to crown position and tree size of Betula papyrifera within fire-origin stands of interior cedar-hemlock." Canadian Journal of Botany 76, no. 7 (1998): 1180–87. http://dx.doi.org/10.1139/b98-128.

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Dimensions of anatomical and morphological attributes of leaves can influence physiological response to changes in environment over time. Linking structural attributes of leaves to crown position and tree size within naturally developing cohorts of trees can provide a clearer understanding of changes in crown morphology for a species. This study examined leaf anatomy and morphology of Betula papyrifera Marsh. growing in two stages of stand development of interior cedar-hemlock forest, northern British Columbia. Anatomical and morphological measurements of leaves located at six different positi

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Xia, Kai, Hao Wang, Yinhui Yang, Xiaochen Du, and Hailin Feng. "Automatic Detection and Parameter Estimation of Ginkgo biloba in Urban Environment Based on RGB Images." Journal of Sensors 2021 (August 6, 2021): 1–12. http://dx.doi.org/10.1155/2021/6668934.

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Individual tree crown detection and morphological parameter estimation can be used to quantify the social, ecological, and landscape value of urban trees, which play increasingly important roles in densely built cities. In this study, a novel architecture based on deep learning was developed to automatically detect tree crowns and estimate crown sizes and tree heights from a set of red-green-blue (RGB) images. The feasibility of the architecture was verified based on high-resolution unmanned aerial vehicle (UAV) images using a neural network called FPN-Faster R-CNN, which is a unified network

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Konôpka, Bohdan, Jozef Pajtík, Vladimír Šebeň, Katarína Merganičová, and Peter Surový. "Silver birch aboveground biomass allocation pattern, stem and foliage traits with regard to intraspecific crown competition." Central European Forestry Journal 66, no. 3 (2020): 159–69. http://dx.doi.org/10.2478/forj-2020-0013.

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Abstract In the conditions of Central Europe, silver birch (Betula pendula Roth) has so far not been an important species for commercial purposes but might be relevant from ecological point of view. For instance, prompt succession by birch and other pioneer tree species at large-scale post-disturbance areas is necessary to compensate for previous carbon losses by natural disasters. Therefore, our attention was focused on 14-year-old birch trees growing at the wind-thrown area in the High Tatra Mts. (northern Slovakia). We sampled aboveground biomass of 20 silver birch trees representing four c

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Dai, Mingrui, and Guohua Li. "Soft Segmentation and Reconstruction of Tree Crown from Laser Scanning Data." Electronics 12, no. 10 (2023): 2300. http://dx.doi.org/10.3390/electronics12102300.

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Point cloud data obtained by laser scanning can be used for object shape modeling and analysis, including forest inventory. One of the inventory tasks is individual tree extraction and measurement. However, individual tree segmentation, especially tree crown segmentation, is challenging. In this paper, we present a novel soft segmentation algorithm to segment tree crowns in point clouds automatically and reconstruct the tree crown surface from the segmented crown point cloud. The soft segmentation algorithm mainly processes the overlapping region of the tree crown. The experimental results sho

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Temesgen, H., Valerie M. LeMay, and Ian R. Cameron. "Bivariate distribution functions for predicting twig leaf area within hybrid spruce crowns." Canadian Journal of Forest Research 33, no. 10 (2003): 2044–51. http://dx.doi.org/10.1139/x03-127.

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The vertical and horizontal distribution of leaf area per centimetre of twig (APCM) for hybrid spruce (Picea engelmannii Parry ex Engelm. × Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière) tree crowns was modelled using bivariate Weibull and beta distribution functions. Horizontal position was represented by relative position on the first-order branch. Vertical position was based on branch position from the tree apex relative to tree height, since the base of the live crown is often difficult to locate. Sample APCM measures were obtained using systematic sampling of 12 tree crow

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Adam, Klepacki. "The relationship between height and crown characteristics of four-year-old common birch (Betula pendula Roth)." Lesne Prace Badawcze / Forest Research Papers 78, no. 2 (2017): 171–78. https://doi.org/10.1515/frp-2017-0019.

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This paper presents the results of an analysis on characteristics of birch crowns (<em>Betula pendula</em> Roth) in relation to measures of the growth space occupied by a single tree at a young age. It also presents the relationships between the seedling height and certain crown characteristics. The study focused on four-year-old common birches growing in four different areas in the Elk Forest District in either fresh mixed coniferous or broadleaved forest. The measurements conducted on the chosen trees were used to calculate their crown characteristics such as crown diameter, length, height t

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Nigh, Gordon D., and Bobby A. Love. "Predicting crown class in three western conifer species." Canadian Journal of Forest Research 34, no. 3 (2004): 592–99. http://dx.doi.org/10.1139/x03-220.

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Assessing the crown class (dominant, codominant, intermediate, suppressed) of a tree is a subjective procedure. Most definitions of crown class are based on the relative height of a tree and (or) the amount of light that is incident on the tree crown. With this research, we devised a classification scheme, based on easily measured tree variables, to assign a crown class to trees. Our data consisted of tree measurements, including crown class, from four stem-mapped 0.05-ha sample plots with buffers. The light model tRAYci was used to assess the light incident on each tree crown. These data gave

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Rudnicki, Mark, Victor J. Lieffers, and Uldis Silins. "Stand structure governs the crown collisions of lodgepole pine." Canadian Journal of Forest Research 33, no. 7 (2003): 1238–44. http://dx.doi.org/10.1139/x03-055.

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We investigated tree sway and crown collision behavior of even-aged lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands of different structure in Alberta, Canada, to examine how these factors might affect loss of leaf area as stands mature. The Two Creeks stand (TC) had high density and slender trees, while the Chickadee stand (CH) had stout trees. The TC stand was then thinned (TCT) to reduce the stand density. For each stand, simultaneous tree sways of a group of 10 trees were monitored with biaxial clinometers during wind speed of 5 m/s (canopy top). Crown collisio

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Mäkelä, Annikki, and Petteri Vanninen. "Impacts of size and competition on tree form and distribution of aboveground biomass in Scots pine." Canadian Journal of Forest Research 28, no. 2 (1998): 216–27. http://dx.doi.org/10.1139/x97-199.

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Studies on tree allometry have often focused on the average tree of a representative stand across an age gradient. Another dimension of change in tree form is the variation caused by differences in competitive status, evident between trees of one stand or between stands of comparable age but different stocking densities. This study compares the structural relationships of dominant Scots pine (Pinus sylvestris L.) trees over a wide age range with those in young trees of similar age but different competitive status. Allometric relationships are developed between biomass components and diameter,

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Kane, Brian, Michael Pavlis, J. Roger Harris, and John R. Seiler. "Crown reconfiguration and trunk stress in deciduous trees." Canadian Journal of Forest Research 38, no. 6 (2008): 1275–89. http://dx.doi.org/10.1139/x07-225.

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In light of the risk of litigation following damage related to tree failure in urban and suburban settings, more empirical data related to tree risk assessment are needed. We measured drag and drag-induced bending moment (M) and calculated drag coefficient (CD) and trunk stress (σ) for three deciduous trees at wind speeds up to 22.4 m/s. We measured the modulus of rupture (MOR) of wood samples from trunks and calculated the factor of safety (SF = MOR / σ) for each tree. We also investigated which tree morphometric variables best predicted drag and M and whether simple two- and three-dimensiona

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Dai, Mingrui, and Guohua Li. "Soft Segmentation of Terrestrial Laser Scanning Point Cloud of Forests." Applied Sciences 13, no. 10 (2023): 6228. http://dx.doi.org/10.3390/app13106228.

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As the three-dimensional (3D) laser scanner is widely used for forest inventory, analyzing and processing point cloud data captured with a 3D laser scanner have become an important research topic in recent years. The extraction of single trees from point cloud data is essential for further investigation at the individual tree level, such as counting trees and trunk analysis, and many developments related to this topic have been published. However, constructing an accurate and automated method to obtain the tree crown silhouette from the point cloud data is challenging because the tree crowns o

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Hagemeier, Marc, and Christoph Leuschner. "Functional Crown Architecture of Five Temperate Broadleaf Tree Species: Vertical Gradients in Leaf Morphology, Leaf Angle, and Leaf Area Density." Forests 10, no. 3 (2019): 265. http://dx.doi.org/10.3390/f10030265.

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The morphology, inclination, and spatial distribution of leaves in different parts of tree crowns are important determinants of the radiation, momentum, and gas exchange between the canopy and the atmosphere. However, it is not well known how these foliage-related traits vary among species differing in successional status. We measured leaf size, leaf mass area (LMA), leaf inclination (angle to the horizontal), leaf area density (LAD), total leaf area (leaf area index, LAI), and leaf area distribution across the crown in adult trees of five common, early to late-successional tree species (Betul

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Cranmer, Nicholas, Robert T. Fahey, Thomas Worthley, Chandi Witharana, Brandon Alveshere, and Amanda Bunce. "Tree Trimming Effects on 3-Dimensional Crown Structure and Tree Biomechanics: A Pilot Project." Arboriculture & Urban Forestry 50, no. 6 (2024): 395–413. http://dx.doi.org/10.48044/jauf.2024.020.

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AbstractBackgroundAlong electric distribution corridors in urban-exurban landscapes, forest edges are susceptible to damage associated with storm events. Disturbances and management interventions designed to preempt their effects (e.g., tree trimming) alter characteristics of tree structure and morphology (e.g., branch and crown structure), which may be associated with tree failure and likelihood of associated infrastructure damage. This study assessed the relationship between 3-dimensional tree crown structure and tree biomechanics and characterized the effect of utility tree trimming on tree

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Karlinasari, L., U. Adzkia, Y. Fredisa, M. M. Rahman, N. Nugroho, and I. Z. Siregar. "Tree form morphometrics of Agathis dammara and Acacia mangium in the IPB’s Dramaga Landscape Campus, Bogor." IOP Conference Series: Earth and Environmental Science 918, no. 1 (2021): 012015. http://dx.doi.org/10.1088/1755-1315/918/1/012015.

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Abstract Tree growth comprises diverse tree forms and crown shapes that are influenced by the growing space and are related to biomechanical responses. Due to the complex structures of tree forms and crown architecture, more understanding of their functions is necessary. The study aimed to evaluate the morphometrics of two tree species of contrasting tree forms. Each represents excurrent and decurrent crown architectures located in the Dramaga Campus Landscape, Bogor. Morphometric analysis was conducted on those two species, namely excurrent agathis (n=23 trees) and decurrent mangium (n= 15 tr

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Li, Jian Ke, Jing Hui Yang, Yan Jun Liu, et al. "Growth and Development of Feijoa with Different Plant Shape and in Greenhouses Environment." Advanced Materials Research 886 (January 2014): 294–98. http://dx.doi.org/10.4028/www.scientific.net/amr.886.294.

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In order to explore the relation between tree crown shape and growth development and age of tree, flowering plants, fruiting plants, bearing plants, bearing branch and floweret, length of bearing branch were studied in greenhouse environments after tree corm shape were divided into three groups by live crown ratio of crown width to height and angle from the central leader to first scaffold branch. The result showed that the plants of upright crown shape were 83% at age one year among all plants, 45% at age two years and tree crown shapes, open tree increased to 25% at age of three years. The f

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Hastings, Jack H., Scott V. Ollinger, Andrew P. Ouimette, et al. "Tree Species Traits Determine the Success of LiDAR-Based Crown Mapping in a Mixed Temperate Forest." Remote Sensing 12, no. 2 (2020): 309. http://dx.doi.org/10.3390/rs12020309.

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The ability to automatically delineate individual tree crowns using remote sensing data opens the possibility to collect detailed tree information over large geographic regions. While individual tree crown delineation (ITCD) methods have proven successful in conifer-dominated forests using Light Detection and Ranging (LiDAR) data, it remains unclear how well these methods can be applied in deciduous broadleaf-dominated forests. We applied five automated LiDAR-based ITCD methods across fifteen plots ranging from conifer- to broadleaf-dominated forest stands at Harvard Forest in Petersham, MA, U

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