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1
Kim, Ju-Chul, and Sang-Joong Lee. "A Lecture Note for Introduction of Steiner (Fermat) Tree to Electrical Engineering Education - Comparison of Path Lengths of Minimum Spanning Tree and Steiner Tree." Journal of the Korean Institute of Illuminating and Electrical Installation Engineers 33, no. 6 (June 30, 2019): 9–18. http://dx.doi.org/10.5207/jieie.2019.33.6.009.
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Schaar, Günter, and Zdzisław Skupień. "Pairs of trees in tree–tree triangulations." Discrete Mathematics 307, no. 11-12 (May 2007): 1499–505. http://dx.doi.org/10.1016/j.disc.2005.11.087.
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Jasmine, Jasmine, Pankaj Bhambri, and Dr O. P. Gupta Dr. O.P. Gupta. "Analyzing the Phylogenetic Trees with Tree- building Methods." Indian Journal of Applied Research 1, no. 7 (October 1, 2011): 83–85. http://dx.doi.org/10.15373/2249555x/apr2012/25.
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Williams, Roger A. "Use of Randomized Branch and Importance Sampling to Estimate Loblolly Pine Biomass." Southern Journal of Applied Forestry 13, no. 4 (November 1, 1989): 181–84. http://dx.doi.org/10.1093/sjaf/13.4.181.
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Abstract A previously developed sampling method utilizing randomized branch and importance sampling for the purpose of quickly estimating tree biomass was tested on five loblolly pine (Pinus taeda L.) trees. Results show a wide range of per-tree sampling error, ranging from 5.3 to 28.9%. Largevariation in foliage content among selected branches per treee may be a major source of error. However, the sampling error for the total biomass of the five trees tested was only 3.3%. This sampling method appears to be reliable and efficient in obtaining precise estimates of the total biomassof a population of trees. Increased sampling intensity per tree is necessary to obtain precise estimates of individual tree biomass. South. J. Appl. For. 13(4):181-184.
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Freilicher, Mollie. "Tree by Tree, Yard by Yard: Replanting Worcester's Trees." Arnoldia 69, no. 1 (2011): 2–13. http://dx.doi.org/10.5962/p.258693.
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Ko, Sang-Ki, Ha-Rim Lee, and Yo-Sub Han. "State Complexity of Regular Tree Languages for Tree Matching." International Journal of Foundations of Computer Science 27, no. 08 (December 2016): 965–79. http://dx.doi.org/10.1142/s0129054116500398.
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We study the state complexity of regular tree languages for tree matching problem. Given a tree t and a set of pattern trees L, we can decide whether or not there exists a subtree occurrence of trees in L from the tree t by considering the new language L′ which accepts all trees containing trees in L as subtrees. We consider the case when we are given a set of pattern trees as a regular tree language and investigate the state complexity. Based on the sequential and parallel tree concatenation, we define three types of tree languages for deciding the existence of different types of subtree occurrences. We also study the deterministic top-down state complexity of path-closed languages for the same problem.
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S Shevtekar, Sumit, Sayeed Khan, Sanket Jhavar, and Harsh Dhawale. "Bo-Tree: An Efficient Search Tree." International Journal of Science and Research (IJSR) 11, no. 12 (December 5, 2022): 273–77. http://dx.doi.org/10.21275/sr221202123124.
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Carmesin, Johannes, Matthias Hamann, and Babak Miraftab. "Canonical trees of tree-decompositions." Journal of Combinatorial Theory, Series B 152 (January 2022): 1–26. http://dx.doi.org/10.1016/j.jctb.2021.08.004.
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Kao, Ming-Yang. "Tree Contractions and Evolutionary Trees." SIAM Journal on Computing 27, no. 6 (December 1998): 1592–616. http://dx.doi.org/10.1137/s0097539795283504.
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Bille, Philip, Inge Li Gørtz, Gad M. Landau, and Oren Weimann. "Tree compression with top trees." Information and Computation 243 (August 2015): 166–77. http://dx.doi.org/10.1016/j.ic.2014.12.012.
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Margot, F., A. Prodon, and Th M. Liebling. "Tree polytope on 2-trees." Mathematical Programming 63, no. 1-3 (January 1994): 183–91. http://dx.doi.org/10.1007/bf01582065.
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Zhai, Feifei, Jiajun Zhang, Yu Zhou, and Chengqing Zong. "Unsupervised Tree Induction for Tree-based Translation." Transactions of the Association for Computational Linguistics 1 (December 2013): 243–54. http://dx.doi.org/10.1162/tacl_a_00224.
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In current research, most tree-based translation models are built directly from parse trees. In this study, we go in another direction and build a translation model with an unsupervised tree structure derived from a novel non-parametric Bayesian model. In the model, we utilize synchronous tree substitution grammars (STSG) to capture the bilingual mapping between language pairs. To train the model efficiently, we develop a Gibbs sampler with three novel Gibbs operators. The sampler is capable of exploring the infinite space of tree structures by performing local changes on the tree nodes. Experimental results show that the string-to-tree translation system using our Bayesian tree structures significantly outperforms the strong baseline string-to-tree system using parse trees.
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Teng, Zhiyang, and Yue Zhang. "Head-Lexicalized Bidirectional Tree LSTMs." Transactions of the Association for Computational Linguistics 5 (December 2017): 163–77. http://dx.doi.org/10.1162/tacl_a_00053.
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Sequential LSTMs have been extended to model tree structures, giving competitive results for a number of tasks. Existing methods model constituent trees by bottom-up combinations of constituent nodes, making direct use of input word information only for leaf nodes. This is different from sequential LSTMs, which contain references to input words for each node. In this paper, we propose a method for automatic head-lexicalization for tree-structure LSTMs, propagating head words from leaf nodes to every constituent node. In addition, enabled by head lexicalization, we build a tree LSTM in the top-down direction, which corresponds to bidirectional sequential LSTMs in structure. Experiments show that both extensions give better representations of tree structures. Our final model gives the best results on the Stanford Sentiment Treebank and highly competitive results on the TREC question type classification task.
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Hasibuan, Moses, Indriyanto ., and Melya Riniarti. "Inventarisasi Pohon Plus Dalam Blok Koleksi Di Taman Hutan Raya Wan Abdul Rachman." Jurnal Sylva Lestari 1, no. 1 (February 17, 2019): 9. http://dx.doi.org/10.23960/jsl119-16.
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Plus tree inventory was an activity for collecting and compiling data.Collection block was an area within Great Forest Park region that contains different types of plant, either endemic or non-endemic plants, which serves for protection and preservation, research, science, education, support the cultivation, culture, tourism and recreation.The information about the existence of plus trees on the collection block still rare.So, plus tree inventory still necessary to fulfill the data.This research was held in Wan Abdul Rachman Great Forest Park Collection Block at February to March 2012.The aim of this research is to identify the trees which has plus tree criterias.Data collected by using line terraced layers method which placed systematically.The collected data include the types of trees, trunk diameter, branch height, trunk straightness, tree’s health condition, fruit production, branch corner, sphericity form of circumference stem, and the location of the plus tree.Based on the results, there were 9 species of trees that identified as plus trees,7 species of wooden trees, which are 3 taboo trees (Tetrameles nudiflora), 1 dadap tree (Erythrina fusca), 1 purple coral tree (Pterospermum javanicum), 1 sandpaper tree (Ficus ampelas), 6 kapok trees (Ceiba pentandra), 1 red cedar tree (Toona sureni), 1 mindi tree (Melia azedarach) and 2 species of MPTS trees, 1 durian tree (Durio zibethinus), and 1 mango tree (Mangifera indica).Total number of individual tree that meets the plus tree criterias are 16 trees.Keywords: inventory, plus trees
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Arlander, Annette. "Becoming a tree with a tree." Journal of Dance & Somatic Practices 14, no. 2 (December 1, 2022): 231–48. http://dx.doi.org/10.1386/jdsp_00081_1.
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This text reflects on an artistic practice based on repeated visits to chosen trees, performing for camera with them in the context of the project ‘Meetings with Remarkable and Unremarkable Trees’. The individual daily practice of becoming a tree, based on a yoga exercise, together with a variety of trees, is complemented with a collective online performance, the ‘Be-coming Tree’ event. The daily practice brought to the fore the tension between a heightened perceptual awareness of the bodymind while balancing and the awareness of the tree and the broader environment. Noticing the tension between an inward and an outward focus, the text proposes that sustaining this very tension is relevant for developing an ecologically informed consciousness of our co-dependency with other life forms, such as trees.
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Zhang, Yaoqi, Bin Zheng, Brenda Allen, Neil Letson, and Jeff Sibley. "Tree Ordinances as Public Policy and Participation Tools: Development in Alabama." Arboriculture & Urban Forestry 35, no. 3 (May 1, 2009): 165–71. http://dx.doi.org/10.48044/jauf.2009.029.
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Following a brief overview of the historical evolution of tree ordinances in the United States, this paper focuses on the development of tree ordinances in the state of Alabama to demonstrate how the tree ordinances evolve into law and the role such ordinances have on urban trees. Even though tree ordinances have a long history in the United States, they have been rapidly developing since the 1970s. Among the 100 municipalities that have some type of tree ordinance in Alabama, based on this investigation, the major responsibilities of tree ordinances include: having a tree commission (board), defining tree planting, removal and replacement of trees on public land, public tree protection and care, tree species selection, and dead tree removal on public and private property. Considering the broadness and complexity of urban trees, this paper indicates tree ordinances provide not only a legal framework, but also an effective tool to engage public participation and awareness of urban trees in the process of formulating, implementing, and amending of the tree ordinances. Development of tree ordinances requires government support, citizen participation, and consideration of local resources.
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Park, Minhyuk, Paul Zaharias, and Tandy Warnow. "Disjoint Tree Mergers for Large-Scale Maximum Likelihood Tree Estimation." Algorithms 14, no. 5 (May 7, 2021): 148. http://dx.doi.org/10.3390/a14050148.
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The estimation of phylogenetic trees for individual genes or multi-locus datasets is a basic part of considerable biological research. In order to enable large trees to be computed, Disjoint Tree Mergers (DTMs) have been developed; these methods operate by dividing the input sequence dataset into disjoint sets, constructing trees on each subset, and then combining the subset trees (using auxiliary information) into a tree on the full dataset. DTMs have been used to advantage for multi-locus species tree estimation, enabling highly accurate species trees at reduced computational effort, compared to leading species tree estimation methods. Here, we evaluate the feasibility of using DTMs to improve the scalability of maximum likelihood (ML) gene tree estimation to large numbers of input sequences. Our study shows distinct differences between the three selected ML codes—RAxML-NG, IQ-TREE 2, and FastTree 2—and shows that good DTM pipeline design can provide advantages over these ML codes on large datasets.
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Hanberry, Brice B., Jacob M. Seidel, and Phillip DeLeon. "Exploring Tree Density Increases after Fire Exclusion in the Northern Front Range and Great Plains, Colorado, USA." Fire 7, no. 4 (March 22, 2024): 103. http://dx.doi.org/10.3390/fire7040103.
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Since Euro-American settlement and associated fire exclusion, grasslands and open forests have converted to forests throughout the United States. Contributing to the weight of evidence, we determined if forestation also occurred in forests and grasslands of Colorado. Our study extent encompassed landscapes of the 0.5 million ha Arapaho and Roosevelt National Forests in the northern Front Range (eastern side) of the southern Rocky Mountains and the 1 million ha Weld County, which contains Pawnee National Grassland, in the Great Plains grasslands. We quantified tree composition, cover, and densities from historical (years 1863 to 1886) tree surveys, current surveys (2002 to 2011), and land cover (2016) to identify departures. In the Arapaho and Roosevelt, historical lack of tree presence and overall low tree densities suggested an open landscape, due to about 70% of 7134 survey points without two trees within 60 m. The treed landscape, which was not continuously forested, had density estimates of about 153 trees/ha. In contrast, the current landscape was 68% forested with high tree densities; fire-dependent pines decreased relative to subalpine fir (Abies lasiocarpa) increases. In Weld County, seven trees were surveyed historically, whereas currently, woody cover totaled 2555 ha. Uniquely applying historical surveys at landscape scales, we documented an open landscape in the northern Front Range, unlike previous research, and rare tree presence in the relatively understudied grasslands of Colorado. Forestation corresponded with changes in U.S. grasslands and forests following Euro-American settlement and associated fire exclusion.
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Michalczuk, Jerzy. "The importance of non-forest tree stand features for protection of the Syrian Woodpecker Dendrocopos syriacus in agricultural landscape: a case study from South-Eastern Poland." Agroforestry Systems 94, no. 5 (May 13, 2020): 1825–35. http://dx.doi.org/10.1007/s10457-020-00498-2.
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Abstract Non-forest tree stands are important habitats for many species of birds in the agricultural landscape. They are also the main habitat of the Syrian Woodpecker Dendrocopos syriacus, whose numbers have been decreasing in recent years in some parts of Europe. Recognition of the habitat requirements of this species may help better planning of its protection in the context of the treed agricultural landscapes. During this study, the habitat preferences of the Syrian Woodpecker were determined in the agricultural landscape of South-Eastern Poland. A set of 12 habitat parameters of tree stands located in the breeding territories of the Syrian Woodpecker (n = 122) and in randomly chosen control areas (n = 122) located outside the range of the breeding territories of this species were characterized. The number and species diversity of trees was significantly higher in stands located in Syrian Woodpecker territories than in the random control areas. Stands occupied by breeding pairs also had trees of worse health condition and a larger proportion of fruit trees. The model best explaining the probability of the occurrence of the species indicates that the Syrian Woodpecker requires mainly the presence of tree stands with a greater species diversity of trees, as well as tree stands in worse health condition. When planning the protection of this species’ habitats in the agricultural landscape, the characteristics of non-forest tree stands noted above should be taken into account.
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Beasley, LeRoy B. "Tree Covers of Graphs and their Linear Preservers." Journal of Combinatorial Mathematics and Combinatorial Computing 122, no. 1 (September 30, 2024): 149–55. http://dx.doi.org/10.61091/jcmcc122-12.
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Let G be an undirected graph. A \textit{vertex tree cover} of G is a collection of trees such that every vertex of G is incident with at least one tree. Similarly, an edge tree cover is a collection of trees such that every edge of G is contained in at least one tree. The tree cover number is defined as the minimum number of trees required in such a cover. In this paper, we demonstrate that when considering specific types of tree covers, only vertex permutations act as linear operators that preserve the tree cover number of G .
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Eastham, J., and CW Rose. "Tree pasture interactions at a range of tree densities in an agroforestry experiment. I. Rooting patterns." Australian Journal of Agricultural Research 41, no. 4 (1990): 683. http://dx.doi.org/10.1071/ar9900683.
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The effects of tree density on the distribution of tree and pasture roots under an agroforestry experiment were investigated. Trees were planted in a Nelder fan design, and three planting densities of 2150,304 and 82 stems per hectare were chosen for this study. Proximity to trees and increase in tree density reduced pasture root growth, with lowest concentrations of pasture roots occurring under the highest tree density. Tree root systems were deeper and denser at high tree densities, although total length and mass of roots produced per tree decreased with increasing tree density. Tree root:shoot ratios increased as tree density decreased owing to greater root production at low tree densities.
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Fu, Qingcheng, Erfa Qiu, Yuan Zhang, Lanhong Huang, Huichao Wang, and Shasha Jiang. "Discussion of the Distribution Pattern and Driving Factors of 2 Large Old Tree Resources in Beijing." Forests 13, no. 9 (September 16, 2022): 1500. http://dx.doi.org/10.3390/f13091500.
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Known as “living fossils”, large old trees play an important role in ecology, landscape, and culture and are an important part of ecosystems and human settlements. The aim of this paper is to provide suggestions for the protection of urban large old tree resources and the selection of large old tree backup resources. First, we conducted a statistical analysis on the composition, distribution, and important values of large old tree species in Beijing and used Downtrend correspondence analysis (DCA) to analyze the composition of different types of habitat tree species. Second, we created a 3 km × 3 km grid within the administrative scope of Beijing, extracted the number of large old trees and tree species richness in the grid, and used geographic detectors to determine the driving factors of the spatial distribution of large old trees, as well as tree species richness differences and their interactions. A total of 40,590 large old trees in Beijing were found, belonging to 72 species, 52 genera, and 29 families. Platycladus orientalis (L.) Franco was the dominant tree species, with an importance value of 0.51. Among the different habitats, the large old trees were found in parks and temples, and the greatest tree species number of old trees were found in communities and the countryside; meanwhile, microgreen spaces had the lowest number of trees and tree species. The distribution of large old trees and tree species was mainly concentrated in the center of the city and the northwest. The distribution pattern of large old tree resources in Beijing is affected by the interaction of various factors. Social factors were the dominant in the distribution of large old tree resources in Beijing. The spatial distribution of large old trees was mainly affected by the scenic resort and historic site (SRHS), and the SRHS and gross domestic product (GDP) level were the most important factors influencing the richness of large old tree species. In addition, the functional value and characteristics of tree species determined the distribution of large old tree habitats. Therefore, the protection of large old tree resources requires developing scientific management and planning by managers, increasing investment in management and protection, and strengthening ecological culture publicity.
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KUMAR, Dr D. SURESH. "THE BAOBAB TREE." Hygeia J. D.Med.10 (1) August 2018 - January 2019 10, no. 1 (September 15, 2018): 1–2. http://dx.doi.org/10.15254/h.j.d.med.10.2018.16.
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Trees are known to live for many years. Gautama Buddha attained enlightenment while meditating underneath a peepal tree (Ficus religiosa). A branch of the original tree was rooted in Anuradhapura, Sri Lanka in 288 B.C. and is known as Jaya Sri Maha Bodhi. It is the oldest plant in the world. Long-living plants are found in many parts of the world. The Baobab tree is one among them. Baobab is the common name of a genus of trees (Adansonia) distributed in Madagascar, Africa, Australia and India. The Baobab is the national tree of Madagascar. The Baobab is also known as “bottle tree”, “the tree of life”, “upside-down tree”, and “monkey bread tree”.
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Li, Tie Hua, Shi Zhi Wen, Gong Xiu He, Liang Chen, and Shi Jia Huang. "Study on Superior Tree Selection Methods of Phoebe Hui in Hunan." Advanced Materials Research 1010-1012 (August 2014): 1198–201. http://dx.doi.org/10.4028/www.scientific.net/amr.1010-1012.1198.
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Phoebe hui is a precious timber tree species. In order to get excellent seedlings and stands with good genes and develop Phoebe hui better, it is necessary to select superior trees. The dominant trees comparative method and small sample plot method were used to evaluate and select Phoebe hui superior trees in Longshan county, Hunan province, and the evaluation factors included diameter at breast height (DBH), tree height, timber volume and other quality factors. The results showed that, using the dominant trees comparative method, the DBH, tree height and timber volume values of the superior tree were more than 1.12, 1.06 and 1.23 times of the mean values of 5 dominant trees respectively, and 6 superior trees were selected in two stands. Using small sample plot method, the DBH, tree height and timber volume of the superior tree were more than the mean value and 1 times standard deviation value of the stand, and 4 trees were selected as superior tree. These 2 methods can be used for superior tree selection of Phoebe hui in Hunan, and the dominant trees comparative method is more simple and easier for operation.
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Wang, J., and R. Lindenbergh. "VALIDATING A WORKFLOW FOR TREE INVENTORY UPDATING WITH 3D POINT CLOUDS OBTAINED BY MOBILE LASER SCANNING." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2 (May 30, 2018): 1163–68. http://dx.doi.org/10.5194/isprs-archives-xlii-2-1163-2018.
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Urban trees are an important component of our environment and ecosystem. Trees are able to combat climate change, clean the air and cool the streets and city. Tree inventory and monitoring are of great interest for biomass estimation and change monitoring. Conventionally, parameters of trees are manually measured and documented in situ, which is not efficient regarding labour and costs. Light Detection And Ranging (LiDAR) has become a well-established surveying technique for the acquisition of geo-spatial information. Combined with automatic point cloud processing techniques, this in principle enables the efficient extraction of geometric tree parameters. In recent years, studies have investigated to what extend it is possible to perform tree inventories using laser scanning point clouds. Give the availability of a city of Delft Open data tree repository, we are now able to present, validate and extend a workflow to automatically obtain tree data from tree location until tree species. The results of a test over 47 trees show that the proposed methods in the workflow are able to individual urban trees. The tree species classification results based on the extracted tree parameters show that only one tree was wrongly classified using k-means clustering.
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Evert, Dean R., and Paul F. Bertrand. "Survival and Growth of Peach Trees Planted in Killed Bahiagrass at an Old Orchard Site." HortScience 28, no. 1 (January 1993): 26–28. http://dx.doi.org/10.21273/hortsci.28.1.26.
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More peach [Prunus persica (L.) Batsch.] trees survived when planted in killed bahiagrass (Paspalum notatum Flugge `Paraguayan-22') sod growing between previous orchard tree rows (98%) than when planted in previous tree sites (81%) or in previous tree rows, but halfway between previous tree sites (79%). The previous orchard was removed Nov. 1986, and new trees were planted Feb. 1987. Surviving trees in the killed sod grew better than trees at the other two sites. Tilling the sites before planting did not affect nematode populations or tree survival and growth. Soaking the tree roots in a fenamiphos solution (1 g·liter-1) for 20 minutes before planting resulted in 79% tree survival vs. 93% survival for the nonsoaked trees. Fenamiphos sprayed under the trees at a rate of 11.2 kg·ha-1 during the spring and fall of the planting year did not change nematode populations, tree survival, or tree growth. The fenamiphos sprays reduced the increase in trunk cross-sectional area by 3 cm2 for trees in the sod. Other than leaf Zn concentration, which was low, concentrations of the elements were within the sufficiency range for Georgia for all treatments. Trees planted in the killed sod had an increased leaf K concentration and decreased leaf Mg concentration when compared with trees planted in the rows. Chemical name used: ethyl 3-methyl-4-(methylthio)phenyl (1-methylethyl)phosphoramidate (fenamiphos).
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Zhou, Qianyi, Zhaohong Jiang, Xin Zhang, Qing Lai, Yiming Li, Fei Zhao, and Zhong Zhao. "Tree age did not affect the leaf anatomical structure or ultrastructure of Platycladus orientalis L. (Cupressaceae)." PeerJ 7 (October 29, 2019): e7938. http://dx.doi.org/10.7717/peerj.7938.
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Tree aging is a new research area and has attracted research interest in recent years. Trees show extraordinary longevity; Platycladus orientalis L. (Cupressaceae) has a lifespan of thousands of years. Ancient trees are precious historical heritage and scientific research materials. However, tree aging and tree senescence have different definitions and are poorly understood. Since leaves are the most sensitive organ of a tree, we studied the structural response of leaves to tree age. Experiments investigating the leaf morphological structure, anatomical structure and ultrastructure were conducted in healthy P. orientalis at three different ages (ancient trees >2,000 years, 200 years < middle-aged trees <500 years, young trees <50 years) at the world’s largest planted pure forest in the Mausoleum of the Yellow Emperor, Shaanxi Province, China. Interestingly, tree age did not significantly impact leaf cellular structure. Ancient P. orientalis trees in forests older than 2,000 years still have very strong vitality, and their leaves still maintained a perfect anatomical structure and ultrastructure. Our observations provide new evidence for the unique pattern of tree aging, especially healthy aging. Understanding the relationships between leaf structure and tree age will enhance the understanding of tree aging.
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Zaman, Q. U., A. W. Schumann, and H. K. Hostler. "Rapid Estimation of Citrus Tree Damage from Hurricanes in Florida Using an Ultrasonic Tree Measurement System." HortTechnology 16, no. 2 (January 2006): 339–44. http://dx.doi.org/10.21273/horttech.16.2.0339.
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Many citrus groves in Florida were affected by hurricanes in Summer 2004. A commercial 42-acre `Valencia' sweet orange (Citrus sinensis) grove of 2980 trees was routinely scanned with an automated ultrasonic system to measure and map tree canopy volumes. We estimated tree damage by comparing canopy volumes measured before and after the hurricanes of 2004. Ultrasonically sensed tree canopy volume was mapped and the relative tree canopy volume loss percentage (TCVL%) for each tree was calculated and classified into six categories [≤0 (no damage), 1% to 24%, 25% to 49%, 50% to 74%, 75% to 99%, and 100%]. Authenticity of the ultrasonically sensed missing trees was established by ground truthing or matching visually observed and georeferenced missing tree locations with ultrasonically sensed missing trees in the grove. Ninety-one trees were found missing during ground inspections after hurricanes and they exactly matched with ultrasonically sensed missing tree locations throughout the grove. All of the missing trees were in TCVL% categories 5 and 6 (≥75% damage). Some canopy volume was still detected with ultrasonics at the missing tree locations because of the presence of tall grass, weeds, or branches of large adjacent trees. More than 50% of trees in the grove were damaged (completely or partially) and generally larger trees (>100 m3) were damaged more by the hurricanes than small or medium size trees in each tree canopy volume loss category. The automated ultrasonic system could be used to rapidly identify missing trees (completely damaged) and to estimate partial tree canopy volume loss after hurricanes.
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Marini, Richard P. "618 Tree Form and Tree Density Affect Peach Tree Cropping and Profitability." HortScience 34, no. 3 (June 1999): 554B—554. http://dx.doi.org/10.21273/hortsci.34.3.554b.
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`Norman' peach trees were trained to the central-leader or open-vase form and were planted at high (740 trees/ha) or low (370 trees/ha) density. A third density treatment was a high/low density, where alternate trees in high-density plots were removed after 6 years to produce a low-density treatment. Annual yield per hectare was ≈15% to 40% greater for high-density treatments than for low-density treatments, but tree form had little influence on yield. Fruit size tended to be greater for low-density than for high-density treatments, but cumulative marketable yield was greatest for high-density and lowest for high/low density treatments. After 9 years, cumulative crop value was higher for open-vase than central-leader treatments (P = 0.12), but tree density had less of an effect on crop value (P = 0.21). Cumulative costs were highest for high-density treatments, but were not influenced by tree form. Income minus costs was nearly $4500/ha higher for open-vase than for central-leader trees and net present value was more than $2000/ha higher for high-density than low-density trees (P = 0.20). Open-vase trees were more profitable than central leader trees and should be planted at densities of about 700 trees/ha in the mid-Atlantic region.
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Gong, Haoyu, Qian Sun, Chenrong Fang, Le Sun, and Ran Su. "TreeDetector: Using Deep Learning for the Localization and Reconstruction of Urban Trees from High-Resolution Remote Sensing Images." Remote Sensing 16, no. 3 (January 30, 2024): 524. http://dx.doi.org/10.3390/rs16030524.
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There have been considerable efforts in generating tree crown maps from satellite images. However, tree localization in urban environments using satellite imagery remains a challenging task. One of the difficulties in complex urban tree detection tasks lies in the segmentation of dense tree crowns. Currently, methods based on semantic segmentation algorithms have made significant progress. We propose to split the tree localization problem into two parts, dense clusters and single trees, and combine the target detection method with a procedural generation method based on planting rules for the complex urban tree detection task, which improves the accuracy of single tree detection. Specifically, we propose a two-stage urban tree localization pipeline that leverages deep learning and planting strategy algorithms along with region discrimination methods. This approach ensures the precise localization of individual trees while also facilitating distribution inference within dense tree canopies. Additionally, our method estimates the radius and height of trees, which provides significant advantages for three-dimensional reconstruction tasks from remote sensing images. We compare our results with other existing methods, achieving an 82.3% accuracy in individual tree localization. This method can be seamlessly integrated with the three-dimensional reconstruction of urban trees. We visualized the three-dimensional reconstruction of urban trees generated by this method, which demonstrates the diversity of tree heights and provides a more realistic solution for tree distribution generation.
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Yang, Zi, Ka Wai Hui, Sawaid Abbas, Rui Zhu, Coco Yin Tung Kwok, Joon Heo, Sungha Ju, and Man Sing Wong. "A Review of Dynamic Tree Behaviors: Measurement Methods on Tree Sway, Tree Tilt, and Root–Plate Movement." Forests 12, no. 3 (March 22, 2021): 379. http://dx.doi.org/10.3390/f12030379.
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Urban forest ecosystems are being developed to provide various environmental services (e.g., the preservation of urban trees) to urban inhabitants. However, some trees are deteriorated asymptomatically without exhibiting an early sign of tree displacement, which results in a higher vulnerability under dynamic wind loads, especially during typhoon seasons, in the subtropical and tropical regions. As such, it is important to understand the tilt and sway behaviors of trees to cope up with the probability of tree failure and to improve the efficacy of tree management. Tree behaviors under wind loads have been broadly reviewed in the past literature, yet thorough discussions on the measurement methods for tree displacement and its analysis of broadleaf specimens are lacking. To understand the behavioral pattern of both broadleaf and conifer species, this paper presents a detailed review of sway behavior analysis from the perspectives of the aerial parts of the individual tree, including tree stem, canopy, and trunk, alongside a highlighted focus on the root–plate movement amid the soil-root system. The analytical approaches associated with the time-space domain and the time-frequency domain are being introduced. In addition to the review of dynamic tree behaviors, an integrated tree monitoring framework based on geographic information systems (GIS) to detect and visualize the extent of tree displacement using smart sensing technology (SST) is introduced. The monitoring system aims to establish an early warning indicator system for monitoring the displacement angles of trees over the territory of Hong Kong’s urban landscape. This pilot study highlights the importance of the monitoring system at an operational scale to be applicable in the urban areas showcasing the practical use of the Internet of Things (IoT) with an in-depth understanding of the wind-load effect toward the urban trees in the tropical and subtropical cities.
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Tan, Xiaoyang, Satoshi Hirabayashi, and Shozo Shibata. "Estimation of Ecosystem Services Provided by Street Trees in Kyoto, Japan." Forests 12, no. 3 (March 7, 2021): 311. http://dx.doi.org/10.3390/f12030311.
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Street trees are integral components of urban green infrastructure. The importance of benefits provided by street trees has motivated the development of various tools to quantify the value of ecosystem services. The i-Tree Eco is a widely applied method for quantifying urban forest structure, ecosystem services, and values. Since its first release in 2006, i-Tree Eco has been successfully utilized in over 100 countries around the world. This study described one of the first applications of the i-Tree Eco international project in Kyoto, Japan, by customizing the models and parameters to enhance the accuracy of analysis results. Kyoto’s street trees are prominently dominated by Ginkgo (Ginkgo biloba L.), Trident Maple (Acer buergerianum Miq.), Japanese Zelkova (Zelkova serrata (Thunb.) Makino.), Tuliptree (Liriodendron tulipifera L.), Flowering dogwood (Cornus florida L.), London Planetree (Platanus × acerifolia), Plum/cherry (Prunus spp.), and Weeping willow (Salix babylonica), which account for 92% of the 1230 sample trees and deliver ecosystem service benefits at US$71,434.21 annually or US$58.07/tree/year. The annual value of each function was estimated at US$41.34/tree for carbon storage and sequestration, US$3.26/tree for stormwater runoff reduction, US$11.80/tree for adverse health mitigation effects, and US$1.67/tree for energy savings. The street tree species of Kyoto city that produce the highest average annual benefits are among the largest trees currently in the population, including P. × yedoensis (US$225.32/tree), Z. serrata (US$123.21/tree), S. babylonica (US$80.10/tree), and P. × acerifolia (US$65.88/tree). Our results demonstrated a comprehensive understanding of street trees benefits for Kyoto city, providing baseline information for decision-makers and managers to make effective urban trees management decisions, developing policy, and setting priorities.
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Okonkwo, H. O., R. E. Ubaekwe, A. N. Okeke, and L. C. Malizu. "Phenotypic (Fruit and Seed Characters) Selection of Dacryodes edulis (Don. G. Lam H. J.) Tree for Vegetative Propagation." Nigerian Journal of Environmental Sciences and Technology 5, no. 2 (October 2021): 347–53. http://dx.doi.org/10.36263/nijest.2021.02.0280.
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The study was conducted to identify superior D. edulis trees using phenotypic characters (fruit and seed size) as the criteria to select candidate trees for subsequent multiplication through vegetative propagation. Five D. edulis compound trees were randomly selected within Onne community in Eleme LGA Rivers state in a preliminary effort to assist households in the selection and multiplication of desirable tree phenotypes. Seeds were extracted by softening fruit with warm water at 57oC. Fruit and seed length (mm), breadth (mm), and thickness (mm) were taken using veneer caliper. Size of fruit and seed was calculated as: length × breadth × thickness. The experiment was a completely randomized design in its layout and data analysis was carried out using analysis of variance and regression after a normality test was conducted using Shapiro-Wilk. The results showed that highest mean fruit size (79.38 ± 3.99 mm) was recorded in tree 3 and the lowest was tree 5 (29.60 ± 1.48 mm): while, highest seed size (34.78 ± 2.47 mm) was recorded in tree 3 and the lowest in tree 4 (15.58 ± 0.99 mm). Highest within tree fruit size variability was recorded in tree 1 (24%) and the lowest in tree 4 (12%): while the highest within tree seed size variability was recorded in tree 2 (28%) and the lowest in tree 5 (15%). There was however a significant difference in fruit and seed size between the trees. Pairwise comparison showed that tree 1 was not significantly different from tree 2 in fruit and seed size. There was a significant positive correlation between fruit and seed size among the trees. This implies that selection for large fruit size automatically selects for large seeds size. Large fruited trees can therefore be multiplied from these trees using vegetative propagation.
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Weinbaum, S. A., F. J. A. Niederholzer, S. Ponchner, R. C. Rosecrance, R. M. Carlson, A. C. Whittlesey, and T. T. Muraoka. "Nutrient Uptake by Cropping and Defruited Field-grown `French' Prune Trees." Journal of the American Society for Horticultural Science 119, no. 5 (September 1994): 925–30. http://dx.doi.org/10.21273/jashs.119.5.925.
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Four adjacent heavily cropping 12-year-old `Petite d'Agen' prune (Prunus domestica L.) trees were selected, and two of the trees were defruited in late spring (28 May) after the spring growth flush and full leaf expansion. Trees received K daily through the drip-irrigation system, and 15N-depleted (NH4)2SO4 was applied twice between the dates of defruiting and fruit maturation. Trees were excavated at the time of fruit maturity (28 July) and fractionated into their component parts. The following determinations were made after tree excavation and sample processing: tree dry weight, dry weight distribution among the various tree fractions (fruit, leaves, roots, trunk, and branches), tree nutrient contents, within-tree nutrient distribution, total nonstructural carbohydrates (TNCs), and recovery of labeled N. Trees only recovered ≈3% of the isotopically labeled fertilizer N over the 6-week experimental period. Heavily cropping trees absorbed ≈9 g more K per tree (17% of total tree K content) during the 2-month period of stage III fruit growth than defruited trees. The enhanced K uptake in heavily cropping trees was apparently conditioned by the large fruit K demand and occurred despite greatly reduced levels of starch and TNCs relative to defruited trees. Fruit K accumulation in heavily cropping trees was accompanied by K depletion from leaves and perennial tree parts. Except for K, fruited and defruited trees did not differ in nutrient content.
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Doccola, Joseph, Sheri Smith, Joseph Fischer, and Brian Strom. "Evaluation of Stem-Injected TREE-äge® (4% Emamectin Benzoate) for Protecting Western White Pines (Pinus monticola) from Mountain Pine Beetle (Dendroctonus ponderosae Hopkins)(Coleoptera: Curculionidae: Scolytinae)." Arboriculture & Urban Forestry 46, no. 5 (September 1, 2020): 333–46. http://dx.doi.org/10.48044/jauf.2020.024.
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The protection of high-value trees against bark beetles and the development of alternatives to bole sprays is a priority for the tree manager. The objective of this study was to evaluate stem-injected TREE-äge® (emamectin benzoate [EB]) as a protective treatment for western white pines (Pinus monticola Dougl. ex D. Don) against mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins). Treatment efficacy was based solely on tree mortality as per Shea protocols (i.e., ≥ 60% check vs. ≤ 20% treated tree mortality). Our first experiment was installed in 2007 and included trees stem-injected with TREE-äge and untreated controls. Bole application of S-(-)-verbenone and green leaf volatile (GLV) blend was included for observational comparison. Pressure from MPB was heavy, as indicated by the number and timing of control tree mortality (90%). Strip attacks by MPB in TREE-äge trees indicated that the impacts of EB, and by inference its distribution, were inconsistent. In 2009, the injection protocol was revised to improve EB distribution in the phloem via closer injection points. In the 2009 TREE-äge-treated trees, adult beetle mining stopped when they contacted phloem and was insufficient to cause tree death by girdling. Blue-stain fungi colonized the sapwood of trees in both studies. Isolates from autopsied trees treated with TREE-äge alone were subsequently identified as Grosmannia clavigera and Leptographium longiclavatum (Ophiostomatales: Ascomycota), species that can incite tree mortality. In 2013, we revised our protocol to include GLV plus verbenone or propiconazole with TREE-äge, wherein these treatments proved effective in protecting trees against MPB and their associated pathogenic fungi.
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Harman, Dan M., Anne Bourne, and Amy L. Harman. "LOCUST BORER (COLEOPTERA: CERAMBYCIDAE) ATTACK IN RELATION TO PULSED ELECTRIC CURRENT IN BLACK LOCUST TREES." Journal of Entomological Science 24, no. 1 (January 1, 1989): 124–32. http://dx.doi.org/10.18474/0749-8004-24.1.124.
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Resistance to pulsed electric current (ER) applied to the cambium layer was studied in black locust trees, Robinia pseudoacacia L., in relation to tree thrift indices, and particularly to intensity of current-season attacks by the locust borer Megacyllene robinia. A total of 415 borer attacks were sustained by 241 trees, with a maximum of 20 attacks per tree. Although variation in the data was high both within and among study sites, ER was positively correlated with borer mines per tree and with increased degrees of tree suppression, represented by dominance classes. ER ranged from 2 to 32 kohms per tree, with roughly 95% of the trees reading less than 25 kohms. Borer mines per tree were also correlated with tree dominance class, with more attacks incurred by increasingly suppressed trees.
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Ngetich, Samuel Kiplangat. "Effect of Tapping on Gum and Incense Yield of Selected Trees Species in Elwaye and Dhas Districts, Borana Zone, Southern Oromia." East African Journal of Forestry and Agroforestry 6, no. 1 (July 27, 2023): 211–26. http://dx.doi.org/10.37284/eajfa.6.1.1334.
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Ethiopia is one of the Gum and Resin producing countries with a large potential. Borana pastoralists particularly utilised these resources as a source of revenue. The majority of Ethiopia’s gum-resin products are collected from natural oozing. In southern Ethiopia, improved tapping mechanisms are uncommon. This study was conducted to determine the effect of different tapping machines and tapping at different tree diameter classes on the gum and incense yields of selected tree species. Commiphora corrugata, Boswellia microphylla, and Boswellia neglecta tree species were selected for their potential existence and economic importance. A factorial experiment was arranged in a randomised complete block design (RCBD) in which three types of tapping materials including natural oozing and three levels of tree size (diameter classes) were used. Accordingly, materials (Panga, Axe, Sonki, and control) were applied at diameters of (5-8 cm, 8.1-11 cm and >11 cm) for a tree height below DBH (at < 130 cm) and above DBH (at >130 cm) on selected tree species while natural oozing was remained untapped and used as controls. Accordingly, the highest mean yield was recorded for trees tapped by axe (5.99 g/tree), followed by Sonki (5.01 g/tree) and bigger diameter class >11 cm (7.10 g/tree) for Commiphora corrugata. The highest mean yield was also obtained for trees tapped by axe (10.76 g/tree) in the first year and (43.71 g/tree) in the second year and bigger diameter class >11 cm (15.16 g/tree) in the first year and (47.81 g/tree) in the second year for Boswellia microphylla. Moreover, the highest mean yield was recorded for naturally oozing trees (6.16 g/tree) and bigger diameter class >11 cm (6.33 g/tree) for Boswellia neglecta. Tapped trees generally provided significantly higher yields than untapped or control trees, and frankincense yield increased with increasing tree size
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Abimanyu, Bondan, Rahmat Safe’i, and Wahyu Hidayat. "Application of Forest Health Monitoring Method in Assessing Tree Damage in Metro Urban Forests." Jurnal Sylva Lestari 7, no. 3 (September 29, 2019): 289. http://dx.doi.org/10.23960/jsl37289-298.
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The assessment of tree condition is very important to ensure visitor safety and to maintain the sustainability of Metro Urban Forest. However, data and information on the condition of trees in six locations of Metro Urban Forest are not yet available. Therefore, this study was conducted to assess tree damage in each Metro Urban Forest. Evaluation of tree damage such as location, type, and level of tree damage was conducted for each tree in accordance with the damage criteria of the Forest Health Monitoring method. Data were then analyzed by calculating the damage index and tree damage level index. The results showed that the vegetation in Metro Urban Forests was dominated by trees with the healthy condition of 1.549 trees or 87% of the total trees, hence the Metro Urban Forests could be considered safe for visitors. The level of tree damage in each Metro Urban Forest is as follows: 3% in Islamic Center Urban Forest, 9% in Tesarigaga Urban Forest, 12% in Bumi Perkemahan Urban Forest, 13% in Linara Urban Forest, 23% in Terminal 16c Urban Forest, and 23% in Stadion Urban Forest at 23%. Overall tree damage in the Metro Urban Forest reached 232 trees or 13% of the total trees. Tree maintenance in each urban forest in Metro City is needed to maintain tree health, the safety of visitors, and improve the quality of the urban environment. Keywords: damaged trees, Forest Health Monitoring, Metro Urban Forests
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Reid, M. L., and S. S. Glubish. "Tree size and growth history predict breeding densities of Douglas-fir beetles in fallen trees." Canadian Entomologist 133, no. 5 (October 2001): 697–704. http://dx.doi.org/10.4039/ent133697-5.
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AbstractFor bark beetles (Coleoptera: Scolytidae) breeding in fallen trees, the tree characteristics that are associated with higher breeding densities are poorly known. The breeding densities of Douglas-fir beetles, Dendroctonus pseudotsugae Hopkins, in freshly felled Douglas-fir, Pseudotsugae menziesii (Mirb.) Franco, were examined with respect to tree diameter, phloem thickness, and several measures of tree growth rate over the past year to 10 years prior to tree death. Trees were felled in 8 decks of 3–12 trees to provide a range of tree qualities in a given location. Stepwise regression revealed that of the tree characteristics measured, only diameter was needed to explain the density of beetle attacks on trees within decks. Because diameter, phloem thickness, and growth-increment measures were all highly correlated, attack density also increased with phloem thickness and growth rate prior to felling when these measures were analyzed individually. The apparent preference for larger trees with thicker phloem is consistent with published results for live trees, but the positive effect of tree growth rate prior to death is contrary to results for beetles attacking live trees. Thus, assessments of stand susceptibility to bark beetles based on tree growth rate may differ depending on whether beetles are initially breeding in live or dead trees.
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Li, Jian Ke, Jing Hui Yang, Yan Jun Liu, Jun Xun Huang, Chun Xia Wu, Ting Liu, and Wu Que Gong. "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 flowering trees increased from 5% at age of one year to 55% in age of three years and fruit set increased from 0 to 44% following increase of age tree. Open trees had more flowers with 10.6 in 2-year-old tree, 38.6 in 3-year-old tree. Open trees had more percentage of bearing plants with around 47%. The average length of bearing branches was 11.5 cm at open trees, which was more than other crown shapes at age of three years. Open trees had most fruit number per bearing tree (6.5, 8.5 apart). Therefore, creating open tree crown shape may increase flowering, fruiting and yield in greenhouse production of feijoa.
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Hanum, S. F., A. Rahayu, R. Iryadi, and D. P. Darma. "Tree Architecture Model and Tree Health Assessment Using Sonic 3D Tomograph Relationship in Bali Botanical Garden." Jurnal Manajemen Hutan Tropika (Journal of Tropical Forest Management) 29, no. 1 (April 18, 2023): 99–108. http://dx.doi.org/10.7226/jtfm.29.1.99.
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The incident of fallen trees or broken branches is dangerous for tourists visiting Bali Botanical Garden. Tree health monitoring in locations with high human activity and near valuable properties is mandatory to minimize the potency of tree failure. Since the stand stability is influenced by biological and physical factors, multiple variables consisting of species characteristics (stem form), tree dimensions (height, diameter, and slenderness coefficient), and tree health were used as parameters of tree health. The aim of this study is to examine the health condition of trees located in XIV.G Bali Botanical Garden and to identify the most significant morphological character related to the result of tomograph measurement. A purposive sampling technique was adopted for locations which highly visited. A total of 80 trees were examined as samples to measure tree health. The evaluation used visual observation and tomograph technology. The result showed the most tree defect found were branches covered with epiphyte and moss. However, tomograph examination found only one tree classified at high risk (Bischofia javanica) and seven trees classified at medium risk (Syzygium polyanthum, Syzygium racemosum, Bischofia javanica, Pittosporum mollucanum, Pittosporum sp. and Dacrycarpus imbricatus (2 trees)). This study suggests the use of tree architecture model as the most significant morphological character on tree samples with medium decay.
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Sarathi, Ramanujam, Arya Nandini, and Michael Danikas. "Understanding Electrical Treeing Phenomena in XLPE Cable Insulation Adopting UHF Technique." Journal of Electrical Engineering 62, no. 2 (March 1, 2011): 73–79. http://dx.doi.org/10.2478/v10187-011-0012-4.
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Understanding Electrical Treeing Phenomena in XLPE Cable Insulation Adopting UHF TechniqueA major cause for failure of underground cables is due to formation of electrical trees in the cable insulation. A variety of tree structure can form from a defect site in cable insulationvizbush-type trees, tree-like trees, fibrillar type trees, intrinsic type, depending on the applied voltage. Weibull studies indicate that a higher applied voltage enhances the rate of tree propagation thereby reducing the life of cable insulation. Measurements of injected current during tree propagation indicates that the rise time and fall time of the signal is of few nano seconds. In the present study, an attempt has been made to identify the partial discharges caused due to inception and propagation of electrical trees adopting UHF technique. It is realized that UHF signal generated during tree growth have signal bandwidth in the range of 0.5-2.0 GHz. The formation of streamer type discharge and Townsend type discharges during tree inception and propagation alters the shape of the tree formed. The UHF signal generated due to partial discharges formed during tree growth were analyzed adopting Ternary plot, which can allow one to classify the shape of tree structure formed.
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Rowston, C. "Nest- and refuge-tree usage by squirrel gliders, Petaurus norfolcensis, in south-east Queensland." Wildlife Research 25, no. 2 (1998): 157. http://dx.doi.org/10.1071/wr96065.
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The types of nest trees used by squirrel gliders and the tree types available in the environment were compared. Non-eucalypt trees and smooth-barked eucalypts were significantly under-utilised as nest trees, and iron-barked eucalypts and stags were used as nest trees to a greater degree than would be expected from their availability in the environment. Stags used as nest trees could be of a significantly smaller tree diameter than other tree types, whereas smooth-barked trees used as nest trees were of a significantly larger diameter than all other tree types.
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Kim, Anastasiia, Noah A. Rosenberg, and James H. Degnan. "Probabilities of Unranked and Ranked Anomaly Zones under Birth–Death Models." Molecular Biology and Evolution 37, no. 5 (December 20, 2019): 1480–94. http://dx.doi.org/10.1093/molbev/msz305.
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Abstract A labeled gene tree topology that is more probable than the labeled gene tree topology matching a species tree is called “anomalous.” Species trees that can generate such anomalous gene trees are said to be in the “anomaly zone.” Here, probabilities of “unranked” and “ranked” gene tree topologies under the multispecies coalescent are considered. A ranked tree depicts not only the topological relationship among gene lineages, as an unranked tree does, but also the sequence in which the lineages coalesce. In this article, we study how the parameters of a species tree simulated under a constant-rate birth–death process can affect the probability that the species tree lies in the anomaly zone. We find that with more than five taxa, it is possible for species trees to have both anomalous unranked and ranked gene trees. The probability of being in either type of anomaly zone increases with more taxa. The probability of anomalous gene trees also increases with higher speciation rates. We observe that the probabilities of unranked anomaly zones are higher and grow much faster than those of ranked anomaly zones as the speciation rate increases. Our simulation shows that the most probable ranked gene tree is likely to have the same unranked topology as the species tree. We design the software PRANC, which computes probabilities of ranked gene tree topologies given a species tree under the coalescent model.
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Marini, Richard P., and Donald S. Sowers. "Peach Tree Growth, Yield, and Profitability as Influenced by Tree Form and Tree Density." HortScience 35, no. 5 (August 2000): 837–42. http://dx.doi.org/10.21273/hortsci.35.5.837.
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`Norman' peach [Prunus persica (L.) Batsch] trees were trained to the central-leader or open-vase form and were planted at high (740 trees/ha), or low (370 trees/ha) density. A third density treatment was a HIGH → LOW density, where alternate trees in high-density plots were removed after 6 years to produce a low-density treatment. From 3 to 5 years after planting, trunk cross-sectional areas (TCA) increased most for low-density trees. After 9 years, TCA was greatest for low-density and least for high-density trees. Because of differences in tree training, central-leader trees were taller than open-vase trees and tree spread was greater for low-density than for high-density trees. Annual yield per hectare was 15% to 40% greater for high-density treatments than for low-density treatments, but tree form had little influence on yield. Average fruit weight tended to be greater for low-density than for high-density treatments, but cumulative marketable yield was greatest for high-density and lowest for HIGH → LOW treatments. Income minus costs for 9 years was nearly $4200/ha higher, and net present value was about $2200/ha higher, for open-vase than for central-leader trees (P = 0.08). Cumulative net present value for the 9 years was about $2660/ha higher for high-than for low-density trees (P = 0.36).
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Bakken, Stephen. "Group-Tree Hazard Analysis." Arboriculture & Urban Forestry 21, no. 3 (May 1, 1995): 150–55. http://dx.doi.org/10.48044/jauf.1995.025.
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Tree hazard control programs focus on individual tree risk analysis. Although microsite conditions are often evaluated, whole forests or groups of trees are rarely considered. A tree hazard program was initiated at a northern California state park in 1969. Since then, hundreds of trees have been removed from the campground to reduce the agency's liability. Nevertheless, hundreds more trees have failed, causing injury and property damage. Traditional single tree risk assessment proved to be inadequate to stabilize this forest. Consequently, the environmental dynamics of the entire forest were assessed, and every tree was evaluated for its positive or negative contribution to the long term stability of the forest.
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Li, Haibin, Xiaowei Zhang, Zeqing Li, Jian Wen, and Xu Tan. "A Review of Research on Tree Risk Assessment Methods." Forests 13, no. 10 (September 23, 2022): 1556. http://dx.doi.org/10.3390/f13101556.
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As an important part of the urban environment, trees have certain risks while living in harmony with humans. For example, the failure of trees in extreme weather may cause casualties and damage to public and private; the decline and death of old and valuable trees can have an impact on the diversity and cultural value of trees. This paper outlines the theories related to tree risk and the development of tree risk assessment, evaluates the advantages and disadvantages of various tree risk assessment methods in existing studies, and explains some factors affecting the bearing capacity and related applications using knowledge of tree mechanics. Approaches in modern probing techniques are applied to study the response and loading of tree crowns and branches under wind loads, the application of different non-destructive testing techniques in visual assessment for detecting internal defects and root distribution of trees, and the role and impact of objective quantitative test results on tree risk assessment. Finally, the future development direction of tree risk assessment is predicted, which provides an important reference for research on tree risk assessment.
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Wang, Yunhan, Youlv Wu, Qianting Sun, Chunxia Hu, Hao Liu, Chuyu Chen, and Pengfeng Xiao. "Tree Failure Assessment of London Plane (Platanus × acerifolia (Aiton) Willd.) Street Trees in Nanjing City." Forests 14, no. 9 (August 22, 2023): 1696. http://dx.doi.org/10.3390/f14091696.
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The London plane (Platanus × acerifolia (Aiton) Willd.) street tree is a symbolic tree species in Nanjing City, which is known as the “city card”. However, accidents such as street trees falling over cars, affecting traffic, and hurting people have seriously affected the daily lives of citizens. Thus, it is of vital significance to accurately assess the potential for tree failure in London plane street trees in Nanjing City. This study comprehensively considers the growth condition of London plane street trees and their impact on traffic, establishes a scientific street tree failure assessment scheme that contains eight characteristics, creates a tree failure assessment database by thoroughly collecting data on trees, and develops a tree failure assessment model based on factor analysis and k-means clustering. The assessment results show that street trees that pose a high or medium potential for failure are present in proportions of 4.47% and 34.85%, respectively, and are mostly found in Gulou District, Xuanwu District, and Qinhuai District. The average tree failure score of London plane street trees on Changjiang Road in Xuanwu District is the highest, while the road with the lowest tree failure score is Mufu East Road in Gulou District. The results will provide a scientific basis for the maintenance of London plane street trees in Nanjing City and have reference significance for other street tree failure assessment studies.
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Attis Beltrán, H., G. Martínez Pastur, H. Ivancich, M. V. Lencinas, and L. M. Chauchard. "Tree health influences diameter growth along site quality, crown class and age gradients in Nothofagus forests of southern Patagonia." Journal of Forest Science 59, No. 8 (September 24, 2013): 328–36. http://dx.doi.org/10.17221/30/2013-jfs.
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We examined the influence of tree health on annual diameter increment of trees along gradients in stand site quality, crown classes and tree age in Nothofagus pumilio forests of Southern Patagonia. Healthy trees had higher annual diameter increment than unhealthy trees along all gradients (site quality, crown class, tree age). We argue that tree health could be employed as a qualitative variable in models of tree growth to estimate aboveground biomass and carbon stocks in this forest system. &nbsp;
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Simpson, Peter, and Rufin Van Bossuyt. "Tree-Caused Electric Outages." Arboriculture & Urban Forestry 22, no. 3 (May 1, 1996): 117–21. http://dx.doi.org/10.48044/jauf.1996.018.
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In 1995, Eastern Utilities was among 14 utilities in the United States and Canada participating in a study to collect and evaluate data about the phenomena of how trees cause outages. Results indicate that failure of trees accounted for 40% of the preventable tree-caused outages in the Brockton territory of Eastern Utilities. Even though line clearance tree trimming continues to be the primary strategy, programmatic changes were made in Eastern Utilities' Tree Management Program. A Danger Tree Project was initiated to identify and mitigate trees with structural weaknesses along the 3-phase portion of the electrical distribution circuits. Approximately 4% of the trees in the portion of the urban forest managed by Eastern Utilities will either be removed or stormproof pruned. Reliability has improved by 20% to 30% along the circuits where hazardous trees have been removed or storm-proof pruning has been done. Proactive communication within the community and participation in communitybased tree planting has accompanied this project.