Tree Maintenance Research Articles

Gender Role in Teak Plantation at Paklay District Sayaboury Province, Lao PDR

This paper investigates the gender role in teak (Tectona grandis) plantation in Paklay District, Xayaboury Province. There are two objectives of study: 1) to analyze the state of gender equality in plantation activities, and 2) to analyze the satisfaction of men and women in undertaking their plantation responsibilities. This research gathered data from 124 families in the three villages, which corresponded to 100% of those growing teak. The household interview gathered both quantitative and qualitative data using the data management program KOBO toolbox. The results of showed that men and women participate equally in nine of 12 plantation activities (or 75%) being land clearing, soil preparation, planting lines, planting, tree maintenance, pruning-thinning, building a fire break, weeding and marketing (selling). In terms of satisfaction, women expressed themselves to be ‘very satisfied’ on a Likurt scale, whereas men were only ‘satisfied’. It was found that men and women discussed the work required in the teak plantation together and divided their responsibilities in accordance with whether the work was perceived to be light or heavy and with bodily strength of those in the household. The gender equality and mutual respect between the sexes from this cooperation meant that both men and women were satisfied.

VEGFD signaling balances stability and activity-dependent structural plasticity of dendrites

Mature neurons have stable dendritic architecture, which is essential for the nervous system to operate correctly. The ability to undergo structural plasticity, required to support adaptive processes like memory formation, is still present in mature neurons. It is unclear what molecular and cellular processes control this delicate balance between dendritic structural plasticity and stabilization. Failures in the preservation of optimal dendrite structure due to atrophy or maladaptive plasticity result in abnormal connectivity and are associated with various neurological diseases. Vascular endothelial growth factor D (VEGFD) is critical for the maintenance of mature dendritic trees. Here, we describe how VEGFD affects the neuronal cytoskeleton and demonstrate that VEGFD exerts its effects on dendrite stabilization by influencing the actin cortex and reducing microtubule dynamics. Further, we found that during synaptic activity-induced structural plasticity VEGFD is downregulated. Our findings revealed that VEGFD, acting on its cognate receptor VEGFR3, opposes structural changes by negatively regulating dendrite growth in cultured hippocampal neurons and in vivo in the adult mouse hippocampus with consequences on memory formation. A phosphoproteomic screening identified several regulatory proteins of the cytoskeleton modulated by VEGFD. Among the actin cortex-associated proteins, we found that VEGFD induces dephosphorylation of ezrin at tyrosine 478 via activation of the striatal-enriched protein tyrosine phosphatase (STEP). Activity-triggered structural plasticity of dendrites was impaired by expression of a phospho-deficient mutant ezrin in vitro and in vivo. Thus, VEGFD governs the equilibrium between stabilization and plasticity of dendrites by acting as a molecular brake of structural remodeling.

Exploring Urban Greenery: A Case Study of Roadside Trees in Pokhara Metropolitan City

Roadside trees play a crucial role as important components of urban greenery, significantly enhancing the overall quality of cities and ultimately contributing to the quality of life for residents and visitors alike. This study examines the condition, maintenance, and proximity of roadside trees to electric wire corridors in Pokhara Metropolitan City, Nepal. This study employs field surveys, categorization based on tree attributes, and mapping techniques to analyze the distribution and characteristics of roadside trees. Out of approximately 1500 trees initially collected, 1435 were processed for further analysis. Trees were classified by species, height, condition, and the presence of fencing or resting structures (Chautaro), with proximity to electric wire corridors also assessed. Findings reveal a significant presence of trees in good condition, predominantly Dhupi, Kapur and Ashoka species, with a notable percentage requiring maintenance. A substantial number of trees were found in close proximity to electric wires, posing potential hazards. Mapping techniques facilitated visualizing the spatial distribution of trees, aiding in urban planning and management strategies. The study underscores the importance of sustainable urban greening practices and the need for proactive measures to address challenges related to tree maintenance and safety in urban environments like Pokhara Metropolitan City. This study emphasizes the pivotal role of roadside trees in enhancing the aesthetic appeal and quality of city life, positioning them as decisive factors in shaping urban environments and fostering a welcoming atmosphere for residents and visitors.

Branch Break Assessment: An Unexpected Accident with a Professional Arborist

Abstract Background Arborists are important in both the maintenance of urban trees and research on forest canopies. Tree climbing is hazardous work. This study investigated the causes of a branch-breaking accident involving a certified arborist. Methods The branch was 11 cm in diameter. The density and mechanics of the branch wood were studied; the measurable stresses and deformations until the material ruptured were analyzed. The position of the tree climber and the applied forces were calculated, including the shear stresses, the bending moment, and the support reaction suffered at the point of rupture. Results The shear stress grew exponentially from V = 25.78 MPa; a shifting of the angle of the lanyard by > 45° and moving one meter toward the tip of the branch caused a 64.67% increase in shear stress. The support distance of the arborist’s body on the one anchor point on the branch, combined with the angle of force on the same branch, caused the imminent rupture of the branch’s base. The study provides evidence that the arborists should avoid traveling over small horizontal branches using only one safety point with lanyards.

Impact of sub-acute exposure to nuvan on serum lipoproteins of catfish, Clarias batrachus and their potential effects indirectly on human health

Pesticides are frequently applied in agricultural land, public health programs, and maintenance of trees or plants and also used as preservatives for different food materials for a long time. But these pesticides cause a lot of negative health and environmental impacts which affects the sustainability of an ecosystem. Among the different pesticides organophosphorus pesticide mostly used in agricultural purposes to prevent the disease causing agents like insects, pests, parasite due to its less persistence in our environment. Synthetic pesticide like Nuvan accumulations in the tissues of animals produce cyto-toxicity and have severed health issues due to its persistent nature. When these pesticides intake by aquatic animals specially fishes, they can interfere with the food chain. When such contaminated fishes eaten by someone they can destroy multiple systems in the body of human and other livings. Changes in blood biochemical indices gives signs what is happening in body of animals after exposure of pesticides. Most edible and commercially valuable freshwater fish Clarias batrachus was used in this work for analyzed the hazardous nature of toxic pesticide nuvan on some biochemical parameters. When fish exposed to two sub-lethal levels of nuvan (0.0137 ml/L and 0.0274 ml/L) for 60 days showed that the pesticide induces changes in blood parameters. The results showed very highly significant (p<0.001) increase in Low- density lipoprotein-cholesterol (LDL) and highly significant (p<0.01) increase in Very low- density lipoprotein-cholesterol (VLDL) while very highly significant (p<0.001) reduction in high density lipoprotein- cholesterol (HDL) were noted in treated groups compared with the control. This study implicates that adverse effect on lipoproteins due to synthetic pesticides have a negative health effect as cardiovascular risk status. Research of environmental pollution and its adverse effects on human and other animals including fish is remarkable which can leads the sustainability of our environment.

Development of a molecular maker for sex identification in Thai commercial date palm (Phoenix dactylifera L.).

Date palm (Phoenix dactylifera L.) is a dioecious plant, with male and female plants having distinct characteristics. Female plants are responsible for fruit production, and only approximately 10% of male plants are necessary for effective pollination. The determination of plant sex occurs during the first flowering, a process that typically spans 3-7 years. However, this extended timeframe results in significant time and valuable plantation resources being expended in the maintenance of trees. To address this issue, the study focused on sex identification of date palms using DNA markers. The research aimed to develop sex-specific markers for certain date palm cultivars, employing the high annealing temperature random amplified polymorphic DNA (HAT-RAPD) technique for accurate and reliable sex identification. In this investigation, 45 RAPD primers underwent screening in both male and female date palm plants to pinpoint sex-specific markers. Out of the total primers tested, only one, OPW-18, exhibited a correlation with sex. OPW-18 produced a distinct band of approximately 400 bp, consistently present in all male plants but absent in all female plants. The male-specific fragment from OPW-18 was cloned and sequenced to facilitate the development of sex-specific sequence-characterized amplified region (SCAR) primers. The outcomes revealed that the newly crafted SCAR primer pair, mspW18-2F and mspW18-2R, successfully amplified a unique fragment of 283 bp exclusively in male plants. This capability allowed the identification of 100% of male plants in the KL1 and Barhi cultivars. These markers prove to be efficient, reliable, and reproducible for early-stage sex identification in plants.

Penerapan akuntansi aset biologis berdasarkan PSAK No. 69 pada PT Astra Agro Lestari Tbk

In the agribusiness industry, biological assets emerge as the most crucial assets with significant value. Within this sector, PT Astra Agro Lestari Tbk stands out as a company engaged in various activities, including palm oil plantation. Palm oil serves as a biological asset managed by PT Astra Agro Lestari Tbk, encompassing recognition, measurement, and disclosure aspects. This research aims to examine the implementation of biological asset accounting in accordance with PSAK No. 69 at PT Astra Agro Lestari Tbk. Employing a qualitative research approach rooted in postpositivism philosophy, the study investigates natural phenomena or events. The finding reveal that PT Astra Agro Lestari Tbk adheres to the provisions outlined in PSAK No. 69 concerning the recognition, measurement, and disclosure of biological assets. The company exercises control over biological assets through activities such as planting, maintenance, and upkeep of oil palm trees over time. Biological assets are measured based on fair value less costs to sell. Moreover, PT Astra Agro Lestari Tbk discloses gains and losses incurred during the reporting period in the profit and loss statement, while distinguishing between producing and non-producing plants.

Local Communities Implications’ in Managing Woody Species and Carbon Accumulation in Sahelian parts of Maradi Region, Niger Republic

In Sahel, climate change will intensify especially in West Africa in the future and seasons are observed to have a decrease in rainfall projected. This situation will affect future woody vegetation cover because Sahelian zone was characterized by significant vegetation response to rainfall. Notwithstanding climate change impacts on woody vegetation cover, some human practices can play positive role in Sahelian vegetation change. This study aimed to analyze local community implications’ in managing woody species and carbon accumulation in Sahelian parts of Maradi Region, Niger Republic. Both quantitative and qualitative data were used in this study. Results showed that ecosystem services (provisioning, regulating and supporting) provided by woody trees species in the study area represent the main reasons for maintenance and protection of trees in farmlands. This clearly highlighted the roles of local communities in maintenance and protection of woody trees and consequently carbon accumulation by these woody species. This can allow farmers to be eligible to receive payments for the ‘’Carbon’’ that those practices contribute to sequester under a ‘’Carbon’’ trading arrangement in the Clean Development Mechanism (CDM) of the Kyoto Protocol of United Nations Framework Convention on Climate Change.

The Role of Coastal Women’s Empowerment in Achieving The Success of SDGs: A Study on The Kebaya Group, Bekasi

Land conversion has occurred in the coastal area of Kampung Beting, Pantai Bahagia Village, Bekasi Regency. What used to be a mangrove plantation has transformed into spaces for fish and shrimp ponds. This phenomenon took place from 2001 to the early 2010s. The promise of lucrative income led the community to compete in changing land use without considering the potential consequences. After 2011, the community gradually began to feel the negative impacts of this land conversion. To this day, the entire area that was once used for ponds has turned into the sea, causing the community to lose their livelihoods. Furthermore, not only have they lost their livelihoods, but they have also been confronted with land degradation, which threatens their sustainability. This study examines how coastal women's empowerment activities can contribute to sustainable development. The research employs a phenomenological approach, and data is collected through observation, interviews, and documentation. The findings indicate that Coastal Women's Empowerment Contributes to Sustainable Goals in Climate Change Mitigation, Gender Equality, and Poverty Alleviation. In climate change mitigation activities, there are two key activities: 1) the development of women's behavior in efforts to improve and rehabilitate critical lands, and 2) women's involvement in the maintenance of mangrove trees. In gender equality activities, there is one main activity: 1) active participation of women in productive economic activities, allowing coastal women in Pantai Bahagia Village to have regular activities beyond their domestic responsibilities. The focus of poverty alleviation activities is 2) increasing income by utilizing non-timber mangrove products for food processing and crafts.

An Urban Forest Diversification Software to Improve Resilience to Global Change

Abstract The importance of urban tree diversity for improving resilience is increasingly understood by decision makers. Urban foresters want to prevent the overrepresentation of species on their streets and in their city, which could result in a significant loss of canopy cover in the event of a large-scale disturbance such as a drought or an exotic pest or disease. Although numerous software and tools exist to visualize tree inventories and plan tree maintenance work, only a few offer support for increasing tree diversity. After reviewing the existing tools available for urban forest managers, we present SylvCiT, a novel decision-support and open-source software available on a web platform designed to consolidate information related to the urban forest in one place and facilitate decision-making at different scales. While the first interfaces provide the user with a spatially explicit portrait of the urban forest (species richness, functional diversity, structural diversity, i.e., diameter classes) and associated ecosystem benefits (e.g., stored carbon, ornamental value), the software is designed to produce a list of functional groups and appropriate species to plant considering tree species already present. Based on an artificial intelligence algorithm, SylvCiT identifies the types of trees (species and functional groups) that are absent or underrepresented at different scales to make recommendations that increase species and functional diversity to improve resilience to global change. SylvCiT will continue to be developed to evaluate other ecosystem benefits and integrate criteria such as site characteristics into the recommendation algorithm.

Modeling Management-Relevant Urban Forest Stand Characteristics to Optimize Carbon Storage and Sequestration

Urban forests are an essential part of adaptation and mitigation solutions for climate change. To understand the relationship between carbon storage, sequestration, and stand density in the most heavily-managed aspect of the urban forest—street trees—we modified the parameters and algorithms of a rural forest dynamics model, the perfect plasticity approximation (PPA), to reflect urban street tree conditions. The main changes in the new street tree PPA are the maintenance of a prescribed stand density via management of recruitment, the possibility of crown-roof overlap, and increased mortality rates. Using the street tree PPA, we explored overall productivity, crown allometry relative to stem diameter, and mortality rate to test each mechanism’s impact on urban street tree carbon storage and sequestration across a gradient of prescribed stand density, with the goal of finding conditions in which street tree carbon storage and sequestration are optimized. We compared the qualitative trends in storage from the street tree PPA to those found in the U.S. Forest Service’s Urban Forest Inventory Analysis data. We found that carbon storage and sequestration increase with prescribed density up to a point where carbon storage and sequestration saturate. Optimized carbon storage and sequestration result from a stand with high productivity, maximized crown allometry relative to stem diameter, and a low mortality rate. These insights can be used to inform urban street tree maintenance strategies that effectively increase carbon storage and sequestration within a given city, such as focusing afforestation campaigns on adequate areas with the lowest street tree densities.

Preparation and physicochemical properties of biochar from the pyrolysis of pruning waste of typical fruit tree in north China

Routine maintenance of fruit trees generates a substantial quantity of pruning waste each year. This waste is potential feedstock for producing energy, materials, and other products. The feasibility of making biochar from the waste via pyrolysis was evaluated. The effects of seven tree species, different pruning sites, and temperature on the pyrolysis process, and the physicochemical properties of the biochar were studied. Pyrolysis of different tree species at 500 °C yielded 27.5 to 33.3% biochar, with a high calorific value (approximately 30 MJ/kg), low ash content (approximately 4%), and capturing up to 60% of the carbon element present. Simultaneously, when the temperature was increased from 400 to 700 °C, the yield of biochar decreased from 35.8% to 24.3%, but the properties improved with the higher heating value rising from 29.2 to 31.3 MJ/kg and the iodine value from 234 to 252 mg/g. The biochar has a good pore structure with a specific surface area of 237 m2/g, total pore volume of 0.175 cm3/g, and average pore size of 2.96 nm. In general, biochar from the pyrolysis of fruitwood pruning waste generated here could be an ideal feedstock to produce high-value-added products, such as solid fuels, activated carbon, and electrode materials.

Quantifying the cumulative cooling effects of 3D building and tree shade with high resolution thermal imagery in a hot arid urban climate

Shading is an effective heat-mitigation strategy, with tree and building shade naturally cooling heated surfaces in hot-arid climates. However, increasing shade through tree planting and building arrangement has associated costs, such as tree maintenance and loss of solar access. To make strategic decisions, quantifying shade’s cooling effectiveness is crucial. This study examines the extent to which shade reduces land surface temperature (LST) in a hot-arid residential environment by considering shade’s areal coverage, overall duration, and time of day. Using fine-resolution 3D city models (1 m/pixel), land cover classification (1 m/pixel), and high-resolution thermal imagery (6 m/pixel) for Tempe, Arizona, USA, hourly shade calculations are conducted from 7:30 to 13:30 on July 12, 2011. The relationships among the observed LST at 13:30, land cover types, and shade characteristics are analyzed using linear and spatial regressions. The results reveal that shade’s cooling effect is cumulative, rather than instantaneous, as surface cooling by earlier shade persists to later times to some degree. Areas shaded for longer hours are cooler than those shaded only temporarily. The results further indicate that tree-shaded areas are significantly cooler than those shaded by other features, including buildings, with the difference increasing with shade duration. Shifting a 6 × 6 m area from 0% to 100% shade in the early morning generates a 2.3℃ LST reduction at 13:30. The same shift in shade for the whole morning and the entire period (7:30–13:30) would lower LST by 8.3℃ and 11.3℃, respectively. The importance of temporal shade planning and policy recommendation for urban heat mitigation is discussed.

A Study on Street Tree Maintenance: Focusing on Suseong-gu, Daegu in South Korea

Purpose: In urban society, street trees are closely related to our lives. However, many people do not recognize the existence and necessity of street trees on ordinary days. This study investigated the changes in the growth of street trees exposed to environmental damage and artificial management due to street maintenance. This paper aims to provide necessary data for street tree management by analyzing changes in the growth of street trees according to the road size in terms of temporal change and management of street trees.
 Method: Field surveys were conducted from June to September 2021 to identify the direction of maintenance for street trees by road size. The researchers collected and analyzed data on street tree roads and basic plan data on street trees in Suseong-gu in 1997. This paper conducted One-way ANOVA by six items(tree height, root-collar diameter, crown width, diameter at breast height, degree of tree health, and degree of environmental damage). Microsoft Office Excel 2007 program and Spss Statistics 21 statistical program were used for statistical analysis.
 Results: As a result of analyzing the current state of street trees in 2021 and the change amount by road size in 1997 data, on average, the tree height increased by 5.4m, the root-collar diameter increased by 22.3cm, the crown width increased by 2.1m, and the diameter at breast height increased by 12.8cm. The degree of tree health decreased by 0.2 points, and the degree of environmental damage decreased by 1.1 points.
 Conclusion: The tree form of street trees did not have a natural tree shape due to artificial management, and street trees were damaged due to lack of management and damage from surrounding shops. The analysis results show that the appearance of street trees has grown, but street trees' growth aspects(tree health, environmental damage) have regressed due to incorrect pruning work with tall trees according to laws and ordinances. This paper suggests that street trees' species selection and improvement supplement work should be done through continuous research in the future, and systematic and efficient management should be continuously carried out for satisfaction with street trees and pedestrians.

Tree Failure Assessment of London Plane (Platanus × acerifolia (Aiton) Willd.) Street Trees in Nanjing City

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.

Sensitivity of tropical montane birds to anthropogenic disturbance and management strategies for their conservation in agricultural landscapes.

Tropical montane bird communities are hypothesized to be highly sensitive to anthropogenic disturbance because species are adapted to a narrow range of environmental conditions and display high rates of endemism. We assessed avian sensitivity at regional and continental scales for a global epicenter of montane bird biodiversity, the tropical Andes. Using data from an intensive field study of cloud forest bird communities across 7 landscapes undergoing agricultural conversion in northern Peru (1800-3100m, 2016-2017) and a pan-Andean synthesis of forest bird sensitivity, we developed management strategies for maintaining avian biodiversity in tropical countrysides and examined how environmental specialization predicts species-specific sensitivity to disturbance. In Peru, bird communities occupying countryside habitats contained 29-93% fewer species compared with those in forests and were compositionally distinct due to high levels of species turnover. Fragments of mature forest acted as reservoirs for forest bird diversity, especially when large or surrounded by mixed successional vegetation. In high-intensity agricultural plots, an addition of 10 silvopasture trees or 10% more fencerows per hectare increased species richness by 18-20%. Insectivores and frugivores were most sensitive to disturbance: abundance of 40-70% of species declined in early successional vegetation and silvopasture. These results were supported by our synthesis of 816 montane bird species studied across the Andes. At least 25% of the species declined due to all forms of disturbance, and the percentage rose to 60% in agricultural landscapes. The most sensitive species were those with narrow elevational ranges and small global range sizes, insectivores and carnivores, and species with specialized trophic niches. We recommend protecting forest fragments, especially large ones, and increasing connectivity through the maintenance of early successional vegetation and silvopastoral trees that increase avian diversity in pastures. We provide lists of species-specific sensitivities to anthropogenic disturbance to inform conservation status assessments of Andean birds.

The routes to fruit: Governance of urban food trees in Canada

Interest in planting urban food trees (UFTs) in public spaces is growing in popularity as a form of urban greening and a potential food source. Currently there is minimal research on the governance and policy aspects of integrating food trees into cities. To fill this gap, we investigated the characteristics of UFT site governance and how it compares to current urban forest governance. Semi-structured interviews were conducted with relevant municipal officials in Calgary, Edmonton, Toronto and Victoria about their perspectives and involvement with UFT sites in their city. A scan of policy documents was completed to supplement the interviews. The interviews were analyzed using a deductive coding framework based on the Policy Arrangement Approach. We found that key actors at the UFT sites were local organizations and site champions, with minimal municipal engagement. Most site resources provided by municipalities were in-kind. There are also basic knowledge gaps about how to care for UFTs. Currently municipal by-laws prohibit the harvesting and removal of plant material, and are at odds with the purpose of UFT sites, with few municipalities fully integrating UFTs in policies. The primary discussion around UFTs centre concerns for public health and safety, management, and use of public space with limited discussions of benefits. This research demonstrates the value of co-governance models to support UFTs, while a shift in focus from risks to benefits could encourage additional resources and policy integration. Further, including UFTs into policy would also support foraging and food tree maintenance in public spaces, and more fully reflect the plurality of urban forest engagement.

SOSIALISASI PRUNING SANITASI POHON KELAPA SAWIT DI AFDELING VI WILAYAH 1 PT. NUSAINA GROUP

Oil palm (Elaeis guineensis) is an important commodity in the national economy. The demand for national vegetable oil which continues to increase throughout the year makes this commodity popular with local and even foreign businesses. The oil from this plant is processed into CPO and KPO. Good quality oil palm fruit is inseparable from good maintenance of oil palm trees. One of the maintenance carried out is sanitation pruning of oil palm trees. Oil palm pruning activities are one of the problems faced in oil palm plantations because they consider the task to be trivial. Therefore, one way to remind farmers and employees of oil palm plantations about the importance of pruning sanitation is by empowering them to maintain oil palm trees. To support this program, socialization was carried out regarding the importance of sanitary pruning of oil palm trees in increasing production by Pattimura University Individual Thematic Community Service Students Batch XLIX Batch II Academic Year 2022/2023. One of the villages targeted for implementing this program is the village of Waimusi, North Seram Timur Kobi District, Central Maluku Regency. This service activity uses the socialization method and direct practice in the field. The socialization process related to the importance of Sanitation Pruning Oil palm trees as one of the important objects in the maintenance of oil palm is presented in oral form, then followed by work practices in the field. The results of this activity are employees who are specifically engaged in sanitation pruning work objects

PiCUS Sonic Tomograph: A Case Study of Crimson Bottlebrush Tree (Melaleuca citrina (Curtis) Dum.Cours)

Trees with a decreasing level of health and structure can become a threat to life and property if they are not properly managed. Thus, a regular visual tree assessment (VTA) is essential to monitor the trees’ conditions. A recent assessment, July 2022, by VTA on an existing Melaleuca citrina in the Forest Research Institute Malaysia (FRIM) showed poor canopy growth colonised by parasitic plants with the emergence of fruiting bodies (conk or mushroom) on its trunk, indicating internal wood decay. Tree inspection using an advanced approach of PiCUS Sonic Tomograph (PiCUS) was performed to evaluate the severity of the decayed trunk. As a non-invasive method, PiCUS measures the wood deterioration in trees using sound wave velocity that moves through the density of the wood. The thicknesses of the residual wall of trees with internal defects were recorded as colour-coded tomograms. The results were then compared with previous observations in the year 2017. The soil penetration test, pH and “The Jar Test” were also adopted to analyse soil properties and condition around the tree. The tomogram images showed an increased percentage of decay from 2017 to 2022 of approximately 2 to 78%, respectively. The sound wood also decreased from 82 to 14% for the respective period. The soil is categorised as silt loamy with pH value of 5.6 to 6.4 while the soil penetration test exceeds a value of 2.06 MPa, which restricts the root growth. This information is vital for further maintenance of urban trees and very useful for managerial decisions.

基于人机交互智能树干涂白装置的设计与实验研究

Tree whitewash has the functions of parasite prevention and cold protection and is therefore commonly used in the maintenance and management of trees. At present, tree whitewash mainly relies on manual operation, which has the problems of low efficiency, poor quality, and uneven distribution of the whitewash agent. To address this issue, this study developed a smart tree whitewash device based on human–computer interaction. The device was controlled mainly by a programmable logic controller (PLC). Once the trunk information collected by sensors was received by the PLC, it would control the up and down motions of the ball screw to manipulate the mechanical arm for whitewash. In addition, a Mitsubishi GT12 touch screen was adopted to facilitate system operation. Subsequently, a whitewash experiment was performed on poplar trunks with lengths of 10–35 cm using three different whitewash devices, i.e., a backpack sprayer, a semi-automatic tree sprayer, and the proposed smart tree whitewash device; the efficiency and the amount of whitewash agents used were compared. The results suggested that as the tree diameter at breast height increased, the amount of required whitewash agent elevated accordingly. In this case, the time required by the backpack sprayer and the semiautomatic tree sprayer to complete the job both increased, whereas that required by the smart tree whitewash device remained almost identical. In terms of work efficiency, the time required by the smart whitewash device to whitewash a tree was 109.89 s, which was approximately 1/2 of the time required by the backpack sprayer or 2/3 of that required by the semiautomatic tree spraying device. Meanwhile, the amount of whitewash agent required by the smart whitewash device to whitewash a tree was 140.23 g, which was approximately 0.46 of the amount required by the backpack sprayer or 0.74 of that required by the semiautomatic tree spraying device. Therefore, it was concluded that the proposed smart tree whitewash device could not only improve the work efficiency of tree whitewash but also greatly reduce the amount of whitewash agent required, thereby decreasing the cost and minimising environmental pollution. This study provides theoretical guidance and technical support for future research on smart tree whitewash devices.