Hazard Evaluation of Mature Urban Street Trees in Kuala Lumpur

The hazard status of mature urban street trees in Kuala Lumpur has not being studied. Therefore, there has been a paucity of data pertaining to the current status of mature urban street trees in Malaysia. In order for municipalities to manage urban street trees effectively, a thorough understanding of the resource base is needed. Inventories and inspection are essential in order to provide a current record of resources as well as to assist in management decision making. The data obtained can be used to serve as source of information for developing tree maintenance and management programme, particularly hazard prevention programme. Thus, the purpose of this study were : (l) to determine and evaluate hazard status of mature urban street trees in Kuala Lumpur. which is limited to the central area of Kuala Lumpur. and (2) to propose guideline for a proper tree work in Malaysia. The study employed a combination of cluster and systematic sampling technique. Ten percent (232 trees) of the total street trees in the study area were sampled. The results indicated that the status of urhan street trees in Kuala Lumpur were in moderate l62.50%) to high (32.75%) hazard risk status. Only less than five percent (4.74%) had a low hazard risk status suggesting that most of the trees in the study area suffered from various structural defects requiring urgent attention by the management. Sound arboricultural practices as well as the use of systematic hazard inspection programme should be adopted in managing urban street trees in Malaysia

The effect of root architecture and root loss through trenching on the anchorage of tropical urban trees (Eugenia grandis Wight).

Eugenia grandis (Wight) is grown in urban environments throughout Malaysia and root systems are often damaged through trenching for the laying down of roads and utilities. We investigated the effect of root cutting through trenching on the biomechanics of mature E. grandis. The force necessary to winch trees 0.2 m from the vertical was measured. Trenches were then dug at different distances (1.5, 1.0 and 0.5 m) from the trunk on the tension side of groups of trees. Each tree was winched sideways again and the uprooting force recorded. No trenches were made in a control group of trees which were winched until failure occurred. Critical turning moment (TMcrit) and tree anchorage rotational stiffness (TARS) before and after trenching were calculated. Root systems were extracted for architectural analysis and relationships between architectural parameters and TMcrit and TARS were investigated. No differences were found between TMcrit and trenching distance. However, in control trees and trees with roots cut at 1.5 m, significant relationships did exist between both TMcrit and TARS with stem dimensions, rooting depth and root plate size. TARS was significantly decreased when roots were cut at 0.5 m only. Surprisingly, no relationships existed between TMcrit and TARS with any root system parameter when trenching was carried out at 0.5 or 1.0 m. Our study showed that in terms of TARS and TMcrit, mechanical stability was not greatly affected by trenching, probably because rooting depth close to the trunk was a major component of anchorage

The use of plants to improve indoor air quality in small office space

Exposure to volatile organic compounds (VOC) can cause a series of effects towards human health. VOC is also associated with Sick Building Syndrome and other building related illnesses. Common materials found in every home and place of business may cause elevated exposure to toxic chemicals. The aim of this study was to examine the best indoor plants that could be used to improve indoor air quality in a small office space. In this study, the concentration of VOC inside a room was monitored before and after the test, using Aeroquol Model S500 VOC Gas Detector and by using oil-based paint painted on a panel measuring 0.05 x 0.05 m in order to create a minimum of 3ppm of VOC. Three types of tropical indoor plants were used in this study; Nephrolepis exaltata, Rhapis excelsa and Dracaena fragrans. Data were monitored for eight hours at 10 minutes interval. The results showed no significant differences between the number of pots and the type of plants used in reducing VOC content in the real room environment. This was probably due to several factors, such as the interference of outside air and the condition of the experimental room. This experiment suggests that further experiments should be carried out in a controlled environment to improve our knowledge of how indoor plants can improve indoor air quality, and thus improve human health and well-being

Software maintainability assessment based on collaborative CMMI model

Software constantly needs new features or bug fixes. Maintainable software is simple to extend and fix which encourages the software's uptake and use. The Software Sustainability Institute can advise you on the design and development of maintainable software that will benefit both you and your users. Therefore, capability maturity model integration (CMMI) is a process improvement approach that provides organisations with the essential elements of effective processes that ultimately improve their performance. The propose maintainability assessment of cmmi based on multi-agent system (MAS) to identify the processes measurement of SM. in order to verify our proposed CMMI framework based on MAS architecture, pilot study is conducted using a questionnaire survey. Rasch model is used to analyse the pilot data. Items reliability is found strong correlation between measured and the model designed. The results shows that the person raw score-to-measure correlation is 0.51 (approximate due to missing data) and Cronbach Alpha (kr-20) person raw score reliability = .94

A comprehensive study of CMMI based framework for collaborative software maintenance

Software maintenance (SM) environment is a highly complex area, knowledge-driven and collaborative. Therefore, Capability Maturity Model Integration (CMMI) is a process improvement approach that provides organizations with the essential elements of effective processes that ultimately improve their performance. We propose a new framework of CMMI based on Multi-Agent System (MAS) to identify the process measurement of SM. The proposed MAS architecture includes three types of agents: Personal Agent (PA), Maintenance Agent (MA) and Key Process Area Agent (KPAA). In order to verify our proposed CMMI framework based on MAS architecture, a pilot study is conducted using a questionnaire survey. Rasch Model is used to analyze the pilot data. Item reliability is found to be poor and a few respondents and items are identified as misfits with distorted measurements

Gestion des risques relatifs à la stabilité des arbres paysagers : biomécanique et architecture du système racinaire

L’impact de la perte racinaire sur l’ancrage d’Eugenia grandis Wight et de Pinus pinaster Ait ainsi que la capacité de trois différentes espèces d’arbres (Fagus sylvatica L, Abies alba Mill et Picea abies L) à résister au déracinement ou à la rupture sous l’effet d’un éboulement en pente raide ont été étudiés au moyen de tests de treuillage et le creusement de tranchées (tree winching and trenching tests) et les résultats ont été corrélés avec la structure du système racinaire. Aucune différence n’a été observée entre TMcrit et la distance de creusement de tranchée sur E. grandis. Les résultats obtenus ont révélé qu’en termes de rigidité rotationnelle de l’ancrage des arbres (TARS) et de TMcrit, la stabilité mécanique n’a pas été significativement affectée par le creusement de tranchées en sol argilo-sableux en raison de la profondeur d’enracinement des racines pivotantes (« sinker roots ») qui se sont formées près du tronc et en raison de la taille de la plaque racinaire qui augmente la rigidité et constitue donc une composante importante de l’ancrage d’E. grandis. Toutefois, pour P. pinaster, la stabilité mécanique a été significativement affectée par le creusement de tranchée, probablement en raison de la coupe des racines latérales qui a considérablement altéré la taille de la plaque racinaire et, en conséquence, la somme des surfaces en section (CSA= cross-sectional area) de la plupart des racines latérales et d’un certain nombre de racines traçantes, ce qui constitue une des composantes essentielles de l’ancrage d’arbres P. pinaster adultes plantés en podzol sableux. Pour les espèces forestières de protection plantées en pente raide, les résultats obtenus ont révélé que les espèces d’arbre présentant un système racinaire profondément enfoui et fortement ramifié avec une grande proportion de racines obliques (par exemple, le hêtre et le sapin pectiné) seront mieux ancrées et auront une meilleure fonction anti-éboulement que epicéa commun qui possède un système racinaire superficiel et peu profond. Les connaissances apportées par cette étude peuvent être utilisées pour la sélection et la production d’arbres qui résistent aux risques naturels ainsi qu’aux risques provoqués par l’Homme.The impact of root loss on tree anchorage on Eugenia grandis Wight and Pinus pinaster Ait and the ability of three different trees species (Fagus sylvatica L, Abies alba Mill and Picea abies L) to resist uprooting or breakage due to rockfall on steep slopes were investigated using tree winching and trenching tests and results correlated to root system architecture. No differences were found between TMcrit and trenching distance in E. grandis trees. The results showed that in terms of Tree Anchorage Rotational Stiffness (TARS) and TMcrit, mechanical stability was not significantly affected by trenching on sandy clay soil, due to rooting depth of the sinkers which occurred close to the trunk and root plate size which provide greater stiffness thus play a major component of anchorage in E. grandis. However, in P. pinaster, mechanical stability was significantly affected by trenching, possibly due to severing of lateral roots greatly altered the size of the root plate and subsequently root CSA of major lateral roots and number of sinkers, which are crucial components in anchorage of mature P. pinaster trees grown on sandy podzol soil. For protection forest species grown on steep slopes, the results showed that tree species with deep, highly branched root systems with a higher proportion of oblique roots (e.g. European beech and Silver fir) will be better anchored and provide better protective function against rockfall as compared to Norway spruce that possessed a superficial plate-like root system. The knowledge gained from this study can be utilized in selection and production of trees which are resistant to both man made or natural hazards

Gestion des risques relatifs à la stabilité des arbres paysagers : biomécanique et architecture du système racinaire

L’impact de la perte racinaire sur l’ancrage d’Eugenia grandis Wight et de Pinus pinaster Ait ainsi que la capacité de trois différentes espèces d’arbres (Fagus sylvatica L, Abies alba Mill et Picea abies L) à résister au déracinement ou à la rupture sous l’effet d’un éboulement en pente raide ont été étudiés au moyen de tests de treuillage et le creusement de tranchées (tree winching and trenching tests) et les résultats ont été corrélés avec la structure du système racinaire. Aucune différence n’a été observée entre TMcrit et la distance de creusement de tranchée sur E. grandis. Les résultats obtenus ont révélé qu’en termes de rigidité rotationnelle de l’ancrage des arbres (TARS) et de TMcrit, la stabilité mécanique n’a pas été significativement affectée par le creusement de tranchées en sol argilo-sableux en raison de la profondeur d’enracinement des racines pivotantes (« sinker roots ») qui se sont formées près du tronc et en raison de la taille de la plaque racinaire qui augmente la rigidité et constitue donc une composante importante de l’ancrage d’E. grandis. Toutefois, pour P. pinaster, la stabilité mécanique a été significativement affectée par le creusement de tranchée, probablement en raison de la coupe des racines latérales qui a considérablement altéré la taille de la plaque racinaire et, en conséquence, la somme des surfaces en section (CSA= cross-sectional area) de la plupart des racines latérales et d’un certain nombre de racines traçantes, ce qui constitue une des composantes essentielles de l’ancrage d’arbres P. pinaster adultes plantés en podzol sableux. Pour les espèces forestières de protection plantées en pente raide, les résultats obtenus ont révélé que les espèces d’arbre présentant un système racinaire profondément enfoui et fortement ramifié avec une grande proportion de racines obliques (par exemple, le hêtre et le sapin pectiné) seront mieux ancrées et auront une meilleure fonction anti-éboulement que epicéa commun qui possède un système racinaire superficiel et peu profond. Les connaissances apportées par cette étude peuvent être utilisées pour la sélection et la production d’arbres qui résistent aux risques naturels ainsi qu’aux risques provoqués par l’Homme.The impact of root loss on tree anchorage on Eugenia grandis Wight and Pinus pinaster Ait and the ability of three different trees species (Fagus sylvatica L, Abies alba Mill and Picea abies L) to resist uprooting or breakage due to rockfall on steep slopes were investigated using tree winching and trenching tests and results correlated to root system architecture. No differences were found between TMcrit and trenching distance in E. grandis trees. The results showed that in terms of Tree Anchorage Rotational Stiffness (TARS) and TMcrit, mechanical stability was not significantly affected by trenching on sandy clay soil, due to rooting depth of the sinkers which occurred close to the trunk and root plate size which provide greater stiffness thus play a major component of anchorage in E. grandis. However, in P. pinaster, mechanical stability was significantly affected by trenching, possibly due to severing of lateral roots greatly altered the size of the root plate and subsequently root CSA of major lateral roots and number of sinkers, which are crucial components in anchorage of mature P. pinaster trees grown on sandy podzol soil. For protection forest species grown on steep slopes, the results showed that tree species with deep, highly branched root systems with a higher proportion of oblique roots (e.g. European beech and Silver fir) will be better anchored and provide better protective function against rockfall as compared to Norway spruce that possessed a superficial plate-like root system. The knowledge gained from this study can be utilized in selection and production of trees which are resistant to both man made or natural hazards