Interpretation of upper-storey canopy area in subtropical broadleaved forests in Okinawa Island using laser scanning data

Conventional forest inventory practice took huge of effort, and is time- and cost- consuming. With the aid of remote sensing technology by light detection and ranging (LiDAR), those unbearable factors could be minimized. LiDAR is able to capture forest characteristic information and is well known for estimating forest structure accurately in many studies. Forest monitoring related to forest resource inventory (FRI) becomes more effective by utilizing LiDAR data and it is tremendously useful, especially to distinguish information on density, growth and distribution of trees in a selected area. In this study, LiDAR data was utilized aimed to delineate crown cover and estimate upper-storey canopy area in Yambaru Forest using object-based segmentation and classification techniques. Agreement between field survey and LiDAR data analysis showed that only 33.7% of upper- storey canopy area was successfully delineated. The low accuracy level of canopy detection in Yambaru Forest area was expected mainly due to tree structure, density and topographic condition

Terrain characterization of mountanious forest area in Cameron Highland

The paper presents the analysis of terrain parameters based on Digital Terrain Model (DTM) generated in the mountainous forest reserve of Cameron Highland. Terrain analysis was conducted within SAGA GIS using DTM of 10m resolution, where elevation, slope, LS Factor and TW Index were computed. The results indicated that Cameron Highland is described by various terrain characteristics, steep slopes and the forested area can be classified as sensitive. The method applied enables evaluation of forest site stability and productivity based on terrain perspective, which are important to assist forest resource management planning

Accuracy of LiDAR-based tree height estimation and crown recognition in a subtropical evergreen broad-leaved forest in Okinawa, Japan

Aim of study: To present an approach for estimating tree heights, stand density and crown patches using LiDAR data in a subtropical broad-leaved forest. Area of study: The study was conducted within the Yambaru subtropical evergreen broad-leaved forest, Okinawa main island, Japan. Materials and methods: A digital canopy height model (CHM) was extracted from the LiDAR data for tree height estimation and a watershed segmentation method was applied for the individual crown delineation. Dominant tree canopy layers were estimated using multi-scale filtering and local maxima detection. The LiDAR estimation results were then compared to the ground inventory data and a high resolution orthophoto image for accuracy assessment. Main results: A Wilcoxon matched pair test suggests that LiDAR data is highly capable of estimating tree height in a subtropical forest (z = 4.0, p = 0.345), but has limitation to detect small understory trees and a single tree delineation. The results show that there is a statistically significant different type of crown detection from LiDAR data over forest inventory (z = 0, p = 0.043). We also found that LiDAR computation results underestimated the stand density and overestimated the crown size. Research highlights: Most studies involving crown detection and tree height estimation have focused on the analysis of plantations, boreal forests and temperate forests, and less was conducted on tropical and/or subtropical forests. Our study tested the capability of LiDAR as an effective application for analyzing a highly dense fores

Awareness of risk and safety preparedness among hikers in Bukit Tabur

Repeated incidents and hikers' awareness of risk had become a prolonged issue in Bukit Tabur, an adventurous hiking spot. Understanding of risk and safety is vital to be nurtured among hikers. This study was conducted to examine the hikers' awareness and knowledge of potential risks during hiking, hikers' attention to safety preparedness, and the relationship between experience and safety preparedness towards hiking activity. Data was collected from 468 respondents among those who had hiking experience in Bukit Tabur. The result suggested that hikers are aware of potential risks during hiking. However, the awareness of risk caused by human factors is more significant than awareness of environmental factors. Surprisingly, only 50% to 60% of hikers showed explicit knowledge and precise information about the study area. Hikers' awareness of safety preparedness is high, where the findings highlight that a healthy body and fitness are crucial elements. Interestingly, the study suggested that in the case of Bukit Tabur, experience has a low influence on safety preparedness for the hiking activity

Landform classification for site evaluation and forest planning: integration between scientific approach and traditional concept

In this paper, we present an automated classification method of landform elements using an application of SAGA GIS software. The spatial assessment was done on the Yambaru forest area (YFA) in the northernmost part of Okinawa Island, Japan. This task is performed through the detailed elevation grid analyses from DTM of YFA with a spatial scale of 10 × 10 m2 supported by The Geospatial Information Authority of Japan. The classification has ten classes; high ridges, midslope ridges, upland drainage, upper slopes, open slopes, plains, valleys, local ridges, midslope drainage and streams. Classes were defined using the ‘topographical position index’ module and selected terrain variables were integrated to vegetation data for site evaluation. Information on terrain characteristics is very important to explain geographical constraints and map variability of natural resources in maintaining sustainable forest management as well as supporting decision making processes. Taking this into account, we adapted a traditional concept of forest terrain introduced by Sai On, a council member of the Ryukyu Kingdom (former name of Okinawa Island) when evaluating the potential site for forestry use

The roles of technology compatibility and relational boundary on the performance of rescue frontliners

Purpose: This paper examines the relationship between technology compatibility, relational boundary, and rescue frontliners' performance. Design/methodology/approach: The quantitative method was used to achieve the research objectives. This study was done on selected search and rescue teams in Malaysia, and data were collected from 100 team members. Findings: Technology compatibility and relational boundary were found to have a significant relationship with rescue frontliners’ performance. Research limitations/implications: First, the quantitative method used unable the researchers to explore beyond the variables tested. Thus, exhaust understanding could be limited, particularly in enhancing the voice of the frontliners on the team performance. Secondly, the study collected responses from a single SAR team in Malaysia. Thus, the findings could not be generalized to other SAR teams. Practical implications: The findings of this study provide practical implications for the rescue frontliners in Malaysia in terms of knowledge regarding the relationship between technology compatibility, relational boundary, and rescue frontliners’ performance. Team selection should always be based on appropriate knowledge and skills, creating a higher sense of empowerment among team members. Originality/value: The study on rescue frontliners' performance is uniquely fascinating, where a practical framework based on these criteria can be developed and thus will be useful as a guideline in the context of rescue frontliners

The significance of social exchange theory on the internal performance of the Malaysian Search and Rescue (SAR) teams

The social exchange theory (SET) is a social form of exchange that includes tangible or intangible, material or nonmaterial goods between individuals with other individuals. The social exchange involves actions that relate to reward reactions from others. In short, social costs and rewards affect human decisions and behavior. In this paper, SET highlights the reciprocal relationship between the internal factors of Search and Rescue (SAR) team performance, which are team communication, team leadership, and team time management. The essential belief of SET is that individuals in the team enter into and maintain the relationship with the expectation to gain a net positive value. This study involved 209 SAR teams from Peninsular Malaysia. Data were collected using the survey method. Respondents’ demographics and descriptive data such as percentages and frequencies were analyzed using the Statistical Package for Social Sciences (SPSS) Version 26 software for Windows. For deeper analysis and hypothesis testing, data were analyzed using the Structural Equation Modelling (SEM) technique using partial least square analysis by SmartPLS. Analysis revealed that only team communication and team time management were found to be significantly related to SAR team performance. Discussions are provided at the end of this paper to justify the finding

Accuracy of LiDAR-based tree height estimation and crown recognition in a subtropical evergreen broad-leaved forest in Okinawa, Japan

Aim of study: To present an approach for estimating tree heights, stand density and crown patches using LiDAR data in a subtropical broad-leaved forest.Area of study: The study was conducted within the Yambaru subtropical evergreen broad-leaved forest, Okinawa main island, Japan.Materials and methods: A digital canopy height model (CHM) was extracted from the LiDAR data for tree height estimation and a watershed segmentation method was applied for the individual crown delineation. Dominant tree canopy layers were estimated using multi-scale filtering and local maxima detection. The LiDAR estimation results were then compared to the ground inventory data and a high resolution orthophoto image for accuracy assessment. Main results: A Wilcoxon matched pair test suggests that LiDAR data is highly capable of  estimating tree height in a subtropical forest (z = 4.0, p = 0.345), but has limitation to detect small understory trees and a single tree delineation. The results show that there is a statistically significant different type of crown detection from LiDAR data over forest inventory (z = 0, p = 0.043). We also found that LiDAR computation results underestimated the stand density and overestimated the crown size.Research highlights: Most studies involving crown detection and tree height estimation have focused on the analysis of plantations, boreal forests and temperate forests, and less was conducted on tropical and/or subtropical forests. Our study tested the capability of LiDAR as an effective application for analyzing a highly dense forest.Key words: Broad-leaved; inventory; LiDAR; subtropical; tree height.Abbreviations: DBH: Diameter at Breast Height, CHM: Canopy Height Model, DEM: Digital Elevation Model, DSM: Digital Surface Model, LiDAR: Light Detection and Ranging, YFA: Yambaru Forest Area

(Penilaian awal perubatan sel salur kayu Baeckea frutescens yang dipengaruhi oleh impak akibat aktiviti rekreasi di Gunung Tahan, Malaysia)Preliminary assessments on the changes in wood vessel characteristics of Baeckea frutescens influenced by the impacts of recreational activities at Mount Tahan, Malaysia

Vessel arrangement of Baeckea frutescens were studied to determine its anatomical differences as impacted by recreational activities at Gunung Tahan, Malaysia. Plots sized 20 m × 20 m represent disturbed and control areas were established in the most visited camping sites. The study demonstrated that there were differences of vessel arrangements in B. frutescens selected among the study areas. Our result showed that B. frutescens grew in the disturbed plot had higher vessel areas compared with the control plot with the mean values of 177.06 μm2 and 106.40μm2, respectively. For growth attributes, the average tree diameters in all the test sites were 2.10 and 1.55 cm at disturbed plot and control plot, respectively while the tree heights varied from 0.95±0.04 to 0.82 ±0.06 m for the disturbed and the control plots, respectively. Most previous studies indicated that wood anatomical characteristics are genetically fixed by species. However, interestingly, it was found from this study that vessel arrangement which is genetically influenced can change as a response to interferences and disturbances, depending on the ecological conditions