"Tree Finders - Giant Tree Map" Presentation in NCKU, with the story of the tallest tree in Taiwan "Da'an River Yitian Sword"
Taiwan's unique geographical advantage has led to the growth of extensive giant tree forests that are difficult to reach due to transportation challenges, resulting in limited logging activities. Professor Chi-Kuei Wang from the Department of Geomatics at NCKU and Dr. Chia-Chun Hsu, a doctoral alumnus of NCKU and deputy researcher at the Forestry Research Institute of the Ministry of Agriculture, jointly planned the "Tree Finders - Giant Tree Map Project." They utilized airborne LiDAR data and a unique algorithm to explore Taiwan's mountains and forests in search of giant trees. The fifth presentation of the project's achievements, held at National Cheng Kung University, focused on the process of finding the "Da'an River Yitian Sword" and related stories of giant trees.
The fifth "Tree Finders - Giant Tree Map Project" presentation took place at the Department of Geomatics at National Cheng Kung University. Professor Wang stated that Taiwan has approximately 9.5 billion trees, but due to difficulties in observing the treetops from the ground, it is challenging for researchers to measure the height of each tree. To explore the areas where giant trees grow in Taiwan, the project started in 2011, using airborne LiDAR data and professional identification to locate 941 giant trees with heights exceeding 65 meters in the deep central mountainous regions. After on-site exploration, it was discovered that among them, eight giant trees exceeded 70 meters in height, with the tallest being the "Da'an River Yitian Sword" at 84.1 meters, currently the tallest tree in Taiwan.
Professor Wang expressed anticipation for the annual presentation event, stating that through expert sharing, much interesting knowledge could be gained. He emphasized that only 2.1% of the world's land area is suitable for the growth of giant trees, and many regions are gradually disappearing due to logging and climate change. The project's second-phase airborne LiDAR data, spanning from 2016 to the present, examined the survival rates of 941 giant trees over nearly a decade. Among the 632 trees searched, the average growth was approximately 0.3 centimeters. However, 4% of them, totaling 21 trees, had disappeared. The project aims to continue exploring the reasons for giant tree disappearance and updating the national distribution map of giant trees for future scientific research and ecological tourism promotion.
Dr. Chia-Chun Hsu, a skilled tree finder, shared the process of searching for the "Da'an River Yitian Sword" during the presentation. Using LiDAR point cloud raw data, the team processed it into multi-angular tree-shaped vertical profile image files. By leveraging the collective efforts of an online community, stories of giant trees with heights exceeding 65 meters across Taiwan were interpreted. Dr. Hsu recounted the efforts over the years, revealing the discovery of the "Taoshan Divine Tree" with a height of 79.1 meters, "Ka-a-lang" giant tree with a height of approximately 82 meters, and the tallest known tree in Taiwan, the "Da'an River Yitian Sword," standing at 84.1 meters.
Dr. Hsu further described the search for the tallest tree in Taiwan, the "Da'an River Yitian Sword," which began in June of the previous year using LiDAR in the upper reaches of Da'an River. “55214”, filtered from 941 giant trees, appeared to have heights exceeding 79 meters. Through careful estimation based on the tall and slender tree trunks and the surrounding vegetation, it was highly likely to be the tallest tree in Taiwan. Therefore, during the Chinese New Year period this year, a team of nearly 20 people, including a photography team, spent seven days exploring and confirming the existence of this massive Taiwan red cypress. It was officially named the "Da'an River Yitian Sword."
Dr. Hsu expressed that the process of exploring giant trees is highly challenging, but the unknown adventure is filled with crises and fruitful rewards. The difficulty of exploration lies in the precise measurement and photography of the trees, with any slight misstep leading to a setback. The journey involves traversing rarely visited mountainous areas, requiring navigation through streams and rock climbing. Without the assistance of the National Cheng Kung University surveying team and Everfortune Consumer Goods Co., Ltd., accurate positioning and helicopter transportation would be difficult, making the mission nearly impossible. Dr. Hsu also extended gratitude to Director Li Xiangxiu for directing the documentary "Island of the Divine Trees" about the Tree Finders team. The documentary, currently in production, is expected to bring the audience into the mountains and forests of Taiwan, allowing them to experience the changes in the environment and ecology, as well as the challenges faced during the measurement tasks.
The fifth presentation of the "Tree Finders - Giant Tree Map Project" also included "Parent-Child Tree Climbing Activities" and a "LiDAR Tree Measurement Experience Camp." Professional tree-climbing instructors from the Forestry Research Institute led the public in leisurely tree-climbing activities, promoting ecological observation and research in the canopy layer. Zhi-jie Zhang, the JS Digital Culture Enterprise Co., Ltd., shared his journey of creating the "Old Tree Newspaper, Hug Old Tree" initiative since last year, promoting citizen science related to trees. The vivid explanations and hands-on experiences left many participating families delighted, offering a glimpse into Taiwan's mountains and forests and the majestic stature of giant trees through shared images and stories.
Professor Chi-Kuei Wang from the Department of Geomatics: https://researchoutput.ncku.edu.tw/zh/persons/chi-kuei-wang
The fifth "Tree Finders - Giant Tree Map Project" presentation took place at the Department of Geomatics at National Cheng Kung University.
The tallest tree in Taiwan "Da'an River Yitian Sword"
Professor Wang from NCKU department of Geomatics shared the process of LiDAR measure.
Dr. Chia-Chun Hsu, a skilled tree finder, shared the process of searching for the "Da'an River Yitian Sword" during the presentation.
Professional tree-climbing instructors from the Forestry Research Institute led the public in leisurely tree-climbing activities, promoting ecological observation and research in the canopy layer.
Zhi-jie Zhang, the JS Digital Culture Enterprise Co., Ltd., shared his journey of creating the "Old Tree Newspaper, Hug Old Tree".