ASESMEN KESEHATAN POHON PUSAKA Eucalyptus alba Reinw. ex Blume DI KEBUN RAYA BOGOR SECARA VISUAL DAN TEKNOLOGI TOMOGRAFI

Eucalyptus alba Reinw. ex Blume is a heritage tree in the Bogor Botanic Gardens, planted in 1892 (130 years old in 2022). Only one specimen in the Garden has a unique trunk shape. Trees that are a match for the heritage category need to be preserved by paying attention to its health condition. The study aimed to analyze tree health conditions based on visual tree assessment (VTA), tomographic technology, and recommendations for its maintenance. The method used is VTA using the International Society of Arboriculture (ISA) and tomographic technology using PiCUS 3 Sonic Tomograph. The results showed that visually E. alba had a low fall/break potential on the main stem. However, using tomographic technology found that decaying on the main stem at various height levels was as follows: 50 cm (95%), 140 cm (76%), 550 cm (18%), and 810 cm (11%). Therefore, E. alba has a high potential to fall on the lower stems because the percentage of decay exceeds 70% with a large diameter (275 cm). Some recommendations are provided, such as maintaining the physiological process of trees by keeping soil fertility, installing termite bait, making a circular fence to the north, periodically decaying measurements (once a year), and providing information boards related to current tree conditions as well as hazard mitigation. Complete or partial logging is not recommended, given the status of E. alba as a heritage tree.Eucalyptus alba Reinw. ex Blume merupakan pohon pusaka di Kebun Raya Bogor yang ditanam pada tahun 1892 (umur 130 tahun di tahun 2022), hanya ada satu spesimen, dan memiliki bentuk batang yang unik. Pohon dengan kategori pusaka ini perlu dilestarikan dengan memperhatikan kondisi kesehatannya. Tujuan penelitian ini adalah menganalisis kondisi kesehatan pohon secara visual dan teknologi tomografi serta rekomendasi penanganannya. Metode yang digunakan adalah pengamatan visual berdasarkan International Society of Arboriculture dan teknologi tomografi menggunakan PiCUS 3 Sonic Tomograph. Hasil penelitian menunjukkan bahwa secara visual E. alba memiliki potensi tumbang/patah yang rendah pada batang utama. Namun setelah dilakukan pengukuran pelapukan pada batang utama di berbagai level ketinggian dengan teknologi tomografi, hasilnya adalah di ketinggian 50 cm (95%), 140 cm (76%), 550 cm (18%), dan 810 cm (11%). Oleh karena itu, E. alba memiliki potensi tumbang yang besar pada batang bagian bawah karena persentase pelapukan yang melebihi 70% dengan diameter yang besar (275 cm). Rekomendasi penanganan pohon berisiko adalah mempertahankan proses fisiologis pohon dengan menjaga kesuburan tanah, pemasangan umpan rayap, pembuatan pagar melingkar ke arah utara, pengukuran pelapukan berkala (satu tahun sekali), dan pemberian papan informasi terkait kondisi terkini dan mitigasi bahayanya. Penebangan total atau sebagian tidak direkomendasikan mengingat status E. alba sebagai pohon pusaka

PREDICTION OF SUSCEPTIBILITY FOR OLD TREES (> 100 YEARS OLD) TO FALL IN BOGOR BOTANICAL GARDEN

Since the establishment of the Bogor Botanical Garden (BBG) in 1817, the protection of the tree collections, even the loss of aging trees (> 100 years old), has been one of its most important tasks. Abiotic factors such as intense extreme events, i.e., heavy rainfall and strong winds, as well as biotic factors from human activities, pests and diseases, and the deterioration of the health of the plant collection with age, has threatened the survival of the old tree collections. As the BBG has many functions for conservation and human ecological activities, tree fall accidents have become a primary concern in preventing the loss of biodiversity and human life. Therefore, disaster map zonation is required to prevent and minimize such accident together with a prediction of which individual specimen is likely to fall. We examined the health of 154 to determine the falling probability of 1106 aged trees based on several factors that might cause the fall in the past and to make model predictions generated by nine supervised machine learning algorithms to get a binary value of falling probability and then classified into four categories (neglectable, low, moderate, and high probability of falling). Inverse Distance Weighted interpolation method was used to depict a zone map of trees prone to fall in BBG. We found 885 susceptible trees, of which 358 individual trees were highly susceptible to fall (red zone color), dominated by families from Fabaceae, Lauraceae, Moraceae, Meliaceae, Dipterocarpaceae, Sapindaceae, Rubiaceae, Myrtaceae, Araucariaceae, Malvaceae, and Anacardiaceae. This result was based on Random Forest model due to its highest accuracy among algorithms and its lowest false negative (FN) value. The FN value was important to minimize error calculation on aged trees that were not prone to fall but turned out to be prone to fall. The dominant factor contributing to high falling intensity was hollow and brittle on the tree trunks where many were found to have pests inside damaged parts such as termites, wood-borers, and bark-eaters. Several trees were found to have combined damages with more than a single causative factor that exacerbated tree’s health and increased falling probability

Decay Tree Detection in Bogor Botanic Gardens Collection Using Sonic Tomograph Technology

Bogor Botanic Gardens is an ex-situ plant conservation area in Indonesia. Since BBG is 103 years old, many collections are 100 years old or older. These antique collections may sustain damage, such as broken or collapsing, endangering visitors and employees. As a result, monitoring tree health at BBG is a critical task. According to the tree health monitoring data, 73 of 244 trees were further checked using the PiCUS Sonic Tomograph. Trees from the Fabaceae (31%) and Myrtaceae (10%) families were the most frequently checked. Walnuts trees from the Burseraceae family had the most specimens (47,94%). The PST effectively provides an immediate picture of the stem condition by calculating solid and decaying wood percentage values

Decay Tree Detection in Bogor Botanic Gardens Collection Using Sonic Tomograph Technology

Bogor Botanic Gardens is an ex-situ plant conservation area in Indonesia. Since BBG is 103 years old, many collections are 100 years old or older. These antique collections may sustain damage, such as broken or collapsing, endangering visitors and employees. As a result, monitoring tree health at BBG is a critical task. According to the tree health monitoring data, 73 of 244 trees were further checked using the PiCUS Sonic Tomograph. Trees from the Fabaceae (31%) and Myrtaceae (10%) families were the most frequently checked. Walnuts trees from the Burseraceae family had the most specimens (47,94%). The PST effectively provides an immediate picture of the stem condition by calculating solid and decaying wood percentage values