Dr. Ronggo Sadono of the UGM Faculty of Forestry was inaugurated as a professor in forestry statistics on Thursday (November 2) at the UGM Senate Hall.
During the inaugural ceremony, Professor Ronggo Sadono delivered a speech titled “Forestry Statistics: Measurement, Modeling, and Upscaling for Estimating Forest Resource Potential.”
Professor Sadono mentioned that the trees that constitute forests are only commonly measured for some of their attributes across the entire area due to time and cost constraints.
Even for a single plot area, only the essential practical attributes are measured, which can be used to estimate required information, such as tree volume, biomass, carbon, and energy potential.
These crucial variables, such as the diameter at breast height, are treated as the single predictors to describe the studied response variable, which is the volume of branch-free trees or total tree volume.
“In order to obtain tree volume data, the priority procedure involves sample logging,” he said.
Field plot measurements are believed to provide accurate estimation values. However, implementing this in vast areas will take a considerable amount of time, leading to financial consequences.
Moreover, circumstances like forest areas being challenging to reach due to limited access or rugged terrain need consideration.
“Additionally, in forest areas, there may be wild animals such as tigers that can endanger the safety of the measurement team or other animals that may disrupt the health of the surveying personnel, such as malaria-carrying mosquitoes,” he explained.
He suggested that combining field measurements from several training plots, where measurements are taken on-site, and testing plots, where a portion of the training plot parameter is suspected using remote sensing technology for validation, will expedite the work process to obtain estimations of the desired parameters, such as volume, biomass, carbon, and energy potential.
“Remote sensing technology allows capturing the spectral reflection of objects on the earth’s surface. Depending on its image resolution, the higher the spatial resolution, the more detailed the captured and recognizable earth’s surface objects,” he stated.
For high-precision object detection needs, satellite image categories with high resolution, such as Sentinel-2A or 2B, with spatial resolution in multispectral bands of 10 x 10 meters, should be used.
However, it’s important to note that the desired satellite image isn’t always available from a targeted area, given that the images are often cloud-covered to a large extent, making them impossible to process with image processing software like ArcGIS or QGIS.
“This situation is quite understandable, especially in Indonesia, which is located in a tropical region where clouds frequently cover images,” he added.
“If the image is available in the target area, it can be processed through geometric, radiometric corrections, among other things, to achieve a good visualization of the target area.”
Regarding the potential of forest resources, Professor Sadono explained that the trees composing the forest ecosystem, aside from having an essential role in carbon storage, some species have significant roles in renewable energy programs.
“There are several tree species with high-calorific wood. Unfortunately, however, these tree species’ wood is still prioritized for construction, for example, teak and mahogany trees,” he said.
According to him, Indonesia has the potential to develop tree species with high-calorific wood that does not compete for construction wood, such as Kaliandra. The calorific value of Kaliandra is relatively high, approximately 4,500-4,900 kcal/kg.
However, the entire woody parts above the ground are used, making it no longer function as a carbon store.
From this reality, parts of the tree are utilized, for instance, Nyamplung tree seeds (Calophyllum inophyllum L) for biodiesel, ensuring the carbon storage function is retained.
“My team and I in the laboratory are researching the energy potential of Eucalyptus species growing naturally in East Nusa Tenggara. Allometric equations are being developed to estimate the calorific value as the basis of this species’ energy potential,” he concluded.
Author: Gusti Grehenson