Heath forest identification using remote sensing in the surrounding area of the new capital city of Indonesia

Abstract

The construction of Indonesia’s new capital city, Nusantara, is envisioned as a forest city that heavily relies on biodiversity. One of the forest ecosystem types surrounding the Nusantara landscape is the heath forest ecosystem, also known as Kerangas. Heath forest is a rare and extreme habitat, thriving in nutrient-poor environments characterized by low pH, quartz sand soil, and podsol soil. However, there is still a lack of knowledge regarding the heath forest in East Kalimantan, particularly in the Nusantara region. This research aims to map the location and characteristics of the heath forest in the surrounding area of Nusantara, specifically in Penajam Paser Utara Regency and Kutai Kartanegara Regency, East Kalimantan. The creation of a tentative heath forest map requires four parameters: elevation, soil texture, NDVI, and a land cover map. Landsat 9 imagery was employed to conduct unsupervised classification and generate a land cover map. The Normalized Difference Vegetation Index (NDVI) was also applied as an image transformation. The parameters were then overlaid using Geographic Information System (GIS) with a binary model. The results indicate that the heath forest covers an area of 56,646 hectares, representing 23% of the total Nusantara area, while the non-heath forest covers 194,610 hectares. The heath forest tentative map aligns with the RePPProT (Regional Physical Planning Project for Transmigration) land system map. Kerangas forests exhibit unique vegetation types, characterized by stunted trees, shrubs, and various epiphytes. Due to the nutrient-poor soil conditions, the vegetation in heath forests is typically sparse and of low height.