In their latest study, a group of researchers from Indonesia, the U.K., and the U.S. find that heath forests (locally known as kerangas) span 16,586 square kilometers (6,400 square miles) — almost the size of Hawaii’s land area — across Kalimantan. This figure suggests about a 33% loss of forest cover since a 1996 estimate of 24,750 km² (9,550 mi²), they write in a paper published July 16 in Cambridge University Press’ Journal of Tropical Ecology. The authors say their research offered a baseline by clarifying the mosaic structure of lowland kerangas and highlighting their distinct role as a unique habitat within the landscape, given limited research on these forests and the resulting gaps in understanding the effects of human pressures and conservation measures. “Research into kerangas forest coverage in Kalimantan was inspired by our discovery of the Rungan forest landscape’s fascinating forest and exceptional conservation value,” Namrata Biligeri Anirudh, a Ph.D. ecologist from the University of Indonesia who is the paper’s lead author, told Mongabay in an email interview. A new study mapping lowland heath forests (kerangas) in Indonesian Borneo reveals major changes in their extent and limited formal protection. Image courtesy of Bernat Ripoll Capilla. Anirudh noted that the landscape was nestled between the Rungan and Kahayan rivers in Central Kalimantan, serving as home to an extraordinary variety of endangered plants and animals, thanks to its rare mix of heath forests on sandy soils, swamps, lowland forests and abundant Borneo ironwood (Eusideroxylon zwageri). “The fact that such a…This article was originally published on Mongabay