The forest and land fires (karhutla) that occurred from September 6–15, 2023, turned the expanse of savanna around Mount Bromo into a sea of ash. The fires were reportedly caused by the use of flares as props for pre-wedding photos, which triggered fires in the savanna. As a result, more than 500 hectares of vegetation were scorched, particularly within the Bromo Tengger Semeru National Park (TNBTS) conservation area, which spans four regencies in East Java: Malang, Probolinggo, Pasuruan, and Lumajang.

TNBTS Has a Unique Ecosystem

Dr. Luthfiralda Sjahfirdi, M.Biomed, an environmental biologist and wildlife conservationist from the Faculty of Mathematics and Natural Sciences, University of Indonesia (FMIPA UI), also expressed his regret over the fire, considering that TNBTS is a conservation area listed by UNESCO as a World Network of Biosphere Reserve. TNBTS has a unique ecosystem consisting of both a desert or sea of sand and a savanna. Within the savanna ecosystem, there is a stretch of grassland known as Teletubbies Hill.

In addition to the savanna, TNBTS also boasts centuries-old trees, such as the mountain pine (Casuarina junghuhniana), the jamuju conifer (Dacrycarpus imbricatus), the edelweiss (Leontopodium nivale), and various rare orchids and grasses. Plants and trees surrounding TNBTS include centigi (Vaccinium varingiafolium), acacia (Acacia), cypress, and numerous grasses.

These plants also serve as habitat for various animals living in the TNBTS. This area is home to at least 38 protected wildlife species, including 24 bird species, 11 mammal species, 1 reptile species, and 2 insect species. These include the Javan hawk-eagle (Nisaetus bartelsi), the Javan leopard (Panthera pardus melas), and the Javan langur (Trachypithecus auratus).

The Impact of Forest and Land Fires in TNBTS on Biodiversity

Forest and land fires in the Mount Bromo area can have short- and long-term impacts on biodiversity in the TNBTS. In the short term, a number of endemic vegetation species, such as malela grass, edelweiss, and the tosari orchid, are charred, a species endemic to the Javanese mountains. Some experts argue that fires tend to “weed out” certain plants and encourage the growth of others, particularly grasses. The relatively rapid growth of grasses can, in the long term, transform burnt areas into grass-dominated areas.

Furthermore, forest and land fires in the Mount Bromo area also have a devastating impact on wildlife. Animal species that are too weak to move and hide will perish in the flames. Young and small animals are particularly at risk when facing disasters because some natural escape strategies fail. Some species with slow locomotion choose to remain still and hide in trees, only to be trapped by the flames.

In the long term, even if some animal species are able to escape the flames, it’s possible that herbivores won’t be able to survive due to the loss of plants or trees that provide food. Carnivorous species that are able to escape also won’t necessarily survive if there are no prey species.

Steps to Take After a Fire

Dr. Luthfiralda stated that, based on various research reports collected, fires trigger a series of changes in plants, microbes, fungi, and other organisms inhabiting post-fire forests. Fires not only affect living organisms but also the environment. Water flow, such as rivers, can experience changes depending on turbidity, chemical content, and river structure. This can result in the death of aquatic invertebrate species, which impacts terrestrial animal life and, in turn, the food chain.

To restore post-fire land function, according to Dr. Luthfiralda, several steps must be taken, including recording the affected vegetation and understanding the biology of vegetation species and forest characteristics. Some plant species have seeds that prefer heat. Fires often encourage dormant seeds to germinate. High temperatures are essential for the reproduction of many plant species, whose seeds respond not only to water but also to fire

It Will Take a Long Time to Restore the Ecosystem in TNBTS

A one-year-old forest will have a more diverse collection of plants and animals than a forest decades old. In tropical regions, burned areas can initiate the succession process when the rainy season arrives. According to Patricia Kennedy, a wildlife biologist from Oregon State University, forest fires can act as a ‘reset’ button, allowing old-growth forests to regenerate. However, this succession process is highly dependent on biotic and abiotic factors, including the environment and seed availability.

“The recovery of a forest ecosystem after a fire depends on the landscape, the extent of damage, and the species within it. Human intervention in the recovery process is essential to accelerate it. Many experts have conducted research on land recovery after fires. They believe that it will take a long time, even decades, to return the environment to its original condition,” said Dr. Luthfiralda.