Theme 1. Managing Smoke

Posters on Managing Smoke

Impact of Forest Fire on Berbak National Park's Biodiversity and Water Quality in Jambi - Sumatera

by Nyoman Ngurah Suryadhi Putra¹ and Irwansyah Reza Lubis

The impact of forest fire on the bio-diversity and water quality in Berbak National Park was studied during March to October 1998. The study covered three swampy areas: Simpang Palas, Simpang Datuk and Air Hitam Dalam. The first two had been burnt twice (1994 and 1997) and the third once (1997).

Impact on Water Quality. The survey indicated that forest fire had caused acidification and increased ion concentration in the water of the areas studied. The pH of these areas was very low (3.3 - 3.5) with acidity ranging 120 - 760 ppm, compared to the adjacent area which received no direct impact from forest fire (i.e. the Batanghari river: pH 5.8 - 7.1, no acidity values detected). The acidification of these swampy areas is thought to have resulted from the release of sulfate (through drought and fire) from soils containing sulfides or free sulfur, which then oxidized in the presence of water to form sulfuric acid. The survey recorded that the sulfate (136-695 ppm) and iron (1.7 - 6.4 ppm) content of these swampy areas was very high compared to the Batanghari river (sulphate: 14-29 ppm, total iron 0.30 - 0.62ppm). Physical degradation of organic matter during the forest fire in Berbak had also significantly increased ion (Ca, Na, Mg, K, SO₄⁼ and CO₃⁼) concentration in the waters. This effect has been demonstrated in the laboratory using a simulation model.

Impact on vegetation. Forest fire has destroyed 75-98 % (24 - 48 species) of plant species in the study areas. The highest loss was recorded in Air Hitam Dalam (98% or 48sp from a total of 49 species found in unburnt areas), followed by Simpang Palas (96% or 25 from total 26 species) and Simpang Datuk (75% or 8 from total 32 species). Although significant numbers of plant species were destroyed during the fire, the loss of thick canopies has enabled several dormant plant species to emerge from the ex-forest fire floors.

Impact on fauna. Forest fire has created many patches of open areas in Berbak. This implies loss of living habitat, feeding grounds and nesting habitat for certain creatures (e.g. sun bear). During the October 1998 survey, crowds of predator birds (e.g. Lesser adjutant, and Brahminy kite) were observed searching for food in these open areas, while sun bears (also other herbivorous mammals) were reported frequently attacking the villagers' crops (e.g. coconut trees). Villagers reported finding many freshwater fishes dead in Berbak NP during the 1997 dry season, due to the disappearance of water from the swamps, and also in the 1998 early rainy season. The 1998 fish deaths are suspected to be due to water acidification. A number of these fishes (e.g. the climbing perch (Anabas testudineus), snakeheads (Channa striata), sepat rawa (Trichogaster leeri) and Seluang (Rasbora agyrotaenia) have since reappeared in these ex-forest fire swampy areas. A minimum of between 20-21 adult individuals and 15 ducklings of WWD (White Winged Duck, Cairina scutulata) were found in Desa Sei Rambut and Air Hitam Dalam. (These areas have now become new records for WWD populations found in Sumatera). In the short term forest fire has had no significant impact on the occurrence of WWD in these areas, but in the long term due to habitat loss this might affect their presence.

Footnote_______________

¹ Wetland International-Indonesia Programme