Vegetation dynamics of permanent plot in dipterocarp forest Bukit Bangkirai, East Kalimantan, Indonesia

Abstract

Vegetation dynamics in dipterocarp forest permanent plots after fire (1997-1998) is important to monitor due to the successional process. Monitoring was conducted from 2001 to 2013 to record tree individuals with a more than 4.8 cm diameter. The highest species diversity was found in 2013 (249 species), then decreased in 2022 (237 species). Dominant species during monitoring change from Macaranga gigantea (Euphorbiaceae) and Madhuca kingiana (Sapotaceae) (2001-2002) to M. gigantea (Euphorbiaceae) and Vernonia arborea (2005-2013) and then M. gigantea (Euphorbiaceae) and M. kingiana (Sapotaceae) (2022). Shannon-Wiener diversity index (H') in 2022 indicates that species diversity in this permanent plot is high (4.85). The class diameter of trees in the permanent plot is dominated by small individuals (DBH <10 cm). The highest diameter increments are M. gigantea (0.42 cm year-1) and V. arborea (0.41 cm year-1) in the 5-10 cm diameter class. The highest tree recruitment found in 2005 (41.62%). Mortality rate from 2013-2022 was 3.16%, with high contribution from M. gigantea (141 individuals). Carbon storage value from 2001 to 2022 increased from 38.91 tons ha-1 (2001) to 114.29 tons ha-1 (2022). Successional process in this permanent plot needs to be monitored to assess forest health.