Undergrowth vegetation in the riparian zone of the Upper Bengawan Solo River, Central Java, Indonesia and its potential uses

Abstract. Saputra AF, Utomo AN, Pramesthi AZ, Madjid AA, Sulton MN, Dewangga A, Setyawan AD. 2024. Undergrowth vegetation in the riparian zone of the Upper Bengawan Solo River, Central Java, Indonesia and its potential uses. Asian J For 8: 194-206. Riparian zone is the transitional zone between terrestrial water and land ecosystems, and an important part of river ecosystem. In riparian zone, the presence of vegetation, ranging from trees to undergrowth, is important to maintain ecosystem functions. Undergrowth vegetation in riparian zone is also widely utilized by local people for various purposes. This study aimed to determine the understory vegetation in riparian zone of the Upper Bengawan Solo River, Central Java, Indonesia and its potential use in the community. This research was conducted in three stations, i.e., Giriwono Village, Wonogiri District for the upstream, Sidowarno Village, Klaten District for the middle stream, and Gadingan Village, Sukoharjo District for the downstream. Data collection used transect method with size of 2×2 for seedlings and herbaceous plants and 5×5 plots for saplings and shrubs, each with five replications at each station. The study documented 78 species from 38 families of undergrowth vegetation across the three riparian locations. The vegetation diversity index (H') studied across the three stations is included in the medium category. The plant with the highest Index of Important Value (IVI) for seedlings and herbaceous plants was Chromolaena odorata with 15.56%, while that for saplings and shrubs was Bambusa blumeana with 47.74%. The higher elevation in the upstream (Wonogiri District) led to higher soil temperatures, while the midstream (Klaten District) had a more acidic soil pH and the highest air humidity. In the downstream (Sukoharjo District), high humidity due to proximity to the river, led to lower soil temperatures. Riparian vegetation along the Upper Bengawan Solo River also has diverse potentials with the dominance of medicinal uses, while other plants are used as animal feed, ornamental plants, food ingredients, and others.