Effect of fire and digestion by herbivores on seeds of the exotic invasive species Acacia nilotica from savanna at Baluran national parks Indonesia
School of Science
Acacia nilotica is abundant in Africa but has been scantly studied in relation to savanna ecology. In Australia, a study by Radford et al. (2001), acknowledged that A. nilotica has negative impacts on savannas. A. nilotica can be threatening to savannas as its adult trees are apparently fire tolerant and can form thorny thickets. Acacia nilotica was introduced into Zizyphus rotundifolia savanna in Baluran National Park, East Java, Indonesia in the late 1960s, where its original purpose was to create fire breaks to prevent fire spreading from savanna to the adjacent teak forest. However, A. nilotica has spread rapidly and is threatening the existence of savanna in Baluran National Park, as it has been observed to change the ecosystem from open savanna to a closed canopy of A. nilotica in some areas (Figure 1) (Sutomo et al., 2016). There has been a lack of empirical studies on the cause and extent of the spread of A. nilotica in the Baluran savanna. We propose an hypotheses that fire and grazing by the introduced water buffalo (Buballus sp.) play an important role in the establishment of A. nilotica.