Impacts of invasive tree species Bellucia pentamera on plant diversity, microclimate and soil of secondary tropical forest in West Sumatra, Indonesia

Abstract

Abstract. Solfiyeni, Syamsuardi, Chairul, Mukhtar E. 2022. Impacts of invasive tree species Bellucia pentamera on plant diversity, microclimate and soil of secondary tropical forest in West Sumatra, Indonesia. Biodiversitas 23: 3135-3146. The invasion of alien species in a region can alter species diversity. Bellucia pentamera Naudin is considered an alien invasive plant that has spread from Mexico to tropical America, and it is now invading some areas in Indonesia, including the tropical forest of Sumatra. Yet, the effects of its invasion on vegetation and the abiotic environment are not yet well understood. The objective of this study was to investigate the impacts of B. pentamera on species diversity and structure of vegetation, and microclimate and soil conditions of secondary tropical forests in West Sumatra. Vegetation analysis was conducted in secondary forest Bukit Tengah Pulau, South Solok, with three levels of dominance of B. pentamera namely: site 1 and 2 (60% and 16% dominance of B. pentamera respectively) and site 3 (no individual of B. pentamera). Sampling was conducted using a nested plot to collect data for tree, sapling and understorey vegetation for each site. The results showed the total number of tree species at sites 1, 2, and 3 were 23 species, 46 species, and 74 species respectively. For sapling, 20 species were found at site 1, 31 species at site 2, and 58 species at site 3. For understorey plants, 13, 16 and 36 species were detected at site 1, 2 and 3 respectively. The number of species at tree and sapling levels differed significantly among sites. The basal area also differed significantly among sites but not for sapling level. Site 1 was dominated by B. pentamera with Important Value Index (IVI) 130.8%), followed by Croton argyratus (27.63%), and Ficus variegata (26.47%). At site 2, B. pentamera dominated with IVI of 33.68%, followed by Lepisanthes sp. (20.01%) and Sizygium sp. (14.44%). Site 3 was dominated by Palaquium warsurifolium with IVI of 21.15% followed by Croton argyratus (20.02%) and Macaranga hypoleuca (13.21%). Diversity index (H') for tree-level was moderate at site 1 (H' = 1.78) and high at sites 2 and 3 (H' = 3.48 and 4.05). Similarly, the index for sapling was moderate at site 1 (H'= 2.12) and high at sites 2 and 3 (H'= 3.22 and 3.84). For understorey, the diversity index was low at site 1 (H'= 0.82) and moderate at sites 2 and 3 (H'= 1.8 and 2.86). Sites invaded by B. pentamera had a lower soil water content and higher temperature and light intensity, although they had higher nitrogen and phosphorus contents. Our findings suggest that the invasion of B. pentamera had negative impacts on plant biodiversity and microclimate, yet the impact was not clear cut on the soil.

Vegetation diversity and habitat suitability modeling of the invasive plant Bellucia pentamera in conservation forests of West Sumatra, Indonesia

“…In Lembah Harau, five individuals of B. pentamera were observed along with 16 local tree species, while in KBT, seven individuals of B. pentamera were found alongside 13 local tree species. The number of species observed in this study aligns closely with the findings of Solfiyeni et al (2022a), who reported 23 plant species in locations dominated by B. pentamera in the conservation forest of PT. Kencana Sawit Indonesian.…”

“…Invasive species like Bellucia pentamera prefer slightly shaded environments for germination, such as under the canopy of bushes or other plants, and exhibit rapid growth to compete for light with surrounding vegetation. A previous study of Solfiyeni et al (2022a) suggests that the habitat of B. pentamera to be typically at the forest edge or within forest gaps, where higher light intensity and temperature prevail.…”

“…This plant dominates high conservation value forests in PT. Kencana Sawit Indonesia, impacting plant diversity, microclimate, and soil conditions, with distribution patterns varying from clustered, random, to regular, according to existing forest gap conditions (Solfiyeni et al 2022a;2022b).…”

Pinus contorta Alters Microenvironmental Conditions and Reduces Plant Diversity in Patagonian Ecosystems

“…Nevertheless, literature has shown comparable effects of other invasive tree species on these local conditions as found in our study. For example, the invasive tree Bellucia pentamera invading forest ecosystems in Indonesia caused an increase in mean air temperature and phosphorus and nitrogen content, while reducing water content [24]. The invasion of Pinus mugo in alpine ecosystems of central Europe has a similar effect, where ecosystems invaded by P. mugo generated drier, shadier, and more nutrient-rich ecosystems compared with non-invaded alpine grasslands [4].…”

Structure, composition and diversity of tree species in Martelu Purba Nature Reserve, North Sumatra, Indonesia

“…Therefore, periodic monitoring becomes very important and should be conducted. Solfiyeni et al (2022) explained that B. pentamera is an introduced plant with negative impacts on biodiversity and microclimate in secondary forest areas in West Sumatra. The existence of a negative association between B. pentamera and surrounding plants is due to the allelopathic compounds possessed by this species which inhibit the growth of other species and make this species able to invade an area rapidly (Inayah and Solfiyeni 2021).…”