Search

Nepenthes occur in various habitat types in West Kalimantan. But some species are categorized as vulnerable on the IUCN red list. Autecological studies of Nepenthes spp. are required for species management and conservation. The study aimed to analyze species diversity, distribution pattern, association, and environmental factors that correlated with Nepenthes spp. at peat swamp and heath forest in Pematang Gadung. Data was collected in September 2021 by purposive sampling on 60 plots measuring 3 x 3 m2 in each habitat type. Species diversity was analyzed based on the presence and abundance of species in the plots. The distribution pattern was determined using a standardized Morisita index (Ip). Meanwhile, the association type was determined based on the Jaccard index (JI). Environmental data were analyzed by Canonical Correspondence Analysis (CCA) using Past Version 4.03. This study found six wild species in a peat swamp and four species in a heath forest. The population of Nepenthes spp. has clumped distribution pattern with Ip>0. Nepenthes spp. are associated with plants such as Barringtonia racemosa, Syzygium sp., Nephrolepis biserrata, and Campnosperma auriculatum. The result of CCA revealed that environmental factors in both habitat types affected the presence of each Nepenthes species. The air temperature, humidity, soil moisture, and light intensity show different influences on different species.

Bantimurung Bulusaraung National Park is an area that has the largest karst ecosystem in Indonesia. Karst is prone to damage and difficult to reuse, so it requires conservation efforts. One of the plant species that can maintain this sustainability is Ficus which acts as key species in karst ecosystems. However, at this time the species is experiencing disturbances, one of which is due to the experience of invasive plants that can threaten the existence of Ficus because the weeds can colonize habitats and are dominant which can change species diversity. This study aimed to analyze the diversity and distribution of Ficus, compare species composition, and analyze environmental factors that affect Ficus spp. in Pattunuang Resort and Bantimurung Resort. Vegetation analysis method with nesting plots placed by purposive sampling and supported with environmental and soil data measurements to determine the factors that indicate the habitat preference of Ficus. We found 18 plant species of Ficus spp. in total. At Resort Pattunuang we found 14 Ficus species with the highest abundance being Ficus sundaica (27.55%), while we recorded 15 Ficus species at Resort Bantimurung with the highest abundance being Ficus ampelas (29.23%). Ficus species were uniformly distributed with a relatively high ratio of species composition in both resorts. Principal Component Analysis (PCA) showed that the presence of Ficus in Pattunuang Resort is influenced by wind speed, soil temperature, air temperature, soil moisture, soil pH, and air humidity. In Bantimurung Resort, the existence of Ficus is influenced by wind speed, soil temperature, soil moisture, and air humidity.

The red list of the International Union for the Conservation of Nature and Natural Resources (IUCN) reported Castanopsis argentea as an endangered species. Studies about autecology on its natural habitat become important to perform species conservation. This study aimed to analyze the population structure, distribution pattern, and environmental factors that influence the presence of C. argentea in the Telaga Warna Nature Reserve. Data was collected in September 2020 by making 21 plots with a single plot. The purposive sampling method was used based on C. argentea representatives to determine plot location. Measurement of environmental factors, including soil sampling was carried out on each plot. Population structure was analyzed based on plant density, and Morisita index determined the distribution pattern. Environmental data were analyzed using PCA with Minitab 19 programs. Our field observation showed that C. argentea seedling has the highest density (1071 ind/ha) and decreased in the mature phase. C. argentea was found to have a clumped distribution pattern with an Id value of 1.03. PCA analysis showed differences in environmental factors that were thought to influence the presence of C. argentea individuals in four growth phases. The highest population structure of C. argentea was found in the growth phase of seedlings and saplings at an altitude of 1400 m asl. The spread population distribution of C. argentea was clumped. The influences of environmental variables on the existence of C. argentea were Mg, Ca, CEC, pH, and soil moisture.