Vascular epiphytes are an understudied and particularly important component of tropical forest ecosystems. However, owing to the difficulties of access, little is known about the properties of epiphyte-host tree communities and the factors structuring them, especially in Asia. We investigated factors structuring the vascular epiphyte-host community and its network properties in a tropical montane forest in Xishuangbanna, SW China. Vascular epiphytes were surveyed in six plots located in mature forests. Six host and four micro-site environmental factors were investigated. Epiphyte diversity was strongly correlated with host size (DBH, diameter at breast height), while within hosts the highest epiphyte diversity was in the middle canopy and epiphyte diversity was significantly higher in sites with canopy soil or a moss mat than on bare bark. DBH, elevation and stem height explained 22% of the total variation in the epiphyte species assemblage among hosts, and DBH was the most important factor which alone explained 6% of the variation. Within hosts, 51% of the variation in epiphyte assemblage composition was explained by canopy position and substrate, and the most important single factor was substrate which accounted for 16% of the variation. Analysis of network properties indicated that the epiphyte host community was highly nested, with a low level of epiphyte specialization, and an almost even interaction strength between epiphytes and host trees. Together, these results indicate that large trees harbor a substantial proportion of the epiphyte community in this forest.

Cibodas Botanic Garden area is adjacent with natural forest of Mt. Gede Pangrango National Park which consequences both vegetation in the border area are influence each other. The aims of this research were to study plant vegetation of forest area adjacent to Cibodas Botanical Garden and compare it with forest interior using transect method. The results showed that species richness in forest interior were higher than adjacent forest area. Furthermore, number of tree species, basal area and Shannon-Wienner diversity index in forest boundaries were higher rather than forest interior. Habitats along the forest edge were inhabited by trees with large dbh and low tree density. While trees inhibited forest interior areas with high density but small in size. The trees in forest interior were dominated by Schima wallichii, Lithocarpus pallidus and Turpinia sphaerocarpa. While trees in the forest boundary vegetation were dominated by Engelhardtia spicata, Litsea firma and Lithocarpus indutus. The tree age structure of forest interior and forest edge showed an inverted J-pattern and flat pattern respectively. Meanwhile, tree communities on edge forest vegetation showed similar age structure, especially in middle diameter class.

Abstrak. Kebun Raya Cibodas merupakan kawasan konservasi ex situ yang terletak di Cagar Biosfer Cibodas Jawa Barat. Sebagai bagian dari Cagar Biosfer Cibodas, Kebun Raya Cibodas berfungsi sebagai konservasi, penelitian, pariwisata dan pendidikan. Penelitian inventarisasi tumbuhan air bertujuan untuk mendapatkan informasi jenis tumbuhan air yang tumbuh di kawasan Kebun Raya Cibodas. Penelitian inventarisasi tumbuhan air dilakukan dengan metode eksplorasi pada 6 lokasi di Kebun Raya Cibodas dan pengumpulan specimen tumbuhan air untuk identifikasi. Hasil penelitian menunjukkan bahwa kategori tumbuhan air emergent plants merupakan tumbuhan air yang paling banyak ditemukan di Kebun Raya Cibodas dan lokasi terbanyak ditemukan jenis tumbuhan air adalah lokasi 4 yaitu sebanyak 29 jenis tumbuhan air.Kata kunci: Tumbuhan air, Kebun Raya Cibodas

Abstract. Nurdiana DR, Buot IE Jr. 2021. Vegetation community and species association of Castanopsis spp. at its habitat in the remnant forest of Cibodas Botanical Garden, Indonesia. Biodiversitas 22: 4799-4807. Castanopsis is one of the genera of Fagaceae with a large distribution in Indonesia. The genus can be found easily in Java, Sumatera and Kalimantan. Several studies have found an association between Castanopsis and environmental factors dealing with the diversity, dispersal and propagation. So far, there has been no agreement on how Castanopsis interacts with other species within the same genus in nature, especially in the remnant forest under a fragmented state. The objectives of the study were to determine the vegetation associated with Castanopsis and whether each species of the genus Castanopsis co-occur within the remnant forest? A total of 60 plots have been studied in 3 different sites of the remnant forest. The nested sampling method was used to identify the trees, saplings and seedlings. Sixty-seven total species of trees, 140 species of saplings and 121 species of seedlings in Cibodas Botanical Garden remnant forest were recorded. The diversity index for tree, sapling and seedling were 3.5, 3.9 and 4.1, respectively, while evenness index for tree, sapling and seedling were 0.81, 0.8 and 0.85 respectively. The interspecific association of the genus Castanopsis was restricted to C. javanica x C. tungurrut. They are associated positively at sapling stage with Jaccard index of 0.2. However, at tree stage, there was no association out of the pair, C. javanica x C. tungurrut. Competition within genus Castanopsis occurred in the same habitat, though at a lesser degree which needs to be studied further. Dominance of many pioneer species (Oreocnide integrifolia (Gaudich.) Miq., Ostodes paniculata Blume, Cestrum aurantiacum Lindl. and others) at tree stage had been evident. This implies that the Cibodas remnant forest is still in the process of succession towards a more stable climax state.