Herwint Simbolon

Habitat differentiation among tree species with small-scale variation of humus depth and topography in a tropical heath forest of Central Kalimantan, Indonesia

Small-scale spatial association of the distribution for 55 abundant tree species with two environmental factors (humus depth and surface microtopography) was examined in two 1-ha plots of a heath (kerangas) forest in Central Kalimantan, Indonesia. More than 80% of the 55 species showed a significant habitat preference in humus depth and/ or relative elevation in at least one plot. In particular, ten species occurring in both plots showed a consistent significant preference for humus depth or relative elevation in the two plots. Using randomization tests, however, only five species significantly associated with humus depth and no species with relative elevation. These results suggest that edaphic and topographic factors, especially humus depth, contribute to determining local spatial distribution and floristic composition of abundant tree species in the forest.

Forest Structure and Productivity of Tropical Heath and Peatland Forests

Allometric relationships between tree dimensions, aboveground forest structure and productivity were examined in tropical heath (kerangas) forest and peatland forest in Central Kalimantan, to determine the stand level properties of these forest types growing under stressful conditions, by comparing with those in mixed dipterocarp forests. In the peatland forest, tree density, trunk diameter-height relationships and aboveground biomass differed between sites, partly due to differences in disturbance history such as the intensity of selective logging in the past. The heath and peatland forests shared common characteristics such as high leaf mass per area and long leaf residence time at the stand level. Both forest types had high wood mass increment rates (maximum of 8.2 Mg ha−1 year−1 in the heath forest and 10.9 Mg ha−1 year−1 in the peatland forest), which fluctuated greatly during and after the severe 1997–1998 drought. The results here suggest that the heath and peatland forests maintain moderately high productivity under stressful conditions, probably owing to the adaptive leaf properties. The results also suggest that the aboveground forest structure of these forest types as well as peat deposit has the potential to play a significant role in the carbon balance in an area. To be able to properly conserve these forest ecosystems, more attention must be paid to elucidating the mechanisms maintaining primary productivity of heath and peatland forests.

Some Vegetation Types Studied with the Same Methodology in Indonesia

Indonesian natural resources have long attracted many botanists of the world—in fact, since Rumphius initiated the work of Herbarium Amboinense during the seventeenth century (Rumphius 1743, van Steenis 1950). Much botanical literature has appeared as the result of botanical explorations and expeditions during the Dutch colonization. Dilmy and Kostermans (1958) compiled studies on vegetation in Indonesia from before 1958, and Kartawinata (1990) reported the state of vegetation studies in Indonesia up to 1980. The general ecological studies in Indonesia were summarized and published in several books in The Ecology of Indonesia Series, including those on: Sumatra (Whitten et al. 1984), Sulawesi (Whitten et al. 1989), Kalimantan (MacKinnon et al. 1996), Nusa Tenggara (Monk et al. 1997), Java and Bali (Whitten et al. 1996), and Papua (Marshal and Beehler 2007). Riswan and Yamada (2006) reported on the progress of biodiversity research in Indonesia. Kartawinata (2005) summarized six decades of natural vegetation studies in Indonesia.

DISTRIBUSI VERTIKAL DAN HORIZONTAL Asplenium nidus L. DI TAMAN NASIONAL GUNUNG HALIMUN, JAWA BARAT [Vertical and Horizontal Distributions of Asplenium nidus L. in Gunung Halimun National Park, West Java]

Studi taksonomi jamur di Taman Nasional Gunung Halimun (TNGH) belum dilakukan dengan intensif.Sebanyak 35 jenis Agarics dikoleksi dari kawasan TNGH meliputi 23 marga dan 9 suku.Kekayaan keanekaragaman jamur ini diperoleh dari eksplorasi di 3 lokasi yaitu Cikaniki, Gunung Botol dan Gunung Telaga (Ciptarasa).Sejumlah sampel belum teridentifikasi karena karakter yang belum jelas.Oleh karena itu, jumlah jenis-jenis baru dari eksplorasi ini belum dapat diketahui.Fifty strains of Bacillus sp. isolated from Gunung Halimun National Park (GHNP) were characterized. All strains are characterized by amylase, protease, phosphatase, ligninase, and cellulase activity.Thirtyseven isolates gave positive reaction for amylase activity, 46 isolates for protease activity, 3 isolates for phosphatase activity, 3 isolates for ligninase activity, and 36 isolates for cellulose activity.These findings indicates that Bacillus sp. that isolated from GHNP is a potential microbe for enzymes technology and biotechnology application.Fish fauna survey were conducted in Cimadur, Ciujung and Ciberang Rivers. From these studies six fishes species were found as additional record for fishes living in Gunung Halimun National Park and its adjacent area. This finding brings the fish species living at this park to be sixty.In this record, it includes Cypriniid fishes that attain large size: Barbodes balleroides and Osteochilus hasseltii, found in the segment of the middle of R. Ciujung (18.3 m asl).The fieldworks for inventory and collection on mammals in Gunung Halimun National Park (OHNP) had been carried out for long time; however the works only focused on the areas belong to Bogor District. Therefore, the fieldwork was carried out in the buffer zone of the GHNP in Lebak District.The fieldwork had collected 70 numbers consisted of 16 species of mammals, of which five species were new records for GHNP and of those five species, two species (Glischropus javanus and Myotis sp.)were new collection for the Museum Zoologicum Bogoriense-Research Center for Biology-The Indonesian Institute of Sciences (LIPI).The Baduy people were noticed to hunt fruit-bats from some caves for their food.It was suggested a monitoring activity on the utilization of fruit-bats should be conducted for the conservation of the fruit-bats.Further fieldwork outside the Bogor District in the future should also be considered, particularly on the area along the river.