Kajian Ekologi Tumbuhan Langka Rotan Beula Ceratolobus glaucescens Blume di Cagar Alam Sukawayana Sukabumi Jawa Barat

Abstract

Indonesian forest possesses a huge number species of plants. Among those plants, there is a species of rattan, called Rotan Beula (Ceratolobus glaucescen Blume), has been protected by Indonesian Government through Governmental Regulation (Peraturan Pemerintah) No.7/1999 about Preservations of Flora and Fauna Species. Sustainability of Rotan Beula should be kept through various efforts. One of efforts to keep the sustainability of this rattan is conducting the ecological study of Rotan Beula. The aims of this study is to determine the structure, composition, and diversity vegetation which grows at habitat of rotan beula; to know the population condition of rotan beula; and to identify the ecological factors of rotan beula. Sample units were made by using purposive sampling method at every place which is grown by rotan beula. The form of each sample unit is circular plot. The width of circular plot for trees and poles were 0.1 ha, for sapling were 0.01 ha, and for seedlings were 0.001 ha. The data that were collected are biological and physical factors of rotan beula. The processing and analysis of data was done using Minitab's program version 14 . Vegetation structure at the habitat of rotan beula consisted of fledged strata (A=1.18%, B=2.29%, C=8.87%, D=26.67% and E=60.98%). Vegetation composition at habitat of rotan beula was dominated by teureup (Artocarpus elastica) (Importance Value Index [IVI]=26.5%) for tree level, heucit (Baccaurea javanica) (IVI=31.95%) for pole level, patat (Phrynium capitatum) (IVI=28.44%) for sapling level, and Derris trifoliate (IVI=38.95%) for seedling level. The vegetation richness at habitat of rotan was 8.79 for tree level, 7.58 for pole level, 7.12 for sapling level, and 3.77 for seedling level. The variety index for level of tree, pole, sapling, and seedling respectively was 3.43; 3.31; 3.33; and 2.87. Rotan beula is supported by physical factor such as relative humidity of air (71-95%), air temperature (26-320C), optimum pH (6.5-6.8), Ca (4.06-10.67 me/100 g), Mg (2.77-6.14 me/100 g), K (0.72-1.32 me /100 g), Na (0.66-1.3 me/100 g), N (0.09-0.14%), S (2.65-4.24 ppm), P (3.4-5.7 ppm) and litter's depth was 1-2 cm. The condition of rotan beula populations are well, they still grow normally. This conditions was described with young age (446 individuals) is more than the total of Rotan beula in old age (162 individuals). The sustainability of rotan beula’s population at Sukawayana Natural Reserve (SNR) was being threatened by society activity surround the SNR. The density of Rotan beula was affected by density of pole level (n=7; t=7.81; p=0.001) and relative humidity of air (n=7; t=12.10; p=0.000). It can be formulated with regression: rotan beula density = -1155 + 0.154 density of pole + 13.9 relative humidity of air.