jurnal.krbogor.lipi.go.id Buletin Kebun Raya Vol. 19 No. 1, Januari 2016 [57–66] e-ISSN: 2460-1519 | p-ISSN: 0125-961X Scientific Article POPULATION SIZE OF TWO ENDANGERED VIREYA RHODODENDRON SPECIES AND THEIR SURROUNDING VEGETATION ON THE TOP OF THE MT. RANTEMARIO, SULAWESI Ukuran Populasi Dua Jenis Vireya Rhododendron Berkategori Genting dan Vegetasi Sekitarnya di Puncak Gunung Rantemario, Sulawesi Wiguna Rahman and Andes H. Rozak Cibodas Botanic Garden, Indonesian Institute of Sciences Sindanglaya Cianjur 43253 PO.BOX SDL, West Java, Indonesia * Email: [email protected] Received/Diterima: November 25, 2015; Accepted/Disetujui: January 25, 2016 Abstrak Lima dari 29 jenis Rhododendron di Sulawesi terancam kepunahan dan dua diantaranya termasuk dalam kategori Genting (EN D). Pengamatan di lapangan telah dilakukan untuk menentukan ukuran populasi terkini dari R. eymae dan R. nanophyton var. nanophyton yang berkategori Genting tersebut. Seratus empat puluh plot 2 (masing-masing berukuran 5x5 m ) dibuat pada tujuh transek di kawasan puncak G. Rantemario (3,269–3,445 m dpl), Sulawesi Selatan. Hasil pengukuran berhasil menemukan 318 individu R. eymae dan dua individu R. nanophyton var. nanophyton dalam plot yang dibuat. Berdasarkan data yang diperoleh, ukuran populasi hasil estimasi dari dua jenis Rhododendron tersebut tidak memenuhi kriteria Genting (EN D). Kategori yang lebih tepat untuk dua jenis tersebut yaitu Rawan (VU D2). Pertimbangan perubahan kategori tersebut dijelaskan dalam makalah ini. Semak dan herba yang dominan di puncak G. Rantemario yaitu Leptospermum javanica (IVI=37.08), Eriocaulon truncatum (IVI=34.83), dan Styphelia suaveolens (IVI=24.63). Asosiasi ketiga jenis tumbuhan tersebut dengan dua jenis Rhododendron telah dianalisis. Kata kunci: Genting, Rhododendron, Sulawesi, tropikal alpin, vegetasi Abstract Five of the 29 species of Rhododendron of Sulawesi are threatened and two of which have endangered category (EN D). Field assessment had been conducted to measure the current population size of the endangered R. eymae and R. nanophyton var. nanophyton. One hundred and fortyplots (of each 5x5 m2) along seven transects were established around the summit of Mt. Rantemario (3,269–3,445 m asl.), South Sulawesi. The results showed that there were 318 individuals of R. eymae and two individuals of R. nanophyton var. nanophyton within the plots. We also found that the estimated population sizes of those two species have not met the criteria previously stated (EN D). The appropriated status for both species is Vulnerable (VU D2). The reasons for proposing this new category are discussed. The dominated shrubs and herbs on the summit area of | 57 W. Rahman & A. H. Rozak. Population Size of Two Endangered Vireya Rhododendron Species and Their Surrounding Vegetation…….. Mt. Rantemario were Leptospermum javanica (IVI=37.08), Eriocaulon truncatum (IVI=34.83), and Styphelia suaveolens (IVI=24.63). The association of those three plants with the Rhododendron’s were analysed. Keywords: Endangered, Rhododendron, Sulawesi, tropical alpine, vegetation INTRODUCTION Cannon et al. (2005) classified the forests above 2,200 m elevation of Sulawesi as Tropalpine Sulawesi is the largest island of Wallacea (Tropical alpine). This type mostly still shows good region in Indonesia. The element of Sulawesi flora condition but is vulnerable to disturbances and is was associated between Sundaland on the west, slow to recover. The total extent of this forest type Phillipines on the north, and Australasia components was only about one percent of the total Sulawesi on the east. Therefore, Sulawesi flora were more land area and it was scattered across the island on heterogenous than other islands in Indonesia but small pathces (Cannon et al., 2005). The woody plant higher in endemicity (Widjaja et al., 2011). The species diversity is often quite low but herbaceous endemicity of Sulawesi flora is relatively similar to plants are often most diverse and unique in such Sumatera (12.3%) but is lower than Borneo (28.4%) forest type (Cannon et al., 2005). One of plant groups and Papua (46.6%) (Roos et al., 2004). The flora of that can be found at this habitat type is Sulawesi remains poorly known (Kessler, 2002) and Rhododendron (Ericaceae) (Argent, 2006). the collection rates of plant material amongst areas were not equivalent in Sulawesi (Cannon et al., About 1,157 species of Rhododendrons have 2007). been assessed through IUCN Red List criteria and 316 among them were categorized as threatened species One of the poorly studied areas in the (Gibbs et al., 2011). In Sulawesi, there were 29 highlands of Sulawesi is Mount Rantemario (Figure species of Rhododendron (Argent, 2007). Five of 1). This mountain is the highest in Sulawesi (3,478 m which are threatened and four of these five asl.). It is one of the peak on Latimojong highland threatened species were endemic to Mt. Rantemario area of 580 km2 and is located in three different (Argent, 2006). Two threatened species of the subdistrict authorities of South Sulawesi Province. Sulawesi Rhododendrons have been listed as This area is a protected forest managed by the local “Endangered” species and are endemic to the area of goverment and designated since 1940. Based on the Mt. Rantemario, i.e. Rhododendron eymae Sleumer World Database on Protected Areas (IUCN & UNEP- and R. nanophyton var. nanophyton Sleumer (Argent, WCMC, 2014), Latimojong highland has been 2006; Gibbs et al., 2011. The assessment of those categorized as a protected area implementing species was predominantly based on indirect sustainable use of natural resources (category VI). evidences, i.e. from herbarium specimen, taxonomic This category possesses several objectives besides publication, and expert opinion. These techniques the protection of the natural resources. One of those result in a hard work especially to re-assess the objectives is ensuring sustainable livelihood of the species in the future (Brummit & Bachman, 2010). local communities in the context of inter- generations. However, anthropogenic disturbances Brummit et al. (2015) suggested a field-based seem to continue in this area through logging, the assessment for species which were previously establishment of pine forest, coffee plantation, and categorized by indirect assessments to increase the small-agricultural plots in a massive scale (Thomas et convidence level of the data. This data are needed to al., 2009). Those activities are unsustainable practical evaluate the Sample Red List Index (SRLI). The aims for the natural resources in the future. of the index are to measure projected extinction risk of species and to track changes of this risk (Butchart et al., 2007). 58| Buletin Kebun Raya Vol. 19 No.1, Januari 2016 [57–66] Figure 1. Location of Mt. Rantemario, South Sulawesi The current status of Rhododendron eymae where no trees occurred and dense green area and R. nanophyton var. nanophyton showed that the where trees (mostly at sapling size) occurred. We species had only very small or restricted populations decided to establish randomly four transects in rocky in which the numbers of mature individuals were less sites and three transects in dense green area since than 250 (Gibbs et al., 2011). On the other hand, the element compositions seem to be homogenous. there was no clear information about the population 2 sizes of those two Rhododendron species. This paper Within each transect, there were 20 of 5x5 m were aims to re-asses the current population size of plots where those two Rhododendron species were R. eymae and R. nanophyton var. nanophyton and to counted. Half of the plots on each transects were 2 describe the summit vegetation of Mt. Rantemario. also used on vegetation analysis and three of 1x1 m This information will be useful to monitor the of subplot were established to be nested to those population size of those two species in the future. plots to measure herbs and seedling diversity. In total, there were 140 (5x5m2) plots to measure population of the Rhododendrons and 70 (5x5 m2) MATERIALS AND METHODS plots which contains 210 (1x1 m2) plots. Population sizes of Rhododendron eymae and The numbers of individuals of each species R. nanophyton var. nanophyton were measured within the plots and subplots were counted to based on the seven of each 50 m long transects with describe the population status within the area. When 10 m width on the summit area of Mt. Rantemario, the plants cover more than one subplots, we counted South Sulawesi, Indonesia (Table 1). Gillison (2006) each parts as its occured on those plots. Data were 2 2 stated that a 40x5m (200m ) transect is adequate analyzed to measure the indices of density, for vegetation survey and larger plot size is used in frequency, and importance values. The herbarium complex vegetation such in rough terrain sites. In specimens were collected and identified at the general, there were two types of vegetation on the Cibodas Botanic Gardens’Herbarium (CHTJ) and the summit of Mt. Rantemario, i.e. rocky vegetation Herbarium Bogoriense (BO). |59 W. Rahman & A. H. Rozak. Population Size of Two Endangered Vireya Rhododendron Species and Their Surrounding Vegetation…….. Interspesific plant association between and herbs were recorded (Table2). The top five plant herbs/seedling species and R. eymae and R. species dominated the vegetation on the summit of nanophyton var. nanophyton was calculated using Mt. Rantemario were Leptospermum javanica (IVI = the 2x2 contingency table of the species 37.078), Eriocaulon truncatum. (IVI = 34.832), presence/absence data and analysed by the Chi- Styphelia suaveolens. (IVI= 24.626), Rytidosperma 2 2 square (χ ) test. The significance of χ test is oreoboloides(IVI = 14.921), and Gentiana sp1. (IVI = 2 2 determined by comparing the χ observed and χ 13.778). R. eymae (IVI = 5.388) was only found theoretical distribution at p=0.05; df=1. Type of within 30 subplots consisting 56 individuals. R. 2 2 association is positive (+) if the χ observed > the χ nanophyton (IVI = 0.185) was only found on one theoretical and the observed co-occurence of both subplot (2 individuals).