Out of 25 biodiversity hotspots of the world, Southeast Asia harbor four of these hotspots each of which has a unique geological history that has contributed to its rich and often unique biota.
with Max van Balgooy at Lore Lindu Park
During the Pleistocene glacial period, some temperate species from northern Asia expanded their ranges southwards into Indo-Burma and retained their presence thereafter. Fluctuating sea levels periodically converted mountain into geographically isolated islands, creating conditions that were ideal for speciation. The episodes sea level changes also repeatedly connected the islands of Sundaland (covering the westerns half of the Indo-Malayan archipelago) to the Asian mainland, enabling biotic migration from the mainland to the archipelago. As the sea level rose, the isolation of these island also facilitated speciation.
The presence of rain forest refugees in part of Sundaland during the Pleistocene also enabled the persistence of its forest biota. Australia and New Guinea are still isolated from Southeast Asia by marine barriers, but the northward movement of Australia in the Miocene gave rise to the Indonesian archipelago, which has permitted an increasing interchange with Southeast Asia plants. The distinctive differences in animal communities between Southeast Asia and New Guinea were first noted in the 19th century by the naturalist Alfred Russel Wallace (Wallace 1858). In recognition of his discovery, the line of separation between these two biotic regions is now called Wallace’s line and the region between Borneo and New Guinea, with its numerous central Indonesian islands including Sulawesi, is known as Wallacea. Although it was never connected to the Asia mainland, Wallacea is one of the most geologically complex regions in the world, because its island originated from land fragment that rifted from Gondwanaland at different geological time periods. This unique geological history, together with its stable tropical climate and numerous insular biotas, enabled Wallacea to evolve highly endemic biotas of its own.
Sulawesi, formerly known as Celebes, is one of the large islands of Indonesia. It is the most important island in the “Wallacea subregion”, situated in the centre of the Indonesian archipelago, between Borneo (Kalimantan) and the Moluccan islands. The subregion of Wallacea is an area delimited by Wallace’s line in the west and Lydekker’s line in the east.
Knowledge of Indonesia’s flora especially Sulawesi island is poorly known due to lack of study or botanical exploration in this area (Baas et al. 1990). For example the amount of botanical collecting in Sumatera is 20 times higher than in Sulawesi ( Veldkamp et al. 1997), even though Sulawesi has recently been identified as one of the world’s biodiversity hotspots, especially rich in species found nowhere else in the world and under major threat from widespread deforestation (Pitopang and Gradstein 2003). The island‘s position directly to the east of the modern version of Wallace’s line, the biogeographical division between Laurasian and Gondwana elements of the flora and fauna, makes it a key for the understanding both the biogeography of Southeast Asia and the evolution of many Southeast Asian plant groups (Moss and Wilson, 1998).
Sulawesi is comprised of about 182,870 km2 of land surface and has more forest per inhabitant than most other islands of Indonesia due to its rugged topography (Newman et al. 2004; Keßler et al. 2002). The “spider shape” of the island of Sulawesi results from a very complex geological history, as yet not fully elucidated (Whitten et al. 1987). The central part of Sulawesi is an area of mountainous landscape with rising over 3000 m, and huge tracts of rolling forest. The southern arms of Sulawesi have had an active agricultural population since early times and little forest area is left. From Tana Toradja southward the land is given over to grazing and rice production. Just North of Makassar are peculiar-shaped limestone cliffs and spectacular karst scenery, a wonderful setting for the Bantimurung butterfly sanctuary. Near Kendari is the large Rawa Aopa swamp with rather dry and seasonal climate (MacKinnon 1992).
There are several protected areas in Sulawesi (Fig. 2.2) including Dumoga Bone National Park, Bunaken National Park, Lore Lindu National Park, Togian Island National Park, Morowali Nature Reserve, Tinombala Nature Reserve, Pangi-Binangga Nature reserve, Bakiriang Wildlife Reserve, Palu Grand Forest Park, Rawa Aowa National Park, Tanjung Api Nature Reserve, Gunung Ambang Nature Reserve, Tangkoko Dua Saudara National Park, Manembo-nembo, Peruhampesi Nature Reserve, Lompobatang, Bantimurung, Lambusango, Buton Utara, Matano/Mahalano, and Togian Island National Park, the last one just established as National Park in 2005. These protected areas offer suitable habitats for the rich flora and fauna of Sulawesi. However, even within these parks the flora and fauna is now threatened by human activities such as illegal logging, hunting, land conversion, etc. (Pitopang et al. 2004a)
Total species richness and endemism of Sulawesi are comparable to those of Sumatra, Java, Borneo and New Guinea, in spite of the very different geological history of Sulawesi and the greater distance of the island to the mainland (Roos et al. 2004). Whereas the islands of Borneo, Sumatra and Java had terrestrial connections to mainland Asia in the past, Sulawesi was always isolated from these islands as well as from New Guinea by deep maritime straits as shown by Hall (1995) and Moss and Wilson (1998) through the reconstruction of the Malay archipelago since 50 million ago (Fig.2.3). Approximately 15% of the known flowering plant species of Sulawesi are endemic (Whitten et al. 1987). Van Balgooy et al. (1996) recognized 933 indigenous plant species on Sulawesi and of these 112 were endemic to the island. Endemism varies among groups, however, and is very high in orchids and palms which total 817 orchid species (128 genera) including 493 endemic ones (Thomas and Schuiteman 2002). Critical study of the endemic taxa is urgently needed. Yuzami and Hidayat (2002) discussed 134 endemic species from Sulawesi, half of them being orchids, e.g., Phalaenopsis celebensis Sweet, Vanda celebica J.J.Smith, Coelogyne celebica, Abdominiea miniflora. Goodyera reticulata, Goodyera celebica, Orophea celebica, Eucalyptus deglupta, Diospyros celebica Bakh., Polyalthia celebica Miq. Agathis celebica, Allocasia suhirmaniana Yuzammi and A. Hay, etc. According to Keßler et al. (2002) approximately there are 5000 species of vascular plants (including more than 2100 woody one) in Sulawesi. Compared to other main islands of Indonesia (Sumatera, Java, Borneo, New Guinea) the composition of the flora of Sulawesi is unique even though being less rich in species.
Van Steenis (1950) recorded 59 endemic genera in Borneo but only seven (7) in Sulawesi. Striking biogeographically features of Sulawesi are the almost total absence of Dipterocarpaceae (the dominant trees in the rain forest of Borneo, Sumatera, and the Malaysian Peninsula), only 6 species of this family occurring in Sulawesi. Fagaceae show an almost similar pattern, with only six species of Lithocarpus and Castanopsis being known from Sulawesi, compared to 60 and 21 respectively recorded from Borneo (Keßler 2002).
Publication dealing specifically with the bryophytes of Sulawesi are very few, and records are very scattered and often mentioned casually in literature with the bryoflora of Java and other islands. Gradstein et al. (2005) reported about 476 are found in Sulawesi so far, including 340 of moss (in 145 genera), 134 of liverwort (in 46 genera), and 2 of hornwort (in 2 genera). One liverwort and four moss species are only known from Sulawesi and two names, Calyptrochaeta perlimbata (Dixon) B.C. Tan & B.C.Ho, comb.nov and Macromitrium novorecurvulum B.C. Tan & B.C. Ho, nom.nov, are newly proposed. As compared with other Indonesian islands, the flora of Sulawesi is very poor in bryophyte species, which is most likely due to lack of collecting activities. In comparison, about 4-5 times as many bryophyte species are known from Borneo and New Guinea. The incomplete knowledge of the flora of Sulawesi is also shown by recent botanical explorations, which yielded many new species, e.g., Alocasia megawatii (Yuzami et al. 2000), Impatien punaensis (Utami and Wiriadinata 2002), Calamus sp nov. 1 (ahlidurii), Caryota sp. nov.1 (angustifolia), Caryota sp.nov.2 (pumila), Pinanga sp.nov.2 (rubiginosa), Pinanga sp.nov.3 (tenuirachis), Pinanga sp.nov. 4 (longipes), Pinanga sp.nov.5 (soroakoensis), Pinanga sp.nov.6 (dentata), Pinanga sp.no.7 (mogeana) (Mogea 2002), Eltingeria sp. (no.937) (Newman et al. 2004).
HERBARIUM CELEBENSE (CEB) TADULAKO UNIVERSITY PALU
Due to the absence of the Herbarium in Wallacea region, Some botanist including Prof. Dr. Stephan Robbert Gradstein, Prof. Christoph Leuschner, Prof. Edi Guhardja, Dr. Sri Tjitrosudirdjo and Dr. Ramadanil Pitopang were initiated to establish a Herbarium in Sulawesi. The Herbarium Celebense (CEB) was build at the Tadulako University of Palu in 2000. The establisment of the Herbarium was supported by the German Research Foundation (DFG) within the framework of the STORMA Project (Stability of Rainforest Margins) with the technical supported by Herbarium Bogoriense (BO) and Nationaal Herbarium of Netherland, Leiden (L) and the Herbarium of the University of Gottingen (GOET). The Herbarium has been registered in the International Index Herbariorum (New York) with the abbreviation CEB. Thus far, more than 10.000 dried plant specimens are kept at the Herbarium Celebense . Herbarium collections are mainly consisting of: spermatophytes, rattan, fern, mosses and Lichenes. The herbarium also houses the types three (3) specimens new species described from Sulawesi (in the genera Artabotrys, Nepenthes and Begonia ) and several Artifacts of Ethnobotany are mainly from Tao Taa Wana Ethnics in Morowali Nature Reserve.