Biodiversity of the Sebangau tropical peat swamp forest, Indonesian Borneo S.J. Husson1, S.H. Limin2,3, Adul1,2, N.S. Boyd1, J.J. Brousseau1, S. Collier1,4, S.M. Cheyne1,5, L.J. D’Arcy1, R.A. Dow6, N.W. Dowds1,4, M.L. Dragiewicz1, D.A. Ehlers Smith1,7, Iwan1,2, Hendri1,2, P.R. Houlihan1,8, K.A. Jeffers1, B.J.M. Jarrett1,9, I.P. Kulu2, H.C. Morrogh-Bernard1,4, S.E. Page10, E.D. Perlett1, A. Purwanto1,2, B. Ripoll Capilla1, Salahuddin1,2, Santiano1,2, S.J.J. Schreven1,11, M.J. Struebig12, S.A. Thornton1,10, C. Tremlett1, Z. Yeen1,2,3 and M.E. Harrison1,10 1Borneo Nature Foundation, Palangka Raya, Central Kalimantan, Indonesia; 2UPT CIMTROP, University of Palangka Raya, Central Kalimantan, Indonesia; 3Deceased; 4University of Exeter, Penryn, Cornwall, UK; 5Oxford Brookes University, Oxford, UK; 6Naturalis Biodiversity Center, Leiden, The Netherlands and Sarawak Museum Campus Project, Jabatan Muzium Sarawak, Kuching, Sarawak, Malaysia; 7Current address: University of KwaZulu-Natal, School of Life Sciences, Scottsville, Pietermaritzburg, South Africa; 8Florida Museum of Natural History, University of Florida, Gainesville, Florida, USA; 9Current address: Department of Zoology, University of Cambridge, Cambridge, UK; 10School of Geography, Geology and the Environment, University of Leicester, Leicester, UK; 11Plant Ecology and Nature Conservation Group (current address: Laboratory of Entomology, Plant Sciences Group), Wageningen University & Research, Wageningen, The Netherlands; 12Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, Canterbury, UK _______________________________________________________________________________________ SUMMARY The importance of Southeast Asia’s tropical peat swamp forests for biodiversity is becoming increasingly recognised. Information on species presence within peatland areas is scant, however, limiting our ability to develop species conservation strategies and monitor responses to human activities. We compile species presence records for the Sebangau forest in Indonesian Borneo since 1993 and present the most complete Bornean PSF biodiversity inventory yet published. Including morpho-species that are likely to represent true species, this list comprises 215 tree, 92 non-tree flora, 73 ant, 66 butterfly, 297 spider, 41 dragon/damselfly, 55 fish, 11 amphibian, 46 reptile, 172 bird and 65 mammal taxa. Of these, 46 species are globally threatened and 59 are currently protected in Indonesia; 22 vertebrate species are Borneo endemics. Because our sampling is both biased and incomplete, the true number of species found at this site is likely to be much higher. Little is known about many of these taxa in Sebangau and peat swamp forests elsewhere. Many of these species are considered forest dependent, and the entire community is expected to be important for maintaining the resilience of the peat swamp forest ecosystem and the environmental services that it provides. This highlights the need for urgent conservation of Sebangau and its diverse biological community. KEY WORDS: biodiversity, Central Kalimantan, conservation, Sebangau, species presence _______________________________________________________________________________________ INTRODUCTION nor important, which combined with most PSF areas not being claimed by local communities, resulted in Indonesia’s tropical peatlands cover 206,950 km2 most PSFs in Indonesia being designated as (Page et al. 2011) yet, with the exception of some production or agricultural forests by previous early botanical studies (e.g., Sewandono 1937, 1938; national governments. Anderson 1963, 1976), received relatively little Studies over the last twenty years have begun to attention from the scientific and conservation reverse this impression, however, and the high value communities until the end of the 20th century. of Indonesia’s peatlands for carbon sequestration, Ecologists long regarded tropical peat swamp forest storage and emissions is now widely appreciated (PSF) as less interesting than other forest types in the (Page et al. 2002, Hooijer et al. 2009, Page et al. region, namely the highly biodiverse dryland 2011). PSFs are also appreciated for their role in dipterocarp forests (Prentice & Parish 1992, Yule providing other ecosystem services of importance to 2010). The obvious swampy nature of PSFs, plus local and international communities, such as flood difficulty of access, further dissuaded scientists from prevention and provision of non-timber forest working in these environments. This resulted in an products (Graham 2013, Harrison 2013, Giesen overall impression that PSFs were neither interesting 2015). Mires and Peat, Volume 22 (2018), Article 05, 1–50, http://www.mires-and-peat.net/, ISSN 1819-754X © 2018 International Mire Conservation Group and International Peatland Society, DOI: 10.19189/MaP.2018.OMB.352 1 S.J. Husson et al. BIODIVERSITY OF THE SEBANGAU PEAT SWAMP FOREST, INDONESIAN BORNEO Alongside this increased awareness of PSF thus contributing towards better informed and more ecosystem functions and services, studies have successful conservation management. revealed that, contrary to earlier beliefs, these forests are home to a wide variety of flora and fauna (Page et al. 1997, Yule 2010, Posa et al. 2011). Indeed, METHODS compilation of species records across sites indicates Study site that at least 1,524 plant, 123 mammal, 268 bird, 75 Species presence records described here were reptile, 27 amphibian and 219 fish species can be collected in the 500 km2 NLPSF, part of the found in Southeast Asia’s PSFs (Posa et al. 2011), 7,347 km2 Sebangau peat dome in Central although this does not necessarily translate into high Kalimantan, Indonesia (2° 19′ S, 113° 54′ E, levels of habitat endemicity (e.g., plants: Giesen et al. Figure 1). This site has been the focus of intensive 2018). Studies have also revealed the importance of research efforts on many aspects of PSF ecology and these forests - which still cover large areas, management by the Centre for International particularly in Indonesia - for conservation of Cooperation in Sustainable Management of Tropical threatened animal species including primates (Pongo Peatlands at the University of Palangka Raya (UPT spp.: Morrogh-Bernard et al. 2003, Wich et al. 2008; CIMTROP UPR), the Universities of Nottingham Hylobatidae: Campbell et al. 2008, Cheyne et al. and Leicester, the Borneo Nature Foundation and 2008; Presbytis rubicunda: Ehlers Smith & Ehlers other institutions since 1993. Sebangau is a truly Smith 2013), clouded leopard (Neofelis diardi) and ombrogenous peat swamp forest; i.e. it receives all its other felid species (Cheyne et al. 2011, 2013b) and nutrient influx from aerial sources (rain, aerosols and wetland birds, such as the Storm’s stork (Ciconia dust; Page et al. 1999), with the exception of the stormi: Cheyne et al. 2014) and white-winged duck riverine margins which are almost entirely (Asarcornis scutulata: Silvius & Verheugt 1986). deforested. Consequently, it is relatively poor in plant Despite this increased appreciation, Indonesia’s nutrients, which has resulted in fewer forest strata PSFs remain threatened by human activities and a lower canopy height (15–25 m) than in forests including drainage and subsequent fire, conversion on mineral soils (Page et al. 1999). for agriculture (especially oil palm), plus logging and Borneo’s inland PSFs typically comprise a wildlife hunting (Morrogh-Bernard et al. 2003, number of different habitat sub-types, with the Struebig et al. 2007, Harrison et al. 2009a, Page et al. following occurring in the NLPSF (Page et al. 1999, 2009b, Miettinen & Liew 2010, Harrison et al. Morrogh-Bernard et al. 2003, Cheyne et al. 2008, 2011a, Meijaard et al. 2011, Posa et al. 2011, Husson et al. 2015; Figure 1): Miettinen et al. 2012a, Miettinen et al. 2012b). These threats have led to the loss of 1.8 Mha of PSF in • Mixed swamp forest: found on the shallowest Borneo, Sumatra and Peninsular Malaysia from 2007 peat, from the limits of river flooding to 5.5 km to 2015; equivalent to an annual deforestation rate of inland from the forest edge. Characterised by 4.1 % (Miettinen et al. 2016). Further advancing our intermediate tree size (15–25 m closed canopy understanding of PSF biodiversity, its distribution height), species richness and ape population and responses to disturbance is important for densities. Contains many commercial timber trees providing the enhanced knowledge base needed to and consequently suffered relatively high logging make better PSF conservation management decisions disturbance. Its proximity to forest edge and and monitor the impacts of management (or lack greater accessibility leads to relatively high thereof) on PSF biodiversity (Harrison et al. 2012). encroachment and hunting prevalence. In this article we present a list of flora and fauna • Low pole forest: a relatively stunted, depauperate species documented in the Natural Laboratory of Peat forest, found 5.5–10 km from the forest edge on swamp Forest (NLPSF), Sebangau, in the southern peat of 6–10 m depth. Characterised by small tree lowlands of Central Kalimantan, Indonesia. Building size (12–15 m closed canopy), species richness on earlier preliminary lists for the area (e.g., Page et and ape population densities. Contains few trees al. 1997, Shepherd et al. 1997), we compile 25 years of commercial timber size and has consequently of records and list the species found, highlighting suffered little from direct logging disturbance.