The Rimba Raya Biodiversity Reserve REDD Project

of water supplies and prevention of floods, but they alsoprovide an important de facto biodiversity supportfunction for aquatic wildlife, including amphibians,reptiles, fish, crustaceans, and birds (see discussion ofSembuluh Lake in section G 1.8.1.d below for moreinformation).b. threatened species.The aim of HCV 1.2 is to identify critically endangered (CR)species and sub-­‐species that occur in or near themanagement unit (MU) and that may suffer negative off-­siteimpacts from operational activities.Birds and MammalsNo HCV 1.2 birds or mammals are thought to be presentin the Project Zone. The CR Sumatran rhino (Dicerorhinussumatrensis), once present in nearby Tanjung PutingNational Park (TPNP), is now extinct in the region.PlantsTwenty-­‐five HCV 1.2 plants were identified as likelypresent in the Rimba Raya Project Zone (see Table 11below). All are in the Dipterocarpaceae family: five in thegenus Dipterocarpus, one in the genus Dryobalanops, fourin the genus Hopea, and 15 in the genus Shorea.Distribution of these species is restricted to maturelowland rainforest in its various forms (freshwater swampforest, peat swamp forest and lowland dipterocarp forest)and all are considered CR due primarily to habitat loss.Proposed HCV 1.2 management will, therefore, be donein parallel with HCV 1.3 and 3 (see below), where therequirement is to maintain and manage sufficient habitatto ensure long-­‐term population viability.HerptofaunaOnly one HCV 1.2 species of herptofauna was identified aspotentially present in the Project Zone, the CR Paintedriver terrapin (Callagur borneoensis). This species isknown to inhabit the tidal portions of rivers and estuarinemangrove areas and feed on fruit, leaves, and clams.Females nest on sand beaches along riverbanks andcoastal beaches. The distribution of the terrapin onBorneo is unclear. Using the precautionary principle, it istherefore noted here. This species will be furtherinvestigated during the HCV full assessment. As theproject aims to prevent further degradation of theSeruyan River and its tributaries through stabilizing landuse and potentially replanting some areas to restoreriparian zone and flood plain buffers, these successfulconservation actions will have a positive net impact onthis HCV, if present.c. endemic species.HCV 1.3 aims to identify areas where viable populationsof endangered, restricted range, or protected species areknown or likely to occur, and to ensure that managementaction is taken to conserve sufficient habitat forcontinued viability of the population. In the assessmentof this HCV, populations of species confirmed or likelypresent are assumed to be viable until credibly provenotherwise, through population modeling, analysis of58