Dry forest specialist: past to present habitat changes and its effect on population status

Seasonally open dry tropical forest in Asia, recognized as natural savannahs ecosystem type due to vegetation similarities with vegetation physiognomy to those commonly found in Africa (Rantnam et al. 2016). Open dry tropical forests in South Asia are found to be dominated by high diversity of C4 grasses on herbaceous layer, which appeared during the late Miocene (9.3-6.5 Ma), long before human arrival refuting the original theory that those habitat where the consequence of early human activities (Ratnam et al. 2011). The savannah forest types with its characteristic scattered trees mixed with grasses have wrongly viewed it as degraded forest, resulting to heavily use by human, and therefore it has been unprotected or inappropriately managed. Moreover, trees species in dry tropical forest have high commercially value, for example teak (Tectona grandis) and Shorea species, making this forest type drastically declining in the region from high demand and extraction (Sodhi et al. 2004). Consequence of this degradation and loss, the dry forest specialist species are classified as threatened according to the IUCN Red List criteria (IUCN 2019); including Asian elephant (Elephas maximus), Banteng (Bos javanicus), Wild Water Buffalo (Bubalus arnee) (Pedrono et al. 2009, IUCN-SSC Asian Wild Cattle Specialist Group 2010), Eld’s deer (Rucervus eldii) (Gray 2015), and several bird species such as Green peafowl (Pavo muticus), Red-headed vulture (Sarcogyps calvus) (BirdLife International 2021), Great slaty woodpecker (Mulleripicus pulverulentus), and White-rumped falcon (Polihierax insignis). However, all dry forests in the region show differences in the resident dry forest specialist communities with species commonly found in some area completely absent in others of similar appearance. It still remaining unclear what are the ecological parameters that contribute to a suitable dry forest which could guarantee its specialist a long-term survival. As not only the threatened specialist but also “least-concern” specialist, such as Rufous-bellied woodpecker (Dendrocopos hyperythrus), White-browed fantail (Rhipidura aureola), Yellow-crowned woodpecker (Dendrocopos mahrattensis), have been disappearing from most of dry forest habitat in the region

    This is rising up a question on how much suitability dry forest remains to guarantee the long-term survival of rich dry forest specialist community. This research aims to provide quantitative information on remaining suitable dry forest areas in Southeast Asia range, and will provide necessary information and data for drafting appropriate management scenario for dry forest habitats. The main results will provide 1) situation of dry forest changed from the past to present, 2) understanding limiting factors of suitable dry forest that can potentially host a long-term survival of dry forest specialist community, 3) a population status of remaining dry forest specialist, and 4) understanding mechanism of threats to dry forest habitat from the past, present and into the future.