PHENOLOGY, CLIMATE, AND ADAPTATION: HOW DOES DIPTEROCARPS RESPOND TO CLIMATE?

Temperature, rainfall and extreme weatherhave been indicated to affect the phenologicalpatterns and forest productivityby shifting flowering and fruiting seasons and patterns, as well as crop production. Dipterocarpaceaeare high value trees for both timber and non-timber forest products. This study aims to determine the response of phenologicalpatterns of flowering and fruiting of Dipterocarps to climate variables. The study was conducted at Way Canguk Research Station of the Bukit Barisan Selatan National Park (BBSNP), Lampung during May-November 2012 by analyzing 14 years (1998-2012) of phenologicaldata of Dipterocarps. The phenologysurveys were carried out on monthly basisby estimatingthe percentage of flowering, fruiting (divided into 0-4 scoring) and the crop production. The results indicated that the phenologicalpatterns of Dipterocarps in the area depicted major and minor patterns without mass-flowering time, different from what have been reported for Kalimantan or North Sumatra. Minor peak flowering season showed regular flowering, particularly during March to July every year. However, there were major flowering seasons in November 2002 (20.2%), September 2006 (21%), and October-November 2011 (20.3%). Average monthly fruit production showed a peak at the end of the dry season. Major flowering season seemed to coincide with the period of major El Nino events in November 2002 and September 2006, while others associated with La Nina. This study suggest that phenologyand climate change may have implications in designing strategies for collection of seed materials to support the conservation and plantation programs of the Dipterocarps.