Skip to content

Asia-Pacific Network for Global Change Research

Asia-Pacific Network for Global Change Research

Read our Science Bulletin
Project • ARCP2007-10NMY, ARCP2008-03CMY

Collaborative Studies in Tropical Asian Dendrochronology: Addressing Challenges in Climatology and Forest Ecology

Dendrochronology was temperate-oriented (Worbes, M. 2004). Asian tropical trees with distinct growth rings should exist as in tropical America (Worbes, M. 1999). If true, then Asian dendrochronology would go beyond pine-teak locations. This inspired the setting of a tree ring laboratory in the Philippines complementing existing ones. Like in tropical America, climatology will be addressed (Villalba, R. et al., 1998) and as in Africa (Worbes, M. et al., 2003) forest ecology too.

Reconnaissance, the finding of tree species with distinct rings, paid off. Of the 400 tree species investigated, 100 have distinct growth rings. More than a thousand corewood samples are filed inxylarias. If these tree species crossmatch and crossdate, the aforementioned vision will be realized. Aiming to show crossmatch and crossdate was barely met because of the huge number of samples against limited manpower resources.

Notwithstanding the aforementioned limitations, tree ring patterns of 5 species from India and the Philippines show evidence of crossmatching (e.g. ring pulses between trees tend to agree). When overlaid with the Southern Oscillation Index, very narrow rings correspond with El Niño events while broad rings reflect La Niña events. A sequel dendrochronology study should answer more questions addressing tropical Asian climatology/forest ecology.

The main objectives of the project were: to establish tree ring laboratories in the region; to conduct reconnaissance of indigenous tropical Asian tree species with clear distinct growth rings; to undergo preliminary work to find if tree species with distinct growth rings have relevance to reconstructing past events; and to establish and maintain xylaria.