A Dendrometer band study of Teak (Tectona grandis L.F.) in North Thailand

Abstract

We present results from a dendrometer band study of teak in north Thailand. We track daily circumferential changes for three trees over nearly sixteen months from November 3, 1998 to February 29, 2000. This period encompasses one complete cycle of dry and wet seasons, along with the very important transitions from wet to dry (November) and from dry to wet (April). Circumferential changes were observed for all three stems; decreasing in response to the onset of drought, and increasing following rain events, particularly after leafout and during the wet season. Dry-season rain events also resulted in stem swelling, when the trees were devoid of leaves and thought to be dormant. While these dormant-season fluctuations can be attributed to hydration/dessication of the stem tissue and not cambial cell division, there appears to be a net gain in circumference following a rain event in the middle of the first dry season. We therefore stress the importance of climate/physiology relationships even during periods of dormancy. We recognise the need for more detailed monitoring of environmental and growth factors, to maximize our understanding of the effects of climate on cambial activity and radial growth. This information is critical for understanding the complex relationships between climate and tree growth in these tropical forests, for which precious little data exist.