TROPICS Vol. 17 (3) Issued May 30, 2008 Comparison of nitrogen content in tree litterfall in three dry dipterocarp forests under different fire regime in northeast Thailand 1,* 2 3 1 4 Tetsuya TODA , Hiroshi TAKEDA , Naoko TOKUCHI , Seiichi OHTA , Chongrak WACHARINRAT and 4 San KAITPRANEET 1 Laboratory of Tropical Forest Resources and Environments, Division of Forest Science, Graduate School of Agriculture, Kyoto University, Kyoto 606−8502, Japan 2 Laboratory of Forest Ecology, Division of Environmental Science and Technology, Graduate School of Agriculture, Kyoto University, Kyoto 606−8502, Japan 3 Field Science Education and Research Center, Kyoto University, Kyoto 606−8502, Japan 4 Department of Silviculture, Faculty of Forestry, Kasetsart University, Bangkok 10900, Thailand * Corresponding author: Tel: +81−75−753−6361, Fax: +81−75−753−6372, E-mail:
[email protected] ABSTRACT Tree litterfall was measured and of forest. In addition, transformations of N are variable nitrogen (N) return by tree litterfall was estimated and dynamic in forest ecosystems. Consequently, many in three plots, F0, F10, and F35, with different studies on nutrient cycling place special emphasis on N fire histories (protected from fire for 0, 10, and 35 dynamics. years, respectively) in dry dipterocarp forests (DDF) Fire is a major disturbance and causes substantial in northeast Thailand. Annual litterfall was 3.92, loss of N from terrestrial ecosystems, especially through 7.13, and 8.79 Mg ha−1, for F0, F10, and F35, volatilization (Gillon and Rapp, 1989). The frequency respectively. Leaf litter was the main component of fire affects the extent of N loss from the ecosystem in all the plots, ranging from 67.4 % to 77.9 %, (Marafa and Chau, 1999).