Keywords :
Acetylene reduction assay; asymbiotic nitrogen fixation; decomposition process; litter and dead wood; nitrogen fixation by termites; tropical
forests.
บทคัดย่อ :
Nitrogen (N) fixed by termites was evaluated as a N input to decomposition processes in two tropical forests, a dry deciduous forest (DDF) and the neighboring dry evergreen forest (DEF), Thailand. A diverse group of termite species were assayed by acetylene reduction method and only the wood/ litter-feeding termites were found to fix N. More intensive samplings of two abundant species, Microcerotermes crassus and Globitermes sulphureus, were done across several seasons, suggesting N fixation rates of 0.21 and 0.28 kg ha-1 y-1 by termites in the DDF and DEF, respectively. Also, estimates of asymbiotic N fixation rates were 0.75 and 3.95 kg ha-1 y-1. N fixed by termites and by asymbiotic fixers is directly supplied to decomposers breaking down dead plant material and could be a major source of their N. N fixed by termites was 7-22% of that fixed by termites and asymbiotic fixers. Although N fixed by termites is a small input compared to other inputs, this N is likely important for decomposition processes.
เอกสารอ้างอิง :
Yamada, A., Inoue, T., Wiwatwitaya, D., Ohkuma, M., Kudo, T., & Sugimoto, A. (2006). Nitrogen fixation by termites in tropical forests, Thailand. Ecosystems, 9(1), 75-83.
