Long-term fluctuation of biological activities in a lowland dipterocarp forest : Does general flowering contribute to maintenance of biodiversity

2007 Fiscal Year Final Research Report Summary

• Project/Area Number: 16405006
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Ecology/Environment
• Research Institution: Kyoto University
• Principal Investigator: SAKAI Shoko Kyoto University, Center for Ecological Research, Assoc. Prof. (30361306)
• Co-Investigator(Kenkyū-buntansha): ITIOKA Takao Kyoto University, Graduate school of Human and Environmental Studies, Assoc. Prof (40252283)
• Project Period (FY): 2004 – 2007
• Keywords: General flowering / Lowland dipterocarp forest / Pollination / Seed predator / Herbivore

Research Abstract

General flowering, one of the most spectacular and mysterious phenomena in tropical biology, is a masting phenomenon unique to Asian dipterocarp forests. It is unique in involving the synchronization of flowering thus fruiting across diverse plant groups. GF occurs at irregular intervals of less than 1 year to several years. We showed that this phenomenon was most likely triggered by irregular droughts based on 10 years of observations. In the aseasonal forests of SE Asia, droughts tend to occur during transition periods from La Nina to El Nino, which results in an irregular 6-7-yr cycle involving a dry period with several droughts and a wet period without droughts. On the other hand, reproductive success was positively correlated with the magnitude of general flowering. We have aim monitored population dynamics of various insects and small mammals, which are likely to be affected by general flowering. Leaf beetles collected by light traps showed various fluctuation patterns depending on species, but species sharply corresponding general flowering were very rare Therefore, we consider that general flowering is not the major driving forces of fluctuation of populations of leaf beetles. Possibly, leaf flushing may explain part of the patterns. On the other hand, population fluctuation of terrestrial and arboreal small mammals largely followed flowering and fruiting patterns. Abundance of young individuals were larger just after flowering event, thus they may depending on general flowering for reproduction. Since they are considered to be predators of dipterocarp seeds, synchronized fruiting may contribute reduction of seed predation by such mammal species.

Research Products

• [Journal Article] Population fluctuations of light-attracted chrysomelid beetles in relation to supra-annual environmental changes in a Bornean rainforest (2008)
  • Author(s): Kishimoto-Yamada, K., Itioka, T., Sakai, S., Momose, K., Nagamitsu, T., Kaliang, H., Meleng, P., Chong, J., Hamid, A. A., Yamane, S., Kato, M. Nakashizuka, T. and Inoue, T.
  • Journal Title: Biotropica (印刷中)
  • Description: 「研究成果報告書概要(和文)」より
  • Peer Reviewed
• [Journal Article] Population fluctuations of light-attracted chrysomelid beetles in relation to supra-annual environmental changes in a Bornean rainforest (2008)
  • Author(s): Kishimoto-Yamada, K., Itioka, T., Sakai, S., Momose, K., Nagamitsu, T., Kaliang, H., Meleng, P., Chong, J., Hamid, A., A., Yamane, S., Kato, M., Nakashizuka, T., Inoue, T
  • Journal Title: Biotropica (in press)
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Population dynamics of arboreal and terrestrial small mammals in a tropical rain forest, Sarawak, Malaysia. (2007)
  • Author(s): Nakagawa, M., Miguchi, H., Sato, K., Sakai, S. and Nakashizuka, T.
  • Journal Title: Raffles Bulletin of Zoology 55 Pages: 389-395
  • Description: 「研究成果報告書概要(和文)」より
  • Peer Reviewed
• [Journal Article] Population dynamics of arboreal and terrestrial small mammals in a tropical rain forest, Sarawak, Malaysia (2007)
  • Author(s): Nakagawa, M., Miguchi, H., Sato, K., Sakai, S., Nakashizuka, T
  • Journal Title: Raffles Bulletin of Zoology 55 Pages: 389-395
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Irregular droughts trigger mass flowering in aseasonal tropical forests in Asia. (2006)
  • Author(s): Sakai, S., Harrison, R. D., Momose, K., Kuraji, K., Nagamasu, H., Yasunari, T., Chong, L. and Nakashizuka, T.
  • Journal Title: American Journal of Botany 93 Pages: 1134-1139
  • Description: 「研究成果報告書概要(和文)」より
  • Peer Reviewed
• [Journal Article] Irregular droughts trigger mass flowering in aseasonal tropical forests in Asia (2006)
  • Author(s): Sakai, S., Harrison, R., D., Momose, K., Kuraji, K., Nagamasu, H., Yasunari, T., Chong, L., Nakashizuka, T
  • Journal Title: American Journal of Botany 93 Pages: 1134-1139
  • Description: 「研究成果報告書概要(欧文)」より
• [Presentation] ランビルヒルズ国立公園における小型鳥類2群の異なる果実選択 (2008)
  • Author(s): 鴨井環・Braken O・百瀬邦泰・酒井章子
  • Organizer: 日本生態学会
  • Place of Presentation: 福岡国際会議場
  • Year and Date: 2008-03-16
  • Description: 「研究成果報告書概要(和文)」より
• [Presentation] Fruit selection by two groups of frugivorous birds in Lambir Hills National Park (2008)
  • Author(s): Kamoi, T., Brakean, O., Momose, K., Sakai, S
  • Organizer: Japan Society of Ecology
  • Place of Presentation: Fukuoka International Convention Hall
  • Year and Date: 2008-03-16
  • Description: 「研究成果報告書概要(欧文)」より