title: Size-related flowering and fecundity in the tropical canopy tree species, Shorea acuminata (Dipterocarpaceae) during two consecutive general flowerings.
abstract: We monitored the reproductive status of all trees with diameters at breast height (dbh) >30 cm in a 40-ha plot at Pasoh, west Malaysia, and investigated the individual fecundity of 15 Shorea acuminata Dyer (Dipterocarpaceae) trees using seed-trapping methods during two consecutive general flowering periods in 2001 (GF2001) and 2002 (GF2002). The proportion of flowering trees was higher, and not dependent on size, in GF2002 (84.2%), than in GF2001 (54.5%), when flowering mainly occurred in trees with a dbh < or =70 cm. Fecundity parameters of individual trees per event varied widely (221,000-35,200,000 flowers, 0-139,000 mature seeds, and 1.04-177 kg total dry matter mass of fruit (TDM) per tree). Monotonic increases with increasing tree size were observed for flower production and TDM amongst trees up to 90 cm in dbh, but not for mature seed production or for any of these parameters amongst larger trees. The pattern of reproductive investment during the two consecutive reproductive events clearly differed between medium-sized and large trees; the former concentrated their reproductive investment in one of the reproductive events whereas the latter allocated their investment more evenly to both reproductive events. Our results suggest size-related differences in the resource allocation pattern for reproduction.
authors.affiliation: Laboratory of Tropical Forest Resources and Environments, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake, Sakyo, Kyoto 606-8502, Japan. naiko@kais.kyoto-u.ac.jp
authors.forename: Yoko
authors.initials: Y
authors.lastname: Naito
authors.forename: Mamoru
authors.initials: M
authors.lastname: Kanzaki
authors.forename: Shinya
authors.initials: S
authors.lastname: Numata
authors.forename: Kyoko
authors.initials: K
authors.lastname: Obayashi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Konuma
authors.forename: Sen
authors.initials: S
authors.lastname: Nishimura
authors.forename: Seiichi
authors.initials: S
authors.lastname: Ohta
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Tsumura
authors.forename: Toshinori
authors.initials: T
authors.lastname: Okuda
authors.forename: Soon Leong
authors.initials: SL
authors.lastname: Lee
authors.forename: Norwati
authors.initials: N
authors.lastname: Muhammad
mesh_terms: D053958:Dipterocarpaceae / Q000502:physiology*; D017753:Ecosystem; D035264:Flowers / Q000502:physiology*; D012098:Reproduction / Q000502:physiology; D013997:Time Factors; D014329:Tropical Climate