Pollination systems in a warm temperate evergreen broad‐leaved forest on Yaku Island

Abstract

Animal pollination in a warm temperate evergreen broad-leaved forest was observed on Yaku-shima Island, south of Kyushu, Japan. Three groups of plants were categorized: canopy-flowering tree species, understory-flowering tree species, and climber and epiphyte species. Each of these formed different pollination systems. The canopy-flowering tree species had shallow, dish-shaped flowers and utilized various types of opportunistic pollinators. Most of the climber and epiphyte species had deep, tube-shaped flowers and specialized pollinators, although some climber species which bloomed in the canopy especially in winter, had opportunistic pollinators. The understory-flowering tree species had large dish-or funnel-shaped flowers and endothermic pollinators able to tolerate the dark and cold conditions under the canopy. The individual trees of canopy-flowering tree species produced large numbers of flowers simultaneously (mass-flowering) and had a well synchronized flowering period. Each canopy-flowering tree species segregated its flowering time from those of the anothers. Climber and epiphyte species and most of the understory-flowering tree species produced small numbers of flowers sequentially (extended flowering) and showed a tong flowering period.

Temporal aspects of the fine-scale genetic structure in a population of Cinnamomum insularimontanum (Lauraceae)

“…Some of these species are also important members of coastal forest vegetation in Japan and Korea, and through a series of studies of population dynamics (eg, Yamamoto, 1992), pollination ecology (eg, Yumoto, 1987), allozyme variation in local populations (eg, Wendel and Parks, 1985;Chung and Kang, 1994), and population genetic structure (eg, Chung et al, 2000;Ueno et al, 2000;Chung et al, 2003), the dynamics of these populations are beginning to become elucidated. As mentioned in the Introduction, parts of this study were undertaken to address how the relationships between trees and birds affect the internal spatial genetic structure of newly founded plant populations.…”

“…Many fruit-eating birds (eg, Zosterops palpebrosa insularis) living in warm temperature broad-leaved evergreen forests in southern Korea and Japan feed on insects from spring to autumn. When insect food is scarce in winter, the birds collect fruits (drupes) from members of Lauraceae and also nectar from flowers of understory trees (eg, Camellia japonica [Theaceae]) (Yumoto, 1987;MY Chung and MG Chung, personal observation). This situation favors mutualism between the canopy trees (with their drupes having an edible portion) and the associated birds (endozoochory).…”

“…These populations have areas ranging from ca 500 m 2 to several hectares on talus slopes with well-drained, rocky and humus soils (MY Chung and MG Chung, personal observation). C. insularimontanum has a mass-flowering pattern from mid-May to mid-June, and diverse insect pollinators such as bees, wasps, flies, and beetles visit its perfect flowers (Yumoto, 1987). Adults typically produce hundreds of single-seeded fruits becoming fully mature about 6 months after flowering.…”

“…C. insularimontanum is self-compatible (T Yahara, Kyushu University, personal communication), but the flowers show protandry and bagged inflorescences do not bear fruits (T Yumoto, Kyoto University, personal communication). Although selfing within a flower is not likely, selfing within a tree is possible, because different flowers on the same tree can be found at different stages of development (Yumoto, 1987).…”

Genetic Structure of Age Classes in Camellia Japonica (Theaceae)

“…Camellia japonica is almost entirely self-incompatible under garden conditions (C. R. Parks, unpubl. data, cited in Wendel and Parks 1985), and the flowers have red, tough petals, several elevated whorls of fused stamens, dilute nectar, and are pollinated by birds (Zosterops palpebrosa insularis) and syrphid flies (Yumoto 1987;M. G. Chung, pers.…”