Tropics
Online ISSN : 1882-5729
Print ISSN : 0917-415X
ISSN-L : 0917-415X
Volume 2, Issue 3
Displaying 1-5 of 5 articles from this issue
Regular papers
  • Makoto KATO, Takao ITINO, Teruyoshi NAGAMITSU
    1993 Volume 2 Issue 3 Pages 129-142
    Published: 1993
    Released on J-STAGE: August 31, 2009
    JOURNAL FREE ACCESS
    Pollination of seven zingiberaceous and two gesneriaceous species was studied in natural forests at various altitudes in West Sumatra, Indonesia. Terrestrial, red, long-tubed flowers of Achasma macrocheilos were visited by a large, remarkably long-tongued anthophorine bee, Amegilla elephas. The swiftly-flying bees showed traplining foraging behavior just like euglossine bees in the Neotropics. This bee species was oligolectic to the plant species and almost the only pollinator of it. Yellow (rarely white), long-tubed flowers of Zingiber puberulum, Grobba aurantiaca, Amomum aculeatum and Cyrtandra pendula were pollinated by median-sized, shade-loving, traplining, long-tongued anthophorine bees in the genera Amegilla and Elaphropoda. White, short-tubed flowers of Amomum uliginosum and Cyrtandra aff. grandiflora were pollinated by traplining halictid bees in the genus Nomia. Long-tubed flowers borne on red stout spikes of Hornstedtia aff. conica and Phaeomeriafulgens were pollinated by a long-billed sunbird, Arachnothera longirostra. These ornithophilous flowers produced significantly more nectar of lower sugar concentration than the melittophilous flowers.
    According to the proboscis lengths, long-tongued bees were classified into three groups, which corresponded to the three pollination guilds of the melittophilous flowers. Among species in a bee guild, convergence of proboscis lengths was detected, and the floral hosts of the bee species were sometimes overlapping. Twenty-five percent of melittophilous species were visited by more than one bee species, but nonetheless most individual plants were visited by only a single bee species. At higher altitudes more than 1400 m, anthophorine bees were displaced by bumblebees and the guild structure of longtongued bees was simpler than at lower altitudes.
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  • Tukirin PARTOMIHARDJO, Edi MIRMANTO, Soedarsono RISWAN, Eizi SUZUKI
    1993 Volume 2 Issue 3 Pages 143-156
    Published: 1993
    Released on J-STAGE: August 31, 2009
    JOURNAL FREE ACCESS
    The disseminules and seedlings on beaches of Anak Krakatau Island on the Sunda Straits between Sumatra and Jawa Islands were surveyed in east monsoon season 1990 and west monsoon season 1991. The island emerged from the sea through many eruptions since 1930. It is close to the other three Krakatau Islands, where plants have been established after a great eruption in 1883. Sixty-six species and 38 families of disseminules were found in 62 transects set on the beaches. Thirty species of these disseminules were possibly produced by mature plants growing on the Krakatau Islands themselves. and the remainder were derived from elsewhere. The former species were mostly coastal plants common on all Krakatau Islands. We also found many disseminules of inland species of Java or Sumatra, although seedlings of these were very rare on the coast. The East Foreland has the most diverse drift flora in both seasons due to the right angle to the predominant currents. It might be one of the reasons why the most advanced vegetation on Anak Krakatau was found on the East Foreland.
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  • Virat TANPIBAL, Katsutoshi SAKURAI
    1993 Volume 2 Issue 3 Pages 157-168
    Published: 1993
    Released on J-STAGE: August 31, 2009
    JOURNAL FREE ACCESS
    The effect of chemical fertilizer and city compost application was evaluated on the biomass of Stylosanthes guianensis on the barren land after a tin mining at the Mine Area Rehabilitation Station, Takuapa, Phang-nga, Thailand. Clayey materials were added to every plot at the ratio of 300 m3 ha-l to prevent plant from mortality and to enhance the nutrient holding capacity. An optimum biomass yield (5.12 t ha-l), which was lower than the maximum yield (6.15 t ha-l) realized through heavy fertilization, was obtained by the application of city compost (6.25 t ha-l) and chemical fertilizer (1.25 t ha-l). The soil fertility was improved at the end of the experiment, through the cultivation of S. guianensis.
    The amount of precipitation, soil moisture (at 15 cm in depth) and soil temperature (at 0 and 15 cm in depth) was monitored throughout the experiment. The severe drought and over-wetting conditions reduced the biomass yield of S. guianensis, significantly. The crude fiber and crude protein content in the stems and leaves showed an appropriate amount as food for cattle.
    It can be concluded that the cultivation of S. guianensis is one of the promising way of agriculture in Takuapa and very good practice to improve the very low native soil fertility, in combination with the incorporation of clayey materials to diminish the water deficiency problem and to increase the nutrient retention capacity.
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  • Misa MASUDA, Suleiman KUDU
    1993 Volume 2 Issue 3 Pages 169-181
    Published: 1993
    Released on J-STAGE: August 31, 2009
    JOURNAL FREE ACCESS
    Butyrospermum paradoxum is a common species in upland habitats of Savanna zone in West Africa. Local people have traditionally utilized fat extracted from the kernels for cooking, and it was one of staple trading commodities in the northern Nigeria as well. Recent reports including those on forestry have made, however, almost no mention of it, as it lost the position in commercial trade. This was mainly brought by declining demand, especially in domestic market. Through a case study in the Niger state, it is ascertained that the trees are selectively left on farmland at the time of clearing. Harvesting activities are done only by women, which provide an important opportunity for them to earn income at their own disposal. In consequence, it seems this interaction between man and sheanut has produced significant effect on the distribution range and density of the trees. To find a countermeasure to forest deterioration which has become a nation-wide problem in Nigeria, it is required to encourage such customary activities by local people through stabilization of the market of non-wood forest products and introduction of more effective and proper land management system including tree crops.
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Short Communication
  • Robert W. PEMBERTON, Mikio ONO
    1993 Volume 2 Issue 3 Pages 183-186
    Published: 1993
    Released on J-STAGE: August 31, 2009
    JOURNAL FREE ACCESS
    Extrafloral nectar has been demonstrated in many studies to promote a food for defense mutualism between the plants that secrete the nectar and ants. The removal of extrafloral nectar from many leaves of Terminalia catappa by a bird, the Japanese white-eye, was observed in the Bonin Islands. Some possible consequences of the loss of the extrafloral nectar (including nectar robbery, disruption of ant-based protection, and delayed protection by the bird) are discussed.
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