Tropics
Online ISSN : 1882-5729
Print ISSN : 0917-415X
ISSN-L : 0917-415X
12 巻, 4 号
選択された号の論文の5件中1~5を表示しています
原著論文
  • Masatoshi SASAOKA
    2003 年 12 巻 4 号 p. 247-260
    発行日: 2003年
    公開日: 2008/12/26
    ジャーナル フリー
    There is a customary regulation of forest use in Seram Island, Maluku, Eastern Indonesia, which is called seli kaitahu. This paper describes seli kaitahu forest management. The main findings of the field research in Manusela village, located in the interior forest of Central Seram, can be summarized in the following five points: 1) The major forest use pattern is the hunting of cuscus, timor deer, and wild boar. These game animals are indispensable for local people who are highly dependent on sago, which is mainly composed of pure starch. 2) In order to obtain wild meat, local people erect two kinds of traps in the forest: sohe for cuscus, and hus panah for timor deer and wild boar. 3) From the view point of land tenure, the forest as a hunting ground can be classified into household forest and kin-group forest. 4) Although the “ownership” of each forest lot belongs to a household or a group of joint owners, the actual patterns of forest use can be described as nonexclusive. If permission is given by the owner or the head of the joint ownership group, villagers are able to use the forest held by another owner/joint ownership group. 5) Based on the results of field research concerning the use of seli kaitahu, 104 (76%) forest lots out of 138 are preserved by seli kaitahu.
    Although the ecological function of the seli kaitahu system is still not precisely clear, judging from the fact that hunting is banned in most forest lots, it may be reasonable to conclude that seli kaitahu plays an important role in sustaining game animal populations.
  • Naofumi NOMURA, Kihachiro KIKUZAWA, Kanehiro KITAYAMA
    2003 年 12 巻 4 号 p. 261-276
    発行日: 2003年
    公開日: 2008/12/26
    ジャーナル フリー
    Light and water have only been discussed in the leaf phenology studies of low latitude tropics, though soil nutrients were also included as potential contributive factors. We investigated the relationship between these environmental factors and leaf phenology in the tropical montane forests of Mount Kinabalu, Borneo. Three montane forests of different vegetation were compared during the 1998 El Niño drought in order to differentiate the effect of each environmental factor. As a result, the relationship between soil pulsed nutrient release and leaf flushing was denoted in the forests with an affluent water supply, while water stress suppressed leaf flushing in all vegetation. However, the contribution of light could not be determined. This study is the first to indicate the contribution of soil nutrients to leaf phenology in the tropics.
  • Joeni Setijo RAHAJOE, Takashi KOHYAMA
    2003 年 12 巻 4 号 p. 277-286
    発行日: 2003年
    公開日: 2008/12/26
    ジャーナル フリー
    In order to determine the effects of frequent forest fire on the decomposition process, two dominant species of heath forests were studied: T. obovata and C. pulcherrimum. During a period of two years, it was observed that T. obovata decomposed more rapidly with higher nutrient release than C. pulcherrimum in intact and post-fire stands. The decomposition rates of the two species were higher in the intact stand than in the post-fire stand. C/N ratio dynamics and nitrogen release were determined showing that T. obovata rapidly released nutrients and C. pulcherrimum retained nutrients. The results suggest that forest fire did not change the nutrient release pattern of these two dominant species, but did slow the decomposition rate and, consequently, affected the rate of nitrogen release.
  • Edi MIRMANTO, Shiro TSUYUZAKI, Takashi KOHYAMA
    2003 年 12 巻 4 号 p. 287-294
    発行日: 2003年
    公開日: 2008/12/26
    ジャーナル フリー
    A plot census for trees over 5 cm in diameter at breast height was conducted in tropical wetlands to understand the effects of distance from river and peat depth on the development of communities, using 14 50 m_50 m plots in Central Kalimantan, Indonesia. There are 294 taxa of woody species were recorded. Combretocarpus rotundatus, Palaquium leiocarpum, Stemonurus scorpioides and Tristania whittiana are the common species. In the 14 plots, Stem density and cumulative basal diameter ranged from 1612-3088/ha, and 18.5-44.6 m2//ha, respectively. Species richness (S) ranged from 41 to 87. Diversity index (H’) and evenness (J’) varied from 1.29 to 1.68 and 0.771 to 0.910, respectively. Stem density was positively related to distance from river but not to peat depth. Geographical differences were also related to the stem density. H' was related to distance from river, but S and J' were not explained by any environmental factors examined. Plot distribution patterns were examined by detrended canonical correspondence analysis (DCCA). DCCA ordination indicated that distance from river, and hence the intensity and/or frequency of flooding more adequately explained plant community distribution patterns than peat depth. Geographical differences also significantly affected the distribution patterns. Therefore, the distance from river is a suitable parameter to use to investigate plant community distribution in tropical wetland forests, even if peat thickness differs greatly.
Review
  • Rishi Kumar BEHL, Mitsuru OSAKI, Jun WASAKI, Toshihiro WATANABE, Takur ...
    2003 年 12 巻 4 号 p. 295-312
    発行日: 2003年
    公開日: 2008/12/26
    ジャーナル フリー
    Wheat (Triticum aestivum L.) is one of the most important cereal crops of the world. Zinc deficiency is one of the most common deficiencies in soils worldwide. Several plant metabolic processes and biological functions are impaired under Zn deficient conditions. The most visible symptoms of zinc deficiency are a reduction in shoot growth, decrease in leaf size, chlorophyll degeneration and the emergence of whitish-brown necrotic patches on leaves. The genotypes that show the highest percent response to added Zn and are unable to grow well without Zn are defined as being susceptible to Zn deficiency and vice versa. Zinc efficiency is the ability of a plant to grow and produce grain when Zinc availability is low. Breeding cereals with enhanced zinc efficiency can decrease fertilizer dependency, improve seed-ling vigor, increase resistance to abiotic and biotic stress and enhance yield and nutritional value of wheat. A survey of the literature, as well as own experiences, show that there is enough genetic variation in wheat and alien species, particularly rye, for suitable zinc-efficient alleles. Genetic control is fairly simple, making breeding for this trait feasible. Since selection for Zinc efficiency in a breeding program is limited by the high spatial variability of zinc in field sites, better field screening techniques and selection criteria are needed to allow screening of early-generation segregating materials. Zn specific diagnostic methods like reflectance analysis and molecular markers (proteins /DNA markers) could complement the screening of wheat genotypes for zinc efficiency. Breeding wheat for enhanced zinc efficiency and higher grain yield would require concentrating the quantitative trait loci governing these traits in a few agronomic backgrounds through recombination breeding. This literature review paper delves into genetic variability, screening methods, plant breeding options and methodologies and other related issues for improving zinc efficiency in wheat.
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