Tropics
Online ISSN : 1882-5729
Print ISSN : 0917-415X
ISSN-L : 0917-415X
Volume 10, Issue 2
Displaying 1-6 of 6 articles from this issue
  • Hisao BABA
    2000Volume 10Issue 2 Pages 231-241
    Published: 2000
    Released on J-STAGE: January 31, 2009
    JOURNAL FREE ACCESS
    Late Pleistocene Minatogawa people possessed small and slender bodies, with poor muscle development, especially in the upper limbs, indicating adaptation to poor nutrient conditions and moderate stress in manipulation and locomotion. Yet they exhibited stout faces with strong masticatory muscle development resulting from high chewing stress. Minatogawa people are thus regarded to have been adapted to the island environment in the Ryukyu Islands, Japan. Since morphological features of Minatogawa postcranial bones are extremely rare, they might have not evolved into either Jomon people or modem Ryukyuans.
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  • Kiyonori TOMIYAMA
    2000Volume 10Issue 2 Pages 243-249
    Published: 2000
    Released on J-STAGE: January 31, 2009
    JOURNAL FREE ACCESS
    Daily movement of the giant African snail Achatina fulica was studied. This snail is nocturnal and in the daytime prefers to rest in shrubs, often along the forest edge. The density was low in primary or secondary forests. The cumulative distance of movements of young adults was longer than that of old adults. They forage and mate in open fields. This behavior is likely to be a cause of serious damages to field crops cultivated next to the forest.
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  • Satoshi ISHIZUKA, Katsutoshi SAKURAI, John SABANG, Joseph Jawa KENDAWA ...
    2000Volume 10Issue 2 Pages 251-263
    Published: 2000
    Released on J-STAGE: January 31, 2009
    JOURNAL FREE ACCESS
    Since 1996 ecosystem rehabilitation by tree planting has been carried out on the degraded land after shifting cultivation at Bakam Forest Reserve (BFR), Sarawak, Malaysia. In order to evaluate the performance of the rehabilitation of a degraded land after shifting cultivation, at first, it needs to define the current status of degraded soils. In this study, the morphological, physico-chemical, mineralogical, and charge characteristics of soils on the degraded land were investigated.
    Nutrient content of soils in the degraded land was quite low at the same level as was seen in the subsurface soil of the remnant forest due to soil erosion after shifting cultivation. The soils in the degraded land were harder than those in the remnant forest due to. soil compaction. The soils showed strongly weathered characteristics, such as low PZSE (Point of Zero Salt Effect) value, high proportion of variable-charge minerals due to loss of 2: 1 type clays with permanent negative charge, and low oxide contents. Soil properties become worse easily and shortly after soil erosion, and are modified by the water action and topography in situ. Once the vegetational cover is destroyed, it could not regenerate easily in such an intrinsic infertile soil condition even under enough rainfall and high temperature.
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  • Akira HARAGUCHI, Sawahiko SHIMADA, Hideki TAKAHASHI
    2000Volume 10Issue 2 Pages 265-272
    Published: 2000
    Released on J-STAGE: January 31, 2009
    JOURNAL FREE ACCESS
    We surveyed the distribution and the chemical properties of peat in the Lahei district, northeast of Palangka Raya, Central Kalimantan, Indonesia. Along a transect line parallel to the Mangkutup River, peat was deposited only in a deep valley, which had a mineral surface ca. 10 m below the surrounding area. Along a transect line perpendicular to the river, the maximum thickness of the peat was 773 cm, 150 m from the river. The peat contained several clayey or carbonized layers, which suggested frequent flooding and drawdown during peat formation. We also studied the vertical profile of the chemical properties of the peat pore water. The properties changed at a depth of ca. 500 cm. pH and electrical conductivity were greater below this depth than above 500 cm. Major ions in the peat pore water reached maximum values below 500 cm. The redox potential reached minimum values at around 200 cm depth, remaining oxidative. These chemical properties suggest the presence of an under-ground water flow that supplies minerals and oxygen to the peat layer.
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  • Yukako TANI
    2000Volume 10Issue 2 Pages 273-286
    Published: 2000
    Released on J-STAGE: January 31, 2009
    JOURNAL FREE ACCESS
    Taungya system that originally started in 19th century British Burma is now applied in many countries to serve as a tool for reforestation of degraded areas. Understanding the behavior of taungya farmers is crucial for better management of taungya plantation projects but so far little research has been conducted on this subject. Through a case study in the Bago Range of Myanmar, this paper argues that ecological factors and the Burmans' customary land tenure were affecting the taungya farmers attitude towards the project. In the Reserved Forests (RF) there are cultivators who live on agriculture utilizing lowlands as well as uplands. Some of these cultivators were recruited by the Forest Department for the project, but at the same time the project itself was distributing taungya farmers as new cultivators in the RF, since the lowland was not involved in the project. Through this procedure the department was achieving plantation targets in remote areas, and virtually demarcating the boundary of the RF. However, the recruitment of cultivators is uncertain, and the lowlands escape from forest legislation. The cultivators are granted no legal right to live in the RF and they receive little administrative support from the government. Therefore, to ascertain sustainable man-made forest management, more investment in forest administration and social welfare might be required, and the department may face the necessity of seeking a way to accommodate more funding.
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  • Yuta HARAGO
    2000Volume 10Issue 2 Pages 287-312
    Published: 2000
    Released on J-STAGE: January 31, 2009
    JOURNAL FREE ACCESS
    Conditions and determinants were studied leading to successful inputs of community forest management systems in the Brazilian Amazon. Among four local population types in the Amazon, such as ribeirinhos (riverine population) , seringueiros (rubber tappers) , indios (Indians) and recent colonists since 1970s, four villages of riverine population in Gurupa of the Amazon estuary were studied and analyzed.
    Community forest management systems among riverine populations in the Amazon can be assumedly induced in three preconditions: 1) the presence of ‘forest peoples’ - the local population depending on forest resources for their livelihood; 2) the tendency to resource depletion due to heavy exploitation pressures; 3) a social organizing process of the local population aiming at defending the resources on which they depend for livelihood.
    The riverine populations of Gurupa region of the Amazon estuary embarked on forest management practices since the end of 1980s, supported by NGOs and research as well as funding organizations. Camutá do Purucí, Jocojó, Sao Sebastião and Gurupaí villages in Gurupa were among those already practicing or discussing the possibility of introducing a community resource management system. While endorsing the existence of the above three preconditions, a family structure, land tenure, forest ecosystems, the degree of forest use, farming and management practice among others were studied and compared totaling 20 households in those villages.
    Classifying household revenues into three types, such as those from 1) harvesting forest produce, 2) farming, and 3) other sources including employment and pensions, the dependency ratio to forest resources was gauged for each village, analyzing co-relations between the forest resource dependency and the incentive to developing a community forest management strategy.
    It was confirmed that the more a community is dependent on harvesting forest resources, the more it gets interested in introducing a resource management system so that they can safeguard and guarantee their livelihood means.
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