以下の条件での結果を表示する: 検索条件を変更
クエリ検索: "サバナ" 植生
160件中 1-20の結果を表示しています
  • 市川 澄雄
    2011年 4 巻 1 号 36-42
    発行日: 2011年
    公開日: 2014/09/10
    ジャーナル フリー
  • ナイジェリアの事例をもとに
    内村 悦三
    1986年 05 巻 42-
    発行日: 1986/01/25
    公開日: 2022/06/03
    解説誌・一般情報誌 オープンアクセス
  • 地理教育との関連において
    正井 泰夫, 萩原 八郎, 洪 忠烈
    1993年 40 巻 4 号 14-23
    発行日: 1993/03/25
    公開日: 2010/04/30
    ジャーナル フリー
    An East African country with an area of 580, 000km2 and a population of 23 million, Kenya supplies a large amount of information even in geographic education. The natural environments of Highland Kenya, especially of climates, are often referred to “savannah”, but it should be restricted to those of vegetation. Its luxuriant fauna is well known, but seldom is dealt with as a topic in geographic education on secondary level. But the fauna there should be paid more attention because of its peculiarity depicting the local reality very well. Never is it a simple tourist attraction of no use in geographic education. The Masai, or Maasai, is well known and very often treated as an ethnic group maintaining their own rich cultural traits significantly different from others. It is true that many of them retain Masai rituals and daily life to a great extent, but at the same time, modernization is infiltrating in various aspects. A large number of Masai people now live in towns and cities without practicing a semi-nomadic life at all. Whether or not this kind of peculiar life should be treated in geographic education is a problem to be further discussed. If it is discussed as a topic out of many representative Black African cultures, it would be understandable. However, if it is singled out as if it typifies the Black African culture, much commentary ought to be added. Kenya has developed a metropolis at the altitude of 1, 700m above sea level. Good climate there has attracted European settlers first and a large number of African people have been drawn in as labor force, ousting many Masais living in a place what is now known as Nairobi. With more than 1.5 million people, the city is still expanding both in population and area. Central Nairobi boasts many highrise architectures in an atmosphere of any modern city. Vast residential areas are characterized by a very low density of structures, and of population, by Japanese standards, but African sections are compact and often of squatter type, making a sharp contrast. A problem is the recent rapid influx of refugees pouring into the latter. In this respect, Nairobi can be treated as a good example of a multi-ethnic third world city.
  • 松井 健
    1986年 30 巻 2 号 174-175
    発行日: 1986/12/30
    公開日: 2018/06/30
    ジャーナル フリー
  • 北澤 新
    1990年 38 巻 144-147
    発行日: 1990/03/01
    公開日: 2018/04/04
    ジャーナル フリー
  • 式 正英
    1984年 93 巻 5 号 plate1-plate2
    発行日: 1984/10/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 篠崎 由依, 藤原 誠士, 白川 直樹
    2018年 74 巻 6 号 II_85-II_92
    発行日: 2018年
    公開日: 2019/03/29
    ジャーナル フリー
  • 藤井 一至, 松浦 陽次郎, 菅野 均志, 高田 裕介, 平舘 俊太郎, 田村 憲司, 平井 英明, 小崎 隆
    2019年 63 巻 2 号 73-81
    発行日: 2019年
    公開日: 2020/12/31
    ジャーナル フリー


  • 矢沢 大二
    1968年 77 巻 4 号 247-248
    発行日: 1968/08/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 式 正英
    1984年 93 巻 4 号 256-258
    発行日: 1984/08/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 白倉 伸一, 服部 眞幸, 松尾 光弘, 牛木 純
    2002年 47 巻 4 号 246-249
    発行日: 2002/12/27
    公開日: 2009/12/17
    ジャーナル フリー
  • *吉田 圭一郎
    2014年 2014a 巻 803
    発行日: 2014年
    公開日: 2014/10/01
    会議録・要旨集 フリー
    I はじめに
    外来植物の生物学的侵入(biological invasion)はグローバルな環境問題の一つである(Vitousek et al. 1997).特に,太平洋島嶼では外来植物の生物学的侵入が顕著にみられ,外来植物の分布予測やその影響評価に関する研究が数多く行われてきた(Daehler et al. 2004など).
    近年,外来植物の生物学的侵入が気候変化に影響をうけることが指摘されつつある(Dukes & Mooney 1999).特に,乾湿条件の変化は外来植物の侵入定着や分布拡大に有利に働くとされ(Davis et al. 2000),長期的な気候変化を考慮した外来植物への対策が急務となっている.
    こうした背景から本研究では,1)気候条件の異なるいくつかの島嶼において,同一の外来植物の生物学的侵入による影響を明らかにし,2)それらの地理的な比較から,気候変動と外来植物の生物学的侵入との関連性を検討することを目的とした.本発表では,特に外来植物ギンネム(Leucaena leucocephala)の生物学的侵入による影響の地理的な差異について明らかにする.

    II 調査地と方法
    III 結果と考察
  • 神山 和則
    2008年 79 巻 4 号 397-398
    発行日: 2008/08/05
    公開日: 2017/06/28
    ジャーナル フリー
  • 西山 喜一
    1977年 20 巻 4 号 263-271
    発行日: 1977/03/25
    公開日: 2010/03/19
    ジャーナル フリー
  • 矢沢 大二
    1977年 86 巻 2 号 135
    発行日: 1977/04/25
    公開日: 2009/11/12
    ジャーナル フリー
  • ブルキナ・ファソの農家家計データを用いた実証
    櫻井 武司
    2006年 78 巻 1 号 34-49
    発行日: 2006/08/25
    公開日: 2014/09/30
    ジャーナル フリー
    This paper, taking covariate shocks induced by the civil war in Côte d'Ivoire in West Africa as an example, investigates their impact on soil degradation in rural Burkina Faso, a neighboring country. Burkina Faso is located in the semi-arid zone on the southern edge of the Sahara desert, and frequent drought due to erratic rainfall keeps its agricultural productivity low and unstable. As a result, its rural population relies on external migration as well as remittance from relatives living outside the country.
    The war has caused two significant shocks in rural Burkina Faso: an increase in household size due to returnees from Côte d'Ivoire and a decrease in remittance received from Côte d'Ivoire. Hence transitory poverty took place among farm households. Regression analyses show that both of the shocks have incurred the expansion of cropping area and that the in-crease in household size reduces the use of chemical as well as organic fertilizer per hectare. Moreover there is a significant reduction in livestock holdings due to distressed sales, and the reduction in livestock value also induces an increase in cropping area and a decrease in the use of organic fertilizer per hectare. In sum, the shocks incurred by the civil war in Côte d'Ivoire have induced soil-fertility-depriving agriculture in rural Burkina Faso as households' coping strategies. Agro-ecological zone-wise analyses indicate that such a tendency is significant in the southern Sudanian zone and the southern Guinean zone relative to the other two zones. The policy implication is that interventions should focus on such zones to prevent the covariate shocks from becoming the onset of soil degradation and desertification.
  • 1.タイ国東北部における塩生植物の耐塩生態
    杉 修一
    1994年 32 巻 3 号 177-186
    発行日: 1994/09/30
    公開日: 2010/06/22
    ジャーナル フリー
    This study aims to establish the development of farmland from saline barren lands which is now attracting much attention in the world. There are several reasons for causing barren land like an unfavorable natural environment as deserts. Artificial caused include development. These activities have finally led the natural ecosystem to many unexpected tragedies. Moreover, they are causing land and soil erosion, floods and other disasters, producing vast areas of barren land. The theme of this study is to investigate methods how to improve saline soil caused by rock salt and convert it into arable land. This is one of the most difficult problems and no good results have been achieved, though some studies have been conducted on this subject. The author has obtained the following ideas through eight times of study abroad for the period of 1985 to 1993. The author found the characteristics of the natural ecosystem of salt-tolerant weeds that succession occurred according to the decrease in the salt concentration of the soil. These merits might be used in order to develop vegetation group artificially and turn barren land into fertile one.
  • *山本 真也, 沢田 健, 中村 英人, 小林 まどか, 河村 公隆
    2012年 59 巻 2P16
    発行日: 2012年
    公開日: 2012/09/01
    会議録・要旨集 フリー
    本研究では,新生代の気候変動に伴う熱帯-亜熱帯域の陸域環境変化を明らかにするために,赤道太平洋の堆積物中(IODP Sites U1331?U1338)の長鎖脂肪酸の安定炭素同位体比(δ13C)を測定した。その結果,陸上植物ワックスに由来する炭素数28と30の直鎖脂肪酸(C28, C30脂肪酸)のδ13C値は,約40~20 Maにかけて約5‰の漸移的な減少傾向を示したが,13Ma以降は一転増加に転じ,現在にかけて約10‰の増加傾向にあった。また,C28, C30脂肪酸のδ13C変動には,13Ma以降3回(1.6Ma, 6.5Ma, 9.5Ma)の短期的な増加イベントが認められ,南アメリカの熱帯-亜熱帯域が,中新世中期以降,複数の乾燥化イベントを繰り返しつつ,徐々に乾燥化に向かい,C4植物が増加していったことが示唆された。
  • 矢沢 大二
    1967年 76 巻 1 号 55-56
    発行日: 1967/02/25
    公開日: 2009/11/12
    ジャーナル フリー
  • 梶川 昌三, 宇根 寛
    2000年 8 巻 27-32
    発行日: 2000/07/06
    公開日: 2011/06/27
    ジャーナル フリー
    The Global Map is the effective tool for understanding current status of the global environment and taking measures for sustainable development. In November 1998, the United Nations recommended the heads of National Mapping Organizations to participate in Global Mapping Project. Until the March of 2000 the number of countries and regions participating in Global Mapping Project was seventy-seven. Target year of the Global Map first edition is 2000. Distribution of the Global Map will also be begun and Global Mapping Forum will be held in Hiroshima in November in this year.