Savannization Processes in Tropical Africa (TAGELAQP/SAPITA 91-92)

热带非洲的草原化过程 (TAGELAQP/SAPITA 91-92)

• 批准号: 03041066
• 负责人: KADOMURA Hiroshi
• 金额: $ 1.28万
• 依托单位: Tokyo Metropolitan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03041066/
• 关键词: Savannization; Desertification; Land; Vegetation Degradation; Tropical Africa; Environmental History; Pollen Analysis; Climatic Changes; Anthropogenic Impact

The field data obtained from the 1989-90 season research in the African savannas were analyzed and were featured into a publication that includes following results :1. Northern Africa (Cameroon)1) East Cameroon forest/savanna contact : A model for explaining savannization processes was constructed on the basis of the relationship between the structure and composition of semideciduous and gallery forests and soil profiles.2) West Cameroon Highlands : Pollen analysis and radiocarbon datings of cores indicate that forest degradation followed by savannization began at 3, 000-2, 500 yr BP and intensified since 2, 000-1, 500 yr BP. Spreading of Podocarpus, a montane forest element, during the LGM to the lower elevations was also confirmed.3) West Cameroon Highlands : A model showing patterns and processes of land and vegetation degradation over cattle-grazed grassy slope was constructed.4) Sudano-Sahelian savanna zone : An attempt was made to formulate progressive land degradation under cond … More itions of increased human impact and persistent drought.5) Recently, deforestation of humid forests has been greatly accelerated due to shortened fallow period of slash-and-burn cultivation and to illegal exploitation of reserved forests.2. Sothern Africa (Zambia, Zimbabwe and Malawi)6) West Zambia : Geoecological analysis of soil profiles and radiocarbon dates of buried soils suggest that human impact creating "miombo" woodland over the Kalahari Sands dates back to to 2, 500 yr BP, widespread from 1, 000 yr BP and intensified from 400 yr BP.7) Nyika Plateau : Widespread grasslands over the plateau have been derived from clearing of evergreen montane forests some 500 years ago for fuelwood by iron-smelting peoples, resulting in widespread soil degradation.3. Throughout equatorial Africa, hitherto available data indicate that the degradation of forest vegetation and savannization have proceeded by the coupled effects of human activities and climatic aridification since 3, 000-2, 500 yr BP. Reconstruction, however, of more detailed history, call for more well-dated data.4. Recent Subsaharan drought seems to be caused by decreased convective activities and may relate with a global-scale anomaly of Walker Circulation.5. Landsurface-atmosphere interaction changes induced by "desertification" and savannization and their climatic and ecological implications remain unanswered. Less

对从 1989-90 季节非洲稀树草原研究中获得的实地数据进行了分析，并发表在一份出版物中，其中包括以下结果：1．北非（喀麦隆）1) 东喀麦隆森林/稀树草原接触：根据半落叶林和廊道森林的结构和组成与土壤剖面之间的关系，构建了一个解释稀树草原化过程的模型。2) 西喀麦隆高地：花粉分析和核心放射性碳测年表明，森林退化和稀树草原化始于距今 3, 000-2, 500 年，并自此加剧。 2, 000-1, 500 年 BP。还证实了末次盛冰期期间罗汉松（一种山地森林元素）向低海拔地区的传播。3) 西喀麦隆高地：建立了一个模型，显示放牧草坡上土地和植被退化的模式和过程。4) 苏丹-萨赫勒稀树草原区：在人类影响增加和持续存在的条件下，试图制定渐进式土地退化的模型。 5)近年来，由于刀耕火种休耕期缩短和非法采伐保留林，湿地森林砍伐速度大大加快。2．南部非洲（赞比亚、津巴布韦和马拉维）6) 赞比亚西部：对土壤剖面和埋藏土壤放射性碳测年的地质生态分析表明，人类对喀拉哈里沙漠上空形成的“miombo”林地的影响可以追溯到距今 2, 500 年，从距今 1, 000 年开始广泛传播，从距今 400 年开始加剧。7) 尼卡高原 ：高原上大面积的草原是由于大约 500 年前熔铁民族为了取薪材而砍伐常绿山地森林而形成的，导致了大范围的土壤退化。 3．在整个赤道非洲，迄今为止的数据表明，自距今3, 000年至2, 500年以来，人类活动和气候干旱化的共同影响导致森林植被退化和稀树草原化。然而，重建更详细的历史需要更多过时的数据。4．最近的撒哈拉以南干旱似乎是由对流活动减少引起的，并可能与全球范围内的沃克环流异常有关。5。 “荒漠化”和稀树草原化引起的地表-大气相互作用的变化及其对气候和生态的影响仍未得到解答。较少的

项目成果

KADOMURA, H.: "The Sahel--An ever changing ecotone." Kadomura, H. & Katsumata, M., eds. : The Sahel--Present and Future. Toto Shuppan.46-78 (1992)

KADOMURA, H.：“萨赫勒——一个不断变化的生态交错带。”

SHINODA, M.: "Drought and desertification in tropical Africa." J. Geogr.100-6. 858-874 (1991)

筱田 M.：“热带非洲的干旱和荒漠化。”

田村 俊和: "熱帯の地形・表層物質形成におけるシロアリの役割" 地形. 12ー3. 203-218 (1991)

Toshikazu Tamura：“白蚁在热带地貌和表面物质形成中的作用”《地貌学》12-3（1991）。

TAMURA, T.: "Formation of woodland environment on the eastern margin of the Kalahari sands, Zambia." J. African Studies.No. 38. 33-53 (1991)

TAMURA, T.：“赞比亚卡拉哈里沙漠东缘林地环境的形成。”

KADOMURA, H., ed.: Geogr. Dept. Tokyo Metropol. Univ.Savannization Processes in tropical Africa II., 240 (1992)

KADOMURA, H.，编辑：地理。