Stand dynamics of a tropical rain forest and its responses to climate changes during the last two decades in Sumatara

苏门答腊热带雨林林分动态及其对过去二十年气候变化的响应

基本信息

批准号：
12575006
负责人：
YONEDA Tsuyoshi
金额：
$ 3.46万
依托单位：
Kagoshima University (2002-2003)Osaka Kyoiku University (2000-2001)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2003
项目状态：
已结题

项目摘要

We could show floristic traits and stand dynamics of a tropical rain forest in Central Sumatra by basing on long-term field observation over the last decades. Forty species of Fagaceae could be observed in west faced slopes of the Barisan Mountains in West Sumatra Province. High species diversity and high dominance in basal area of Fagaceae over Dipterocarpaceae were notable characteristics in vegetation of a hill forest in this area particularly. We could discuss the dominance to be caused not only by natural factors such as climate, soils and geographical factors but also by recent human impacts.The growth rates of basal area of a hill rain forest stand decreased at the last ten years in comparison with one during the former ten years. This was resulted from lower growth rates and higher mortality of a big trees in the last ten years. This phenomenon could be observed at other forest stands in this area synchronously. We discuss impacts of frequent occurrence of abnormal dry weather on these forest trees. We could make clear the time trends of horizontal distribution pattern of canopy-gaps. Basing on this observation, we could estimate the turnover time of forest canopy to be 45 years in a hill rain forest. Recent high mortality of canopy trees caused to increase dominance of tree species with softer wood and higher growth rates in a mature and secondary forest also.

通过过去几十年的长期野外观测，我们可以展示苏门答腊岛中部热带雨林的区系特征和林分动态。在西苏门答腊省巴里桑山脉西面的山坡上可以观察到四十种壳斗科植物。物种多样性高，基底区壳斗科对龙脑香科的优势度高，是该区山地森林植被的显着特征。我们可以讨论这种主导地位不仅是由气候、土壤和地理因素等自然因素造成的，而且还包括最近的人类影响。山地雨林的断面积增长率在过去十年中比一年前有所下降。在过去的十年里。这是由于过去十年大树的生长速度较低和死亡率较高造成的。这一现象在该地区的其他林分上也能同步观察到。我们讨论异常干旱天气频繁发生对这些林木的影响。可以明确冠层间隙水平分布格局的时间趋势。根据这一观察，我们可以估计山地雨林的森林冠层周转时间为 45 年。最近冠层树木的高死亡率导致了在成熟和次生林中木材较软和生长速度较高的树种的优势增加。