A comparison of Guibourtia copallifera Benn. stands in South West Burkina Faso-community structure and regeneration

Shifting agriculture, fire, and over exploitation of wood and copal resin are the major causes of Guibourtia copallifera Benn. vulnerability in the south-west of Burkina Faso. Conservation of endangered species requires a thorough understanding of the dynamics of small populations. In the present study, we investigated the diversity and the dynamics of G. copallifera communities in two different types of land use history, a protected area (stated forest of Comoé-Leraba) and an unprotected area (the woodlands of Tourni and Timba). A total of 17 rectangular plots (50 m × 20 m) were sampled in both protected and unprotected areas. All woody species were systematically identified, measured and classified into diameter and height classes. In the two different types of land use, the dynamics of G. copallifera’s communities were good, and the diversities were similar and low with high β diversity.     

乌冈栎种群天然更新研究

种群更新对维持种群的稳定和发展具有极其重要的意义。通过野外实地调查,对不同地区乌冈栎种群的更新情况进行了分析,结果如下:1)大多数地区乌冈栎种群的幼苗结构呈倒金字塔型,说明乌冈栎种群的更新存在一定的困难;但在乌冈栎顶级群落中,由于仍存在一定数量的幼树,短期内的更新仍能继续进行;2)从乌冈栎幼苗空间分布格局来看,林窗或林缘处呈聚集分布,而林冠下呈均匀分布,这与乌冈栎幼苗生长的需光性有极大的关系;3)乌冈栎的萌发实验表明,1～2个月的沙藏处理有利于提高萌发率,而萌发过程中鼠害和虫蛀是限制出苗率的主要原因之一;4)乌冈栎种子的传播除靠重力外,啮齿类动物对它的影响最大,他们之间存在一定的权衡关系。为了提高乌冈栎种群的天然更新率,适当干扰地开辟林窗是较佳的途径。