The Maintenance of Rare Species in the Dipterocarp Rain Forests of Borneo: Phase II

生态学的一个中心问题是解释 在热带雨林中发现的许多稀有树种， 通过时间维持。 其中70%的物种 密度低于每公顷2棵树。 长期 用一套独特的方法研究物种稀有性和森林动态 婆罗洲西北部的三个截然不同的龙脑香林 自1965年以来一直在进行人口普查。 这些假设解释了 正在使用这些数据测试稀有物种的维护 结合1986年至1988年的树苗和幼苗调查， 详细的森林地图 一个森林会定期 一场灾难性的干旱，树冠树木死亡， 由于当地的山泥倾泻，森林在空间上是不均匀的。 物种 丰富度以森林最高，土壤次之 生育率和干扰水平。 因为这些 森林之间的差异，可能没有一个简单的 解释了这些森林物种的丰富性。 这些数据正在与联合国开发计划署的成员共同分析。 马来西亚林业部关心的实际问题， 森林管理 这些结果也与保护有关 生物学家关心的是维持生物 多样性

A central problem in ecology is to explain how the great numbers of rare tree species found in tropical rainforests are maintained through time. Approximately 70% of these species occur at a density of less than 2 trees per hectare. Long-term studies of species rarity and forest dynamics using a unique set of three contrasting dipterocarp forests from northwest Borneo have been censused since 1965. Hypotheses which explain the maintenance of rare species are being tested using these data combined with sapling and seedling surveys from 1986 to 1988 and detailed forest maps. One forest is subject to periodic catastrophic drought during which canopy trees die while a second forest is heterogeneous in space due to local landslips. Species richness is greatest in forest which is intermediate in soil fertility and levels of disturbance. Because of these differences among forests, there may not be one simple explanation for the great species richness of these forests. These data are being analyzed jointly with members of the Malaysian Forest Department concerned with practical matters of forest management. The results are also relevant to conservation biologists concerned with the maintenance of biological diversity.