Latitudinal and elevational gradients of fern diversity and community composition in Africa and the Indian Ocean Islands

为了研究导致蕨类植物多样性模式的主要驱动因素，将在一个地理区域（非洲和邻近的印度洋岛屿）内沿沿着五个海拔梯度进行详细调查，其基本的大尺度纬度梯度为30°。这项调查将与已经建立的BRYOLAT项目密切相关，该项目旨在解释同一研究地点的bryolat植被的各自模式。蕨类植物的海拔丰富度模式的变化模式沿着纬度梯度和模式的比较，同时评估的brittes将导致进一步的洞察力和更深入的了解环境和其他驱动程序的物种丰富度，这仍然是激烈的争论，在当前的文献。作为评估的第一次，额外的观察物种的生育状况将揭示的见解蕨类植物组合的人口动态，从而给出了可能性，以测试的假设源-汇动态在确定海拔丰富度模式的相对作用。邀请参加BRYOLAT项目提供了一个独特的机会，建立一个类型的调查，可以很少发现：丰富的模式比较沿着两个主要梯度类型的大空间尺度与两组生物，从而可以直接比较物种丰富度模式的基本驱动因素。

To study the principle drivers that cause diversity patterns of pteridophytes, a detailed survey will be undertaken along five elevational gradients within one biogeographic region (Africa and adjacent Indian Ocean islands) with an underlying large-scale latitudinal gradient of 30°. The survey will be closely associated with the already established BRYOLAT project, which aims at explaining the respective patterns in the bryophyte vegetation at the same study sites. The mode of change of elevational richness patterns of pteridophytes along the latitudinal gradient and the comparison with the patterns simultaneously assessed for bryophytes will lead to further insight and a deeper understanding of environmental and other drivers of species richness, which are still hotly debated in current literature. As assessed for the first time, additional observations of the fertility status of the species will reveal insights into the population dynamics of pteridophyte assemblages and thus give the possibility to test the hypothesis of source–sink dynamics in its relative role in determining elevational richness patterns. The invitation to participate in the BRYOLAT project offers the unique opportunity of establishing a type of survey that can rarely be found: the comparison of richness patterns along two main gradient types of large spatial scales with two groups of organisms, which thus can be directly compared with respect to underlying drivers of species richness patterns.