Long-term dynamics of an epiphyte community – pattern and process

热带雨林的特点是物种和生命形式的极端多样性。 在过去几十年中，这些社区的动态和潜在机制一直是许多研究的主题，对树木有很大的偏见，由热带森林研究中心等研究网络在全球范围内协调。其他生命形式（藤本植物，附生植物，半附生植物，林下灌木和草本植物）受到的关注要少得多，但藤本植物在过去几年中已成为研究人员的焦点。 相比之下，我们对附生植物的了解仍然非常有限，尽管这种生命形式在当地物种多样性方面经常胜过土壤植被，并且与树木明显不同，因为树木群落的关键结构因素，如草食动物和病原体压力，似乎在附生植物中没有发挥作用或作用可以忽略不计。观测证据和第一次模拟研究的结果表明，真菌群落的动态在模式和过程上与土壤根共生植物有根本的不同。记录这些模式并了解潜在的过程是本研究的目标，这是因为在该地点进行了20年的工作以及巴拿马史密森热带研究所独特的研究基础设施。在全球范围内，没有其他研究在热带森林环境中，甚至远程覆盖类似的时间跨度。 该项目包括描述性、实验性和建模性内容。在一个未受干扰的低地森林的所有附生植物的0.9公顷的普查将使我们能够跟踪超过20年的社区动态。移植实验将调查宿主树种和相对垂直位置在森林中的相互作用，为成功的早期附生植物建立（=初始附着，发芽，生长和生存），和建模方法将开发正确的零模型，以检测主机特异性附生植物群落与其典型的，高度丛生的物种分布。移植实验还将伴随着对功能性状的全面分析。这种不同方法的结合应该会导致我们对维管真菌群落的组成和长期动态的理解取得实质性进展。

Tropical rainforests are characterised by an extreme diversity of both species and life forms. The dynamics of these communities and the underlying mechanisms have been the subject of much research in the last decades, with a heavy bias towards trees, globally coordinated by research networks like the Center of Tropical Forest Studies. Other life forms (lianas, epiphytes, hemiepiphytes, understorey shrubs and herbs) have received much less attention with the exception of lianas that have moved into focus of researchers in the last years. In comparison, our knowledge of epiphytes is still very limited, in spite of the fact that this life form frequently trumps soil-rooted vegetation in terms of local species diversity and clearly differs from trees, since crucial structuring factors of tree communities like herbivore and pathogen pressure seem to play no or a negligible role in epiphytes. Observational evidence and the results of first modelling studies suggest that the dynamics of epiphyte communities differ fundamentally in pattern and process from soil-rooted co-occurring plants. Documenting these patterns and reaching an understanding of the underlying processes are the objectives of this study, which is only possible because of two decades of work at the site and the unique research infrastructure of the Smithsonian Tropical Research Institute in Panama. Globally, there is no other study in a tropical forest setting that even remotely covers a similar time span. The project has descriptive, experimental and modelling elements. A census of 0.9 ha of all epiphytes in an undisturbed lowland forest will allow us to follow the community dynamics over more than 20 years. A transplant experiment will investigate the interactive role of host tree species and relative vertical position in the forest for the success of early epiphyte establishment (= initial attachment, germination, growth and survival), and a modelling approach will develop the correct null model to detect host specificity in epiphyte communities with their typical, highly clumped species distributions. The transplant experiment will also be accompanied by a comprehensive analysis of functional traits. This combination of different approaches should lead to substantial progress in our understanding of the composition and long-term dynamics of vascular epiphyte communities.