Studying biodiversity-ecosystem function relationships in experimental microcosms among islands

Ecological studies on islands have provided fundamental insights into the mechanisms underlying biodiversity of larger organisms, but we know little about the factors affecting island microbial biodiversity and ecosystem function. We conducted a field experiment on five Baltic Sea islands where we placed aquatic microcosms with different levels of salinity mimicking environmental stress and allowed diatoms to colonize the microcosms via air. Using structural equation models (SEM), we investigated the interconnections among environmental and dispersal-related factors, diatom biodiversity, and ecosystem productivity (represented by chlorophyll a concentration). We also tested whether the body size structure of the community influences productivity together with biodiversity. In SEMs, we found no relationship between species richness or evenness and productivity. Rather, productivity increased with increasing mean body size of species in the communities. The effects of environmental stress...岛屿生态学研究已为大型生物多样性的潜在机制提供了基础性洞见，但目前学界对影响岛屿微生物多样性与生态系统功能的因素仍知之甚少。本研究在5座波罗的海岛屿开展野外实验，设置不同盐度梯度的水生微宇宙（aquatic microcosms）以模拟环境胁迫，并允许硅藻通过空气途径定殖于微宇宙中。本研究借助结构方程模型（structural equation models, SEM），探究了环境因子、扩散相关因子、硅藻多样性与生态系统生产力（以叶绿素a（chlorophyll a）浓度为表征）之间的相互关联。此外，本研究还检验了群落体型结构是否会与生物多样性共同影响生态系统生产力。通过结构方程模型分析，本研究未发现物种丰富度或均匀度与生产力之间存在关联。恰恰相反，群落内物种的平均体型越大，生态系统生产力越高。而环境胁迫的影响……