The role of community assembly processes in biodiversity-ecosystems functioning experiments

生物多样性研究中一个尚未解决的主要问题是，物种数量对生态系统特性的影响是否可以通过跟踪单个物种的命运来解释。两个潜在的机制是生态位互补或抽样。在第一种情况下，物种对生态系统特性的贡献或多或少相等，而在第二种情况下，只有一个或几个物种这样做。为了区分这两者，物种的初始密度将在恒定物种数的子图中变化，并且随着时间的推移将跟踪所实现的密度。将在植物个体（“植物计”）、种群和群落的水平上测量响应变量。当物种具有相似的相对密度（高均匀度）时，植物物种数与响应变量之间的关系应具有互补性。通过取样，物种优势（低均匀度）应加强这种关系。

A major unresolved question in biodiversity research is, whether effects of species numbers on ecosystem properties can be explained by following the fate of individual species. Two potential mechanisms are niche complementarity or sampling. In the first case species contribute more or less equally to ecosystem properties, whereas in the second case only a single or few species do. To distinguish between the two, the initial densities of species will be varied in sub-plots of constant species number, and the achieved densities will be followed over time. Response variables will be measured at the level of the plant individual ("phytometer"), population and community. With complementarity, the relationship between plant species number and response variables should be stronger when species have similar relative densities (high evenness). With sampling, species dominance (low evenness) should strengthen the relationship.