Schittko Conrad, Hawa Mahmoud, Wurst Susanne
Freie Universität Berlin, Functional Biodiversity, Dahlem Center of Plant Sciences, Berlin, Germany.
PLoS One. 2014 Jun 4;9(6):e99065. doi: 10.1371/journal.pone.0099065. eCollection 2014.
A frequent pattern emerging from biodiversity-ecosystem function studies is that functional group richness enhances ecosystem functions such as primary productivity. However, the manipulation of functional group richness goes along with major disadvantages like the transformation of functional trait data into categories or the exclusion of functional differences between organisms in the same group. In a mesocosm study we manipulated plant functional diversity based on the multi-trait Functional Diversity (FD)-approach of Petchey and Gaston by using database data of seven functional traits and information on the origin of the species in terms of being native or exotic. Along a gradient ranging from low to high FD we planted 40 randomly selected eight-species mixtures under controlled conditions. We found a significant positive linear correlation of FD with aboveground productivity and a negative correlation with invasibility of the plant communities. Based on community-weighted mean calculations for each functional trait, we figured out that the traits N-fixation and species origin, i.e. being native or exotic, played the most important role for community productivity. Our results suggest that the identification of the impact of functional trait diversity and the relative contributions of relevant traits is essential for a mechanistic understanding of the role of biodiversity for ecosystem functions such as aboveground biomass production and resistance against invasion.
生物多样性与生态系统功能研究中经常出现的一种模式是，功能群丰富度会增强生态系统功能，如初级生产力。然而，操纵功能群丰富度存在一些重大缺点，比如将功能性状数据转化为类别，或者排除同一组生物之间的功能差异。在一项中宇宙研究中，我们基于Petchey和Gaston的多性状功能多样性（FD）方法，利用七种功能性状的数据库数据以及物种来源（本地或外来）信息，操纵了植物功能多样性。沿着从低到高FD的梯度，我们在受控条件下种植了40种随机选择的八物种混合物。我们发现FD与地上生产力呈显著正线性相关，与植物群落的入侵性呈负相关。基于对每个功能性状的群落加权平均计算，我们发现固氮性状和物种来源（即本地或外来）对群落生产力起着最重要的作用。我们的结果表明，识别功能性状多样性的影响以及相关性状的相对贡献，对于从机制上理解生物多样性在地上生物量生产和抗入侵等生态系统功能中的作用至关重要。
