title: Genotypic richness and dissimilarity opposingly affect ecosystem functioning.
abstract: Biodiversity is an essential determinant of ecosystem functioning. Numerous studies described positive effects of diversity on the functioning of communities arising from complementary resource use and facilitation. However, high biodiversity may also increase competitive interactions, fostering antagonism and negatively affecting community performance. Using experimental bacterial communities we differentiated diversity effects based on genotypic richness and dissimilarity. We show that these diversity characteristics have opposite effects on ecosystem functioning. Genotypic dissimilarity governed complementary resource use, improving ecosystem functioning in complex resource environments. Contrastingly, genotypic richness drove allelopathic interactions, mostly reducing ecosystem functioning. The net biodiversity effect on community performance resulted from the interplay between the genetic structure of the community and resource complexity. These results demonstrate that increasing richness, without concomitantly increasing dissimilarity, can decrease ecosystem functioning in simple environments due to antagonistic interactions, an effect insufficiently considered so far in mechanistic models of the biodiversity-ecosystem functioning relationship.
authors: J.F. Blumenbach Institute of Zoology and Anthropology, Georg-August- University Göttingen, Berliner Straße 28, 37073 Göttingen, Germany. ajousse@gwdg.de
authors: A
authors: A
authors: Jousset
authors: B
authors: B
authors: Schmid
authors: S
authors: S
authors: Scheu
authors: N
authors: N
authors: Eisenhauer
mesh_terms: D044822:Biodiversity; D017753:Ecosystem; D014644:Genetic Variation; D005838:Genotype; D056265:Microbial Interactions / Q000235:genetics*; D011551:Pseudomonas fluorescens / Q000235:genetics* / Q000502:physiology