Dormann, Carsten F.

[["dc.bibliographiccitation.firstpage","564"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Apidologie"],["dc.bibliographiccitation.lastpage","576"],["dc.bibliographiccitation.volume","42"],["dc.contributor.author","Gruber, Bernd"],["dc.contributor.author","Eckel, Katharina"],["dc.contributor.author","Everaars, Jeroen"],["dc.contributor.author","Dormann, Carsten F."],["dc.date.accessioned","2018-11-07T08:52:52Z"],["dc.date.available","2018-11-07T08:52:52Z"],["dc.date.issued","2011"],["dc.description.abstract","A worldwide decline of pollinator abundance is recorded and the worldwide pollination of insect-pollinated crops has traditionally depended on a single species, the honeybee. The risks of relying on a single species are obvious. Other species have been developed for particular crops. Here we present an extension of the framework of Bosch and Kemp (2002) that deals on how to develop a bee species into a crop pollinator. We used nesting aids in different settings to address five important issues that are necessary for an effective management of a bee species in a commercial setting. Our study system was the red mason bee (Osmia bicornis) in apple orchards in eastern Germany, but our approach should be transferable to other settings. The first issue was to demonstrate that it is possible to increase population size of O. bicornis by providing nesting aids. Second, we present how someone can study landscape features that promote the occurrence and abundance of O. bicornis. Further, we studied the dispersal of the species inside the orchard, and could demonstrate that bees prefer to disperse along lines of trees. Finally, we studied the effect of nesting substrate and type of farming on the recruitment of bees. We found a close relationship between the length of nesting tubes and achieved sex ratio and a negative effect of conventional farming on the number of nests built. We conclude with recommendations on how our findings can be used to optimize the management of O. bicornis in apple orchards."],["dc.description.sponsorship","Helmholtz Association [VH-NG-247]"],["dc.identifier.doi","10.1007/s13592-011-0059-z"],["dc.identifier.isi","000293971900003"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7401"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22276"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0044-8435"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","On managing the red mason bee (Osmia bicornis) in apple orchards"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","7"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","The Open Ecology Journal"],["dc.bibliographiccitation.lastpage","24"],["dc.contributor.author","Dormann, Carsten F."],["dc.contributor.author","Fründ, Jochen"],["dc.contributor.author","Blüthgen, Nico"],["dc.contributor.author","Gruber, Bernd"],["dc.date.accessioned","2019-07-10T08:13:17Z"],["dc.date.available","2019-07-10T08:13:17Z"],["dc.date.issued","2009"],["dc.description.abstract","Many analyses of ecological networks in recent years have introduced new indices to describe network properties. As a consequence, tens of indices are available to address similar questions, differing in specific detail, sensitivity in detecting the property in question, and robustness with respect to network size and sampling intensity. Furthermore, some indices merely reflect the number of species participating in a network, but not their interrelationship, requiring a null model approach. Here we introduce a new, free software calculating a large spectrum of network indices, visualizing bipartite networks and generating null models. We use this tool to explore the sensitivity of 26 network indices to network dimensions, sampling intensity and singleton observations. Based on observed data, we investigate the interrelationship of these indices, and show that they are highly correlated, and heavily influenced by network dimensions and connectance. Finally, we re-evaluate five common hypotheses about network properties, comparing 19 pollination networks with three differently complex null models: 1. The number of links per species (“degree”) follow (truncated) power law distributions. 2. Generalist pollinators interact with specialist plants, and vice versa (dependence asymmetry). 3. Ecological networks are nested. 4. Pollinators display complementarity, owing to specialization within the network. 5. Plant-pollinator networks are more robust to extinction than random networks. Our results indicate that while some hypotheses hold up against our null models, others are to a large extent understandable on the basis of network size, rather than ecological interrelationships. In particular, null model pattern of dependence asymmetry and robustness to extinction are opposite to what current network paradigms suggest. Our analysis, and the tools we provide, enables ecologists to readily contrast their findings with null model expectations for many different questions, thus separating statistical inevitability from ecological process."],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/5837"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61194"],["dc.language.iso","en"],["dc.notes.intern","Migrated from goescholar"],["dc.rights","Goescholar"],["dc.rights.access","openAccess"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.subject","Connectance; linkage density; nestedness,;network,;pollination web; specialization"],["dc.subject.ddc","630"],["dc.title","Indices, Graphs and Null Models: Analyzing Bipartite Ecological Networks"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]