Münzenberg, Ute

[["dc.bibliographiccitation.firstpage","1685"],["dc.bibliographiccitation.issue","1477"],["dc.bibliographiccitation.journal","Proceedings of the Royal Society of London. Series B, Biological Sciences"],["dc.bibliographiccitation.lastpage","1690"],["dc.bibliographiccitation.volume","268"],["dc.contributor.author","Steffan-Dewenter, Ingolf"],["dc.contributor.author","Münzenberg, Ute"],["dc.contributor.author","Tscharntke, Teja"],["dc.date.accessioned","2017-09-07T11:49:59Z"],["dc.date.available","2017-09-07T11:49:59Z"],["dc.date.issued","2001"],["dc.description.abstract","We analysed the combined effects of pollination and seed predation on seed set of Centaurea jacea in 15 landscapes differing in structural complexity. In the centre of each landscape, a patch of Centaurea plants was established for standardized measurements of flower visitation, seed predation and seed set. Both the number of flower-visiting bees and the proportion of flower heads damaged by seed predators increased with landscape complexity, which was measured as the proportion of semi-natural habitats. The mean number of seeds per flower head did not increase with the proportion of semi-natural habitats, presumably because of the counterbalancing effects of pollination and seed predation. For a subset of undamaged flower heads, the number of seeds per flower head was positively correlated with the number of flower visits. Further reasons for the unexpected failure to detect a correlation between landscape complexity and seed set appeared to be changes in flower-visitor behaviour and the contrasting responses of honeybees and wild bees to habitat context. Landscape analyses at eight spatial scales (radius of landscape sectors, 250-3000 m) showed that different groups perceived the landscape at different spatial scales. Changes in pollinator numbers could be explained only at small scales (up to 1000 m), while the seed predators also responded to large scales (up to 2500 m)."],["dc.identifier.doi","10.1098/rspb.2001.1737"],["dc.identifier.gro","3149803"],["dc.identifier.pmid","11506681"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6502"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0962-8452"],["dc.title","Pollination, seed set and seed predation on a landscape scale"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","1421"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Ecology"],["dc.bibliographiccitation.volume","83"],["dc.contributor.author","Steffan-Dewenter, Ingolf"],["dc.contributor.author","Münzenberg, Ute"],["dc.contributor.author","Bürger, Christof"],["dc.contributor.author","Thies, Carsten"],["dc.contributor.author","Tscharntke, Teja"],["dc.date.accessioned","2017-09-07T11:53:46Z"],["dc.date.available","2017-09-07T11:53:46Z"],["dc.date.issued","2007"],["dc.description.abstract","Most ecological processes and interactions depend on scales much larger than a single habitat, and therefore it is important to link spatial patterns and ecological processes at a landscape scale. Here, we analyzed the effects of landscape context on the distribution of bees (Hymenoptera: Apoidea) at multiple spatial scales with respect to the following hypotheses: (1) Local abundance and diversity of bees increase with increasing proportion of the surrounding seminatural habitats. (2) Solitary wild bees, bumble bees, and honey bees respond to landscape context at different spatial scales. We selected 15 landscape sectors and determined the percentage of seminatural habitats and the diversity of habitat types at eight spatial scales (radius 250–3000 m) by field inspections and analyses of vegetation maps using two Geographic Information Systems. The percentage of seminatural habitats varied between 1.4% and 28%. In the center of each landscape sector a patch of potted flowering plants (four perennial and two annual species) was placed in the same habitat type, a grassy field margin adjacent to cereal fields. In all, 865 wild bee individuals and 467 honey bees were observed and an additional 475 individuals were caught for species identification. Species richness and abundance of solitary wild bees showed a close positive correlation with the percentage of seminatural habitats at small scales up to 750 m, whereas bumble bees and honey bees did not respond to landscape context at these scales. In contrast, honey bees were correlated with landscape context at large scales. The densities of flower-visiting honey bees even increased with decreasing proportion of seminatural habitats at a radius of 3000 m. We are not aware of any empirical studies showing contrasting foraging patterns related to landscape context at different spatial scales. We conclude (1) that local landscape destruction affects solitary wild bees more than social bees, possibly changing mutualistic plant–pollinator and competitive wild bees–honey bees interactions and (2) that only analyses of multiple spatial scales may detect the importance of the landscape context for local pollinator communities."],["dc.identifier.doi","10.2307/3071954"],["dc.identifier.gro","3149967"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6683"],["dc.language.iso","en"],["dc.notes.status","public"],["dc.relation.issn","0012-9658"],["dc.subject","bees; biotic interactions; community structure; connectivity; habitat fragmentation; landscape ecology; pollination; spatial scales; species diversity"],["dc.title","Scale-Dependent Effects of Landscape Context on Three Pollinator Guilds"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]