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Plant-flower-visitor interaction networks
Collection and identification of all flower-visitors as well as characterization of flower availability and composition on all grassland EPs of the exploratories.
Analysis of the degree of specialization/partitioning of interactions on three different levels:
(1) Individuals: analysis of flower constancy in individuals by means of pollen analysis; identification of pollen in faeces (e.g. from hoverflies)
(2) Population: specialization of each species in its local context
(3) Community: determination of network specialization

Availability and quality of resources
Analysis of nutrient composition in pollen (primarily amino acids)


  1. The individuals of a flower-visitor population differ concerning their flower preferences.
  2. The flower preference of an individual (individual specialization) depends on and changes with flower abundances.
  3. Flower abundances, composition and diversity are influenced by intensity of land use. Dependent on their degree of specialization flower-visitors are affected by these changes in resources.
  4. Flower availability and insect diversity are positively correlated.
  5. Visitation rate, visitor diversity and specialization increase with the amount and quality of pollen offered by a flower (mg pollen per flower plus composition of amino acids).

Given the global decrease in species diversity, the relationship between biodiversity of different taxa and levels and various ecosystem processes and services, such as pollination of many important crops by flower-visiting insects, gains more and more importance.
If, due to mutual specialization, flower-visitors are found to be highly dependent on flower diversity, this would mean that a decrease in flower diversity, known to be driven by agricultural intensification, would lead to parallel declines of both biodiversity and abundance of pollinators.

In this subproject we want to analyse the effect of land use intensity on diversity and specialization of plant-flower-visitor interactions. In this process we need to check firstly how dependent the different species are on each other. How high is the degree of specialization and how does the plant flower-visitor network react to external influences?
Plant-flower-visitor networks are very specialized in comparison to other plant-animal interactions. This is logical as it increases the probability of pollen being transferred among flowers of the same species instead of being wasted on alien flowers.
These analyses are important for the general understanding of ecosystems and their endangerment. If a bluebell species disappears from a grassland interaction network, does this mean a strong disruption? Or will insects just switch to other species if “their” plant suddenly disappears?

Along the land use gradient of the Biodiversity Exploratory plots we want to ascertain what effect land use intensity has upon plant-flower-visitor networks. Furthermore, we aim to identify the keystone species of variable interaction networks, in order to be able to make predictions for nature conservation.


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Wende B., Gossner M. M., Grass I., Arnstadt T., Hofrichter M., Floren A., Linsenmair K. E., Weisser W. W., Steffan-Dewenter I. (2017): Trophic level, successional age and trait matching determine specialization of deadwood-based interaction networks of saproxylic beetles. Proceedings of the Royal Society B-Biological Sciences 284 (1854): 20170198. doi: 10.1098/rspb.2017.0198
More information:  doi.org
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Diversität und Ressourcennutzung Blüten besuchender Insekten in Abhängigkeit von Pollenqualität und Landnutzung
Weiner C. N. (2016): Diversity and resource choice of flower-visiting insects in relation to pollen nutritional quality and land use. Dissertation, TU Darmstadt
More information:  tuprints.ulb.tu-darmstadt.de
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Wende B. (2015): Diversity of saproxylic beetles and host tree specialisation in differently managed forests across Germany. Dissertation, University Würzburg
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Was die Interaktionshäufigkeit zwischen Bestäuber und Blüte über Aussterberisiken sagt
Weiner C. N., Werner M., Linsenmair K. E., Blüthgen N. (2014): Land-use impacts on plant–pollinator networks: interaction strength and specialization predict pollinator declines. Ecology 95 (2), 466–474. doi: 10.1890/13-0436.1
More information:  doi.org
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Die Bedeutung der sukzessiven Entwicklung von Totholz für xylobionte Arthropoden in verschiedenartig bewirtschafteten Wäldern
Weber S. (2012): Die Bedeutung der sukzessiven Entwicklung von Totholz für xylobionte Arthropoden in verschiedenartig bewirtschafteten Wäldern. Thesis, University Würzburg.
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Ein quantitativer Index der Landnutzungsintensität im Grünland: Einbindung von Mahd, Beweidung und Düngung
Blüthgen N., Dormann C.F., Prati D., Klaus V.H., Kleinebecker T., Hölzel N., Alt F., Boch S., Gockel S., Hemp A., Müller J., Nieschulze J., Renner S.C., Schöning I., Schumacher U., Socher S.A., Wells K., Birkhofer K., Buscot F., Oelmann Y., Rothenwöhrer C., Scherber C., Tscharntke T., Weiner C.N., Fischer M., Kalko E.K.V., Linsenmair K.E., Schulze E.-D., Weisser W. W. (2012): A quantitative index of land-use intensity in grasslands: integrating mowing, grazing and fertilization. Basic and Applied Ecology 13 (3), 207–220. doi: 10.1016/j.baae.2012.04.001
More information:  doi.org
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Die Bedeutung von Totholz für xylobionte Arthropoden in unterschiedlich bewirtschafteten Wäldern
Weiß M. (2011): Die Bedeutung von Totholz für xylobionte Arthropoden in unterschiedlich bewirtschafteten Wäldern. Thesis, University Würzburg
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Landnutzungsintensität im Grünland: Änderungen von Biodiversität, Artenzusammensetzung und Spezialisierung in Blütenbesucher-Netzwerken
Weiner C., Werner M., Linsenmair K.E., Blüthgen N. (2011): Land use intensity in grasslands: Changes in biodiversity, species composition and specialisation in flower visitor networks. Basic and Applied Ecology, 12 (4), 292-299. doi: 10.1016/j.baae.2010.08.006
More information:  doi.org
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Funktionelle Komplementarität und Spezialisierung: Die Rolle der Biodiversität auf Pflanzen-Bestäuber-Interaktionen
Blüthgen N., Klein A. M. (2011): Functional complementarity and specialisation: The role of biodiversity in plant–pollinator interactions. Basic and Applied Ecology 12, 282-291. doi: 10.1016/j.baae.2010.11.001
More information:  doi.org
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Aminosäuren von Pollen und Blütenspezialisie-rung bei Einsiedlerbienen
Weiner C. N., Hilpert A., Werner M., Linsenmair K.-E., Blüthgen N. (2010): Pollen amino acids and flower specialisation in solitary bees. Apidologie 41 (4), 476 - 487. doi: 10.1051/apido/2009083
More information:  doi.org
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Warum Netzwerkanalysen oft nicht mit der Ökologie von Gemeinschaften verknüpft sind: Eine kritische Abhandlung und ein Leitfaden für Ökologen
Blüthgen N. (2010): Why network analysis is often disconnected from community ecology: A critique and an ecologist's guide. Basic and Applied Ecology 11 (3), 185-195. doi:10.1016/j.baae.2010.01.001
More information:  doi.org

The so-called core projects of the BE emerged from the site selection project and the establishment of the exploratories (2006-2008). Since 2008, they have been providing the infrastructure and collecting important basic information on land use, diversity and ecosystem processes (long-term monitoring) for all projects. In addition, they coordinate project-wide activities such as various large-scale experiments.

Project in other funding periods

Picture: The collage shows nine photos of different flowers and insects.
Arthropods II (Core project)
#Animals  #2011 – 2014  

Scientific assistants

Prof. Dr. Karl Eduard Linsenmair
Alumni
Prof. Dr. Karl Eduard Linsenmair
Prof. Dr. Nico Blüthgen
Project manager
Prof. Dr. Nico Blüthgen
Technische Universität Darmstadt
PD Dr. Andreas Floren
Alumni
PD Dr. Andreas Floren
Martina Tospann
Alumni
Martina Tospann
Christiane N. Weiner
Alumni
Christiane N. Weiner
Beate Wende
Alumni
Beate Wende
Andrea Hilpert
Alumni
Andrea Hilpert
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