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Tree species diversity effects and the importance of relative timing and species origin for insect-mediated interactions between neighbor plants

Description of the project:
Mixed forests are often assumed to have lower risk of herbivore attack than monocultures. However, tree diversity experiments have not always supported this view, as herbivory was found to both decrease or increase with tree diversity. Analysis of species interaction networks may help to understand why tree diversity effects are so variable. Trees are often attacked by many different specialist and generalist herbivores, and also indirectly linked by natural enemies of herbivores. The temporal dimension is also important here: diversity effects often vary over time, and the influence of neighbor trees on each other’s insect communities may depend on relative timing. A temporally explicit network approach allows to tackle three general mechanisms causing variation in tree diversity-herbivory relationships: networks can be used to quantify the degree of herbivore specialization, to formally describe the influence of natural enemies, and to reveal the importance of timing. In this project, we will sample arthropods throughout the year on multiple tree species in IDENT, an already established international network of tree diversity experiments with several sites that share the same tree species. Sites in both Freiburg and Canada will be sampled and directly compared. IDENT provides a rare opportunity to compare tree species within a genus in both native and exotic contexts (pairs of European and North American species are planted in both Europe and North America), allowing to separate tree species identity from exposure to native or novel herbivores. Here, we will use the temporal networks approach to help explain variation in tree diversity effects on herbivory and understand how exotic trees are integrated into native tree-herbivore networks. This project will advance and integrate the fields of network ecology, biodiversity-functioning research and non-native species biology. Ultimately, improving our understanding of species interactions will help to better predict consequences of global change and develop more sustainable land-use strategies, such as optimizing tree species mixtures for plantations.
Start of project: 01.02.2018
End of project: 31.01.2021
Project Management:
Albert-Ludwigs-University Freiburg
Fruend J
Professur für Biometrie und Umweltsystemanalyse
Prof. Dr. Dormann
Tennenbacherstr. 4
79098 Freiburg i. Br.

Phone: +49 761 203-3749
Fax: +49 761 203-3751
Email: info@biom.uni-freiburg.de
Actual Research Report

  • Fründ J
  • Collaborators in IDENT
  • N.N.
  • Berthelot S
  • Baden-Württemberg-Stiftung (Eliteprogramm für Postdocs), Land