Jochen Fründ

Postdoctoral Researcher Agroecology, Georg-August-University of Göttingen Grisebachstr. 6 D - 37077 Göttingen phone: +49 (0) 551 39 22359 e-mail: jfruend (at) uni-goettingen.de

Research Interests

Community Ecology, Biodiversity, Ecosystem Functioning, Interspecific Interactions, Global Change Ecology & Conservation

I am interested in the causes and consequences of biodiversity. I want to understand how communities and ecosystems change under human influence and what can be done to maintain their functioning in a changing world. Currently I focus on bees and other pollinators, and their importance for the pollination of wild plant communities. In the search for biological mechanisms and processes, I consider it essential to relate my work to theories of ecological networks, ecological niches and optimal foraging, as well as to maintain a close connection to natural history. To understand ecological questions, I prefer to combine field observations, experiments and modeling.

Current Project

In my PhD project, I focused on the role of pollinator diversity for the pollination of wild plants and potential mechanisms for pollinator diversity effects, such as species identity, complementarity and insurance. I studied various aspects relating to this overarching question:
1) I performed an experiment testing the effect of pollinator diversity on seed production of a community of 14 different plant species, using flight cages inhabited by 0 - 5 species of wild bees in different combinations. This experiment provides the unique opportunity to analyze replicated pollination networks that vary in pollinator community composition without confounding variation in other factors such as abundance or environment.
2) I looked at the impact of global environmental change on pollinator communities and pollination. I performed a full-factorial field experiment simulating advance in flowering phenology, shift in plant height and habitat loss, to test potential interactions among multiple aspects of global change. Investigating the preconditions for an insurance effect of wild bee diversity against climate change, I studied responses of different wild bee species to winter temperatures in a lab experiment.
3) I studied within-day temporal dynamics in plant-pollinator interactions. Using experiments and network / community analyses, I focused on the effect of pollination on the timing of flower closure and its importance as a driver of temporal patterns in interaction networks.
4) Employing a global perspective on plant-mutualist interactions, I also compared complementary specialization among tropical and temperate interaction networks.
In most of my work, I put particular emphasis on separating sampling artifacts from biological information with the help of null model simulations.

I also contribute to the R software package bipartite maintained by Carsten F. Dormann (University of Freiburg). The package is freely available on:

Publications

Journal articles

Tscharntke T, Tylianakis JM, Rand TA, Didham RK, Fahrig L, Batáry P, Bengtsson J, Clough Y, Crist TO, Dormann CF, Ewers RM, Fründ J, Holt RD, Holzschuh A, Klein AM, Kleijn D, Kremen C, Landis DA, Laurance WF, Lindenmayer D, Scherber C, Sodhi N, Steffan-Dewenter I, Thies C, van der Putten WH, Westphal C (in press). Landscape moderation of biodiversity patterns and processes - eight hypotheses. Biological Reviews, in press.

Fründ J, Dormann CF, Tscharntke T (2011): Linné's floral clock is slow without pollinators - flower closure and plant-pollinator interaction webs. Ecology Letters, 14, pp. 896-904.
highlighted in Nature | Research Highlights: 476, p. 9 (04 August 2011).

Parsche S, Fründ J, Tscharntke T (2011). Experimental environmental change and mutualistic vs. antagonistic plant flower-visitor interactions. Perspectives in Plant Ecology, Evolution and Systematics, 13, pp. 27-35.

Fründ J, Linsenmair KE, Blüthgen N (2010). Pollinator diversity and specialization in relation to flower diversity. Oikos, 119, pp. 1581–1590, DOI 10.1111/j.1600-0706.2010.18450.x

Dormann CF, Fründ J, Blüthgen N, Gruber B (2009). Indices, graphs and null models: analysing bipartite ecological networks. The Open Ecology Journal, 2, pp. 7-24.

Dormann CF, Fründ J, Gruber B (2008). Introducing the bipartite package: analysing ecological networks. R News, 8 (2).

Blüthgen N, Fründ J, Vazquez DP, Menzel F (2008). What do interaction network metrics tell us about specialization and biological traits? Ecology, 89(12), pp. 3387–3399.

Meyer CFJ, Fründ J, Pineda Lizano W, Kalko EKV (2008). Ecological correlates of vulnerability to fragmentation in Neotropical bats. Journal of Applied Ecology, 45, pp. 381–391.

Ferreras-Romero M, Fründ J, Marquez-Rodriguez J (2005). Sobre la situación actual de Lestes macrostigma (Eversmann, 1836) (Insecta: Odonata) en el área de Doñana (Andalucía, sur de España). Boletín de la Asociación española de Entomología, 29 (3-4), pp. 41-50.

Conference contributions

Fründ J, Dormann CF, Holzschuh A, Tscharntke T (2011): Functional complementarity drives the effect of bee diversity on pollination. Talk at the 12th European Ecological Federation Congress, Ávila, Spain.

Fründ J, Dormann CF, Tscharntke T (2011): Linné's floral clock is slow without pollinators - flower closure and plant-pollinator interaction webs. Poster at the Conference 'Functions and Services of Biodiversity', Göttingen, Germany.

Schleuning M, Fründ J, Klein A-M, Dormann CF, Blüthgen N, Abrahamczyk S, Alarcón R, Albrecht M, Andersson G, Bazarian S, Böhning-Gaese K, Bommarco R, Dalsgaard B, Dehling M, Gotlieb A, Hagen M, Hickler T, Holzschuh A, Kaiser-Bunbury C, Morris RJ, Sandel B, Sutherland W, Svenning J-C, Templin M, Tscharntke T, Watts S, Weiner C, Werner M, Williams NM, Winqvist C (2011): Complementary specialization of mutualistic interaction networks decreases towards tropical latitudes. Talk at the 24th annual meeting of the gtö (Society for Tropical Ecology), Frankfurt, Germany

Fründ J, Dormann CF, Holzschuh A, Tscharntke T (2010). Pollinator diversity and the pollination of wild plants in an experimental setting. Talk at the 95th annual meeting of the Ecological Society of America, Pittsburgh.

Fründ J (2010). Rapid flower closure as a response to pollination. Talk at the Multitrophic Interactions Workshop, Göttingen.

Fründ J, Blüthgen N (2009). Flower preferences of generalist bees and hoverflies compared between interaction webs. Talk at the annual meeting of the DGaaE (German Society for General and Applied Entomology), Göttingen, Germany.

Parsche S, Fründ J, Tscharntke T (2008). Does environmental change reduce pollination success by wild bees? Poster at the 38th annual meeting of the GfÖ (Ecological Society of Germany, Switzerland and Austria), Leipzig, Germany.

Dormann CF, Fründ J, Blüthgen N, Gruber B (2008). Indices, graphs and null models: tools for elucidating the ecological causes of bipartite network topology. Talk at the 38th annual meeting of the GfÖ, Leipzig.

Dormann CF, Fründ J, Blüthgen N, Gruber B (2008). Indices, graphs and null models: tools for elucidating the ecological causes of bipartite network topology. Talk at the annual meeting of the BES, London.

Fründ J, Linsenmair KE, Blüthgen N (2007). Does pollinator diversity and specialization increase with flower diversity? Talk at the 37th annual meeting of the GfÖ, Marburg, Germany.

Fründ J, Meyer CFJ, Kalko EKV (2006). Species sensitivity to fragmentation: bats on land-bridge islands in Gatun Lake, Panama. Poster at the 19th annual meeting of the gtö (Society for Tropical Ecology), Kaiserslautern, Germany.

Other

Fründ J, Beckedorf S (2011). Ohne Bienen geht die Uhr nach. Deutsches Bienen-Journal, 36, p. 468.

Fründ J (2011). Invited Talk, University of Würzburg.

Fründ J (2011). Invited Talk, Leuphana University of Lüneburg.

Reviewing

Articles reviewed for:

• Apidologie
• Basic and Applied Ecology
• Ecology Letters
• Journal of Applied Ecology
• Oecologia
• Oikos
• PLoS ONE

Curriculum Vitae