Functionally complete communities result in better ecosystem functioning: Dung removal and secondary seed dispersal by dung beetles in the Western Palaearctic

Autor: Tanja Milotic, Christophe Baltzinger, Carsten Eichberg, Amy Eycott, Marco Heurich, Jörg Müller, Jorge Noriega, Rosa Menendez, Jutta Stadler, Réka Ádám, Tessa Bargmann, Isabelle Bilger, Jörn Buse, Joaquín Calatayud, Constantin Ciubuc, Gergely Boros, Pierre Jay-Robert, Märt Kruus, Enno Merivee, Geoffrey Miessen, Anne Must, Elham Ardali, Elena Preda, Iraj Rahimi, Dirk Rohwedder, Rob Rose, Eleanor Slade, László Somay, Pejman Tahmasebi, Stefano Ziani, Maurice Hoffmann
Rok vydání: 2018
Zdroj: Research Institute for Nature and Forest
ISSN: 1365-2699
0305-0270
Popis: Aim In several ecosystems, the diversity of functional species traits has been shown to have a stronger effect on ecosystem functioning than taxonomic diversity alone. However, few studies have explored this idea at a large geographic scale. In a multi-site experiment, we unravelled the relationship between ecosystem function and functional completeness of species assemblages using dung beetles as a model group, focusing on dung removal and secondary seed dispersal. Location 17 grassland locations across the Western Palaearctic. Methods We used a randomized block design with different exclosure types to control the dung and seed removing activities of individual functional groups of the local dung beetle assemblage. We classified dung beetle species according to resource specialisation and into functional groups based on dung processing behaviour (dwellers, tunnellers, rollers) and body size (small, large). Additionally, we assessed the role of other soil macro-invertebrates. By sampling the dung beetle community and measuring the remaining dung and seeds after the experiment, the impact of each functional group was estimated. Results Dung beetle assemblages differed along a north-south and east-west gradient. Dwellers dominated northernmost sites, whereas at lower latitudes we observed more tunnellers and rollers indicating a functional shift. Resource specialists were more abundant in southern and eastern areas. Overall, functional group diversity enhanced dung removal. More dung (+46.9%) and seeds (+32.1%) were removed in the southern sites and tunnellers and rollers were more effective. At the northernmost sites, where tunnellers were scarce or absent, other soil macro-invertebrates removed the majority of dung. Main conclusions The conservation of functionally complete dung beetle assemblages is crucial to maintain the ecosystem functions provided by dung beetles. Given the latitudinal variation in functional group diversity, it is reasonable to expect compositional changes due to climate change. These changes could lead to increased dung removal and a higher secondary seed dispersal rate in northern regions.
Databáze: OpenAIRE
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