SPATIAL EXTENT AFFECTS ESTIMATES OF PROCESS CONTRIBUTIONS TO POND METACOMMUNITY ASSEMBLY

Metacommunities are defined as local communities linked with the regional diversity pool via dispersal. The contributing local assembly processes environmental filtering, dispersal limitation and species interactions can be estimated by joint species distribution models (jSDM). However, the three processes may have differently strong contributions at varying spatial extents. We collected empirical data on pond metacommunities, encompassing presence/absence data of fishes, amphibians, zooplankton and benthic macroinvertebrates, in 170 ponds from 30 pondscapes in six European countries. We run jSDMs at three spatial extents, namely the semi-continental (all countries), the regional (countries separated) and the local (ponds in 1-2 pondscapes per country) extents. The pure and shared contributions of space to metacommunity assembly were minor in all models, while environment and species associations contributed strongly. The strongest pure contribution of environment was found for the regional scale, while species interactions were a strong contributor at the semi-continental scale, but also co-contributed with environment at the local scale. Important environmental predictors were pond hydroperiod, trophic state and coverage by macrophytes. Negative species associations at the local scale can plausibly be interpreted as predator-prey or competitive interactions, but positive associations dominate at all spatial extents. The contribution of the three community assembly processes differed among sites and species, suggesting a strong internal structure of pond metacommunities.

Presentation Preference: Standard Oral (12 Minutes)

Primary Presenter: Thomas Mehner, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) (thomas.mehner@igb-berlin.de)

Authors:

Thomas Mehner, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB)  (thomas.mehner@igb-berlin.de)

Consortium PONDERFUL, University of Vic - Central University of Catalonia  (sandra.brucet@uvic.cat)