As time goes by: 20 years of changes in the aquatic macroinvertebrate metacommunity of Mediterranean river networks

Abstract

Aim To analyse temporal metacommunity dynamics in river networks in relation to hydrological conditions and dispersal. Location Fifteen river reaches from the Llobregat, Besòs and Foix catchments in the North‐Eastern Iberian Peninsula. Taxon Aquatic macroinvertebrates belonging to 99 different families. Methods We sampled aquatic macroinvertebrate communities during spring in 20 consecutive years. We built two environmental distances (one related with water chemistry and another one with river flow regime) and two spatial distances (network distance and topographic distance). Then we used Mantel tests (accounting for spatial autocorrelation) to relate macroinvertebrate dissimilarity with environmental and spatial distances. Additionally, we determined the dry and wet years using the Standardized Precipitation Index (SPI) and we classified macroinvertebrate families based on their ability to fly and to drift. Finally, we ran a linear regression model including the correlation value (r) of each Mantel test as response variable and distance type (environmental or spatial), SPI, dispersal mode, their pairwise interactions and a three‐way interaction as predictor variables. Results Metacommunity organization varied over time and it was significantly affected by precipitation, which can be related to river network connectivity. The environmental filters, mainly the flow regime, were generally more important than the spatial filters in explaining community dissimilarity over the study period. However, this depended on the dispersal abilities of the organisms. Network fragmentation due to flow intermittence during the dry years significantly reduced the dispersal capacity of strong aerial dispersers, leading to spatially structured metacommunities. For strong drift dispersers, community dissimilarity patterns were generally best explained by environmental filters regardless of SPI. Main conclusions A significant temporal variation in metacommunity organization can be expected in highly dynamic systems (e.g. Mediterranean rivers) and it might depend on the dispersal modes and abilities of the organisms, since they determine the response to changes in environmental and landscape filters.

Phylogenetic diversity of two geographically overlapping lichens: isolation by distance, environment, or fragmentation?

“…However, this promising approach can currently only be applied to site data (e.g. Cañedo‐Argüelles et al., 2020, in which each site is unique and therefore the spatial vector contains no duplicates. For specimen data in which more than one specimen share the same site, this method is currently not applicable.…”

Effects of the Temporal Scale of Observation on the Analysis of Aquatic Invertebrate Metacommunities

“…However, environmental changes can also determine the temporal turnover due to species sorting, potentially reaching rates higher than those predicted by stochastic dynamics (Dornelas et al, 2014). At the metacommunity level, long-term studies have shown either stable (e.g., Azeria and Kolasa, 2008;Huttunen et al, 2018;Lindholm et al, 2020) or changing metacommunities through time, due to environmental fluctuations or disturbances observed (e.g., Datry et al, 2016;Sarremejane et al, 2017;Cañedo-Argüelles et al, 2020). Nevertheless, the spatio-temporal scale of observation in each study could explain these differences, depending on whether or not the study duration covered those relevant environmental fluctuations (Korhonen et al, 2010).…”

Editorial: Spatio-Temporal Dynamics of Metacommunities - Implications for Conservation and Management

“…According to metacommunity theory (Leibold et al, 2004), the structure of local communities results from the interplay between local factors (e.g., environmental filtering, species interactions) and regional factors (e.g., dispersal rates, landscape configuration). The relative importance of these factors is highly dependent on the organisms' biological traits, landscape connectivity, and the spatial and temporal scales considered (Heino et al, 2015;Tonkin et al, 2018;Viana and Chase, 2019;Almeida-Gomes et al, 2020;Cañedo-Argüelles et al, 2020;Lansac-Tôha et al, 2021). However, the differences in metacommunity assembly mechanisms found among studies are far from being fully understood.…”

“…However, the differences in metacommunity assembly mechanisms found among studies are far from being fully understood. The evaluation of temporal dynamics of metacommunities has only emerged recently (Cañedo-Argüelles et al, 2020;Jabot et al, 2020;Li et al, 2020;Lindholm et al, 2021) and the application of the metacommunity theory in other fields, such as biomonitoring, conservation biology or ecosystem restoration, is yet to be fully explored (Bengtsson, 2010;Heino, 2013;Leibold and Chase, 2018;Chase et al, 2020;Cid et al, 2020;Heino et al, 2021).…”