The role of historic and climatic factors in the distribution of crustacean communities in Iberian Mediterranean ponds

Abstract

Summary We studied 140 freshwater ponds in eastern Spain spanning a wide range of water source, hydroperiod and regional heterogeneity attributable to orographic and climatic differences. Our aim was to provide a typology for Mediterranean ponds using crustacean assemblages and to find key environmental thresholds that define these pond types. To search for the environmental variables that define these communities, two complementary analyses were used: correspondence analyses (CA) and multivariate regression trees (MRT). We found a high level of specificity of crustaceans defining the different pond types. Three ponds, which were not associated with any of the large set of environmental variables used, were clearly separated from the rest in the CA. These held a very specific and probably relict community, characterised by the large calanoid Hemidiaptomus: we refer to these as ‘Hemidiaptomus’ ponds. Taxonomic information suggests a fundamental influence of historical events. The MRT analysis applied to the rest of the ponds allowed us to create a hierarchical order of several current environmental factors that account for their crustacean community composition. Thus, we defined four further pond types. The most important factor structuring communities was hydroperiod, separating temporary ponds, mainly fed by rain, from permanent ponds, fed from more stable sources. Climate‐related factors subsequently separated two groups of temporary ponds: (i) temporary ponds in semi‐arid areas (mean rainfall <600 mm year−1, spring rainfall <150 mm), which contained Neolovenula alluaudi and (ii) temporary ponds in semi‐humid areas, which contained Mixodiaptomus incrassatus. Amongst the permanent ponds, (iii) lowland coastal spring‐fed ponds with quite constant temperatures hosted a singular crustacean community that was well separated from that found in (iv) inland mountain ponds consisting of more ubiquitous crustaceans. These results provide a typology of ponds useful for conservation planning and freshwater biodiversity maintenance. Moreover, the identified ecological thresholds should be helpful in predicting the communities to be expected as a result of changes to land use or climate.

How do freshwater organisms cross the “dry ocean”? A review on passive dispersal and colonization processes with a special focus on temporary ponds

“…As suggested by Allen (2007), this reduction might lead to stronger priority effects (see next subchapter), higher levels of inbreeding and selection against traits favouring high dispersability. Miracle (1982) and Sahuquillo & Miracle (2013), in order to explain the distribution of some peculiar crustacean assemblages in the ponds of the Iberian Peninsula, hypothesized the existence of a former and ancient network of wetlands which allowed the presence of highly diversified crustaceans assemblages. Climate changes and human activities occurring during the Holocene may have caused a reduction in the number of suitable habitats for these assemblages, which nowadays represent a relic remnant surviving in a few isolated ponds.…”

“…Moreover, dispersal often occurs through multiple processes and vectors (Higgins et al, 2003). In this review, we will put a special focus on temporary water bodies, since these ecosystems represent biodiversity hotspots (Williams et al, 2001;Zacharias et al, 2007) and their functioning and conservation strictly depends on the dispersal and colonization abilities of their biota (Sahuquillo & Miracle, 2013;Marrone et al, 2013;Korn et al, 2013). Moreover, temporary ponds, alternating flooded and dry phases, add the duration of their ponding phase as a further temporal dimension to their ''insular features'' (Ebert & Balko, 1987;NaselliFlores & Barone, 2012).…”

Diversity patterns and biogeography of Diaptomidae (Copepoda, Calanoida) in the Western Palearctic

“…This is particularly regrettable, since diaptomid distribution is supposed to be largely influenced by historical factors (i.e., paleogeographical and paleoecological conditions) also depending on Allee effects (e.g., mate finding) during colonization (Leibold et al, 2010;Henriques-Silva et al, 2016). Furthermore, diaptomid species are good indicators of the ecological conditions of water bodies and some taxa are reported to be excellent indicators for the highly biodiverse, often endangered crustacean communities exclusive to the EU priority habitat ''3170* Mediterranean temporary ponds'' (Sahuquillo & Miracle, 2013;Alfonso et al, 2016;Marrone et al, 2016).…”

Elements of regional beetle faunas: faunal variation and compositional breakpoints along climate, land cover and geographical gradients

“…Such breakpoints may occur when there is a clear change in assemblage composition that is typically associated with a clear change in environmental conditions. Surprisingly, very few studies have assessed both continuous variation and breakpoints of community composition in the same study, and these studies have mainly considered local habitat gradients within a small region (Davidson et al 2010;Sahuquillo & Miracle 2013;Heino, Ilmonen & Paasivirta 2014). However, it is at large spatial grain sizes and geographical extents where the occurrence of breakpoints in faunal compositions should be most easily discernible, because studies spanning large spatial scales are likely to cross multiple regional species pools determined by the effects of historical factors and climatic constraints on the distributions of species (Brown & Lomolino 1998;Heino 2011).…”