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The thesis research concerned evolutionary ecology and community ecology of amphibians in two different areas of a Mediterranean region. The goal of the research was to test how anuran species coexist along a lentic freshwater gradient from ephemeral to permanent ponds. The community structure across the gradient has been explained by different ecological models, based on different trade-offs and inherent properties of the species. To test the different models he used four-year field surveys of communities to characterise pond-breeding habitats (with respect to temporariness, predator abundance and competitor abundance) and to evaluate the dynamics and spatial structures of the metacommunity. He also designed lab experiments to quantify species traits and phenotypic plasticity (life-history, morphological and behavioural traits) in response to different circumstances found in nature: pond drying, presence of invertebrate predators and intra- and interspecific competition. Comparative analysis of phenotypic plasticity traits was made in relation to species ecological breadths (quantified from field surveys) and phylogenetic relationships. In general, species that use a wide variety of habitats or unpredictable environments showed a greater plasticity of responses than those occurring in predictable habitats. At the two extremes of the hydroperiod (ephemeral and permanent ponds) there were specialists with limited plasticity, whereas species from intermediate temporary ponds showed higher levels of plasticity. Results therefore supported the hypothesis that interspecific differences in plasticity are adaptive and are related to ecological breadth and unpredictability of habitat. The correlations among traits of the different species reflected trade-offs suggested by the models (colonisation-competition; predator-permanence gradient; and competition ability-permanence gradient), but correlation coefficients did not favour any single trade-off model over the others. These results suggest that the community studied can be interpreted as a metacommunity in which local interactions and regional processes (colonisation-extinction rates) are related, and they emphasise the importance of habitat heterogeneity for both: local and regional diversity maintenance.

Man-made wetlands are often created to compensate for the loss or degradation of natural wetlands, but little is known about the processes taking place in these artificial environments, especially at the community level. Throughout this thesis, we have assessed the phenomena of primary succession over different time (short-, mid- and long-term) and spatial scales (local, regional, interregional levels), applying different approaches (taxonomic and functional) and subject groups (invertebrates and amphibians). Our main findings regarding time scales show a 3-phase successional pattern in Mediterranean man-made wetlands’ communities, where at the short term (1 year) colonization processes dominate; at mid term perspectives (2 to 7 years) succession signs begin to be conspicuous, and later on (≥ 10 years) parameters such as species richness reach an asymptote. At that moment, some biological strategies dominate, and biodiversity surrogates indicate that communities are indistinct between man-made and natural wetlands. Regarding spatial effects, we corroborated that both local and regional factors affect the establishing communities. Particularly, the low hydrological stability of the Mediterranean region has enhanced biological traits favoring resilience and resistance to disturbances when comparing Mediterranean and cold temperate aquatic communities. Even within the Mediterranean region, low levels of hydrological stability have significant effects on the successional dynamics. In these cases, local communities are highly nested within regional natural ones, and so are not able to make net contributions to regional richness. We also showed the influence of the regional pool of recruiters over local communities, both in the case of invertebrates and amphibians. Especially for the latter group, man-made Mediterranean temporary ponds (MTPs) can play an important role in their conservation. / Les zones humides de nova creació són sovint concebudes per compensar la pèrdua i degradació de les naturals, però el coneixement dels processos que tenen lloc en aquests ambients artificials encara és superficial, especialment a nivell de comunitat. Al llarg d’aquesta tesi, hem analitzat el fenomen de la successió primària a diferents escales temporals (a curt, mitjà i llarg termini) i a diferents escales espacials (a nivell local, regional i interregional), mitjançant diverses aproximacions (taxonòmiques i funcionals) i subjectes (invertebrats i amfibis). Les nostres aportacions pel que fa a les escales temporals mostren un patró de successió basat en 3 fases, on a curt termini (1 any) dominen els processos de colonització; en perspectives de mitjà termini (2 a 7 anys) els signes de successió comencen a ser conspicus, i més tard (≥ 10 anys) paràmetres com la riquesa d’espècies arriben a una asímptota. En aquesta fase avançada, algunes estratègies biològiques dominen, i els índexs de biodiversitat indiquen que les comunitats poden ser indistintes entre les llacunes naturals i les de nova creació. Pel que fa als efectes espacials, hem corroborat que tant factors locals com regionals afecten les comunitats que s’hi estableixen. En particular, la baixa estabilitat hidrològica de la regió Mediterrània ha afavorit trets biològics que proveeixen resiliència i resistència enfront de pertorbacions, sobretot quan es comparen amb les comunitats pròpies del clima temperat fred. Fins i tot dins la mateixa regió Mediterrània, nivells baixos d’estabilitat hidrològica poden tenir efectes importants en la dinàmica de la successió. En aquests casos, les comunitats locals estan altament aniuades en les naturals a nivell regional, i per tant difícilment poden fer contribucions netes a la riquesa regional. També hem mostrat la influència del pool regional de colonitzadors sobre les comunitats locals, tant en el cas dels invertebrats com en el dels amfibis. Especialment per aquest darrer grup, les Basses Temporànies Mediterrànies (BTMs) de nova creació poden jugar un paper important per a la seva conservació.