Search

Understanding natural populations trends has emerged as a key objective to bend the curve of biodiversity loss. Of particular concern are the impacts of stressors at the local scale, which are not necessarily reflected in the current global conservation assessments. As a hotspot of biodiversity, the Iberian Peninsula is an area of special interest for conservation. Here, we aim to synthesise the current knowledge about the population trends of marine, terrestrial and freshwater Iberian vertebrates. To that aim, we performed an extensive review, with more than 5000 scientific manuscripts screened and grey literature. From this initial review, and after applying data quality checks, we obtained 1500 population time series of Iberian vertebrates. Once we obtained this global database, we analysed their population trends using two-step modelling process: (i) first we applied state-space models to derive the population trend of each population time series; (ii) we then used multilevel Bayesian models to determine the factors influencing the population trends. Overall, we found that Iberian vertebrate populations display a disparity of trends, with both declines and increases, with fishes being the only taxa showing clear signs of declines. We identified major gaps in the monitoring data across the Iberian peninsula, with amphibians and reptiles being highly underrepresented in our dataset, despite being among the most threatened taxonomic groups. Overall, our approach will help to bridge the gap in our knowledge between the global and local scale conservation status of wild Iberian populations and help to focus the attention of future conservation policies.

Understanding and identifying the impacts of multiple stressors on natural populations has become a key objective for post-2020 biodiversity conservation. Of particular concern are the impacts of stressors at the local scale, which are not necessarily reflected in current global conservation assessments. As a hotspot of biodiversity, the Iberian Peninsula is an area of special interest for conservation, but it is currently facing myriad environmental problems. Yet, a synthesis of the impacts of multiple stressors on the Iberian faunal populations is glaringly missing. To contribute to this challenge, we join our efforts in an Early Career Researchers project funded by SIBECOL, which aims to synthesise current knowledge on population trends of Iberian marine, terrestrial and freshwater vertebrates, and, eventually, to identify the most common stressors for Iberian fauna populations, and their differences between major taxonomic groups and ecosystems. Here, we will present the results of the first phase of this project, whose objective was to describe the trends of Iberian vertebrate populations and identify knowledge gaps related to taxonomic groups and ecosystems. To that aim, we conducted an extensive literature review, with more than 5,000 scientific manuscripts and grey literature screened. From this initial review, and after applying data quality controls, we obtained > 1,000 population time series of Iberian vertebrates across marine, terrestrial, and freshwater ecosystems. Once we compiled this database, we analysed the population trends using a two-step modelling process: (i) first, we applied state-space models to derive the population trend of each population time series; and (ii) second, we used multilevel Bayesian models to determine the factors influencing these population trends. Overall, we found that Iberian vertebrate populations display a disparity in trends, with both declines and increases, with fishes (both marine and freshwater) being the taxa s

Environmental variables are known to regulate the reproductive output of marine intertidal organisms, but typically these variables are studied as averages and interpreted at a macroscale level. Along 200 km of coast in NW Iberia, great variability in the reproductive activity of the stalked barnacle Pollicipes pollicipes was found among 7 different locations. We found the highest number of broods reported to date in this species and suggest a more realistic method of predicting reproductive success that takes into account sea surface temperature (SST). At these same locations, we studied 13 yr of SST, thermal upwelling index (UI), ground skin temperature and chlorophyll a (chl a) satellite data, using spectral analyses to partition their temporal variability over ecologically relevant time scales. SST played the most relevant role as an environmental driver, explaining 48% of the variability in the proportion of breeding individuals (BI), but the SST-BI goodness-of-fit decreased sharply northwards. Variance-partitioning analyses indicated that cycles between 20 and 100 d in SST and UI were more important southwards, which is consistent with a latitudinal gradient in upwelling intensity and frequency along this coast. Thus, we found better biophysical coupling towards the south, where shorter fluctuation time scales in SST match the gonadal development period (around 1 mo). This pattern may explain the spatial variability in the strength of association between key environmental variables and the reproductive cycle of coastal species along their distribution range