Biology subjects

Cunillera-Montcusi, D.

Publications and source records attributed to Cunillera-Montcusi, D..

4 recordsLinked to original sources

bioRxiv2024

Natural disturbances and connectivity shape the seasonal variability of aquatic macroinvertebrate communities across Europe

Understanding the joint influence of natural disturbance, spatial connectivity and biogeography on biodiversity is essential to forecast its responses to climate change. Macroinvertebrate communities in drying river networks constitute an ideal study system to understand the interplay of these ecological processes. We analyze the taxonomic and functional structure of macroinvertebrate communities sampled across 126 reaches with perennial and intermittent streamflow, surveyed in six drying river networks (DRN) across Europe, six times over one year. Drying frequency decreased community richness and functional diversity of communities, whereas spatio-temporal connectivity increased community richness in intermittent reaches. Communities experiencing a high drying frequency increased the proportion of taxa with K-strategies and drying resistance traits. Communities experiencing a long drying duration compensated by high spatio-temporal connectivity had more taxa with a r-strategy and high dispersal ability. Perennial communities varied from taxa-poor communities of r-strategists in spring and autumn and taxa-rich communities of K-strategists in summer and had a constant functional diversity throughout the year. When drying frequency increased, communities showed a similar pattern except in autumn when they shifted towards species-poor communities of K-strategists. Functional diversity then peaked in summer. Community trait structure and in particular optimal drying resistance traits changed across biogeographical scales. It opposed communities from mountainous DRN (with more r-strategies and high dispersal ability) to non-mountainous DRN (with more K-strategies). Drying frequency, drying duration, and spatio-temporal connectivity drive divergent community structures, suggesting the presence of an ecological threshold that explains the variability of disturbed ecosystems across broad spatial scales. These factors also shaped seasonal community variations, particularly after summer, with intermittent communities influenced by stochastic recolonization events in spring and autumn. Spatial-temporal connectivity proved crucial for maintaining diversity in communities subjected to intense drying. Lastly, the effectiveness of drying resistance traits was dependent on the biogeographical and environmental conditions of drying river networks.

ecology↗

bioRxiv2024

Similar Won't Make It: Coexistence, Habitat Availability and Suboptimal Restoration

In the context of the looming biodiversity crisis, adding patches of habitat has been proposed as a restoration strategy in several ecosystems. However, these interventions rarely mimic the conditions of the natural habitats precisely. Consequently, not all species equally benefit from the restored habitat, fostering a difference in species fitness that could generate an imbalance in the equalizing and stabilizing mechanisms that enable species coexistence, leading to competitive exclusion. Using a metapopulation model, we explore how the introduction of habitat patches with biased fitness advantages affects species coexistence. We show that while adding habitat patches generally increases species occupancy, suboptimal patches can favor one species, disrupting the stabilizing and equalizing mechanisms that enable coexistence, leading to competitive exclusion. This impact on the coexistence regime is particularly pronounced in species with high niche overlap and high colonization-extinction ratios. Our results highlight the double-edged sword effect of suboptimal restoration, revealing potential unintended consequences that could exacerbate biodiversity loss. On the other hand, restoration favoring endangered species is also identified as a conservation tool. The present study advances in the mechanistic comprehension of habitat restoration, a necessary endeavor in the face of the challenges posed by global change.

ecology↗

bioRxiv2024

Fall of giants: European diversity resistance to waterscape degradation and its potential continental drivers

Aquatic landscapes, or waterscapes, face severe threats from human activities propelling their deterioration. Waterscape degradation represents a main driver of the current diversity crisis, although its long-term consequences are difficult to quantify. In addition, the understanding of the potential effects of waterscape degradation on biodiversity at large spatial scales, such as biomes and continents, remains limited. In this work, we explore the potential trends in diversity decay in response to waterscape degradation across Europe to provide a first answer to these main threads. We reconstructed the European waterscape based on available satellite data and simulated diversity patterns using a coalescent metacommunity model run for several European ecoregions and considering nine dispersal abilities. Subsequently, we generated a gradient of waterscape degradation by systematically removing a percentage of available habitat and recalculating diversity metrics. For each ecoregion, dispersal ability, and degradation level we obtained a theoretical gamma diversity value. We synthesized the captured diversity decay trends in two parameters: the proportional decay rate and the collapsing rate, which respectively inform about the speed of diversity loss and its acceleration as waterscape degradation progresses. Finally, we mapped these parameters across Europe and related them with ecoregion structural descriptors (i.e. geographic location, water cover, connectivity, and size). Through this exercise, we could identify ecoregions sensitivities and their continental variation based on their diversity decay parameters. Connectivity and water cover emerged as primary descriptors of diversity decay, with more heterogeneous ecoregions generally exhibiting greater resistance to waterscape degradation. Our study provides a first order approximation to an urgently needed information: the continental-scale consequences of waterscape degradation for biodiversity. This data has the potential to improve conservation practices and facilitate the integration of innovative approaches in management, thereby enhancing our understanding of the consequences posed by one of the principal threats to freshwater diversity.

ecology↗

bioRxiv2024

Mapping planktonic communities: a network approach to assess the role of scale and centrality on their diversity and composition

The distribution of habitats across a landscape and their centrality gradient are key elements defining the effective pathways of dispersal, and thus of metacommunity assembly. Understanding how centrality shapes diversity patterns is essential for predicting the impact of future landscape changes on diversity. While alpine lakes have been extensively studied, often considering the fluvial network as a potential landscape, small planktonic communities have frequently been overlooked as potential dispersers due to their assumed ubiquity. In this study, we investigate the diversity patterns of alpine lake planktonic communities along lake networks constructed at different scales, ranging from 6.5 to 650 km and the fluvial network. We sampled 55 lakes in the northern Alps (16S, 18S, phytoplankton and zooplankton) and calculated several diversity metrics (alpha, beta diversity and LCBD) and multivariate analysis. We then constructed several networks responding to different scales, determined their centrality gradients, and finally explored their relationship with the diversity of each planktonic group. We expected that a groups diversity would relate differently across scales based on body size, but the outcomes were varied. Bacterioplankton and zooplankton diversity were both affected across scales higher than 100 km, whereas phytoplankton appeared completely unrelated to centrality. Nonetheless, we could observe that when significant, the relationships between diversity and centrality were shared among organisms. These findings not only underscore that planktonic organisms are influenced by landscape configurations larger than the fluvial system but also emphasise the critical role of dispersal for these groups and the scales at which it impacts metacommunity assembly. Significance statementWhile dispersal is widely recognized as a key driver of assembly, some groups and systems remain insufficiently explored to fully grasp the impact of landscape and dispersal on their assembly. Planktonic communities have traditionally been considered ubiquitous and detached from regional-level structure, primarily due to their small size, leading to the notion that "everything is everywhere". Additionally, alpine lake communities have traditionally been perceived as solely connected through fluvial systems. In this study, we challenge these notions by demonstrating how planktonic communities are indeed influenced by the relative positioning of lakes in the landscape, with significant impacts occurring at larger scales, spanning hundreds of kilometres. However, not all planktonic groups responded uniformly to the analysed factors, emphasizing the marked differences among groups and the diverging drivers shaping planktonic metacommunities.

ecology↗