Biology subjects

Vazquez, D. P.

Publications and source records attributed to Vazquez, D. P..

4 recordsLinked to original sources

bioRxiv2025

Climate-driven specialisation in plant-pollinator networks peaks outside the tropics

Pollination is a key ecological process sustaining biodiversity and food security, yet global patterns of plant-pollinator specialisation have remained unresolved. Using the largest global dataset of quantitative networks (>3,400 networks, >110,000 interactions), we show that the latitudinal specialisation gradient (LSG) exists, but it is non-linear, hemispherically asymmetric, and strongly taxon-dependent. Network-level and pollinator specialisation were lowest in the tropics and peaked at northern mid-latitudes, whereas plants tended to become more specialised toward higher latitudes. Climate consistently outperformed latitude, species richness, and environmental productivity as a predictor of these patterns. Specialisation declined with increasing temperature, rose with moderate rainfall before declining at the wettest sites, and increased with temperature seasonality, but plants and pollinators responded differently to these drivers. Functional groups diverged strongly: ectothermic insects were most specialised in cooler, seasonal climates, while birds showed weaker links to latitude but reduced specialisation in wetter regions. These findings demonstrate that climate, rather than latitude or species richness, structures global variation in specialisation. Because warmer and less seasonal climates promote generalisation, climate change is likely to disrupt the most specialised pollination systems, unevenly across taxa and regions, with important consequences for biodiversity and ecosystem stability.

ecology↗

bioRxiv2020

Core-periphery structure in mutualistic networks: an epitaph for nestedness?

The calculation of nestedness has become a routine analysis in the study of ecological networks, as it is commonly associated with community resilience, robustness and species persistence. While meaningful in species distributional patterns, for an interaction matrix to be nested, specialist species must interact with ordered subsets of subsequently more generalized species -- not just with a lower number of species. However, after reviewing 419 papers on mutualistic networks published since nestedness was introduced for the study of species interactions in 2003, we have found that only two theoretical studies considered explicitly ordered subsets. Instead, most studies interpret nestedness as a core of densely connected generalist species, surrounded by a periphery of specialist species attached to this core -- a so-called core-periphery structure. Such a topological feature is generally perceived as a core-periphery structure in network science. Here, we argue that the concept of core-periphery may be more relevant for studies on mutualistic networks than the concept of nestedness, as ecologists are usually not interested in exploring in detail the ordered subsets that characterize nestedness but instead use nestedness to describe a topology with a core of densely linked generalist species surrounded by a sparsely linked periphery of specialists. To illustrate our arguments and the quantification of core-periphery structures, we calculate core-periphery and nestedness in a large publicly available dataset of mutualistic networks. We also describe the calculation of core-periphery structures, its relationship with nestedness, and provide the code inside the R package econetwork for its calculation in mutualistic networks. We hope that our review will help ecologists to move beyond nestedness towards a more explicit representation of the structure of ecological networks.

ecology↗

bioRxiv2020

Phenological shifts drive biodiversity loss in plant--pollinator networks

Plant-pollinator interactions are key for ecosystem maintenance and world crop production, and their occurrence depends on the synchronization of life-cycle events among interacting species. Phenological shifts observed for plant and pollinator species increase the risk of phenological mismatches, threatening community stability. However, the magnitudes and directions of phenological shifts present a high variability, both among communities and among species of the same community. Community-wide consequences of these different responses have not been explored. Additionally, variability in phenological and topological traits of species can affect their persistence probability under phenological changes. We explored the consequences of several scenarios of plant-pollinator phenological mismatches for community stability. We also assessed whether species attributes can predict species persistence under phenological mismatch. To this end, we used a dynamic model for plant-pollinator networks. The model incorporates active and latent life-cycle states of species and phenological dynamics regulating life-cycle transitions. Interaction structure and species phenologies were extracted from eight empirical plant-pollinator networks sampled at three locations during different periods. We found that for all networks and all scenarios, species persistence decreased with increasing magnitude of the phenological shift, for both advancements and delays in flowering phenologies. Changes in persistence depended on the scenario and the network being tested. However, all networks exhibited the lowest species persistence when the mean of the expected shift was equivalent to its standard deviation and this shift was greater than two weeks. Conversely, the highest species persistences occurred when earlier-flowering plants exhibited stronger shifts. Phenophase duration was the most important attribute as a driver of plant persistence. For pollinator persistence, species degree was the most important attribute, followed by phenophase duration. Our findings highlight the importance of phenologies on the stability and robustness of mutualistic networks. Author summaryPlant-pollinator interactions involve a great number of species and are essential for the functioning of natural and agricultural systems. These interactions are facing a great number of threats. In both plants and pollinators, life-cycle events including flowering and adult emergence are triggered by environmental cues such as temperature and snowmelt. Climate change has the potential to alter the timing of these events. These phenological shifts generate mismatches in the timing of interacting species. Thus, plants and their pollinators may not match in time and/or space, leaving flowers unpollinated and disrupting pollinator feeding. Given that natural communities are composed of multiple species interacting in complex ways, experimentally assessing the effects of this kind of perturbation is difficult. To tackle this challenge, we simulated different scenarios of phenological shifts for several empirical communities. Our results indicate that strong shifts in the timing of life-cycle events may represent a greater risk of community collapse. Likewise, plants with short blooming periods and pollinators with short activity periods or high specialization face a greater risk of extinction.

ecology↗

bioRxiv2018

Towards an applied metaecology

The complexity of ecological systems is a major challenge for practitioners and decision-makers who work to avoid, mitigate and manage environmental change. Here, we illustrate how metaecology - the study of spatial interdependencies among ecological systems through fluxes of organisms, energy, and matter - can enhance understanding and improve managing environmental change at multiple spatial scales. We present several case studies illustrating how the framework has leveraged decision-making in conservation, restoration and risk management. Nevertheless, an explicit incorporation of metaecology is still uncommon in the applied ecology literature, and in action guidelines addressing environmental change. This is unfortunate because the many facets of environmental change can be framed as modifying spatial context, connectedness and dominant regulating processes - the defining features of metaecological systems. Narrowing the gap between theory and practice will require incorporating system-specific realism in otherwise predominantly conceptual studies, as well as deliberately studying scenarios of environmental change.

ecology↗