Biology subjects

Bonachela, J. A.

Publications and source records attributed to Bonachela, J. A..

5 recordsLinked to original sources

bioRxiv2026

Spatial Trophic Dynamics Shape and are Shaped by Desertification Transitions

Drylands, which sustain billions of people, face desertification driven by climate change and grazing pressures. From the bottom up, desertification is affected by water availability, with vegetation often self-organising into spatial patterns that vary with aridity levels. How these patterns and ultimately, desertification transitions, are affected by the spatial dynamics of higher trophic levels remain, however, poorly understood. Here, we introduce a spatially explicit tri-trophic model that links vegetation pattern formation to consumer-resource interactions and foraging behaviour. We find that the nature of vegetation spatial distribution and desertification transition strongly influence consumer spatial organisation, movement, and synchrony. Vegetation organised regularly in space generates "boom--bust" synchronised metapopulations, whereas fractal vegetation organisation generates scale-free consumer clustering and low synchrony. Our results reveal a reciprocal coupling between spatial trophic dynamics and ecosystem resilience, underscoring the need to integrate trophic interactions and behaviour into predictions informing management strategies for dryland ecosystems.

ecology↗

bioRxiv2025

Vegetation clump size and number as indicators for alternative stable states in semi-arid ecosystems

Dryland ecosystems are vulnerable to desertification, a pressing issue in the face of global climate change. In these ecosystems, vegetation often grows in spatially periodic patterns that differ as aridity increases (gaps, labyrinths and clumps), which has been widely studied theoretically, aiming to assess the proximity of the system to desertification. While some theoretical models predict smooth desertification transitions, most typically predict an abrupt transition linked to the possibility of two alternative stable states (desert and vegetated states), predictions that are yet to be confirmed empirically. If this bistability of alternative stable states occurs, however, environmental fluctuations and the history of the ecosystem determine which state ultimately materializes. This uncertainty makes it harder to predict desertification, compounding the challenges posed by it. Here, we combine empirical data and theoretical methods to investigate the links between bistability and vegetation spatial organization, which can help identify the presence of alternative stable states. We found that, although the presence of vegetation clumps is not indicative of bistability, changes in clump morphology can provide reliable indicators of bistability and an impending desertification transition. Thus, our methodology indirectly identifies whether desertification will occur abruptly, and whether restoration efforts should consider a potential ecosystem history-dependence.

ecology↗

bioRxiv2025

Zooplankton feeding behavioral signatures in the morphology of macroscale prey spatial distribution

The problem of pattern and scale remains a central problem in ecology, bridging fundamental and applied questions. Marine microbial communities are a case in point. For instance, to understand the role of zooplankton in oceanic biogeochemistry, their response to changes in environmental conditions, and the implications for ecosystem services (e.g., fisheries), it is critical to understand zooplankton trophic interactions and how they change in a rapidly changing climate. This understanding, however, remains elusive because, unlike for phytoplankton, for which remote sensing of macroscale patterns can provide insight into their microscale dynamics and community composition, obtaining this information for zooplankton largely rests on quantifying the difficult-to-monitor microscale interactions among millions of individuals with different behaviors, and between individuals and their environment. Here, we investigate whether it is possible to obtain indirect information on zooplankton from the macroscale spatial distribution of their prey. To tackle this "problem of scale", we develop a rigorous coarse-graining methodology that connects individual-level properties with macroscale spatial patterns. We demonstrate that the shape of the prey spatial distribution can indeed encode information about zooplankton feeding behavior and community dynamics. Specifically, we predict a change in dominant feeding behavior--from non-motile to motile feeding--as one moves from areas of high to areas of low prey density. These results thus suggest a novel application for remote sensing approaches: the potential tracking of consumer behavioral signatures in the large-scale patterns of the resource. Importantly, the scaling-up methodology that we developed to check whether those signatures exist is general, and can be used to link scales rigorously and systematically in any system in which the complexity of individual dynamics makes connecting scales intractable.

ecology↗

bioRxiv2021

Unconstrained coevolution of bacterial size and the latent period of plastic phage

Viruses play critical roles in the dynamics of microbial communities. Lytic viruses, for example, kill significant proportions of autotrophic and heterotrophic microbes. The dynamic interplay between viruses and microbes results from an overlap of physiological, ecological, and evolutionary responses: environmental changes trigger host physiological changes, affecting the ecological interactions of host and virus and, ultimately, the evolutionary pressures influencing the two populations. Recent theoretical work studied how the dependence of viral traits on host physiology (viral plasticity) affects the evolutionarily stable host cell size and viral infection time emerging from coevolution. Here, we broaden the scope of the framework to consider any coevolutionary outcome, including potential evolutionary collapses of the system. We used the case study of Escherichia coli and T-like viruses under chemo-stat conditions, but the framework can be adapted to any microbe-virus system. Oligotrophic conditions led to smaller, lower-quality but more abundant hosts, and infections that were longer but produced a reduced viral offspring. Conversely, eutrophic conditions resulted in fewer but larger higher-quality hosts, and shorter but more productive infections. The virus influenced host evolution decreasing host radius more noticeably for low than for high dilution rates, and for high than for low nutrient input concentration. For low dilution rates, the emergent infection time minimized host need/use, but higher dilution led to an opportunistic strategy that shortened the duration of infections. System collapses driven by evolution resulted from host failure to adapt quickly enough to the evolving virus. Our results contribute to understanding the eco-evolutionary dynamics of microbes and virus, and to improving the predictability of current models for host-virus interactions. The large quantitative and qualitative differences observed with respect to a classic description (in which viral traits are assumed to be constant) highlights the importance of including viral plasticity in theories describing short- and long-term host-virus dynamics.

microbiology↗

bioRxiv2018

Cell adhesion and fluid flow jointly initiate genotype spatial distribution in biofilms

Biofilms are microbial collectives that occupy a diverse array of surfaces. The function and evolution of biofilms are strongly influenced by the spatial arrangement of different strains and species within them, but how spatiotemporal distributions of different genotypes in biofilm populations originate is still underexplored. Here, we study the origins of biofilm genetic structure by combining model development, numerical simulations, and microfluidic experiments using the human pathogen Vibrio cholerae. Using spatial correlation functions to quantify the differences between emergent cell lineage segregation patterns, we find that strong adhesion often, but not always, maximizes the size of clonal cell clusters on flat surfaces. Counterintuitively, our model predicts that, under some conditions, investing in adhesion can reduce rather than increase clonal group size. Our results emphasize that a complex interaction of fluid flow and cell adhesiveness can underlie emergent patterns of biofilm genetic structure. This structure, in turn, has an outsize influence on how biofilm-dwelling populations function and evolve.\n\nAuthor summaryBiofilms are bacterial groups, often attached to surfaces, in which a broad variety of cooperative and competitive interactions typically occur. The spatial organization of different strains and species within biofilm communities strongly influences their global functioning, but little is known about how such structure arises. Combining experiments on V. cholerae and simulations of a cellular automaton, we show that the complex interaction between bacterial traits (cell adhesion) and environmental factors (fluid flow intensity) strongly influences the early origins of biofilm spatial structure. In most cases, we found that highly-adhesive strains form larger clusters than the weakly-adhesive ones. Against intuition, however, we also found the opposite outcome: weakly-adhesive tend to form larger clusters than the highly adhesive ones when flows are weak or the population density of colonizing cells is high.

microbiology↗