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Berdugo, M.

Publications and source records attributed to Berdugo, M..

6 recordsLinked to original sources

Lonely plants in arid land are functionally hyperdiverse

In Gross et al.1 we produced the largest ever standardized dryland plant trait database including 133,769 trait measurements from 301 perennial plant species surveyed across 326 plots and six continents. Our findings indicate that arid and hyper-arid drylands act as a global reservoir of plant phenotypic diversity, challenging the common assumption that harsh environmental conditions reduce plant trait diversity. Tordoni et al.2 speculate that the larger phenotypic diversity in harsh environments found in our study is overestimated and misinterpreted. The re-analyses presented here further confirm that the patterns we originally reported are robust, and thus that the concerns from Tordoni et al. are not well-founded and do not apply to our study. We stand for the main conclusions of our study and maintain that lonely plants in arid land are functionally hyperdiverse.

ecology↗

Environmental thresholds in the functional mycobiome of global drylands

Fungi are major drivers of ecosystem functions. Increases in aridity are known to negatively impact fungal communities in dryland ecosystems globally, however, much less is known on the potential influence of other environmental drivers. To fill this knowledge gap, we reanalyzed fungal data from 912 soil samples, providing the largest and most complete fungal community dataset from global drylands. We used machine learning tools to examine geographical patterns in community composition and spatial, edaphic, and climatic factors driving them. Further, we determined critical thresholds of community turnover along those gradients. Our analysis identifies UV index, climate seasonality, and sand content as the most important environmental predictors of community shifts, harbouring greatest association with the richness of putative plant pathogens and saprobes. Important nonlinear relationships existed with each of these fungal guilds, with increases in UV and temperature seasonality above 7.5 and 900 SD, respectively, being associated with an increased probability of plant pathogens and unspecified saprotrophs occurrence. Conversely, these environmental parameters had a negative relationship with litter and soil saprotrophs richness. Consequently, these functional groups might be differentially sensitive to environmental changes, which might result in an inevitable disturbance of current plant-soil dynamics in drylands.

ecology↗

Litter decomposition rates of biocrust-forming lichens are similar to that of vascular plants and are affected by warming in a semiarid grassland

Despite the high relevance of communities dominated by lichens, mosses and cyanobacteria living on the soil surface (biocrusts) for ecosystem functioning in drylands worldwide, no study to date has investigated the decomposition of biocrust-forming lichen litter in situ. Thus, we do not know whether the drivers of its decomposition are similar to those for plant litter (e.g., importance of abiotic degradation through UV radiation), the magnitude of lichen decomposition rates and whether they will be affected by climate change. Here we report results from a litter decomposition experiment carried out with two biocrust-forming lichens (Diploschistes diacapsis and Cladonia convoluta) in central Spain. We evaluated how lichen decomposition was affected by warming, rainfall exclusion and the combination of both. We also manipulated the incidence of UV radiation using mesh material that blocked 10% or 90% of incoming UV radiation. Our results indicate that lichens decompose as fast as some plants typical of the region (k~0.3) and that the chemical composition of their thallus drives litter decomposition rates. Warming increased decomposition rates of both lichen species, and mediated the effects of photodegradation. While UV exposure accelerated the decomposition of D. diacapsis, it slowed down that of C. convoluta. Our results indicate that biocrust-forming lichens can decompose in the field at a rate similar to that of vascular plants, and that this process will be affected by warming. Our findings further highlight the need of incorporating biocrusts into carbon cycling models to better understand and forecast climate change impacts on terrestrial biogeochemistry.

ecology↗

The interplay between facilitation and habitat type drive spatial vegetation patterns in global drylands

The size distribution of discrete plant patches (PSD), a common descriptor of the spatial patterns of vascular vegetation, has been linked to variations in land degradation and ecosystem functioning in drylands. However, most studies on PSDs conducted to date have focused on a single or a few study sites within a particular region. Therefore, little is know on the general typology and distribution of PSDs at the global scale, and on the relative importance of biotic and abiotic factors as drivers of their variation across geographical regions and habitat types. We analyzed 115 dryland plant communities from all continents except Antarctica to investigate the general typology of PSDs, and to assess the relative importance of biotic (plant cover, frequency of facilitation, soil amelioration, height of the dominant species) and abiotic (aridity and sand content) factors as drivers of PSDs across contrasting habitat types (shrublands and grasslands). We found that both power-law and lognormal PSDs were generally distributed regardless of the region of the world considered. The percentage of facilitated species in the community drives the emergence of power-law like spatial patterns in both shrublands and grasslands, although mediated by different mechanisms (soil and climatic amelioration, respectively). Other drivers of PSDs were habitat-specific: height of the dominant species and total cover were particularly strong drivers in shrublands and grasslands, respectively. The importance of biotic attributes as drivers of PSDs declined under the most arid conditions in both habitats. We observed that PSDs deviated from power law functions not only due to the loss of large, but also of small patches. Our results expand our knowledge about patch formation in drylands and the habitat-dependency of their drivers. They also highlight different ways in which facilitation may act on ecosystem functioning through the formation of plant spatial patterns.

ecology↗

Species-specific adaptations determine how aridity and biotic interactions drive the assembly of dryland plant communities

O_LIDespite being a core ecological question, disentangling individual and interacting effects of plant-plant interactions, abiotic factors and species-specific adaptations as drivers of community assembly is challenging. Studies addressing this issue are growing rapidly, but they generally lack empirical data regarding species interactions and local abundances, or cover a narrow range of environmental conditions.\nC_LIO_LIWe analysed species distribution models and local spatial patterns to isolate the relative importance of key abiotic (aridity) and biotic (facilitation and competition) drivers of plant community assembly in drylands worldwide. We examined the relative importance of these drivers along aridity gradients and used information derived from the niches of species to understand the role that species-specific adaptations to aridity play in modulating the importance of community assembly drivers.\nC_LIO_LIFacilitation, together with aridity, was the major driver of plant community assembly in global drylands. Due to community specialization, the importance of facilitation as an assembly driver decreased with aridity, and became non significant at the border between arid and semiarid climates. Under the most arid conditions, competition affected species abundances in communities dominated by specialist species. Due to community specialization, the importance of aridity in shaping dryland plant communities peaked at moderate aridity levels.\nC_LIO_LISynthesis: We showed that competition is an important driver of community assembly even under harsh environments, and that the effect of facilitation collapses as driver of species relative abundances under high aridity because of the specialization of the species pool to extremely dry conditions. Our findings pave the way to develop more robust species distribution models aiming to predict the consequences of ongoing climate change on community assembly in drylands, the largest biome on Earth.\nC_LI

ecology↗

Simulated Climate Change Affects How Biocrusts Modulate Infiltration And Desiccation Dynamics

Soil surface communities dominated by mosses, lichens and cyanobacteria (biocrusts) cover most of the soil surface between vegetation patches in drylands worldwide, and are known to affect soil wetting and drying after rainfall events. While ongoing climate change is already warming and changing rainfall patterns of drylands in many regions, little is known on how these changes may affect the hydrological behaviour of biocrust-covered soils. We used eight years of continuous soil moisture and rainfall data from a climate change experiment in central Spain to explore how biocrusts modify soil water gains and losses after rainfall events under simulated changes in temperature (2.5{o}C warming) and rainfall (33% reduction). Both rainfall amount and biocrust cover increased soil water gains after rainfall events, whereas experimental warming, rainfall intensity and initial soil moisture decreased them. Initial moisture, maximum temperature and biocrust cover, by means of enhancing potential evapotranspiration or soil darkening, increased the drying rates and enhanced the exponential behaviour of the drying events. Meanwhile, the warming treatment reduced the exponential behaviour of these events. The effects of climate change treatments on soil water gains and losses changed through time, with important differences between the first two years of the experiment and after five years since its setup. These effects were mainly driven by the important reductions in biocrust cover and diversity observed under warming. Our results highlight the importance of long term studies to understand soil moisture responses to ongoing climate change in drylands.

ecology↗