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Despite host-fungal symbiotic interactions being ubiquitous in all ecosystems, understanding how symbiosis has shaped the ecology and evolution of fungal spores that are involved in dispersal and colonization of their hosts has been ignored in life-history studies. We assembled a spore morphology database covering over 26,000 species of free-living to symbiotic fungi of plants, insects and humans and found more than eight orders of variation in spore size. Evolutionary transitions in symbiotic status correlated with shifts in spore size, but the strength of this effect varied widely among phyla. Symbiotic status explained more variation than climatic variables in the current distribution of spore sizes of plant-associated fungi at a global scale while the dispersal potential of their spores is more restricted compared to free-living fungi. Our work advances life-history theory by highlighting how the interaction between symbiosis and offspring morphology shapes the reproductive and dispersal strategies among living forms.

Soil mosses are among the most widely distributed organisms on land. Experiments and observations suggest that they contribute to terrestrial soil biodiversity and function, yet their ecological contribution to soil has never been assessed globally under natural conditions. Here we conducted the most comprehensive global standardized field study to quantify how soil mosses influence 8 ecosystem services associated with 24 soil biodiversity and functional attributes across wide environmental gradients from all continents. We found that soil mosses are associated with greater carbon sequestration, pool sizes for key nutrients and organic matter decomposition rates but a lower proportion of soil-borne plant pathogens than unvegetated soils. Mosses are especially important for supporting multiple ecosystem services where vascular-plant cover is low. Globally, soil mosses potentially support 6.43 Gt more carbon in the soil layer than do bare soils. The amount of soil carbon associated with mosses is up to six times the annual global carbon emissions from any altered land use globally. The largest positive contribution of mosses to soils occurs under a high cover of mat and turf mosses, in less-productive ecosystems and on sandy and salty soils. Our results highlight the contribution of mosses to soil life and functions and the need to conserve these important organisms to support healthy soils.

Models derived from satellite image data are needed to monitor the status of terrestrial ecosystems across large spatial scales. However, a remote sensing-based approach to quantify soil multifunctionality at the global scale is missing despite significant research efforts on this topic. A major constraint for doing so is the availability of suitable global-scale field data to calibrate remote sensing indicators (RSI) and, to a lesser extent, the sensitivity of spectral data of available satellite sensors to soil background and atmospheric conditions. Here, we aimed to develop a soil multifunctionality model to monitor global drylands coupling ground data on 14 soil functions of 222 dryland areas from six continents to 18 RSI derived from a time series (2006–2013) Landsat dataset. Among the RSI evaluated, the chlorophyll absorption ratio index was the best predictor of soil multifunctionality in single-variable-based models (r = 0.66, P < 0.01, NMRSE = 0.17). However, a multi-variable RSI model combining the chlorophyll absorption ratio index, the global environment monitoring index and the canopy-air temperature difference improved the accuracy of quantifying soil multifunctionality (r = 0.73, P < 0.01, NMRSE = 0.15). Furthermore, the correlation between RSI and soil variables shows a wide range of accuracy with upper and lower values obtained for AMI (r = 0.889, NMRSE = 0.05) and BGL (r = 0.685, NMRSE = 0.18) respectively. Our results provide new insights on assessing soil multifunctionality using RSI that may help to monitor temporal changes in the functioning of global drylands effectively.

Oxidative stress has been linked to the onset and progression of different neoplasia. Antioxidants might help prevent it by modulating biochemical processes involved in cell proliferation. Here, the aim was to evaluate the in vitro cytotoxic effect of Haloferax mediterranei bacterioruberin-rich carotenoid extracts (BRCE) (0–100 µg/ml) in six BC cell lines, representative of the intrinsic phenotypes and a healthy mammary epithelium cell line. Cell index values were obtained using xCELLigence RTCA System. Furthermore, cell diameter, viability, and concentration were measured at 12 h, 24 h, and 30 h. We found that BC cells were selectively affected by BRCE (SI > 1, p < 0.005). After 30 h, the population of BC cells exposed to 100 µg/ml was 11.7–64.6% of the control (p = 0.0001–0.0009). Triple-negative cells were significantly affected [MDA-MB-231 (IC50 51.8 µg/ml, p < 0.0001) and MDA-MB-468 (IC50 63.9 µg/ml, p < 0.0001)]. Cell size was also reduced after 30 h treatment in 3.8 (± 0.1) µm and 3.3 (± 0.02) µm for SK-BR-3 (p < 0.0001) and MDA-MB-468 (p < 0.0001), respectively. In conclusion, Hfx. mediterranei BRCE exerts a cytotoxic effect on BC cell lines representative of all studied intrinsic subtypes. Furthermore, results obtained for MDA-MB-231 and MDA-MB-468 are very promising, considering the aggressive behaviour of the triple-negative BC subtype.

Plant disease outbreaks pose significant risks to global food security and environmental sustainability worldwide, and result in the loss of primary productivity and biodiversity that negatively impact the environmental and socio-economic conditions of affected regions. Climate change further increases outbreak risks by altering pathogen evolution and host–pathogen interactions and facilitating the emergence of new pathogenic strains. Pathogen range can shift, increasing the spread of plant diseases in new areas. In this Review, we examine how plant disease pressures are likely to change under future climate scenarios and how these changes will relate to plant productivity in natural and agricultural ecosystems. We explore current and future impacts of climate change on pathogen biogeography, disease incidence and severity, and their effects on natural ecosystems, agriculture and food production. We propose that amendment of the current conceptual framework and incorporation of eco-evolutionary theories into research could improve our mechanistic understanding and prediction of pathogen spread in future climates, to mitigate the future risk of disease outbreaks. We highlight the need for a science–policy interface that works closely with relevant intergovernmental organizations to provide effective monitoring and management of plant disease under future climate scenarios, to ensure long-term food and nutrient security and sustainability of natural ecosystems.

Conservation biology faces the challenge of safeguarding the ecosystem functions and ecological processes (the water cycle, nutrients, energy flow, and community dynamics) that sustain the multiple facets of biodiversity. Characterization and evaluation of these processes and functions can be carried out through functional attributes or traits related to the exchanges of matter and energy between vegetation and the atmosphere. Based on this principle, satellite imagery can provide integrative spatiotemporal characterizations of ecosystem functions at local to global scales. Here, we provide a multitemporal dataset at protected-area level that characterizes the spatial patterns and temporal dynamics of ecosystem functioning in the Biosphere Reserve of the Sierra Nevada (Spain), captured through the spectral Enhanced Vegetation Index (EVI, using product MOD13Q1.006 from the MODIS sensor) from 2001 to 2018. The database contains, at the annual scale, a synthetic map of Ecosystem Functional Type (EFT) classes from three Ecosystem Functional Attributes (EFAs): (i) descriptors of annual primary production, (ii) seasonality, and (iii) phenology of carbon gains. It also includes two ecosystem functional-diversity indices derived from the above datasets: (i) EFT richness and (ii) EFT rarity. Finally, it provides interannual summaries for all previously mentioned variables, i.e., their long-term means and interannual variability. The datasets are available at two open-source sites (PANGAEA: https://doi.org/10.1594/PANGAEA.924792; Cazorla et al., 2020a; interannual summaries at http://obsnev.es/apps/efts_SN.html, last access: 17 April 2023). This dataset provides scientists, environmental managers, and the public in general with valuable information on the first characterization of ecosystem functional diversity based on primary production developed in the Sierra Nevada, a biodiversity hotspot in the Mediterranean basin and an exceptional natural laboratory for ecological rese

To meet population growth, the excessive abstraction of water resources for irrigating water-intensive crops has become an increasing crisis in arid regions of Northwest China. This contains the perennial contradiction between development and desertification, typical of drylands, which we also find within the United Nations Convention to combat Desertification (UNCCD), where some interpret it as a developmentalist convention and others as a conservationist one. The Land Degradation Neutrality (LDN) concept has been set up as the main tool to combat desertification by the UNCCD and is included in SDG 15.3. LDN refers to a state of zero net land degradation, where “the amount and quality of land resources necessary to support ecosystem functions and services and enhance food security remain stable or increase within specified temporal and spatial scales and ecosystems”. Under the LDN framework, we apply two of its main pillars, prevention and land planning. The aim is to understand the underlying biophysical and socio-economic mechanisms of oasis expansion in NW China, a phenomenon known as oasification. The objective is to detect under what conditions oasification tackles desertification and when it triggers land and economic degradation. From this knowledge, it will be possible to propose guidelines of action to balance land use and comply with LDN.

Questions: Knowledge of how extreme drought events induce plant dieback and, eventually, plant mortality, may improve our forecasting of ecosystem change according to future climate projections, especially in Mediterranean drylands. In them, shrublands are the main vegetation communities in transition areas from a subhumid to semi-arid climate. This study analyzed differences in plant dieback after an unusual drought in 2014 and identified their main underlying factors in relation to three groups of explanatory variables: water availability, soil properties and vegetation structure attributes. Location: Four Mediterranean shrublands along a climatic gradient in SE Spain. Methods: At each experimental field site, we sampled a pool of vegetation structure characteristics, soil depth and soil surface properties, and we also determined water availability by continuously monitoring soil moisture and the microclimate conditions. Results: The climatic analysis showed that there was an extreme drought event in 2014, which was below the first percentile of the driest years. Under such conditions, vegetation dieback occurred at all the study sites. However, plant dieback differed between sites and plant biotypes. Subshrubs were the main affected biotype, with diebacks close to 60% at the driest sites, and up to 40% dieback for shrubs depending on their vertical development. Relative extractable water and bare soil surface cover were the best explanatory variables of plant community dieback but changed between plant biotypes. Vegetation structure variables related to plant vertical development (leaf area index [LAI], plant height, phytovolume) were significant explanatory variables of plant dieback in shrubs, subshrubs and grasses. Consecutive dry days fitted the best model to explain subshrub dieback. Conclusions: We found that rainfall pattern rather than total annual rainfall was the climatic factor that best determined water availability for plants in Mediterranean dryland

A key question in ecological research is whether biodiversity is important for ecosystem functioning. After approximately three decades of empirical studies on this topic, it is clear that biodiversity promotes the magnitude and stability of ecosystem functioning. However, the majority of early biodiversity-ecosystem functioning (BEF) experiments concluded that there is a saturating relationship between biodiversity and ecosystem functioning, seemingly supporting the ‘redundancy hypothesis’ of biodiversity. This hypothesis may suggest that many species can be lost from an ecosystem before any changes in functioning can be detected under the current environmental conditions. Here, we argue that the term functional redundancy (1) may have been overused from an ecological perspective and (2) can be dangerous and misleading in scientific communication. Rather, we propose to use the term ‘functional similarity’, which better highlights the unique contributions of all coexisting species to ecosystem functioning, gradients in niche overlap and has a less negative connotation. In a world where increasing anthropogenic stressors are accelerating biodiversity change and loss and thus threatening ecosystem integrity, important political and societal decisions must be taken to combat the joint climate and biodiversity crisis. We should therefore reconsider and carefully choose terminology in biodiversity science for value-neutral communication.

Editorial on the Research Topic Nitrogen dynamics and load in soils.

1. Soil biota influences nutrient cycling and climate regulation and represents an important fraction of global biodiversity, yet we know very little about how this soil biota responds to habitat fragmentation and degradation of habitat quality. 2. We studied the response of different soil trophic groups (microbes and soil fauna), and their trophic structure, to changes in their habitat derived from forest long-term management and extensive tree die-off in a Mediterranean ecosystem. Specifically, we evaluated changes in (i) habitat size, (ii) habitat resource availability and heterogeneity and (iii) habitat connectivity. To do this, we sampled the soil biota of 43 holm oak trees (and five open interspaces) differing in size, quality, heterogeneity, connectivity and the effect of die-off (healthy or affected). We sorted soil biota by trophic group and related their richness to habitat characteristics. 3. Seven of the 12 trophic groups evaluated increased their species richness with soil organic carbon content, which was the most frequently selected driver of soil biota (both microbial and faunal richness). Habitat connectivity positively affected the richness of larger organisms (fauna) and plant attributes (richness, productivity and specific leaf area) also showed significant but contrasting effects depending on the group evaluated. 4. Due to the idiosyncratic responses of different groups, the entire trophic structure (microbes and fauna) was affected by a more complex set of factors than most trophic groups in isolation, including interactions between habitat size and resource availability or connectivity. A major factor influencing habitat resource availability was the die-off of the dominant tree species (drastically altering tree productivity). We found weaker and more negative relationships between trophic groups under trees suffering from die-off than beneath healthy trees, particularly between microbial rather than faunal groups. 5. Synthesis. We provide a

The assessment of the seismic behaviour of historic residential buildings and the estimation of their possible losses in the event of an earthquake, is a must for defining strategic mitigation plans to prevent irreplaceable heritage losses. In this study an integrated performance based probabilistic risk assessment methodology is developed. An archival study and a field survey allow to identify architectural and construction characteristics of heritage residential buildings in urban areas and determine realistic structural models. These are analysed by using a limit state approach, coded in the FaMIVE method, considering different construction hypotheses, to produce capacity curves which support the identification of a discrete number of typologies representative of the entire building stock in the area. Their fragility functions are then derived using the modified N2 method. Because of the difficulty in quantifying the expected probable losses in purely economic terms, given the heritage value of these assets, losses are computed in terms of damaged floor surface area and mean damage ratio. These have been obtained through the earthquake loss estimation platform SELENA, considering different possible seismic scenarios. The procedure is applied to masonry residential buildings in Pla del Remei area of Valencia, Spain, built between the end of the 19th Century and the end of the Spanish War (1939). This neighbourhood embodies the cultural values, construction techniques and historic legacy of a new and brief era of modernity, inspired by the new urban theories and architectural styles of Eclecticism and Modernism. Despite Valencia being located in an area of low to moderate seismicity, the results show that the maximum percentage of built damaged area ranges from 5.8 to 11.6% for 475 years return period, increasing to 33.59–51.59% for 975 years return period. The high level of resolution of the study allows mapping and identifying the structures at higher risk and is

Ecological restoration (ER hereafter) is situated within a complex socio-political landscape, characterized by competing interests that can hinder effective decision-making and implementation of ER initiatives. Despite its importance, these social factors influencing ER decision-making processes have not been comprehensively examined or interconnected in a systemic manner. This research aims to identify and systematically analyse the social barriers that obstruct ER decision-making processes in the case of the Valencian Autonomous Region, Spain. Employing a qualitative methodological approach, this study utilized causal maps and network analysis to create a systemic representation of social barriers impacting ER, as identified by the key actors involved in the decision-making process. The findings establish a relational model of social barriers that influence ER decision-making. Central nodes of the process, as revealed by this network analysis, include the lack of private sector interest in ER initiatives, the excessive electoral motivation of political decisions and the inefficient civil service structure. This research contributes to a better understanding of the socio-political dimensions of ER and provides valuable insights for overcoming barriers in the decision-making process.

Jellyfish encounters are set to rise as human activity in the marine environment increases. Although jellyfish pose a threat to human health and the economy, there is limited understanding of their population dynamics. To mitigate the impact of jellyfish and gather information on their biogeographical patterns, we created MedusApp, a citizen science tool for collecting data on jellyfish sightings in the Spanish Mediterranean. From 2018 to 2021, the most commonly sighted species were Pelagia noctiluca, Rhizostoma pulmo, Cotylorhiza tuberculata, and Rhizostoma luteum. Sightings increased for all species, but the Jellyfish Intensity (JI) index showed no significant rise in overall abundance. The JI revealed the inter-annual fluctuations in R. pulmo's nature and more a larger purporting of weight on total JI from C. tuberculata while P. noctiluca decreased. The seasonality of the four species remained stable, providing a basis for time-effective management strategies. MedusApp has further provided new evidence that R. luteum is expanding its range northward in the Western Mediterranean and becoming a commonly observed species. The information collected through MedusApp can be used to improve jellyfish management measures, such as monitoring, control, and alert systems, to reduce conflicts with humans and the environment.

As the association of denitrification with global warming and nitrogen removal from ecosystems has gained attention in recent decades, numerous studies have examined denitrification rates and the distribution of denitrifiers across different environments. In this minireview, reported studies focused on coastal saline environments, including estuaries, mangroves, and hypersaline ecosystems, have been analysed to identify the relationship between denitrification and saline gradients. The analyses of the literature and databases stated the direct effect of salinity on the distribution patterns of denitrifiers. However, few works do not support this hypothesis thus making this topic controversial. The specific mechanisms by which salinity influences denitrifier distribution are not fully understood. Nevertheless, several physical and chemical environmental parameters, in addition to salinity, have been shown to play a role in structuring the denitrifying microbial communities. The prevalence of nirS or nirK denitrifiers in ecosystems is a subject of debate in this work. In general terms, in mesohaline environments, the predominant nitrite reductase is NirS type and, NirK is found predominantly in hypersaline environments. Moreover, the approaches used by different researchers are quite different, resulting in a huge amount of unrelated information, making it difficult to establish comparative analysis. The main techniques used to analyse the distribution of denitrifying populations along salt gradients have been also discussed.

Urban areas provide a constant and predictable supply of anthropogenic processed food. The House Sparrow (Passer domesticus Linnaeus, 1758), a declining urban bioindicator species, has recently been reported to have a high level of oxidative stress, with urban diet or pollutants proposed as the potential cause. In this study, we aimed to experimentally determine the effects of two urban trophic resource types (bar snack food leftovers and pet food) on sparrows' physical condition, plasma biochemical nutritional parameters, and blood oxidative status in captivity. To exclude the potential previous effect of urban pollutants, 75 House Sparrows were captured from a rural area in SE Spain and kept in outdoor aviaries. Individuals were exposed to one of three diet treatments: control diet (fruit, vegetables, poultry grain mixture), bar snack diet (ultra-processed snacks), or cat food diet (dry pellets) for 20 days. Blood samples were collected before and after diet treatments to analyze the relative change rates of 12 variables, including physical condition, nutritional status, and oxidant–antioxidant status. A principal component analysis was run to identify gradients of variables covariation, and Generalized Linear Mixed Models were used to determine the effect of diets on each selected PC and on raw variables. The bar snack diet led to signs of anemia and malnutrition, and females tended to lose body condition. The cat food diet increased oxidative stress indicators and protein catabolism. Unbalanced urban diets can affect the body condition and nutritional physiology of House Sparrows and may also induce oxidative stress despite the absence of environmental pollution.

The phylum Gemmatimonadota comprises mainly uncultured microorganisms that inhabit different environments such as soils, freshwater lakes, marine sediments, sponges, or corals. Based on 16S rRNA gene studies, the group PAUC43f is one of the most frequently retrieved Gemmatimonadota in marine samples. However, its physiology and ecological roles are completely unknown since, to date, not a single PAUC43f isolate or metagenome-assembled genome (MAG) has been characterized. Here, we carried out a broad study of the distribution, abundance, ecotaxonomy, and metabolism of PAUC43f, for which we propose the name of Palauibacterales. This group was detected in 4,965 16S rRNA gene amplicon datasets, mainly from marine sediments, sponges, corals, soils, and lakes, reaching up to 34.3% relative abundance, which highlights its cosmopolitan character, mainly salt-related. The potential metabolic capabilities inferred from 52 Palauibacterales MAGs recovered from marine sediments, sponges, and saline soils suggested a facultative aerobic and chemoorganotrophic metabolism, although some members may also oxidize hydrogen. Some Palauibacterales species might also play an environmental role as N2O consumers as well as suppliers of serine and thiamine. When compared to the rest of the Gemmatimonadota phylum, the biosynthesis of thiamine was one of the key features of the Palauibacterales. Finally, we show that polysaccharide utilization loci (PUL) are widely distributed within the Gemmatimonadota so that they are not restricted to Bacteroidetes, as previously thought. Our results expand the knowledge about this cryptic phylum and provide new insights into the ecological roles of the Gemmatimonadota in the environment.

Viruses play an important role in the marine ecosystem. However, our comprehension of viruses inhabiting the dark ocean, and in particular, under the Antarctic Ice Shelves, remains limited. Here, we mine single-cell genomic, transcriptomic, and metagenomic data to uncover the viral diversity, biogeography, activity, and their role as metabolic facilitators of microbes beneath the Ross Ice Shelf. This is the largest Antarctic ice shelf with a major impact on global carbon cycle. The viral community found in the cavity under the ice shelf mainly comprises endemic viruses adapted to polar and mesopelagic environments. The low abundance of genes related to lysogenic lifestyle (<3%) does not support a predominance of the Piggyback-the-Winner hypothesis, consistent with a low-productivity habitat. Our results indicate a viral community actively infecting key ammonium and sulfur-oxidizing chemolithoautotrophs (e.g. Nitrosopumilus spp, Thioglobus spp.), supporting a “kill-the-winner” dynamic. Based on genome analysis, these viruses carry specific auxiliary metabolic genes potentially involved in nitrogen, sulfur, and phosphorus acquisition. Altogether, the viruses under Antarctic ice shelves are putatively involved in programming the metabolism of ecologically relevant microbes that maintain primary production in these chemosynthetically-driven ecosystems, which have a major role in global nutrient cycles.

Sediment samples of deep marine oceanic ODP boreholes from sites 999 in the Caribbean Sea and 1237 in the Eastern Pacific Ocean covering the period between 6 and 4.5 Ma have been studied with a focus on ceratolith evolution. Orthorhabdus rugosus is a nannolith with three blades (sinistral, median, and dextral) that first appeared during the Serravallian, it is not-birefringent in its stable orientation. It shows a high morphological variability time-interval at the end of the Messinian to the basal Pliocene (5.5 to 5 Ma) during which Ceratolithus (5.484 Ma) evolved. Changes occurred in the sinistral and median blades, whilst the dextral blade was reduced. Ceratolithus finifer n. comb is the first species of the evolutionary line. The nannolith stable position changed during its evolution, resulting in the older forms showing low birefringence and the younger ones moderate to high birefringence in the most stable orientation. Ceratolithus acutus, with an arrowhead shape, Ceratolithus armatus, and the morphologically distinct C. larrymayeri evolved from C. finifer with all three species showing high birefringence. The previous O. rugosus and C. finifer continued. Finally, C. armatus gives rise to C. cristatus. Ceratolithus atlanticus and C. tricorniculatus also evolved from C. finifer. All the species mentioned become extinct during the Pliocene except Ceratolithus cristatus that lives today. Detailed observations permit the analysis of the evolutionary trends of the group, possible mechanisms, patterns, and processes of speciation, and establish new criteria to define the species that, by their relative abundance and short geologic range, have permitted adjustment of biostratigraphic markers for this period.

Parental food provisioning is crucial for the growth and survival of offspring. Growth rate depends on food quality and food supplied to offspring may differ from what adults use for their own. In the case of steppe passerine birds, detailed characterization on nestling dietary composition, as well as prey choice and resource partitioning among species, is a pending subject. Dietary differences between nestlings and adults remain also largely unexplored. By using faecal DNA metabarcoding, we described the diet of nestlings and adults of five shrub-steppe passerine species over the 2017–2019 breeding seasons in central Spain. We also monitored arthropod availability in the field to assess dietary selection. We expected interspecific dietary differences to limit competition for food resources among sympatric species, as well as parental selection of high quality prey for nestlings. We also predicted age-related differences, with nestlings being fed nutrient-rich prey more frequently than adults. The main arthropod orders provisioned to nestlings were Orthoptera, Julida, Araneae and Lepidoptera. Nestlings of the different species showed high interspecific diet overlap, indicating both a coincidence in growth needs among bird species and no or little limitation of the most profitable resources during the breeding season. Adults of all species showed higher diet richness than nestlings, and age-related differences in prey composition were mainly driven by the selection of the most easily digestible, larger protein- and calcium-rich prey for nestlings, which may favour their rapid growth, and avoiding highly sclerotized and less nutritional prey such as ants. Our study sheds light on the basic ecology and conservation of these declining steppe birds, indicating that interspecific competition may not be a major factor during the breeding season. Given the current global decline of arthropods, further long-term research would be necessary, along with the implementation of e

How the multiple facets of soil fungal diversity vary worldwide remains virtually unknown, hindering the management of this essential species-rich group. By sequencing high-resolution DNA markers in over 4000 topsoil samples from natural and human-altered ecosystems across all continents, we illustrate the distributions and drivers of different levels of taxonomic and phylogenetic diversity of fungi and their ecological groups. We show the impact of precipitation and temperature interactions on local fungal species richness (alpha diversity) across different climates. Our findings reveal how temperature drives fungal compositional turnover (beta diversity) and phylogenetic diversity, linking them with regional species richness (gamma diversity). We integrate fungi into the principles of global biodiversity distribution and present detailed maps for biodiversity conservation and modeling of global ecological processes.

The sensitivity of soil microbial respiration to warming (Q10) remains a major source of uncertainty surrounding the projections of soil carbon emissions to the atmosphere as the factors driving Q10 patterns across ecosystems have been assessed in isolation from each other. Here we report the results of a warming experiment using soils from 332 sites across all continents and major biomes to simultaneously evaluate the main drivers of global Q10 patterns. Compared with biochemical recalcitrance, mineral protection, substrate quantity and environmental factors, the soil microbiome (that is, microbial biomass and bacterial taxa) explained the largest portion of variation in Q10 values. Our work provides solid evidence that soil microbiomes largely govern the responses of soil heterotrophic respiration to warming and thus need to be explicitly accounted for when assessing land carbon–climate feedbacks.

Increasing wildfire frequency in the Mediterranean Basin could affect future plant-soil–water-dynamics. The capacity of soils to retain water is a key parameter affecting plant post-fire regeneration. Yet, few research has looked at how different soil properties related to water retention is affected by increasing wildfire frequency. This study aimed at understanding the relationship between wildfire frequency, soil–water-related properties and the dynamics of surface water in soils. To this, after a 2012-summer wildfire in Portugal, three sets of three replicate maritime pine stands with contrasted wildfire frequency were selected (0 vs. 1 vs. 4 fires since 1975). At each of the nine study sites, three re-sprouter shrubs and neighbouring bare soil were chosen (54 microsites). There, soil cover, soil–water retention curves and surface (0–5 cm) soil–water-related properties (texture, bulk density, organic matter content, soil moisture, soil surface water repellency) were monitored for one year. Furthermore, records of post-fire soil moisture dynamics were analysed continuously using 72 probes installed at 2.5 and 7.5 cm depth. The hillslopes affected by 1 fire showed higher plant recovery than the 4 fires hillslopes. During the dry season, the threshold for water stress was reached 17 days sooner in the 4 fires hillslopes, and also 10 days sooner on bare microsites. Periods of plant water stress were longer and bare soil patches size bigger. The increase in wildfire frequency promoted high soil organic matter contents but less available water content, stressing the importance of soil organic matter quality characterization in water-related properties.

Soil characterization is essential for planning activities in urban areas in order to detect potential risks and understand the possible impacts derived from those activities. Nine soils located in Alicante (southeast of Spain) developed over construction debris were studied. Soil characteristics including mineralogy, elemental composition and metal availability were analyzed in two consecutive years, 2019 and 2020. These soils were similar to forest soils in the same area, with no evidence of asbestos clays or excess harmful elements. However, the use of DTPA extraction revealed high levels of Mn and Zn in some soils. Organic carbon and metals extracted with DTPA differed in 2019 and 2020, but no relationship between metal-DTPA and organic carbon content was observed. In general, organic matter content was higher in 2019, and elements extracted with DTPA were lower. The above-average rainfall in 2019 could have led to the washing away of dissolved materials and fine soil particles, decreasing elemental availability on the one hand, while promoting the development of natural vegetation, increasing soil organic matter, and immobilizing elements in living organisms on the other hand. The fact that the metal mobility varies depending on weather and soil characteristics is important when planning. Despite the demonstrated advantages of increasing urban green areas from an environmental and social point of view, we should not forget the materials on which urban soils are developed. Therefore, it is essential to establish annual plans for monitoring variations in the availability of heavy metals. This is of the most relevance when the plants are for human consumption. It is therefore also necessary to control the vegetables that grow on these soils and, in the event of possible problems, use the soil for gardening.

Food availability plays a key role affecting almost every aspect of bird ecology, including bird population, distribution, reproduction, and behavior. Understanding the functional relationship between prey availability and insectivorous birds’ diet is important in the current scenario of habitat loss and declining of insect and bird populations. We used a fecal metabarcoding approach coupled with prey availability sampling (arthropod abundance and biomass) to test for evidence of selective foraging in a shrub-steppe passerine assemblage over the 2017–2019 breeding seasons in semi-natural steppes of central Spain. The results showed that the six bird species selected specific arthropod taxa. Heteroptera, Orthoptera, Araneae, Lepidoptera and some Coleoptera families were the main selected prey taxa, while Formicidae appeared to be avoided, suggesting that shrub-steppe passerines tend to select prey items providing essential nutrients and energy during the breeding season, while poor quality ones are neglected. Our findings highlight the utility of metabarcoding dietary data to assess prey selection patterns in insectivorous passerines and provide valuable information for the development of conservation and management programs to ensure the long-term availability of crucial food resources for shrub-steppe birds and other insectivores.

Editorial on the Research Topic Seismic microzonation and risk reduction

Biological invasions have major impacts on a variety of ecosystems and threaten native biodiversity. Earthworms have been absent from northern parts of North America since the last ice age, but non-native earthworms were recently introduced there and are now being spread by human activities. While past work has shown that plant communities in earthworm-invaded areas change towards a lower diversity mainly dominated by grasses, the underlying mechanisms related to changes in the biotic interactions of the plants are not well understood. Here, we used a trait-based approach to study the effect of earthworms on interspecific plant competition and aboveground herbivory. We conducted a microcosm experiment in a growth chamber with a full-factorial design using three plant species native to northern North American deciduous forests, Poa palustris (grass), Symphyotrichum laeve (herb) and Vicia americana (legume), either growing in monoculture or in a mixture of three. These plant community treatments were crossed with earthworm (presence or absence) and herbivore (presence or absence) treatments. Eight out of the fourteen above- and belowground plant functional traits studied were significantly affected by earthworms, either by a general effect or in interaction with plant species identity, plant diversity level and/or herbivore presence. Earthworms increased the aboveground productivity and the number of inflorescences of the grass P. palustris. Further, earthworms and herbivores together affected root tissue density of P. palustris and the specific leaf area of V. americana. In this study, earthworm presence gave a competitive advantage to the grass species P. palustris by inducing changes in plant functional traits. Our results suggest that invasive earthworms can alter competitive and multitrophic interactions of plants, shedding light on some of the mechanisms behind invasive earthworm-induced plant community changes in northern North America forests.

Ecosystem engineers are organisms that cause changes in the physical state of biotic and abiotic structures that modulate the availability of resources to other species, thus affecting biochemical cycles. Molluscs, especially bivalves such as mussels, are widespread in coastal environments and they are excellent ecosystem engineers because of the durability of their shells, which add complexity and heterogeneity to benthic environments. The presence of mussel farms favours the accumulation of shells in benthic environments and may influence surrounding bare sediments, with potential legacy effects on benthic communities. We studied the effects of the accumulation of mussel shells at finfish farms and mussel farms by experimentally comparing bare sediment and sediment with fragmented shells in terms of the abundance of the most relevant faunal groups, specifically polychaete families as well as physical–chemical variables in sediment water samples, specifically organic matter (OM), redox potential, and acid-volatile sulphides (AVS) NH4+ and PO43−. The experiment was replicated under two environmental conditions over a period of 35 days: eutrophic muddy sediments and oligotrophic sandy sediments. The OM and AVS values were significantly higher in the eutrophic sediment with mussel shells. Only NH4+ was positively affected by the mussel shells in the oligotrophic conditions. Differences between the two environments were observed, and the effect of the mussel shells on the polychaete assemblages was more significant in the oligotrophic conditions. Mussel shell accumulations affected the structure of benthic assemblages by modifying their heterogeneity and complexity, which suggests that the presence of mussel farms above bare sediment may affect ecosystem functioning. Aquaculture has potentially negative or positive effects that must be addressed on a large scale, considering the increased input of organic matter and also the simultaneous presence of mussel shell waste

The future of water resources relies heavily on food production. Large-scale agriculture, driven by irrigation technology and cost reduction, has transformed traditional dryland croplands into a very profitable but environmentally and socially impactful agribusiness. The study of groundwater-dependent food systems is fragmented. Hydrology, on one hand, concentrates on water resources while overlooking surface agricultural processes. Meanwhile, the agro-economic sector is fixated on optimizing resource utilization for short-term profit maximization. Consequently, numerous adverse environmental and social consequences are overlooked by these conventional approaches. To steer resource usage and our food systems in a new direction, prioritizing the integration of this collective knowledge is imperative. Here, we analyze the impacts of greenhouse agriculture in SE Spain, one of the global hotspots of fruit and vegetable production. Through the lens of the treadmill of production theory we uncover the model’s significant profitability and its environmental and social effects, which include unequal wealth distribution, precarious working conditions, and the depletion and pollution of belowground water reserves. Reducing water use and limiting the development of new irrigated areas, using crop species adapted to available water resources, and empowering farmers against large distributors are key measures to avoid the social and economic collapse of this region, and of other dryland areas that have followed a similar unsustainable development model. The need for these changes becomes more pressing as the impacts of climate change continue to escalate. Within this context, groundwater reserves represent vital strategic resources that must not be wasted.

Tree transpiration considerably contributes to evaporative fluxes to the atmosphere in terrestrial ecosystems. Accurate transpiration quantification provides relevant information about forest water use and may benefit adaptive forest management, especially in a global change context. Tree transpiration can be measured by several methods, and sap flow measurements are one of the most valued. However, species-specific validations of these techniques are required to avoid undesirable bias. This is especially relevant in species with low transpiration rates where errors may be relevant, such as Aleppo pine trees (Pinus halepensis Mill.). Moreover, another significant source of uncertainty in sap flow measurements is probe misalignment. Hence, the aim of this study was to correlate transpiration rates estimated by sap flow probes using the heat ratio method (THRM) and load cells to independently monitor water transpiration in juvenile Aleppo pine trees. The corrections to improve transpiration measures, including misalignment correction, were applied to THRM results to test if the accuracy of results improved. These measurements were recorded in greenhouse under controlled conditions to implement different environmental conditions. The environmental variables that ruled the experiment, mainly vapour pressure deficit and soil water availability, spanned in a wide range of values. The results showed an accurate linear correspondence between TOBS and THRM for low and medium values, but moderate underestimations at high transpiration rates were observed. These underestimations were partly removed when applying probe misalignment correction. This study supports the notion that HRM offers accurate Aleppo pine transpiration estimations with low and medium values under a variety of abiotic conditions, which also has implications for HRM application in other isohydric species. The results also support the interest in the use of probe misalignment correction to estimate transpirat

Crossing certain aridity thresholds in global drylands can lead to abrupt decays of ecosystem attributes such as plant productivity, potentially causing land degradation and desertification. It is largely unknown, however, whether these thresholds can be altered by other key global change drivers known to affect the water-use efficiency and productivity of vegetation, such as elevated CO2 and nitrogen (N). Using >5000 empirical measurements of plant biomass, we showed that crossing an aridity (1–precipitation/potential evapotranspiration) threshold of ∼0.50, which marks the transition from dry sub-humid to semi-arid climates, led to abrupt declines in aboveground biomass (AGB) and progressive increases in root:shoot ratios, thus importantly affecting carbon stocks and their distribution. N addition significantly increased AGB and delayed the emergence of its aridity threshold from 0.49 to 0.55 (P < 0.05). By coupling remote sensing estimates of leaf area index with simulations from multiple models, we found that CO2 enrichment did not alter the observed aridity threshold. By 2100, and under the RCP 8.5 scenario, we forecast a 0.3% net increase in the global land area exceeding the aridity threshold detected under a scenario that includes N deposition, in comparison to a 2.9% net increase if the N effect is not considered. Our study thus indicates that N addition could mitigate to a great extent the negative impact of increasing aridity on plant biomass in drylands. These findings are critical for improving forecasts of abrupt vegetation changes in response to ongoing global environmental change.

Soils support an immense portion of Earth’s biodiversity and maintain multiple ecosystem functions which are essential for human well-being. Environmental thresholds are known to govern global vegetation patterns, but it is still unknown whether they can be used to predict the distribution of soil organisms and functions across global biomes. Using a global field survey of 383 sites across contrasting climatic and vegetation conditions, here we showed that soil biodiversity and functions exhibited pervasive nonlinear patterns worldwide and are mainly governed by water availability (precipitation and potential evapotranspiration). Changes in water availability resulted in drastic shifts in soil biodiversity (bacteria, fungi, protists and invertebrates) and soil functions including plant–microbe interactions, plant productivity, soil biogeochemical cycles and soil carbon sequestration. Our findings highlight that crossing specific water availability thresholds can have critical consequences for the provision of essential ecosystem services needed to sustain our planet.

Marine viruses play a major role in the energy and nutrient cycle and affect the evolution of their hosts. Despite their importance, there is still little knowledge about RNA viruses. Here, we have explored the Atlantic Ocean, from surface to deep (4.296 m), and used viromics and quantitative methods to unveil the genomics, biogeography, and the mass contribution of RNA viruses to the total viroplankton. A total of 2481 putative RNA viral contigs (>500 bp) and 107 larger bona fide RNA viral genomes (>2.5 kb) were identified; 88 of them representing novel viruses belonging mostly to two clades: Yangshan assemblage (sister clade to the class Alsuviricetes) and Nodaviridae. These viruses were highly endemic and locally abundant, with little or no presence in other oceans since only ≈15% of them were found in at least one of the Tara sampling metatranscriptomes. Quantitative data indicated that the abundance of RNA viruses in the surface and deep chlorophyll maximum zone was within ≈106 VLP/mL representing a potential contribution of 5.2%–24.4% to the total viroplankton community (DNA and RNA viruses), with DNA viruses being the predominant members (≈107 VLP/mL). However, for the deep sample, the observed trend was the opposite, although as further discussed, several biases should be considered. Together these results contribute to our understanding of the diversity, abundance, and distribution of RNA viruses in the oceans and provide a basis for further investigation into their ecological roles and biogeography.

Fairy circles (FCs) are regular vegetation patterns found in drylands of Namibia and Western Australia. It is virtually unknown whether they are also present in other regions of the world and which environmental factors determine their distribution. We conducted a global systematic survey and found FC-like vegetation patterns in 263 sites from 15 countries and three continents, including the Sahel, Madagascar, and Middle-West Asia. FC-like vegetation patterns are found in environments characterized by a unique combination of soil (including low nutrient levels and high sand content) and climatic (arid regions with high temperatures and high precipitation seasonality) conditions. In addition to these factors, the presence of specific biological elements (termite nests) in certain regions also plays a role in the presence of these patterns. Furthermore, areas with FC-like vegetation patterns also showed more stable temporal productivity patterns than those of surrounding areas. Our study presents a global atlas of FCs and provides unique insights into the ecology and biogeography of these fascinating vegetation patterns.

Degradation of ecosystems can occur when certain ecological thresholds are passed below which ecosystem responses remain within ‘safe ecological limits’. Ecosystems such as drylands are sensitive to both aridification and grazing, but the combined effects of such factors on the emergence of ecological thresholds beyond which ecosystem degradation occurs has yet to be quantitatively evaluated. This limits our understanding on ‘safe operating spaces’ for grazing, the main land use in drylands worldwide. Here we assessed how 20 structural and functional ecosystem attributes respond to joint changes in aridity and grazing pressure across China´s drylands. Gradual increases in aridity resulted in abrupt decreases in productivity, soil fertility and plant richness. Rising grazing pressures lowered such aridity thresholds for most ecosystem variables, thus showing how ecological thresholds can be amplified by the joint effects of these two factors. We found that 44.4% of China’s drylands are unsuitable for grazing due to climate change-induced aridification, a percentage that may increase to 50.8% by 2100. Of current dryland grazing areas, 8.9% exceeded their maximum allowable grazing pressure. Our findings provide important insights into the relationship between aridity and optimal grazing pressure and identify safe operating spaces for grazing across China’s drylands.

We report the first occurrence of Rugulopteryx okamurae in Alicante Bay, the northernmost location in the Iberian Mediterranean where this species was detected. Collected specimens were studied using a morphological and molecular approach. A rapid assessment survey was conducted to assess its presence and abundance in the nearest beach-cast and infralittoral areas. The highest abundance was found over dead P. oceanica matte, occupying an important extension in the bay. We found detached fragments of R. okamurae dispersed by local hydrodynamics, accumulating on some tourist beaches in the region. The potential suitability of the Mediterranean for its spread necessitates monitoring programs to study its variation over time and potential impacts on native biota.

Soil-disturbing animals are common globally and play important roles in creating and maintaining healthy functional soils and landscapes. Yet many of these animals are threatened or locally extinct due to habitat loss, predation by non-native animals or poaching and poisoning. Some reintroduction and rewilding programmes have as their core aims to increase animal populations and reinstate processes that have been lost due to their extirpation. Here we use a meta-analytical approach to review the effects of soil-disturbing vertebrates on ecosystem processes, and advance the argument that they can be used to rehabilitate degraded ecosystems by altering mainly composition and function, but with fewer positive effects on structure. We describe four examples where the loss or reintroduction of soil-disturbing vertebrates leads to ecosystem state changes and highlight the role of spatial scale, covarying management changes, and species co-occurrence in modulating their effects. We discuss the advantages and disadvantages of using soil-disturbing vertebrates over mechanized engineering approaches such as pitting and furrowing, considering some advantages to include more self-sustainable and heterogeneous disturbances, creation of new habitats and added recreational values. Finally, we identify key knowledge gaps in our understanding of the use of soil-disturbing vertebrates for rehabilitating degraded ecosystems.

The frequency and intensity of extreme weather events represent a threat for biological diversity and are expected to increase in many regions over the following decades due to climate change. Our current knowledge about the impact of extreme weather events on the population dynamics of bird species is very limited. Here, we evaluated the impact of an extreme winter snowstorm on the abundance of 14 populations of the threatened Dupont’s Lark Chersophilus duponti, a resident bird whose European population is restricted to Spain. We found a drastic and significant population decline in the next reproductive season following the extreme weather event. During the control period (2017–2020) the species suffered an overall annual decline of 19.4% (±5.0, SE). However, the overall annual decline after the storm was 67.6% (±9.4, period 2019–2021), with a mean decline of 66.5% (±15.9) for seven populations monitored both the year before and the year after the snowstorm (period 2020–2021). The snow covered the ground for over 10 days in central and eastern Spain, which together with a subsequent extreme cold wave could have reduced the species ability to find food resources and properly thermoregulate, forcing the species to move to unknown areas. Indeed a few days after the storm, several individuals were reported in areas typically avoided. Such displacements may increase the mortality risk for dispersing individuals, besides the direct effects of the extreme cold event, such as thermal challenges to energy balance or a reduced immune function. We discuss the potential role that extreme weather events may have on the population dynamics and conservation of the species.

Habitat Suitability Index (HSI) derived from Species Distribution Model (SDM) has been used to infer or predict local demographic properties such as abundance for many species. Across species studied, HSI has either been presented as a poor predictor of abundance or as a predictor of potential rather than realized abundance. The main explanation of the lack of relationship between HSI and abundance is that the local abundance of a species varies in time due to various ecological processes that are not integrated into correlative SDM. To better understand the HSI-abundance relationship, in addition to the study of the association between HSI and mean abundance, we explored its variation over time. We used data from 10-years monitoring of a Houbara bustard (Chlamydotis undulata undulata) population in Morocco. From various occurrence data we modelled the HSI. From (independent) count data we calculated four local abundance indices: mean abundance, maximum abundance, the temporal trend of abundance and the coefficient of variation of abundance over the study period. We explored the relationship between HSI and abundance indices using linear, polynomial and quantile regressions. We found a triangular relationship between local abundance (mean and maximum) and HSI, indicating that the upper limit of mean and maximum abundance increased with HSI. Our results also indicate that sites with the highest HSI were associated with least variation in local abundance, the highest variation being observed at intermediate HSI. Our results provide new empirical evidence supporting the generalization of the triangular relationship between HSI and abundance. Overall, our results support the hypothesis that HSI obtained from SDMs can reflect the local abundance potentialities of a species and emphasize the importance of investigating this relationship using temporal variation in abundance.

Organic carbon and aggregate stability are key features of soil quality and are important to consider when evaluating the potential of agricultural soils as carbon sinks. However, we lack a comprehensive understanding of how soil organic carbon (SOC) and aggregate stability respond to agricultural management across wide environmental gradients. Here, we assessed the impact of climatic factors, soil properties and agricultural management (including land use, crop cover, crop diversity, organic fertilization, and management intensity) on SOC and the mean weight diameter of soil aggregates, commonly used as an indicator for soil aggregate stability, across a 3000 km European gradient. Soil aggregate stability (−56%) and SOC stocks (−35%) in the topsoil (20 cm) were lower in croplands compared with neighboring grassland sites (uncropped sites with perennial vegetation and little or no external inputs). Land use and aridity were strong drivers of soil aggregation explaining 33% and 20% of the variation, respectively. SOC stocks were best explained by calcium content (20% of explained variation) followed by aridity (15%) and mean annual temperature (10%). We also found a threshold-like pattern for SOC stocks and aggregate stability in response to aridity, with lower values at sites with higher aridity. The impact of crop management on aggregate stability and SOC stocks appeared to be regulated by these thresholds, with more pronounced positive effects of crop diversity and more severe negative effects of crop management intensity in nondryland compared with dryland regions. We link the higher sensitivity of SOC stocks and aggregate stability in nondryland regions to a higher climatic potential for aggregate-mediated SOC stabilization. The presented findings are relevant for improving predictions of management effects on soil structure and C storage and highlight the need for site-specific agri-environmental policies to improve soil quality and C sequestration.

Increasing the number of environmental stressors could decrease ecosystem functioning in soils. Yet this relationship has not been globally assessed outside laboratory experiments. Here, using two independent global standardized field surveys, and a range of natural and human factors, we test the relationship between the number of environmental stressors exceeding different critical thresholds and the maintenance of multiple ecosystem services across biomes. Our analysis shows that having multiple stressors, from medium levels (>50%), negatively and significantly correlates with impacts on ecosystem services and that having multiple stressors crossing a high-level critical threshold (over 75% of maximum observed levels) reduces soil biodiversity and functioning globally. The number of environmental stressors exceeding the >75% threshold was consistently seen as an important predictor of multiple ecosystem services, therefore improving prediction of ecosystem functioning. Our findings highlight the need to reduce the dimensionality of the human footprint on ecosystems to conserve biodiversity and function.

Background The main clinical symptoms characteristic of Parkinson’s disease (PD) are bradykinesia, tremor, and other motor deficits. However, non-motor symptoms, such as visual disturbances, can be identified at early stages of the disease. One of these symptoms is the impairment of visual motion perception. Hence, we sought to determine if the starburst amacrine cells, which are the main cellular type involved in motion direction selectivity, are degenerated in PD and if the dopaminergic system is related to this degeneration. Methods Human eyes from control (n = 10) and PD (n = 9) donors were available for this study. Using immunohistochemistry and confocal microscopy, we quantified starburst amacrine cell density (choline acetyltransferase [ChAT]-positive cells) and the relationship between these cells and dopaminergic amacrine cells (tyrosine hydroxylase-positive cells and vesicular monoamine transporter-2-positive presynapses) in cross-sections and wholemount retinas. Results First, we found two different ChAT amacrine populations in the human retina that presented different ChAT immunoreactivity intensity and different expression of calcium-binding proteins. Both populations are affected in PD and their density is reduced compared to controls. Also, we report, for the first time, synaptic contacts between dopaminergic amacrine cells and ChAT-positive cells in the human retina. We found that, in PD retinas, there is a reduction of the dopaminergic synaptic contacts into ChAT cells. Conclusions Taken together, this work indicates degeneration of starburst amacrine cells in PD related to dopaminergic degeneration and that dopaminergic amacrine cells could modulate the function of starburst amacrine cells. Since motion perception circuitries are affected in PD, their assessment using visual tests could provide new insights into the diagnosis of PD.

Anthropogenic disturbances, including wildfires, threaten the diversity of tropical Andean ecosystems. However, the response of tropical Andean plant communities to wildfires in human-modified landscapes has to be discovered. Quercus humboldtii is the southernmost species of this genus in the Neotropics and is almost exclusively distributed in Colombia. While the extent of Q. humboldtii forests has decreased recently, to what time these results from the species' inability to thrive under the current climate and disturbance regimes are still being determined. In this study, we describe post-fire resprouting and acorn and seedling density in and around Q. humboldtii forest patches in the Iguaque mountains in Colombia. We discuss the implications for the conservation and restoration of these forests. Resprouting probability was high in burned trees two years after the fire (ca. 80%). Resprouting ability depended on fire severity and tree size. The proportion of trees resprouting from the stump was related to the severity of fire damage and tree size. Acorn density was higher in burned than unburned areas and depended on the slope, distance to the forest edge, and distance to the nearest oak. Conversely, the density of healthy acorns was low across all sites, particularly in burned areas. Seedling density was relatively high in unburned areas, but seedlings could not withstand recurrent fires. The density of acorns and seedlings decreased in the periphery of forest patches. Despite the strong impact of fire on forest structures, Quercus humboldtii adults may withstand the current fire regime thanks to their strong capacity for vegetative and sexual regeneration. However, the ability of this species to establish in areas where oaks are no longer present is scarce. As Q. humboldtii forest cover and spatial continuity have decreased in response to the increasing frequency of wildfires, the current fire regime represents a threat to the recovery of this species. Our results

Rainfall pulses are one of the most important factors affecting soil respiration, especially in drylands where water is limited. Biocrusts are also crucial in dryland ecosystems and play important roles in regulating soil carbon cycling. However, it is unclear how biocrusts mediate the effects of rainfall pulses on soil respiration. Using continuous field monitoring, we explored whether and how different types of biocrusts (including cyanobacteria-, lichen- and moss-dominated biocrusts) modulate the effects of precipitation on soil respiration under drying-rewetting cycles at event and seasonal scales. We found that soil respiration was induced after rainfall pulses, especially at different types of biocrusted microsites. The increments of soil respiration during drying-rewetting cycles were greater in the moss-dominated biocrusts than in the bare soil, which suggested that the response of soil respiration to drying-rewetting cycles was increased by moss-dominated biocrusts. The length of the dry period, number of cycles, intensity of the dry period and frequency of rewetting affected the magnitude of soil respiration at event scales. However, when we analysed all of the drying-rewetting cycles together, that is, at the seasonal scale, the soil temperature was the driving factor affecting the maximum soil respiration after rainfall pulses. Therefore, soil temperature, rather than soil moisture, is the key factor regulating the response of soil respiration to drying-rewetting cycles at the seasonal scale. This study highlights the importance of temperature in regulating soil respiration under drying-rewetting cycles, and the regulatory factors of soil respiration vary at different temporal scales.

Plastic pollution is a global environmental threat. Remote and pristine islands are not safe from this threat. Here, we estimated beach macro- (>25 mm), meso- (5–25 mm) and microdebris (<5 mm) levels in Galapagos and studied the role of environmental variables determining their accumulation. The vast majority of beach macro- and mesodebris were plastic, while most microdebris were cellulosic. The levels of beach macro-, meso- and microplastics were notably high and comparable with exceptional levels reported in contaminated areas. Oceanic currents and the anthropic pressure of use of the beach were the main factors that determined the level of macro- and mesoplastics, as well as the diversity of items, with more types of items in the beaches facing the predominant current. Microplastic levels were mainly driven by the slope and, to some extent, the grain size of the sediment in the beach. The absence of relationship between the levels of large size debris and the level of microplastics suggests that secondary microplastics that accumulated in the beaches were previously fragmented before arriving to the beach. This differential influence of environmental factors in the accumulation of marine debris according to their size should be taken into account when developing strategies to mitigate plastic pollution. Additionally, this study reports high levels of marine debris reported in a remote and protected area such as Galapagos, which are comparable to areas with direct sources of marine debris. This is especially worrying for Galapagos since the sampled beaches are cleaned at least annually. This fact highlights the global dimension of this environmental threat that demands further extensive international commitment to conserve some of the last paradises on Earth.

Surveys based on indirect signs and camera trapping are two non-invasive methods extensively used for monitoring elusive mammals. Both approaches can be useful to obtain key information on wildlife in remote areas, since they may allow for the logistically viable design of optimal field frameworks. The sand cat (Felis margarita) is a feline that inhabits the Sahara Desert, the Arabian Peninsula, and western Asian deserts. Its basic ecology is poorly known and the status and impacts of threats are difficult to assess. Some local population declines have been detected, and more research is needed. Based on field surveys carried out in the Atlantic Sahara, we have evaluated the applications of both methods to study this species. Our results show that (a) camera trapping provided reliable data on several key aspects of its ecology, (b) walking surveys to collect feces for molecular data failed completely, and (c) for footprints, identification problems and the marked effects of the absence of optimal substrates and the prevalence of wind are relevant handicaps. Beyond this evaluation, we provide for the first time some key aspects of the ecology of sand cats in the Sahara Desert, including habitat selection, density, diel activity, and predator–prey relationships.

The objective of the study is to quantify the effect of climate change on the climatic risks associated with droughts and diminished water resources in the eastern Iberian Peninsula. For this purpose, this work analyses the 70-year historical series (1952–2021) of daily rainfall data from 353 meteorological stations. They are located in a key recharge area of the hydrological system, the Sierra de Albarracín, where three important rivers originate, namely the Tagus, the Júcar and the Turia, as do several tributaries of the Guadiana and Ebro rivers. It analyses trends in: annual and seasonal rainfall volumes with specific studies about their intensity according to certain percentiles; the number of rainy days, dry spell duration (< 1 mm/day) and drought evolution with the Standardized Precipitation Evaporation Index. The most relevant results are: (1) the second 35 years of the study period (1987–2021) were notably drier than the first part (1952–1986), with smaller volumes and fewer days with recorded precipitation; (2) summer and winter were most affected by pluviometric decrease, with losses of >50% of rainfall volume at some stations; (3) moderate rainfall significantly reduced between the 50th and 95th percentiles, which were more important in the system's water recharge; (4) the stations with a negative precipitation trend predominated; (5) the medium- and long-term analyses (12 and 36 months) highlighted the drought situation in which the headwaters of the analyzed basins are immersed. The trend indicates that the situation will become critical.

The divergence between agricultural water use and the annual supply of water resources (water gap) has been increasing for decades. The forecast is that this water gap will continue to widen, compromising the water security of a large share of the global population. On the one hand, the increase in demand is attributed to an ever-growing population that, in addition, is adopting a high-water consumption per capita lifestyle (e.g., meat-rich diet, increased use of biofuels and of irrigated agriculture). On the other hand, climate change is increasing aridification and the spatio-temporal heterogeneity of precipitation worldwide. The water gap is particularly acute in drylands, where development and food security has been based on the massive exploitation of water resources, particularly groundwater. Here we analyze the mechanisms underlying this water gap, which is mainly driven by water use in agriculture, and suggest suitable solutions that can help to close it. Using causal diagrams, we show how population generates different demands that create a water gap that prevailing supply-side solutions cannot close. Indeed, it has been widening over the years because water consumption has grown exponentially. This behaviour is explained by a series of mechanisms that it is necessary to understand to realize the complexity of water scarcity problems. For solving the water gap, we propose and exemplify eight lines of action that can be combined and tailored to each territory. Our analyses corroborate the urgent need to plan an integral management of water resources to avoid widespread scenarios of water scarcity under future climatic conditions.