Search

9 páginas.- 5 figuras.- 51 referencias.- Supplementary information The online version contains supplementary material available at https://doi.org/10.1038/s41561-023-01170-x, 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., The study work associated with this paper was funded by a Large Research Grant from the British Ecological Society (no. LRB17\1019; MUSGONET). D.J.E. is supported by the Hermon Slade Foundation. M.D.-B. was supported by a Ramón y Cajal grant from the Spanish Ministry of Science and Innovation (RYC2018-025483-I), a project from the Spanish Ministry of Science and Innovation for the I + D + i (PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033a) and a project PAIDI 2020 from the Junta de Andalucía (P20_00879). E.G. is supported by the European Research Council grant agreement 647038 (BIODESERT). M.B. is supported by a Ramón y Cajal grant from Spanish Ministry of Science (RYC2021-031797-I). A.d.l.R is supported by the AEI project PID2019-105469RB-C22. L.W. and Jianyong Wang are supported by the Program for Introducing Talents to Universities (B16011) and the Ministry of Education Innovation Team Development Plan (2013-373). The contributions of T.G. and T.U.N. were supported by the Research Program in Forest Biology, Ecology and Technology (P4-0107) and the research projects J4-3098 and J4-4547 of the Slovenian Research Agency. The contribution of P.B.R. was supported by the NSF Biological Integration Institutes grant DBI-2021898. J. Durán and A. Rodríguez acknowledge support from the FCT (2020.03670.CEECIND and SFRH/BDP/108913/2015, respectively), as well as from the MCTES, FSE, UE and the CFE (UIDB/04004/2021) research unit financed by FCT/MCTES through national funds (PIDDAC).

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. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. JMV, FTM and EG acknowledge support from the European Research Council (ERC Grant agreement 647038 [BIODESERT]). FTM acknowledges support from Generalitat Valenciana (CIDEGENT/2018/041) and the Spanish Ministry of Science and Innovation (EUR2022-134048). EG acknowledges support from Generalitat Valenciana (CIDEGENT/2018/041 and APOST…). JMV acknowledges support from MICINN through European Regional Development Fund [SUMHAL, LIFEWATCH-2019-09-CSIC-4, POPE 2014-2020].

Drylands cover about 40% of the terrestrial surface and are sensitive to climate change, but their relative contributions to global vegetation greening and productivity increase in recent decades are still poorly known. Here, by integrating satellite data and biosphere modeling, we showed that drylands contributed more to global gross primary productivity (GPP) increase (65% ± 16%) than to Earth greening (33% ± 15%) observed during 1982–2015. The enhanced productivity per unit leaf area, i.e., light-use efficiency (LUE), was the mechanism behind this pattern. We also found that LUE was more sensitive to soil moisture than to atmospheric vapor pressure deficit (VPD) in drylands, while the opposite was observed (i.e., LUE was more sensitive to VPD) in humid areas. Our findings suggest the importance of using different moisture stress metrics in projecting the vegetation productivity changes of dry versus humid regions and highlight the prominent role of drylands as key controllers of the global carbon cycle. This work was supported by the National Natural Science Foundation of China (41991230), the European Research Council (ERC grant agreement 647038 (BIODESERT)) and Generalitat Valenciana (CIDEGENT/2018/041). We especially thanks Hanqin Tian from Auburn University for support with the Trendy v7 GPP data.

This work was supported by the National Natural Science Foundation of China (41991230), the Joint CAS (Chinese Academy of Sciences) & MPG (Max-Planck-Gesellschaft) Research Project (HZXM20225001MI), and the International Partnership Program of the Chinese Academy of Sciences (121311KYSB20170004).

Aim Fungi are major drivers of ecosystem functioning. Increases in aridity are known to negatively impact fungal community composition in dryland ecosystems globally; yet, much less is known on the potential influence of other environmental drivers, and whether these relationships are linear or nonlinear. Time period 2017–2021. Location Global. Major taxa studied Fungi. Methods We re-analysed multiple datasets from different dryland biogeographical regions, for a total of 912 samples and 1,483 taxa. We examined geographical patterns in community diversity and composition, and spatial, edaphic and climatic factors driving them. Results UV index, climate seasonality, and sand content were the most important environmental predictors of community shifts, showing the strongest 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 (standard deviation x 100 of the mean monthly temperature), respectively, being associated with an increased probability of plant pathogen and unspecified saprotroph occurrence. Conversely, these environmental parameters had a negative relationship with litter and soil saprotroph richness. Consequently, these ecological groups might be particularly sensitive to shifts in UV radiation and climate seasonality, which is likely to disturb current plant–soil dynamics in drylands. Main conclusions Our synthesis integrates fungal community data from drylands across the globe, allowing the investigation of fungal distribution and providing the first evidence of shifts in fungal diversity and composition of key fungal ecological groups along diverse spatial, climatic and edaphic gradients in these widely distributed ecosystems. Our findings imply that shifts in soil structure and seasonal climatic patterns induced by global change will have disproportionate consequences for the distribution of fungal groups linked to vegetation and biogeochemical cycling in drylands, with implications for plant–soil interactions in drylands., Global Ecology and Biogeography, 32 (1), ISSN:1466-822X, ISSN:1466-8238

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. Alexander von Humboldt-Stiftung, Grant/Award Number: Feodor-Lynen Fellowship; Australian Research Council, Grant/Award Number: DP190103714 and FT0100590; Bundesministerium für Bildung und Forschung, Grant/Award Number: 01LC1501A; Deutsche Forschungsgemeinschaft, Grant/Award Number: HE6183; Deutscher Akademischer Austauschdienst; Division of Environmental Biology, Grant/Award Number: 1623040 and 1655759; Grantová Agentura České Republiky, Grant/Award Number: 21-17749S; H2020 European Research Council, Grant/Award Number: 647038 and 694368; Universities Australia.

17 páginas.- 4 figuras.- 185 referenicas.- Supplementary information The online version contains supplementary material available at https://doi.org/10.1038/s41579-023-00900-7, 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., B.K.S. acknowledges funding from the Australian Research Council (DP210102081; DP230101448) for microbiome research. E.E. is supported by an Australian Research Council fellowship (DE210101822). E.G. acknowledges funding from Generalitat Valenciana and a European Social Fund grant (APOSTD/2021/188). M.D.-B. is supported by the Spanish Ministry of Science and Innovation (PID202-115813RA-I00). P.T. and J.E.L.’s research is supported by the US National Science Foundation (no. 2120117). J.E.L. receives additional funding from the Foundation of Food and Agriculture (ICRC20-0000000084).

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. Open Access funding enabled and organized by Projekt DEAL. We acknowledge support by the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, funded by the German Research Foundation (FZT 118). The Jena Experiment is funded by the German Research Foundation (FOR 5000). F.T.M. acknowledges support from the Spanish Ministry of Science and Innovation (EUR2022-134048) and Generalitat Valenciana (CIDEGENT/2018/041).

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 research within the Long-Term Social-Ecological Research (LTER) network. This research has been supported by the Plan Propio PhD program of the University of Almería; projects EarthCul (reference PID2020-118041GB-I00); INDALO (grant no. LifeWatch-2019-10-UGR-01); LifeWatch-2019-10-UGR-01_WP-8, LifeWatch-2019-10-UGR-01_WP-7, and LifeWatch-2019-10-UGR-01_WP-4; ECOPOTENTIAL grant agreement no. 641762; “Ecosystem and Socio-Ecosystem Functional Types: Integrating biophysical and social functions to characterize and map the ecosystems of the Anthropocene” (CGL2014-61610-EXP); Project LIFE-ADAPTAMED (LIFE14 CCA/ES/000612); Generalitat Valenciana and the European Social Fund (APOSTD/2021/188).

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. This study was supported by the National Natural Science Foundation of China (grant number 31901225, awarded to C.G., and grant number 32125028, awarded to C.Z.) and the Science and Technology Project of Gansu (grant number 18JR2RA009, awarded to C.Z.). N.C. was supported by the Fundamental Research Funds for the Central Universities (grant number lzujbky-2021-ey16).

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. This research was funded by MICINN through European Regional Development Fund [SUMHAL, LIFEWATCH-2019-09- CSIC-4, POPE 2014-2020] and the regional collaborative innovation project for Xinjiang Uygur Autonomous Region (Shanghai Cooperation Organization Science and Technology Partnership project), grant number 2021E01016.

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., Universidad de Granada/ CBUA, Fundación Barcelona Zoo (PRIC Project 2017 grant)

Desertification is the degradation of drylands, which occupy an increasing proportion of the Earth's surface due to global warming. It is currently the most extensive biome on Earth, occupying 45% and one out of every three inhabitants of the planet live in them. One of the most effective ways to face desertification, as Land Degradation Neutrality points out, is prevention. For this purpose, simulation models are very useful tools. Specifically, System Dynamics models are particularly effective, since they allow bringing together the biophysical and socioeconomic variables involved in the formation of the problem. These integrative models, coupled with other tools such as sensitivity analyses, are used to generate desertification early warning indicators. The objective of this programming routine is to implement climate change scenarios in these simulation models. The script presented here was used to evaluate the sensitivity of dehesa rangelands productivity to the increase in the frequency and intensity of droughts due to climate change. • Integrated simulation models are useful tools to understand complex socioecosystems. • Land-use changes foster the alteration of key hydro-bio-geochemical processes. • By means of automated import processes and data analysis programming, it is possible to implement desertification early warning systems. This work was supported by the funded by the European Research Council [grant agreement n°647038 (BIODESERT)]; Ministerio de Ciencia e Innovación de España (Spain), through European Regional Development Fund (FEDER) [SUMHAL, LIFEWATCH-2019-09-CSIC-13, POPE 2014-2020].

Rangelands are a key resource present all over the world and cover half of all emerged lands. They are even more important in drylands, where they cover 48% of the total area. Their intensification and the additional pressure added by climate change push these socio-ecological systems towards desertification. Over the last two decades, we have developed and applied System Dynamics (SD) models for the study of Mediterranean grasslands. In addition, we have designed procedures and analysis tools, such as global sensitivity analysis, stability analysis condition, or risk analysis, to detect the main drivers of these socio-ecological systems and provide indicators about their long-term sustainability. This paper reviews these works, their scientific background, and the most relevant conclusions, including purely technical and rangeland-related ones, as well as our experience as systemic modelers in a world driven by field specialists. This research was funded by DeSurvey (CE-Integrated Project Contract No. 003950), PADEG (CGL2008/01215/BTE), and BIODESERT (European Research Council grant agreement No. 647038).

Drylands occupy approximately 40 % of the Earth's surface. Their peculiar hydrological regime, with water as the main limiting factor, together with other characteristics, such as the variability of rainfall and their ecological heterogeneity, turn these regions into one of the main and most relevant sets of biomes on the planet. Beyond their stereotypical conception as places with a low economic and ecological profile, these territories have enormous biodiversity and support 40 % of the world's population. Global warming is increasing atmospheric aridity and the strategies developed over millennia by their inhabitants are a model to learn from. Preserving these places is essential to combat climate change, and to do so, it is essential to have an in-depth understanding of their structure and functioning. This work was funded by the European Research Council (Grant Agreement Nº 647038, BIODESERT) and the Valencian Regional Government (CIDEGENT/2018/041). Emilio Guirado receives funding from the Regional Department of Education, Culture, and Sport of the Valencian Regional Government and the European Social Fund [project APOSTD/2021/188].

La desertificación se refiere a la degradación de las tierras secas, que ocupan el 45% de la superficie terrestre y en ellas vive una de cada tres personas. Unos mil millones de personas, en los países más pobres, dependen de la tierra para la mayoría de sus necesidades. La desertificación es consecuencia de las variaciones climáticas –como las sequías– agravadas por el cambio climático, y las actividades humanas, que suponen intensificar el uso del suelo para cubrir las necesidades de una población y consumo per cápita crecientes. Las trabas conceptuales, la falta de soporte científico y la doble visión de la Convención de Naciones Unidas de Lucha contra la Desertificación (CNULD) –ambientalista vs desarrollista– ha lastrado la implementación de soluciones. Para revertir esta situación es necesario comprender que los mismos factores que generan riqueza son los causantes de la desertificación. Degradación y regeneración son procesos que conviven y que deben formar parte del mismo paquete de soluciones, como reconoce el concepto de degradación neutra (NDT). Esta es la iniciativa de la CNULD para lograr la neutralidad en la degradación de tierras en 2030. Para ello, además de las restauraciones ecológicas, debe priorizarse la prevención y un uso del territorio que minimice los impactos ambientales. La NDT forma parte del ODS 15, pero abordar la desertificación pasa por lograr otros ODS, destacando el de la igualdad de género (ODS 5), el hambre cero (ODS 1) o el fin de la pobreza (ODS 2). Solo con un mundo más justo puede lograrse un planeta sostenible. Desertification refers to the degradation of drylands, which cover 45% of the earth’s land surface and are home to one in three people. Some one billion people in the poorest countries depend on the land for most of their needs. Desertification is a consequence of climate variations such as droughts, aggravated by climate change and human activities, which involve intensifying land use to meet the needs of a growing population and per capita consumption. Conceptual obstacles, lack of scientific support and the double vision (environmentalist vs. developmentalist) of the United Nations Convention to Combat Desertification (UNCCD) have hindered the implementation of efficient solutions. To reverse this situation, it is necessary to understand that the same factors that generate wealth are the causes of desertification. Degradation and regeneration are processes that coexist and must be part of the same solution package, as recognized by the concept of land degradation neutrality (LDN), which the UNCCD aims to achieve by 2030. To this end, in addition to ecological restoration, priority should be given to prevention and land use that minimizes environmental impacts. LDN is part of Sustainable Development Goal 15, but tackling desertification involves achieving other SDGs, such as gender equality (SDG 5), zero hunger (SDG 1) and the end of poverty (SDG 2). A sustainable planet can only be achieved with a fairer world. Este trabajo ha sido financiado por el Consejo Europeo de Investigación (Grant Agreement nº 647038, BIODESERT).

Hyper-arid, arid, semi-arid and dry-sub-humid climate zones (all of them considered drylands) occupy over 40 % of the Earth’s land surface and are home to more than 2 billion people. Contrary to the popular image of this important set of biomes, drylands are home to 36 % of carbon stores, 30 % of forested areas, 50 % of the world’s livestock, and 44 % of croplands. These figures give an idea of their social, economic, and ecological importance – the focus of the monograph’s first article – and argue for the need to know and understand their functioning and manage human activities in an increasingly changing climate scenario. This is key to enabling their development and preventing their desertification.

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., Global Change Biology, 29 (11), ISSN:1354-1013, ISSN:1365-2486

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., Remote Sensing in Ecology and Conservation

11 páginas.- 4 figuras.- referencias.- Additional supporting information can be found online in the Supporting Information section at the end of this article., Soil micronutrients are capital for the delivery of ecosystem functioning and food provision worldwide. Yet, despite their importance, the global biogeography and ecological drivers of soil micronutrients remain virtually unknown, limiting our capacity to anticipate abrupt unexpected changes in soil micronutrients in the face of climate change. Here, we analyzed >1300 topsoil samples to examine the global distribution of six metallic micronutrients (Cu, Fe, Mn, Zn, Co and Ni) across all continents, climates and vegetation types. We found that warmer arid and tropical ecosystems, present in the least developed countries, sustain the lowest contents of multiple soil micronutrients. We further provide evidence that temperature increases may potentially result in abrupt and simultaneous reductions in the content of multiple soil micronutrients when a temperature threshold of 12–14°C is crossed, which may be occurring on 3% of the planet over the next century. Altogether, our findings provide fundamental understanding of the global distribution of soil micronutrients, with direct implications for the maintenance of ecosystem functioning, rangeland management and food production in the warmest and poorest regions of the planet., The sampling included in this study were supported by the European Research Council (ERC) grant 647038 (BIODESERT), the BES grant agreement No. LRB17\1019 (MUSGONET) and the Marie Skłodowska-Curie grant agreement 702057 (CLIMIFUN). We would like to thank the researchers originally involved in the BIODESERT, CLIMIFUN and MUSGONET projects for their help with samplings. E.M.-J. acknowledges the Humboldt Foundation for supporting his research stay in Germany (Fellowship for Experienced Researchers) and a project from the Spanish Ministry of Science and Innovation (PID2020-116578RB-I00). M.D.-B. is supported by a Ramón y Cajal grant (RYC2018-025483-I), a project from the Spanish Ministry of Science and Innovation (PID2020-115813RA-I00) and a project PAIDI 2020 from the Junta de Andalucía (P20_00879). E.G. is supported by the Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital de la Generalitat Valenciana, and the European Social Fund grant APOSTD/2021/188 and European Research Council (ERC) grant 647038. F.T.M. is supported by European Research Council (ERC) grant 647038 and Generalitat Valenciana grant CIDEGENT/2018/041. M.D. and T.W.C. were funded by the Marc R. Benioff Revocable Trust and in collaboration with the World Economic Forum. This article is part of the contract between ETH Zurich and University of Alicante “Mapping terrestrial ecosystem structure at the global scale”. R.O.H. is supported by the Ramón y Cajal program from the MICINN (RYC-2017 22032), a PAIDI 2020 project from the Junta de Andalucía (Ref. 20_00323) and a project from the Spanish Ministry of Science and Innovation (PID2019-106004RA-I00/AEI/10.13039/501100011033). Authors acknowledge support by the Open Access Publication Initiative of Freie Universität Berlin. Open Access funding enabled and organized by Projekt DEAL.

Funding: This work has received funding from the European Research Council (ERC grant agreement 647038 [BIODESERT]), the ADAPTAMED LIFE14 CCA/ES/000612 project, the RH2O-ARID project (P18-RT-5130), and the RESISTE project (P18-RT-1927), funded by the Consejería de Economía, Conocimiento, Empresas y Universidad de la Junta de Andalucía; and by the A-TIC-458-UGR18 and DETECTOR (A-RNM-256-UGR18) projects, with the contribution of the European Funds for Regional Development. E.G. was supported by the Generalitat Valenciana and the European Social Fund (APOSTD/2021/188). This work is part of the “Thematic Center on Mountain Ecosystem & Remote sensing, Deep learning-AI e-Services University of Granada-Sierra Nevada” (LifeWatch-2019-10-UGR- 01) project, which has been co-funded by the Ministry of Science and Innovation through the FEDER funds from the Spanish Pluriregional Operational Program 2014–2020 (POPE), LifeWatch-ERIC action line, within theWorkpackages LifeWatch-2019-10-UGR-01_WP-8, LifeWatch-2019-10-UGR-01_WP-7, and LifeWatch-2019-10-UGR-01_WP-4., Wildfires affect the structure, functioning, and composition of ecosystems. Long-term monitoring of the occurrence, abundance, and growth of plant species is key to assessing the responses of the dynamics of plant populations with regard to environmental disturbances, such as wildfires. In this work, we evaluated the changes in the number of individuals and the canopy cover extent of a population of Juniperus communis L. during a four-decade period following a wildfire in a Mediterranean high-mountain ecosystem (Sierra Nevada, Spain). To do this, we used object-based image analysis (OBIA) applied to very high-resolution aerial images. Our study also provides a new approach to optimize the shrub identification process and to semi-automatically evaluate the accuracy of the number of shrubs and their canopy cover. From the 752 individuals present in 1977, only 433 remained immediately after a fire (1984), a few more disappeared one decade later (420 shrubs in 1997), while by 2008, the population had partially recovered to 578 shrubs. The wildfire decreased juniper canopy cover from 55,000 m2 to 40,000 m2, but two decades later it had already recovered to 57,000 m2. The largest shrubs were more resistant to fire than the smallest ones and recovered in a shorter time period. The protection measures introduced with the park declaration seemed to have contributed to the post-fire recovery. The potential of this methodology in the management and conservation of biodiversity in the future is also discussed., European Research Council (ERC grant agreement 647038 [BIODESERT]), ADAPTAMED LIFE14 CCA/ES/000612 project, RH2O-ARID project (P18-RT-5130), RESISTE project (P18-RT-1927) funded by the Consejería de Economía, Conocimiento, Empresas y Universidad de la Junta de Andalucía, A-TIC-458-UGR18 and DETECTOR (A-RNM-256-UGR18) projects, with the contribution of the European Funds for Regional Development, Generalitat Valenciana and the European Social Fund (APOSTD/2021/188), “Thematic Center on Mountain Ecosystem & Remote sensing, Deep learning-AI e-Services University of Granada-Sierra Nevada” (LifeWatch-2019-10-UGR- 01) project, which has been co-funded by the Ministry of Science and Innovation through the FEDER funds from the Spanish Pluriregional Operational Program 2014–2020 (POPE), LifeWatch-ERIC action line, within theWorkpackages LifeWatch-2019-10-UGR-01_WP-8, LifeWatch-2019-10-UGR-01_WP-7, and LifeWatch-2019-10-UGR-01_WP-4

Rainfall partitioning into stemflow, throughfall, and interception loss by vegetation alters hydrological and biogeochemical fluxes between vegetation and soil. Here, we compiled a comprehensive dataset of rainfall partitioning by forests, shrublands, croplands, and grasslands in China from 287 peer reviewed papers (71 in English and 216 in Chinese). Based on this dataset, we summarized the best-fit functions reported for rainfall partitioning (in both mm and %) as a function of rainfall amount, as well as the rainfall thresholds for throughfall and stemflow initiation. We explored the pattern of the proportions of stemflow, throughfall, and interception loss of vegetation in China, and performed boosted regression trees (BRT) analysis to model the relative effects of cross-site biotic and abiotic predictors on each of the rainfall partitioning fluxes (%). Our results identified the scarcity of rainfall partitioning data, particularly for grasslands. A substantial variability of each rainfall partitioning flux (mm) could be explained solely by rainfall amount, with median R2 values of 0.91, 0.99, and 0.82 for stemflow, throughfall, and interception loss, respectively, and with linear functions most often reported as the best-fit functions. Significant differences (p < 0.0001) were detected in rainfall thresholds for initiating stemflow (median: 3.3 mm; interquartile range, IQR: 1.8–5.4 mm) and throughfall (median: 1.2 mm; IQR: 0.8–2.2 mm). Stemflow (%) had a median (IQR) of 2.7 % (1.2–6.0 %), and that value was 74.3 % (66.7–80.3 %) for throughfall (%) and 21.6 % (16.3–28.5 %) for interception loss (%), respectively. Significant differences were detected in the proportion of stemflow (p < 0.001) and throughfall (p < 0.01) between forests and shrublands, respectively; whereas no significant differences in the proportion of interception loss were found among vegetation types. BRT analysis indicated that of the eleven biotic and abiotic predictors examined, six were classified as significant predictors in determining stemflow (%) and interception loss (%), respectively, whereas throughfall (%) had four significant predictors. Non-linear partial effects of predictors on rainfall partitioning fluxes were prevalent. This study avails a global readership to the findings of a large cache of Chinese studies that have been inaccessible hitherto, providing a mechanistic understanding of the effects of cross-site biotic and abiotic predictors on rainfall partitioning fluxes. This research was funded by the Youth Innovation Promotion Association of Chinese Academy of Sciences (grant 2019415), and the National Natural Science Foundation of China (grants 41901038 and 31971452).

7 páginas.- 4 figuras.- 32 referencias.- Supplementary materials: science.org/doi/10.1126/science.abq4062 Materials and Methods Figs. S1 to S19 Tables S1 to S28 References (33–269) MDAR Reproducibility Checklist Movie S1.- Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that interactions between grazing pressure, climate, soil, and biodiversity are critical to explain the delivery of fundamental ecosystem services across drylands worldwide. Increasing grazing pressure reduced ecosystem service delivery in warmer and speciespoor drylands, whereas positive effects of grazing were observed in colder and species-rich areas. Considering interactions between grazing and local abiotic and biotic factors is key for understanding the fate of dryland ecosystems under climate change and increasing human pressure. Copyright © 2022 the authors, Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that interactions between grazing pressure, climate, soil, and biodiversity are critical to explain the delivery of fundamental ecosystem services across drylands worldwide. Increasing grazing pressure reduced ecosystem service delivery in warmer and species-poor drylands, whereas positive effects of grazing were observed in colder and species-rich areas. Considering interactions between grazing and local abiotic and biotic factors is key for understanding the fate of dryland ecosystems under climate change and increasing human pressure. Copyright © 2022 the authors, Funding: This research was funded by the European Research Council [ERC grant agreement 647038 (BIODESERT)] and Generalitat Valenciana (CIDEGENT/2018/ 041). F.T.M. acknowledges support from a Rei Jaume I Award, the Alexander von Humboldt Foundation, and the Synthesis Center (sDiv) of the German Centre for Integrative Biodiversity Research Halle–Jena–Leipzig (iDiv). C.A.G., S.C., and N.E. acknowledge support from iDiv and the Deutsche Forschungsgemeinschaft (DFG– FZT 118, 202548816; Flexpool proposal 34600850). Y.L.B.-P. was supported by a Marie Sklodowska-Curie Actions Individual Fellowship (MSCA-IF) within the European Program Horizon 2020 (DRYFUN Project 656035). N.G. was supported by CAP 20-25 (16-IDEX-0001) and the AgreenSkills+ fellowship program, which has received funding from the EU’s Seventh Framework Programme under grant agreement N° FP7-609398 (AgreenSkills+ contract). B.B. and B.E. were supported by the Taylor Family–Asia Foundation Endowed Chair in Ecology and Conservation Biology. J.D., A.Ro., and H.C. acknowledge support from the Fundação para a Ciência e a Tecnologia (IF/00950/ 2014 and 2020.03670.CEECIND, SFRH/BDP/108913/2015, and in the scope of the framework contract foreseen in the numbers 4-6 of the article 23, of the Decree-Law 57/2016, August 29, changed by Law 57/2017, July 19, respectively), as well as from the MCTES, FSE, UE, and the CFE (UIDB/04004/2020) research unit financed by Fundação para a Ciência e a Tecnologia/MCTES through national funds (PIDDAC). C.P. acknowledges support from the Spanish Ministry of Science and Innovation (ref. AGL201675762-R, AEI/FEDER, UE, and PID2020-116578RB-I00, MCIN/AEI/10.13039/501100011033) and the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement no. 101000224. E.V. was funded by the 2017 program for attracting and retaining talent of Comunidad de Madrid (no. 2017‐T2/ AMB‐5406). M.A.B. acknowledges support from the School of Forestry and College of the Environment, Forestry and Natural Sciences of Northern Arizona University. E.H.-S. acknowledges support from the Consejo Nacional de Ciencia y Tecnología (SEP-CB-2015-01-251388, PN 2017-5036 and PRONAII 319059). F.M.H. acknowledges support from the National Council for Scientific and Technological Development (CNPq - PCI/INMA) of the Brazilian Ministry of Science, Technology and Innovation (MCTI, processes number 302381/2020-1). H.L.T. acknowledges support from the US National Science Foundation (NSF) (DEB 0953864). A.N. and M.K. acknowledge support from the Fundação para a Ciência e a Tecnologia (SFRH/BD/130274/2017, CEECIND/02453/2018/CP1534/CT0001, PTDC/ASP-SIL/7743/2020 and UIDB/00329/2020). A.A.C. acknowledges support from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. J.E.K. and T.P.M. acknowledge the National Research Foundation of South Africa (grant no. 114412). F.J. and N.B. acknowledge support from the German Federal Ministry of Education and Research (BMBF) in the framework of the SPACES projects OPTIMASS (FKZ: 01LL1302A) and ORYCS (FKZ:01LL1804A). A.Li. and A.S.K.F. acknowledge support from the German Federal Ministry of Education and Research (BMBF) in the framework of the SPACES projects Limpopo Living Landscapes (FKZ: 01LL1304D) and SALLnet (FKZ: 01LL1802C). L.W. acknowledges support from the US NSF (EAR 1554894). L.H.F. acknowledges support from the Natural Sciences and Engineering Research Council of Canada Industrial Research Chair Program in Ecosystem Reclamation. S.C.R. acknowledges support from the US Geological Survey Ecosystems Mission Area and the US Bureau of Land Management. G.M.W. acknowledges support from the Australian Research Council. L.v.d.B. and K.T. acknowledge support from the German Research Foundation (DFG) priority research program SPP-1803 “EarthShape: Earth Surface Shaping by Biota” (TI 338/14-1). M.D.-B. acknowledges support from the Spanish Ministry of Science and Innovation for the I+D+i project PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033. M.D.-B. is also supported by a project of the Fondo Europeo de Desarrollo Regional (FEDER) and the Consejería de Transformación Económica, Industria, Conocimiento y Universidades of the Junta de Andalucía (FEDER Andalucía 2014-2020 Objetivo temático “01 - Refuerzo de la investigación, el desarrollo tecnológico y la innovación”) associated with the research project P20_00879 (ANDABIOMA). P.J.R. and A.J.M. acknowledge support from Fondo Europeo de Desarrollo Regional through the FEDER Andalucía operative program, FEDER-UJA 1261180 project. A.F. thanks ANID PIA/BASAL FB210006 and Millennium Science Initiative Program NCN2021-050. A.J. acknowledges support from the Bavarian Research Alliance Germany (BayIntAn_UBT_2017_61). C.B. acknowledges the National Natural Science Foundation of China (grant no. 41971131). Biodiversity and ecosystem function research in the B.K.S. laboratory is funded by the Australian Research Council (DP210102081). Any use of trade, product, or firm names in this paper is for descriptive purposes only and does not imply endorsement by the US government. H.S. is supported by a María Zambrano fellowship funded by the Ministry of Universities and European Union-Next Generation plan. G.P. and C.V.L. acknowledge support from Universidad Nacional de Río Negro (PI 40-C-873 and 654). V.R. acknowledges support from the Regional Government of Extremadura (Spain) through a “Talento” fellowship (TA18022). M.F. acknowledges support from the Department of Range and Watershed Management, Ferdowsi University of Mashhad, Mashhad, Iran. Participation of recent graduates in collecting field data at four sites in Namibia was supported by a capacity building grant to Gobabeb–Namib Research Institute by the Environmental Investment Fund in Namibia.

Land-Use and Land-Cover (LULC) mapping is relevant for many applications, from Earth system and climate modelling to territorial and urban planning. Global LULC products are continuously developing as remote sensing data and methods grow. However, there still exists low consistency among LULC products due to low accuracy in some regions and LULC types. Here, we introduce Sentinel2GlobalLULC, a Sentinel-2 RGB image dataset, built from the spatial-temporal consensus of up to 15 global LULC maps available in Google Earth Engine. Sentinel2GlobalLULC v2.1 contains 194877 single-class RGB image tiles organized into 29 LULC classes. Each image is a 224 × 224 pixels tile at 10 × 10 m resolution built as a cloud-free composite from Sentinel-2 images acquired between June 2015 and October 2020. Metadata includes a unique LULC annotation per image, together with level of consensus, reverse geo-referencing, global human modification index, and number of dates used in the composite. Sentinel2GlobalLULC is designed for training deep learning models aiming to build precise and robust global or regional LULC maps., Ministry of Science and Innovation through the FEDER funds from the Spanish Pluriregional Operational Program LifeWatch-2019-10-UGR-01, LifeWatch-ERIC action line, within the Workpackages LifeWatch-2019-10-UGR-01 WP-8 LifeWatch-2019-10-UGR-01 WP-7 LifeWatch-2019-10-UGR-01 WP-4, European Research Council (ERC), European Commission 647038, Center for Forestry Research & Experimentation (CIEF) APOSTD/2021/188 A-RNM-256-UGR18 A-TIC-458-UGR18 PID2020-119478GB-I00 P18-FR-4961

Accumulating evidence suggests that warming associated with climate change is decreasing the total amount of soil organic carbon (SOC) in drylands, although scientific research has not given enough emphasis to particulate (POC) and mineral-associated organic carbon (MAOC) pools. Biocrusts are a major biotic feature of drylands and have large impacts on the C cycle, yet it is largely unknown whether they modulate the responses of POC and MAOC to climate change. Here, we assessed the effects of simulated climate change (control, reduced rainfall (RE), warming (WA), and RE + WA) and initial biocrust cover (low ( 50%)) on the mineral protection of soil C and soil organic matter quality in a dryland ecosystem in central Spain for 9 years. At low initial biocrust cover levels, both WA and RE + WA increased SOC, especially POC but also MAOC, and promoted a higher contribution of carbohydrates, relative to aromatic compounds, to the POC fraction. These results suggest that the accumulation of soil C under warming treatments may be transitory in soils with low initial biocrust cover. In soils with high initial biocrust cover, climate change treatments did not affect SOC, neither POC nor MAOC fraction. Overall, our results indicate that biocrust communities modulate the negative effect of climate change on SOC, because no losses of soil C were observed with the climate manipulations under biocrusts. Future work should focus on determining the long-term persistence of the observed buffering effect by biocrust-forming lichens, as they are known to be negatively affected by warming. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research has received funding from the European Research Council (ERC Grant agreement 647038 [BIODESERT]), the European Union’s Horizon 2020 research and innovation programme (Marie Skłodowska-Curie Grant Agreement No 654132 [VULCAN]), the Spanish Ministerio de Ciencia e Innovación (PID2020-116578RB-I00 [VULCOCLIM]) and Generalitat Valenciana (CIDEGENT/2018/041). P.D.-M. was supported by Spanish Ministerio de Ciencia, Innovación y Universidades (FPU17/02949), M. Panettieri acknowledge the financial support by the Comunidad de Madrid and the Spanish National Council of Scientific Researches research grant Atracción de Talento (grant number 2019T1/AMB14503).

Purpose Biocrust communities, which are important regulators of multiple ecosystem functions in drylands, are highly sensitive to climate change. There is growing evidence of the negative impacts of warming on the performance of biocrust constituents like lichens in the field. Here, we aim to understand the physiological basis behind this pattern. Methods Using a unique manipulative climate change experiment, we monitored every 30 minutes and for 9 months the chlorophyll a fluorescence and microclimatic conditions (lichen surface temperature, relative moisture and photosynthetically active radiation) of Psora decipiens, a key biocrust constituent in drylands worldwide. This long-term monitoring resulted in 11,847 records at the thallus-level, which allowed us to evaluate the impacts of ~2.3 °C simulated warming treatment on the physiology of Psora at an unprecedented level of detail. Results Simulated warming and the associated decrease in relative moisture promoted by this treatment negatively impacted the physiology of Psora, especially during the diurnal period of the spring, when conditions are warmer and drier. These impacts were driven by a mechanism based on the reduction of the length of the periods allowing net photosynthesis, and by declines in Yield and Fv/Fm under simulated warming. Conclusion Our study reveals the physiological basis explaining observed negative impacts of ongoing global warming on biocrust-forming lichens in the field. The functional response observed could limit the growth and cover of biocrust-forming lichens in drylands in the long-term, negatively impacting in key soil attributes such as biogeochemical cycles, water balance, biological activity and ability of controlling erosion. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was funded by the European Research Council (ERC Grant Agreements 242658 [BIOCOM] and 647038 [BIODESERT] awarded to FTM). FTM and DSP also acknowledge support from Generalitat Valenciana (CIDEGENT/2018/041) and Comunidad de Madrid (REMEDINAL TE-CM, S2018/EMT-4338) respectively. JR, DSP and LGS acknowledge to research projects funded by the Spanish Government, CTM2015–64728-C2–1-R and PID2019-105469RB-C21 for providing financial support at different stages of the data analyses and manuscript development. EV was supported by the 2017 program for attracting and retaining talent of Comunidad de Madrid (no. 2017-T2/ AMB-5406).

14 páginas.- 7 figuras.- 49 referencias, Background Little is known about the global distribution and environmental drivers of key microbial functional traits such as antibiotic resistance genes (ARGs). Soils are one of Earth’s largest reservoirs of ARGs, which are integral for soil microbial competition, and have potential implications for plant and human health. Yet, their diversity and global patterns remain poorly described. Here, we analyzed 285 ARGs in soils from 1012 sites across all continents and created the first global atlas with the distributions of topsoil ARGs. Results We show that ARGs peaked in high latitude cold and boreal forests. Climatic seasonality and mobile genetic elements, associated with the transmission of antibiotic resistance, were also key drivers of their global distribution. Dominant ARGs were mainly related to multidrug resistance genes and efflux pump machineries. We further pinpointed the global hotspots of the diversity and proportions of soil ARGs. Conclusions Together, our work provides the foundation for a better understanding of the ecology and global distribution of the environmental soil antibiotic resistome., This project received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement 702057 (CLIMIFUN), a Large Research Grant from the British Ecological Society (agreement no. LRA17\1193; MUSGONET), and from the European Research Council (ERC grant agreement no. 647038, BIODESERT). M. D. B. was also supported by a Ramón y Cajal grant (RYC2018-025483-I). M.D-B. also acknowledges support from the Spanish Ministry of Science and Innovation for the I+D+i project PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033. M.D-B. is also supported by a project of the Fondo Europeo de Desarrollo Regional (FEDER) and the Consejería de Transformación Económica, Industria, Conocimiento y Universidades of the Junta de Andalucía (FEDER Andalucía 2014-2020 Objetivo temático “01 - Refuerzo de la investigación, el desarrollo tecnológico y la innovación”) associated with the research project P20_00879 (ANDABIOMA). FTM acknowledges support from Generalitat Valenciana (CIDEGENT/2018/041). J. Z. H and H. W. H. are financially supported by Australian Research Council (DP210100332). We also thank the project CTM2015-64728-C2-2-R from the Ministry of Science of Spain. C. A. G. and N. E. acknowledge funding by the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, funded by the German Research Foundation (FZT 118). TG was financially supported by Slovenian Research Agency (P4-0107, J4-3098 and J4-4547)

Phosphorus (P) acquisition is key for plant growth. Arbuscular mycorrhizal fungi (AMF) help plants acquire P from soil. Understanding which factors drive AMF-supported nutrient uptake is essential to develop more sustainable agroecosystems. Here we collected soils from 150 cereal fields and 60 non-cropped grassland sites across a 3,000 km trans-European gradient. In a greenhouse experiment, we tested the ability of AMF in these soils to forage for the radioisotope 33P from a hyphal compartment. AMF communities in grassland soils were much more efficient in acquiring 33P and transferred 64% more 33P to plants compared with AMF in cropland soils. Fungicide application best explained hyphal 33P transfer in cropland soils. The use of fungicides and subsequent decline in AMF richness in croplands reduced 33P uptake by 43%. Our results suggest that land-use intensity and fungicide use are major deterrents to the functioning and natural nutrient uptake capacity of AMF in agroecosystems. The Digging Deeper project was funded through the 2015-2016 BiodivERsA COFUND call for research proposals, with the national funders Swiss National Science Foundation (grant 31BD30-172466), Deutsche Forschungsgemeinschaft (317895346), Swedish Research Council Formas (contract 2016-0194), Ministerio de Economía y Competitividad (Digging_Deeper, Ref. PCIN-2016-028) and Agence Nationale de la Recherche (ANR, France; grant ANR-16-EBI3-0004-01).

Drylands are important reservoirs of soil phosphorus (P) at the global scale, although large uncertainties remain regarding how climate change will affect P cycling in these ecosystems. Biocrust-forming lichens are important regulators of abiotic and biotic processes occurring in the soil surface, including nutrient availability and redistribution, across global drylands. However, their role as modulators of climate change impacts on soil P cycling is poorly known. We conducted a manipulative microcosm experiment to evaluate how six biocrust-forming lichens (Buellia zoharyi, Diploschistes diacapsis, Fulgensia subbracteata, Psora decipiens, Squamarina lentigera, and Toninia sedifolia) with diverse morphology and chemistry affect soil available P concentration and the activity of acid phosphatase after 50 months of simulated ~2°C warming and 35% rainfall reduction. Lichens increased soil available inorganic and total available P, and the activity of acid phosphatase, although the magnitude of these effects was highly species-specific. Climate change treatments increased available organic P regardless of lichen species. Our findings provide novel experimental evidence on the importance of biocrusts as modulators of P cycling in drylands and highlight the necessity to take into account the identity of biocrust constituents when evaluating their effects on soil fertility. This research was funded by the European Research Council (ERC Grant Agreements 242658 [BIOCOM] and 647038 [BIODESERT] awarded to F.T.M), and by the Marie Skłodowska-Curie Actions (MSCA Grant Agreement 795380 [INDECRUST] awarded to L.C-Z.). E.V. was supported by the 2017 program for attracting and retaining talent of Comunidad de Madrid (no. 2017‐T2/ AM B‐ 5406). F.T.M . also acknowledges support from Generalitat Valenciana (CIDEGENT/2018/041).

Grazing by domestic livestock is both the main land use across drylands worldwide and a major desertification and global change driver. The ecological consequences of this key human activity have been studied for decades, and there is a wealth of information on its impacts on biodiversity and ecosystem processes. However, most field assessments of the ecological impacts of grazing on drylands conducted to date have been carried out at local or regional scales and have focused on single ecosystem attributes (e.g., plant productivity) or particular taxa (mainly aboveground, e.g., plants). Here we introduce the BIODESERT survey, the first systematic field survey devoted to evaluating the joint impacts of grazing by domestic livestock and climate on the structure and functioning of dryland ecosystems worldwide. This collaborative global survey was carried out between 2016 and 2019 and has involved the collection of field data and plant, biocrust, and soil samples from a total of 326 45 m × 45 m plots from 98 sites located in 25 countries from 6 continents. Here we describe the major characteristics and the field protocols used in this survey. We also introduce the organizational aspects followed, as these can be helpful to everyone wishing to establish a global collaborative network of researchers. The BIODESERT survey provides baseline data to assess the current status of dryland rangelands worldwide and the impacts of grazing on these key ecosystems, and it constitutes a good example of the power of collaborative research networks to study the ecology of our planet using much-needed field data. This research has been supported by the European Research Council (ERC grant agreement no. 647038 – BIODESERT) and the Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital, Generalitat Valenciana (grant no. CIDEGENT/2018/041). Nicolas Gross was supported by CAP 20-25 (16-IDEX-0001) and the AgreenSkills+ fellowship program which has received funding from the EU's Seventh Framework Programme under grant agreement no. 996 FP7-609398 (AgreenSkills+ contract). Hugo Saiz is supported by a María Zambrano fellowship funded by the Ministry of Universities and European Union Next Generation plan.

15 páginas.- 6 figuras.- 93 referencias, Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here, we examined endemicity patterns, global change vulnerability and conservation priority areas for functional groups of soil fungi based on six global surveys using a high-resolution, long-read metabarcoding approach. We found that the endemicity of all fungi and most functional groups peaks in tropical habitats, including Amazonia, Yucatan, West-Central Africa, Sri Lanka, and New Caledonia, with a negligible island effect compared with plants and animals. We also found that fungi are predominantly vulnerable to drought, heat and land-cover change, particularly in dry tropical regions with high human population density. Fungal conservation areas of highest priority include herbaceous wetlands, tropical forests, and woodlands. We stress that more attention should be focused on the conservation of fungi, especially root symbiotic arbuscular mycorrhizal and ectomycorrhizal fungi in tropical regions as well as unicellular early-diverging groups and macrofungi in general. Given the low overlap between the endemicity of fungi and macroorganisms, but high conservation needs in both groups, detailed analyses on distribution and conservation requirements are warranted for other microorganisms and soil organisms., The bulk of the funding is derived from the Estonian Science Foundation (grants PRG632, PRG1170, PRG1615, MOBTP198), EEA Financial Mechanism Baltic Research Programme (EMP442), and Novo Nordisk Fonden (NNF20OC0059948).

17 páginas.- 4 figuras.- 68 referencias.- Supplementary information The online version contains supplementary material available at https://doi.org/10.1038/s41477-022-01198-8, Knowing the extent and environmental drivers of forests is key to successfully restore degraded ecosystems, and to mitigate climate change and desertification impacts using tree planting. Water availability is the main limiting factor for the development of forests in drylands, yet the importance of groundwater resources and palaeoclimate as drivers of their current distribution has been neglected. Here we report that mid-Holocene climates and aquifer trends are key predictors of the distribution of dryland forests worldwide. We also updated the global extent of dryland forests to 1,283 million hectares and showed that failing to consider past climates and aquifers has resulted in ignoring or misplacing up to 130 million hectares of forests in drylands. Our findings highlight the importance of a wetter past and well-preserved aquifers to explain the current distribution of dryland forests, and can guide restoration actions by avoiding unsuitable areas for tree establishment in a drier world., This research was funded by the European Research Council (ERC Grant agreement 647038 (BIODESERT)) and Generalitat Valenciana (CIDEGENT/2018/041). E.G. was supported by the Consellería de Educación, Cultura y Deporte de la Generalitat Valenciana, and the European Social Fund (APOSTD/2021/188). D.A-S. was partially supported by DETECTOR (grant no. A-RNM-256-UGR18, Universidad de Granada/FEDER), LifeWatch SmartEcoMountains (grant no. LifeWatch-2019-10-UGR-01, Ministerio de Ciencia e Innovación/Universidad de Granada/FEDER), RESISTE (grant no. P18-RT-1927, Consejería de Economía, Conocimiento y Universidad from the Junta de Andalucía/FEDER) and EBV–ScaleUp project (funded by Google Earth Engine and the Group on Earth Observations). M.D-B. acknowledges support from the Spanish Ministry of Science and Innovation (for the I+D+i project PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033), and from a project of the Fondo Europeo de Desarrollo Regional (FEDER) and the Consejería de Transformación Económica, Industria, Conocimiento y Universidades of the Junta de Andalucía (FEDER Andalucía 2014-2020 Objetivo temático ‘01 - Refuerzo de la investigación, el desarrollo tecnológico y la innovación’) associated with the research project P20_00879 (ANDABIOMA). S.T. was supported by DeepL-ISCO (grant no. A-TIC-458-UGR18, Ministerio de Ciencia e Innovación/FEDER), BigDDL-CET (grant no. P18-FR-4961, Proyectos I+D+i Junta de Andalucia 2018) and LifeWatch SmartEcoMountains.

Mycorrhizal symbiosis is an ancient association of plants and mycorrhizal fungi central to woody plant evolution and expansion. This symbiosis has established a complex exchange of services between plants and mycorrhizal fungi that ultimately helps plants thrive in extreme abiotic conditions and build resistance against lack of nutrients and water, pathogens, herbivores, or pollutants. Here, we briefly comment on the roles of mycorrhizal symbiosis as modulators of the responses of woody plants to multiple abiotic stress factors typical to ongoing global change. We comment on the most studied factors, i.e. drought, extreme temperatures, nutrient and light deficiency. There is a general lack of understanding of the interaction among stress factors and their combined effects on woody plants, their symbiotic interaction with mycorrhizal fungi and their impact on ecosystem processes. As a first step, identifying and ranking the severity of stress factors and situations/locations where multiple stress factors co-occur could guide initial expectations and hypotheses to comprehend the mycorrhizal benefits to woody species tolerance under multifactorial stress combinations. We finally highlight topical areas that require more information and research. CGB and YM have been funded by the Estonian Ministry of Education and Research (PRG1065) and an ERC incentive grant from the University of Tartu to CGB (PLTOMARENG70).

En la segunda mitad del siglo XX se llevaron a cabo extensas repoblaciones en el SE de la Península Ibérica utilizando casi exclusivamente el pino carrasco (Pinus halepensis). El objetivo de las mismas era recuperar una cierta cubierta arbórea, desaparecida como consecuencia de diferentes usos y perturbaciones. Pese a su magnitud y a la sensibilidad de estas zonas a la desertificación, hasta la fecha no disponemos de una revisión exhaustiva de las consecuencias de estas repoblaciones y una evaluación objetiva del éxito conseguido en la restauración de estos ecosistemas. Esta revisión sería muy útil para poder desarrollar una gestión adaptativa de estos ecosistemas, y con ello optimizar los recursos asignados a su restauración. En este trabajo hemos recopilado información propia y bibliográfica sobre estas cuestiones, tratando de extraer conclusiones y de identificar cuestiones aún no solucionadas. Aleppo pine (Pinus halepensis) has been extensively used for the afforestation in SE Spain during the second half of the XXth century. The main objectives of these plantations were to increase plant protective cover and to regulate hydrological cycles. Despite the magnitude of these interventions and the sensitivity of this area to desertification, the ecological consequences of these plantations and the degree of success in restoring ecosystem integrity has not been fully evaluated. An integrated study could be very helpful to develop an adaptive management of these areas, and to optimise resources allocation. Here we review available information on the effect of P. halepensis afforestations under semiarid conditions, and identify the main lacks of knowledge. Esta revisión ha sido posible gracias a la financiación recibida a través del proyecto FANCB (Ministerio de Ciencia y Tecnología y FEDER; REN2001-0424-C02-02 / GLO).

22 páginas.- 6 figuras.- 58 referencias.- Extended data is available for this paper at https://doi.org/10.1038/s41559-022-01756-5 Supplementary information The online version contains supplementary material available at https://doi.org/10.1038/s41559-022-01756-5 .-The raw data associated with this study are available at https://figshare.com/s/5299f4b83c1abec736fc (https://doi.org/10.6084/m9.figshare.14905236). ITS sequencing data associated with global surveys 1, 2 and 3 are available at https://figshare.com/s/9772d31625426d90778222 (https://doi.org/10.6084/m9.figshare.5923876.v1), the Short Read Archive (accession SRP043706)23 and https://figshare.com/s/5e16fa5b0475880c0fa5 (https://doi.org/10.6084/m9.figshare.19419335), respectively, oil fungi are fundamental to plant productivity, yet their influence on the temporal stability of global terrestrial ecosystems, and their capacity to buffer plant productivity against extreme drought events, remain uncertain. Here we combined three independent global field surveys of soil fungi with a satellite-derived temporal assessment of plant productivity, and report that phylotype richness within particular fungal functional groups drives the stability of terrestrial ecosystems. The richness of fungal decomposers was consistently and positively associated with ecosystem stability worldwide, while the opposite pattern was found for the richness of fungal plant pathogens, particularly in grasslands. We further demonstrated that the richness of soil decomposers was consistently positively linked with higher resistance of plant productivity in response to extreme drought events, while that of fungal plant pathogens showed a general negative relationship with plant productivity resilience/resistance patterns. Together, our work provides evidence supporting the critical role of soil fungal diversity to secure stable plant production over time in global ecosystems, and to buffer against extreme climate events. The authors link fungal diversity to the stability of terrestrial ecosystem productivity across three global datasets, finding that richness of decomposers and mycorrhizae are positively associated with stability while the richness of plant pathogens is negatively related to stability., This project received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 702057 (CLIMIFUN). M.D.-B. was supported by a Ramon y Cajal grant from the Spanish Ministry of Science and Innovation (RYC2018-025483-I). M.D-B. is also supported by a project from the Spanish Ministry of Science and Innovation (PID2020-115813RA-I00), and a project of the Fondo Europeo de Desarrollo Regional (FEDER) and the Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades of the Junta de Andalucia (FEDER Andalucia 2014-2020 Objetivo tematico "01 -Refuerzo de la investigacion, el desarrollo tecnologico y la innovacion") associated with the research project P20_00879 (ANDABIOMA). S.L. was supported by the National Natural Science Foundation of China (grant no. 32101491) and fellowship of China Postdoctoral Science Foundation (2021M701968). P.G.-P. was supported by a grant from the Spanish Ministry of Science and Innovation (DUALSOM, PID2020-113021RA-I00). E.G. is supported by the European Research Council grant agreement 647038 (BIODESERT) and the Conselleria de Educacion, Cultura y Deporte de la Generalitat Valenciana, and the European Social Fund (APOSTD/2021/188).