Fernando T Maestre

King Abdullah University of Science and Technology | KAUST · Division of Biological and Environmental Sciences and Engineering (BESE)

Aims Biocrusts, communities dominated by mosses, lichens, cyanobacteria, algae, and fungi living on the soil surface, constitute a vital biotic component of dryland ecosystems that play critical roles in maintaining their structure and functioning. However, there are substantial knowledge gaps regarding the global distribution of biocrusts, which h...

Introduction Increasing soil organic carbon (SOC) in croplands is a natural climate mitigation effort that can also enhance crop yields. However, there is a lack of comprehensive field studies examining the impact of SOC on crop yields across wide climatic, soil, and farming gradients. Furthermore, it is largely unknown how water retention, soil mi...

Increases in the abundance of woody species have been reported to affect the provisioning of ecosystem services in drylands worldwide. However, it is virtually unknown how multiple biotic and abiotic drivers, such as climate, grazing, and fire, interact to determine woody dominance across global drylands. We conducted a standardized field survey in...

The increasing prevalence of drought events in grasslands and shrublands worldwide potentially has impacts on soil organic carbon (SOC). We leveraged the International Drought Experiment to study how SOC, including particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) concentrations, responds to extreme drought treatments (1...

Land degradation from water erosion poses a significant threat to water security and ecosystem stability, driving global efforts in soil conservation. Quantitative assessment of soil conservation benefits—both on-site and off-site—is crucial for guiding effective conservation strategies. However, existing methodologies often fall short in quantifyi...

Grasslands are integral to maintaining biodiversity and key ecosystem services and are under threat from climate change. Plant and soil microbial diversity, and their interactions, support the provision of multiple ecosystem functions (multifunctionality). However, it remains virtually unknown whether plant and soil microbial diversity explain a un...

Earth harbours an extraordinary plant phenotypic diversity¹ that is at risk from ongoing global changes2,3. However, it remains unknown how increasing aridity and livestock grazing pressure—two major drivers of global change4–6—shape the trait covariation that underlies plant phenotypic diversity1,7. Here we assessed how covariation among 20 chemic...

Mineral-associated organic carbon (MAOC) constitutes a major fraction of global soil carbon and is assumed less sensitive to climate than particulate organic carbon (POC) due to protection by minerals. Despite its importance for long-term carbon storage, the response of MAOC to changing climates in drylands, which cover more than 40% of the global...

The crossing of aridity thresholds triggers abrupt changes in multiple functional and structural ecosystem attributes across global drylands. While we understand the consequences associated with aridity thresholds, the key factors influencing dryland vegetation resistance when crossing them remain unclear. Here, we used field observations from 58 d...

Protists, a crucial part of the soil food web, are increasingly acknowledged as significant influencers of nutrient cycling and plant performance in farmlands. While topographical and climatic factors are often considered to drive microbial communities on a continental scale, higher trophic levels like heterotrophic protists also rely on their food...

Soils support a vast amount of carbon (C) that is vulnerable to climatic and anthropogenic global change stressors (for example, drought and human-induced nitrogen deposition). However, the simultaneous effects of an increasing number of global change stressors on soil C storage and persistence across ecosystems are virtually unknown. Here, using 1...

Research carried out in drylands over the last decade has provided major insights on the biodiversity–ecosystem functioning relationship (BEFr) and about how biodiversity interacts with other important factors, such as climate and soil properties, to determine ecosystem functioning and services. Despite this, there are important gaps in our underst...

Perennial plants create productive and biodiverse hotspots, known as fertile islands, beneath their canopies. These hotspots largely determine the structure and functioning of drylands worldwide. Despite their ubiquity, the factors controlling fertile islands under conditions of contrasting grazing by livestock, the most prevalent land use in dryla...

Species‐specific differences in nutrient acquisition strategies allow for complementary use of resources among plants in mixtures, which may be further shaped by mycorrhizal associations. However, empirical evidence of this potential role of mycorrhizae is scarce, particularly for tree communities. We investigated the impact of tree species richnes...

Las zonas áridas ocupan casi la mitad de la superficie de la Tierra. Su peculiar régimen hidrológico hace del agua su principal factor limitante, junto con otras señas de identidad propias de estas regiones, como las adaptaciones morfológicas y funcionales de su fauna y flora, y las culturales y sociales de sus más de 2.000 millones de habitantes,...

Background and aims In dryland regions, patches of vegetation play a crucial role in sequestering carbon and vital nutrients, creating what have been described as ‘fertile islands’ within the surface soil beneath their canopies. Nevertheless, a persistent question remains regarding the variability of fertile island effect in relation to soil depth....

Ongoing global warming is expected to augment soil respiration by increasing microbial activity, driving self-reinforcing feedback to climate change. However, the compensatory thermal adaptation of soil microorganisms and substrate depletion may weaken the effects of rising temperature on soil respiration. To test this hypothesis, we collected soil...

Intrinsic water use efficiency (WUEi) reflects the trade‐off between photosynthetic carbon gain and water loss through stomatal conductance and is key for understanding dryland plant responses to climate change. Stipa tenacissima is a perennial tussock C 3 grass with an opportunistic, drought‐avoiding water use strategy that dominates arid and semi...

Self-organized spatial patterns are a common feature of complex systems, ranging from microbial communities to mussel beds and drylands. While the theoretical implications of these patterns for ecosystem-level processes, such as functioning and resilience, have been extensively studied, empirical evidence remains scarce. To address this gap, we ana...

Understanding soil microbial populations influencing biogeochemical cycles with potential implications for greenhouse gas (GHG) fluxes emissions is crucial. Methanotrophic, nitrifying and N2O-reducing microorganisms are major drivers of CH4 and N2O fluxes in soils. The metabolism of these organisms relies on enzymes that require as cofactors metal...

Climate change is increasing the frequency and severity of short-term (~1 y) drought events—the most common duration of drought—globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in t...

Soil fungi are a key constituent of global biodiversity and play a pivotal role in agroecosystems. How arable farming affects soil fungal biogeography and whether it has a disproportional impact on rare taxa is poorly understood. Here, we used the high-resolution PacBio Sequel targeting the entire ITS region to investigate the distribution of soil...

Preserving and restoring terrestrial ecosystems is crucial to halting the collapse of life on Earth. To guide global conservation and restoration efforts, we present a comprehensive map, encompassing all ecosystems, revealing the Earth's potential tree, short vegetation, and bareground cover accounting for various land management scenarios such as...

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 h...

Species-specific differences in nutrient acquisition strategies allow for complementary use of resources among plants in mixtures, which may be further shaped by mycorrhizal associations. However, empirical evidence of these relationships is scarce, particularly for tree communities. We investigated the impact of tree species richness and mycorrhiz...

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 sit...

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 lev...

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 lev...

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 earth...

Background and aims In arid regions, patches of vegetation serve a vital function in carbon and nutrient sequestration, fostering the emergence of 'fertile islands' within the soil beneath their canopies. However, the variation in the fertile island effects across soil depth remains an open question. Methods To explore this, we sampled soils from t...

The crossing of specific aridity thresholds has been shown to trigger abrupt changes in multiple functional and structural ecosystem attributes across global drylands. While we understand the consequences associated with aridity thresholds, a significant knowledge gap remains concerning the key biotic and abiotic factors that influence the resistan...

Saudi Arabia, a country characterized by its vast deserts, unique geographical features, and rich cultural heritage, stands at the precipice of a transformative challenge: adapting to the impacts of a rapidly changing climate. As global temperatures continue to rise due to the accumulation of greenhouse gasses in the atmosphere, Saudi Arabia is p...

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 c...

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 product...

Soil is one of the largest reservoirs for antibiotic resistance in the world. Bacteria can carry antibiotic resistance genes (ARGs) and share them via mechanisms like mobile genetic elements. Antibiotic resistance in the soil microbes impacts microbial community dynamics and it can spread to human and animal pathogens. Despite this importance, this...

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 o...

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...

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 suitab...

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 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 c...

Organic carbon and aggregate stability are key features of soil quality and 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...

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...

Across free-living organisms, the ecology and evolution of offspring morphology is shaped by interactions with biotic and abiotic environments during dispersal and early establishment in new habitats. However, the ecology and evolution of offspring morphology for symbiotic species has been largely ignored despite host-symbiont interactions being ub...

Grasslands are integral to maintaining biodiversity and key ecosystem services under climate change. Plant and soil biodiversity, and their interactions, support the provision of multiple ecosystem functions (multifunctionality). However, whether plant and soil biodiversity explain unique, or shared, contributions to supporting multifunctionality a...

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 earth...

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 produ...

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...

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 in...

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 in...

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...

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. Her...

Unlabelled: 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...

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....

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 used high‐resolution sequencing to assess endemicity patterns, global change vulnerability and conservation priority areas...

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-Eur...

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 driver...

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,...

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...

Determining the influence of climate in driving the global distribution of soil microbial communities is fundamental to help predict potential shifts in soil food webs and ecosystem functioning under global change scenarios. Herein, we used a global survey including 80 dryland ecosystems from six continents, and found that the relative abundance of...

Ongoing global warming and alterations in rainfall patterns driven by climate change are known to have large impacts on biogeochemical cycles, particularly on drylands. In addition, the global increase in atmospheric nitrogen (N) deposition can destabilize primary productivity in terrestrial ecosystems, and phosphorus (P) may become the most limiti...