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Climate‐vegetation interaction assessments often focus on vegetation response to concurrent climatic perturbations, seldom on the time‐lag effect of climate. Here we employ global satellite observations, climate data records and CO2 flux measurements to calculate the time‐lag of vegetation response to climate. We analyze the time‐lags of various climate variables under distinct environmental conditions to gain insight into how the long‐term climatic regimes and tree cover influence the time‐lag effects. Our findings reveal that terrestrial ecosystems characterized by arid and cold climates show more concurrent climate‐vegetation interactions than other ecosystems. Whereas areas with higher tree cover and humid ecosystems with both high mean annual temperature and precipitation show substantial time‐lag response of vegetation to climate by up to 6 months. Since the global climate‐vegetation interaction is dominated by time‐lag effects, incorporating these effects is paramount to improve our understanding of vegetation dynamics under a changing climate. Plain Language Summary: When studying how climate affects vegetation, many studies usually focus on immediate plant responses, without considering the long‐term effects of climate. In our study, we used satellite data to look at how plant photosynthesis and growth changed over time in response to concurrent and past climates. We found that in dry and cold areas, plants respond quickly to changes in climate. But in regions with high tree cover and humid climate, plant responses to climate can take up to 6 months. Understanding these delays is crucial for predicting how vegetation will respond as the climate changes around the world. Key Points: Terrestrial ecosystems with higher tree cover respond to climate perturbation more slowly than grasslands and croplandsTemperature consistently has more significant impacts on vegetation in the longer term than VPD and soil moistureArid and cold ecosystems show shorter time‐lag responses of vegetation to climate [ABSTRACT FROM AUTHOR]

Archeological evidence from loess sediments from Shangchen on the southeastern Chinese Loess Plateau indicates a suspension of hominin occupation around the time of the early mid‐Pleistocene climate transition, prompting a re‐assessment of climate‐vegetation‐hominin interactions. Loess deposits with in situ lithic records cover the period of hominin occupation and reveal four distinct climate‐vegetation periods (2.1–1.8, 1.8–1.26, 1.26–0.9, and 0.9–0.6 Ma). Major oscillations in climate superimposed upon an aridification trend and an expansion of C4 herbaceous vegetation from about 1.26 Ma may have driven early humans to move to more hospitable locations in the region. Comparison with the record at Nihewan indicates that large‐scale climate oscillations induced disparate hominin responses due to distinctive local environmental conditions. Plain Language Summary: A combination of several lines of evidence suggests that changes in climate and their impacts on the availability of food and shelter from around 1.26 million years ago may have driven the dispersal of early humans from the southeastern Chinese Loess Plateau to more hospitable environments elsewhere in the region. Key Points: Pleistocene temperature, rainfall, and C4 plants ratios are quantitatively reconstructed from the Shangchen loess deposits with artifactsHigh climate variability, C4 plants expansion and aridification suspended hominin occupation at Shangchen during the early mid‐Pleistocene climate transitionHominins responded differently to large‐scale climate oscillations depending on distinctive local environmental conditions [ABSTRACT FROM AUTHOR]

Local homogeneity, in ecology, is the often undisclosed assumption that variability within populations is negligible or mostly distributed evenly. In large areas, this can lead to the aggregation of different populations without regard for their unique needs and characteristics, such as drought sensitivity and functional trait distributions. Here, we discuss whether this assumption can be justified, and we hypothesize that discerning the source of variation between plasticity and adaptation could be a feasible approach to formulate an informed decision. We test this hypothesis on plants, resorting to a common garden experiment to determine the source of variation of several plant functional traits at a local scale (~60 km) of three wild species: Quercus ilex, Pistacia lentiscus, and Cistus salviifolius. Individuals of each species were sourced from three key sites chosen along a local aridity gradient. Our approach led to the rejection of the local homogeneity assumption for Q. ilex and C. salviifolius at this scale due to the adaptive divergence observed among neighboring populations. This case study provides evidence that addressing local homogeneity can highlight diverging populations in a relatively simple way. We conclude that gathering empirical evidence on intraspecific variability is a feasible approach that can provide researchers with solid bases to decide whether to adopt the local homogeneity assumption or not. [ABSTRACT FROM AUTHOR]

Spatial vegetation patterns are associated with ecosystem stability and multifunctionality in drylands. Changes in patch size distributions (PSDs) are generally driven by both environmental and biological factors. However, the relationships between these factors in driving PSDs are not fully understood. We investigated 80 vegetation plots along an aridity gradient in the Alxa plateau, Northwest China. The sizes of vegetation patches were obtained from aerial images, and the heights of patch‐forming species were measured in the field. Soil samples were collected on the bare ground between patches for determination of physiochemical properties. Point pattern analysis was used to infer plant–plant interactions. A model selection procedure was employed to select the best predictors for the shape of PSDs and biological factors (vegetation total cover, community plant height, and plant–plant interactions). We then used structural equation modeling to evaluate the direct and indirect effects of environmental and biological factors on the shape of PSDs. In our study area, two types of PSDs coexisted, namely those that best fit to power law distributions and those that best fit to lognormal distributions. Aridity was the main environmental factor, while community mean height and competition between plants were the main biological factors for the shape of PSDs. As aridity and community mean height increased, power law‐like PSDs were exhibited, whereas competition led to deviations of PSDs from power laws. Aridity affected the shape of PSDs indirectly through changes in community mean height. Community mean height was correlated with competition, thereby indirectly affecting the shape of PSDs. Our results suggest the use of community functional traits as a link between the environment and plant–plant interactions, which may improve the understanding of the underlying mechanisms of PSD dynamics. [ABSTRACT FROM AUTHOR]

Groundwater is an invaluable global resource, but its long‐term viability as a resource for consumption, agriculture, and ecosystems depends on precipitation recharging aquifers. How much precipitation recharges groundwaters varies enormously across Earth's surface, yet recharge rates often remain uncertain. Here we use a global synthesis of field‐estimated recharge across six continents to show that globally recharge first‐order follows a simple function of climatic aridity. We use this relationship to estimate long‐term recharge in energy‐limited systems outside of permafrost regions. Our aridity‐based recharge estimates are consistent with the global field data but, on average, double previous estimates of global models. Our higher recharge estimates are likely caused by preferential groundwater recharge and discharge occurring at grid scales finer than global models. The higher recharge estimates suggest that more groundwater contributes to evapotranspiration and streamflow than previously represented by global hydrological models and global water cycle diagrams. Plain Language Summary: Groundwater is an essential resource for societies and ecosystems. The rate at which rainfall and snow replenish groundwater storage is important as it dictates the upper limit of sustainable groundwater use. Here we use measurements of groundwater recharge to show how climate determines groundwater recharge rates. Measured recharge rates, on average, strongly exceed those of models. This suggests there is more recharge globally than currently acknowledged. Consequently, also more groundwater recharge must get back to Earth's surface via river flow or water use of vegetation. Key Points: A global recharge data set indicates that climate strongly shapes the fraction of precipitation that will recharge groundwatersThis recharge data set indicates more recharge globally than existing global hydrological models suggestThus, more groundwater must contribute to evaporation and streamflow than represented by current global models and water cycle diagrams [ABSTRACT FROM AUTHOR]

Regular vegetation patterns have been predicted to indicate a system slowing down and possibly desertification of drylands. However, these predictions have not yet been observed in dryland vegetation due to the inherent logistic difficulty to gather longer‐term in situ data. Here, we evaluate the theoretical prediction that regular vegetation patterns are associated with empirically derived temporal indicators (autocorrelation, variance, responsiveness) of critical slowing down in a dryland ecosystem in Sudan using different remote sensing products. We use recently developed methods using remote‐sensing EVI time‐series in combination with classified regular vegetation patterns along a rainfall gradient in Sudan to test the predicted slowing down. We tested our empirical findings against theoretical predictions from a stochastic version of a spatial explicit model that has been used to describe vegetation dynamics in drylands under aridity stress. Overall, three temporal indicators (responsiveness, temporal autocorrelation, variance) show slowing down as vegetation patterns change from gaps to labyrinths to spots towards more arid conditions, confirming predictions. However, this transition exhibits non‐linearities, specifically when patterns change configuration. Model simulations reveal that the transition between patterns temporarily slows down the system affecting the temporal indicators. These transient states when vegetation patterns reorganize thus affect the systems resilience indicators in a non‐linear way. Our findings suggest that spatial self‐organization of dryland vegetation is associated with critical slowing down, but this transition towards reduced resilience happens in a non‐linear way. Future work should aim to better understand transient dynamics in regular vegetation patterns in dryland ecosystems, because long transients make regular vegetation patterns of limited use for management in anticipating critical transitions. [ABSTRACT FROM AUTHOR]

Aim: Patterns of species richness along elevation gradients vary with geographic and environmental factors but evidence for similar variation in functional and phylogenetic diversity remains scarce. Here, we provide the most comprehensive evaluation to date of elevational gradients in taxonomic, functional, and phylogenetic diversity of rodents – one of the most ecologically diverse groups of mammals – and test the effects of latitude and aridity on their variation for the first time. Location: Forty‐nine mountains on five continents. Time period: Contemporary. Major taxa studied: Rodents (Rodentia). Methods: We compiled elevational distributions of 374 rodent species across 49 elevational gradients. For each gradient, we quantified – in 100‐m elevational bins – rodent species richness and functional and phylogenetic richness, evenness, and dispersion, and their species richness‐corrected equivalents. To assess how rodent diversity varies with elevation, we fitted a series of models that included elevation, average latitude, and aridity of each mountain system while accounting for variation in study design and sampling effort. Results: A common mid‐elevational peak in species richness among mountains contrasts with functional and phylogenetic diversity pattern variation (model shape and slope) explained by the aridity at a mountain's base. Specifically, we find that functional and phylogenetic richness and dispersion decline with elevation in wet mountain systems but increase with elevation in arid mountains. Main conclusions In this first comparative analysis of mammal functional and phylogenetic elevational gradients, we find that the decoupling of each from species richness is particularly pronounced in arid regions. Wet‐mountain lowlands and arid‐mountain highlands harbour the most functionally and phylogenetically diverse rodent communities, indicating that water availability is a strong environmental filter in structuring diversity of small mammals on mountain gradients. High regularity of species distances within assemblages supports a constant role for competition across all elevations and niche expansion in elevations with greater species richness. [ABSTRACT FROM AUTHOR]

Earth System Models' complex land components simulate a patchwork of increases and decreases in surface water availability when driven by projected future climate changes. Yet, commonly‐used simple theories for surface water availability, such as the Aridity Index (P/E0) and Palmer Drought Severity Index (PDSI), obtain severe, globally dominant drying when driven by those same climate changes, leading to disagreement among published studies. In this work, we use a common modeling framework to show that Earth System Model (ESM) simulated runoff‐ratio and soil‐moisture responses become much more consistent with the P/E0 and PDSI responses when several previously known factors that the latter do not account for are cut out of the simulations. This reconciles the disagreement and makes the full ESM responses more understandable. For ESM runoff ratio, the most important factor causing the more positive global response compared to P/E0 is the concentration of precipitation in time with greenhouse warming. For ESM soil moisture, the most important factor causing the more positive global response compared to PDSI is the effect of increasing carbon dioxide on plant physiology, which also drives most of the spatial variation in the runoff ratio enhancement. The effect of increasing vapor‐pressure deficit on plant physiology is a key secondary factor for both. Future work will assess the utility of both the ESMs and the simple indices for understanding observed, historical trends. Plain Language Summary: Rivers and groundwater provide almost all water used by humans, and soil moisture is critical for vegetation and crops worldwide. Supercomputer model simulations of rivers, groundwater and soil moisture under future global warming routinely project that some world regions will experience increases in the availability of these resources, while others will experience decreases. Yet the simple formulas that scientists have traditionally relied on to measure climatic "drought" and "aridity" obtain large future decreases in water availability (drying) almost everywhere. This has led to confusion in prior studies and reports. In this study, we resolve this apparent paradox by pinpointing exactly why the supercomputer simulations are less pessimistic than the simple formulas. For rivers and groundwater, the most important reason is that precipitation gets "flashier" and more intense with global warming. For soil moisture, the most important reason is that increasing carbon dioxide allows vegetation to use less water, keeping more water in the soil. Both of these processes are included in the computer models, but not in the simple formulas. This new understanding gives us greater confidence that the computer models are behaving reasonably. Key Points: Community Land Model 5 runoff ratio and soil moisture responses to climate change closely follow the Aridity Index (P/E0) and Palmer Drought Severity Index (PDSI) in a simplified simulationRunoff ratio increases much more than P/E0 in full simulations primarily due to changes in the temporal pattern of precipitationSoil moisture increases more than PDSI in full simulations primarily due to CO2 and vapor pressure deficit effects on plant physiology [ABSTRACT FROM AUTHOR]

Summary: The discovery and characterization of plant species adapted to extreme environmental conditions have become increasingly important. Hoffmannseggia doellii is a perennial herb endemic to the Chilean Atacama Desert that grows in the western Andes between 2800 and 3600 m above sea level. Its growing habitat is characterized by high radiation and low water and nutrient availability. Under these conditions, H. doellii can grow, reproduce, and develop an edible tuberous root.We characterized the H. doellii soil‐associated microbiomes to understand the biotic factors that could influence their surprising ability to survive.We found an increased number of observed species and higher phylogenetic diversity of bacteria and fungi on H. doellii root soils compared with bare soil (BS) along different sites and to soil microbiomes of other plant species. Also, the H. doellii‐associated microbiome had a higher incidence of overall positive interactions and fungal within‐kingdom interactions than their corresponding BS network.These findings suggest a microbial diversity soil modulation mechanism that may be a characteristic of highly tolerant plants to diverse and extreme environments. Furthermore, since H. doellii is related to important cultivated crops, our results create an opportunity for future studies on climate change adaptation of crop plants. [ABSTRACT FROM AUTHOR]

Aridity associated with rising air temperatures in northern latitudes is expected to contribute to increased frequency of wildland fires. Here, we examined regenerating vegetation following short return interval (SRI) fire (56 years post‐fire) compared to long return interval (LRI) fire (>80 years post‐fire) in boreal peatlands and their adjacent transitional areas. The objectives of this study were to quantify if differences exist between (1) peatland and transitional soil characteristics in LRI versus SRI areas and (2) regenerating vegetation species, structural characteristics and diversity. We also determined if patterns of vegetation structural characteristics observed using field data also occur across the broader landscape using airborne lidar data. The Utikuma Region Study Area (URSA) is located in central Alberta, Canada. Here, 19 peatlands were sampled, coincident with an airborne lidar survey of the broader region, where 120 peatlands in short and long fire return intervals were identified. We found that SRI transitional areas had significantly deeper organic soil deposits than those found in LRI (p < 0.0001). Proportions of regenerating species differed significantly between peatlands and transitional areas in SRI versus LRI, where greater proportion of coniferous species were observed in LRI. Deciduous transitional–upland species and taller post‐fire vegetation heights were more commonly found SRI peatlands compared with LRI. This suggest that fires with SRIs in this region may result in enhanced deciduous succession, which may transition boreal peatlands into ecosystems that have some characteristics of transitional and upland forests. [ABSTRACT FROM AUTHOR]

Aridity Index (AI) indicates the balance between water supply and water demand on the atmosphere–land interface. Despite continuous improvements, coupled climate models still have significant systematic errors in simulating AI in terms of temporal and spatial variabilities. One of the approaches to bias‐correct simulations is extracting the linear relationship between historical observations and model outputs by utilizing the empirical orthogonal function (EOF). In this study, the methodology of ensemble EOF‐based bias‐correction by observational constraints is developed based on previous bias‐correction approach, with the improvement on seeking the optimal combinations of the leading modes with sensitivity test and replacing the certain correction with the ensemble means of optimal members. In verification, the ensemble mean of Coupled Model Intercomparison Project phase 5 (CMIP5‐EM) is bias‐corrected towards the CPC/GLDAS observations, and the extracted leading modes present high correlations with internal climate variability. By cross‐validation and posteriori independent validation of hindcasts over the historical period (1948–2005), the ensemble EOF‐based bias‐correction could better present spatial patterns compared to the CMIP5‐EM after systematic bias‐correction, as indicated by the anomaly correlation and the root mean square error. The verifications also indicate that the temporal variability in aridity over different dryland regions is much closer to that in the observations and that the dryland subtype changes are improved significantly by bias‐corrections. Besides, another observational dataset of UDel/CRU is applied to assess the uncertainty on different datasets and the improvement on skill scores is robust. The above results verify that the ensemble EOF‐based bias‐corrections provide better reference for assessing and projecting global aridity changes by climate models. [ABSTRACT FROM AUTHOR]

Aridity Index (AI) indicates the balance between water supply and water demand on the atmosphere-land interface. Despite continuous improvements, coupled climate models still have significant systematic errors in simulating AI in terms of temporal and spatial variabilities. One of the approaches to bias-correct simulations is extracting the linear relationship between historical observations and model outputs by utilizing the empirical orthogonal function (EOF). In this study, the methodology of ensemble EOF-based bias-correction by observational constraints is developed based on previous bias-correction approach, with the improvement on seeking the optimal combinations of the leading modes with sensitivity test and replacing the certain correction with the ensemble means of optimal members. In verification, the ensemble mean of Coupled Model Intercomparison Project phase 5 (CMIP5-EM) is bias-corrected towards the CPC/GLDAS observations, and the extracted leading modes present high correlations with internal climate variability. By cross-validation and posteriori independent validation of hindcasts over the historical period (1948-2005), the ensemble EOF-based bias-correction could better present spatial patterns compared to the CMIP5-EM after systematic bias-correction, as indicated by the anomaly correlation and the root mean square error. The verifications also indicate that the temporal variability in aridity over different dryland regions is much closer to that in the observations and that the dryland subtype changes are improved significantly by bias-corrections. Besides, another observational dataset of UDel/CRU is applied to assess the uncertainty on different datasets and the improvement on skill scores is robust. The above results verify that the ensemble EOF-based bias-corrections provide better reference for assessing and projecting global aridity changes by climate models. [ABSTRACT FROM AUTHOR]

The significant impact of flash droughts (FDs) on society can vary based on a combination of FD characteristics (event counts, mean severity, and rate of intensification), which is largely unexplored. We employed root‐zone soil‐moisture for 1980–2018 to calculate the FD characteristics and integrated them to formulate a novel multivariate FD indicator for mapping the global FD hotspot regions. The potential influence of climate characteristics (i.e., anomalies, aridity, and evaporative fractions) and land‐climate feedbacks on the evolution of multivariate FD indicator is investigated. Our results indicate that precipitation is the primary driver of FD evolution, while the effect of temperature, vapor pressure deficit, and land‐climate interaction varies across the climate divisions after the onset of the events. The magnitude of multivariate FD indicator decreases with increased climate aridity, and it is significant in the global humid regimes, underscoring the importance of water and energy supply as limiting factors regulating FD‐risk. Plain Language Summary: Flash drought (FD) can significantly impact multiple sectors (e.g., agriculture, economy, and environment) very rapidly. Previous studies focused on a subset of FD characteristics at a time and over confined locations. In the light of such diversification, this study, for the first time, explored the most dominant climate controls of global FDs using an integrated approach that combines the FD frequency, severity, and intensification rates into a composite indicator. The results highlight the critical FD hotspots for prioritization and intervention. The key findings strengthen our perspective on FDs by improving our knowledge of the underlying physical processes and essential drivers across different climate divisions and ecosystems. The findings can be further extended to explore the combined influence of seasonality and magnitude of climate variables and develop suitable mitigation strategies to minimize the impact of FD events. Key Points: A multivariate flash drought indicator is proposed to identify key hotspots locations across the globeMeteorological forcings show a varying and cascading effect on regional flash drought evolutionMultivariate indicator identifies humid regions as most vulnerable to flash drought with exceptional intensification rates [ABSTRACT FROM AUTHOR]

Seed viability is a crucial factor affecting the regeneration potential of seeds, but there is little information on how this trait varies across habitats, populations, species, and higher taxonomic units, as well as on the relative contributions of evolutionary history and environmental factors to this trait. Here we evaluate the relative contributions of climatic variability and phylogenetic history to seed viability in a group of species of Bursera that belong to two distinct lineages (sections Bursera and Bullockia). We analyzed 39 seed lots from 11 species, comprising several populations and 2 years, and estimated embryo presence and viability in each lot. We examined spatial and temporal variation in viability and analyzed the relationship between this trait and water availability using regression models; the amount of phylogenetic signal in seed viability was also estimated. Mean seed viability was consistently low in species of section Bursera (mean 29.7%) and substantially higher in species of section Bullockia (mean 79.6%). A high proportion of unviable seeds were embryoless. Spatial and temporal variation in seed viability was significant but usually low among populations and species. The relationship between water availability and seed viability was not significant, but the amount of phylogenetic signal in seed viability was high and significant (λ = 0.74). There is a clear difference in seed viability among the two sections of Bursera. During the split of the two sections in the middle Eocene, the reorganization of the genome may have involved changes in fruit morphology associated with differences in parthenocarpy among them. [ABSTRACT FROM AUTHOR]

Aims: Monitoring rangeland above‐ground net primary production (ANPP) requires information on the variation of radiation use efficiency (RUE). We studied the spatial and temporal variations of RUE of the herbaceous layer (RUEH) in woodlands and shrublands and its association with grazing regime, environmental, and vegetation variables. Location: We worked in the Arid Chaco (Argentina), an ecotone region between the Chaco and Monte phytogeographic provinces. Woody and herbaceous species coexist in variable proportions in relation to a regional precipitation gradient and local edaphic variations. Methods and results: Over eight growing seasons, we estimated RUEH at 12 sites, each with two contrasting grazing regimes (moderate and severe). To do this, we related estimated ANPPH from biomass harvests and APARH (absorbed photosynthetically active radiation of the herbaceous layer) calculated from the MODIS normalized difference vegetation index (NDVI). Then we linked the RUEH with precipitation, physiognomy, soil, and landscape data. Most of the spatial variability of RUEH was accounted for by the grazing regime. Moderately grazed areas had a three times greater RUEH than severely grazed ones (0.507 and 0.180 g MJ−1 respectively). They also exhibited different proportions of herbaceous functional types. Physiognomic characteristics of the woody layer explained a significant proportion of the spatial variation of RUEH not explained by grazing regime. RUEH was between 30 and 150% greater in woodlands than in shrublands depending on whether the sites were under moderate or severe grazing respectively. Conclusion: Grazing regime and woody physiognomy accounted for most of the variation in herbaceous radiation use efficiency. Our results show that RUEH may be predicted with greater accuracy from a combination of vegetation maps and information on grazing regime. Thus, our models could be incorporated into web platforms that provide ANPPH (forage) monitoring services based on satellite data, in order to improve their estimates in woodlands, shrublands and savanna ecosystems. [ABSTRACT FROM AUTHOR]

The Dalongkou section in Xinjiang, Northwest China has preserved a continuous terrestrial Late Permian–Early Triassic sequence with well‐studied information of biota evolution and isotopic excursion. In order to know the corresponding palaeoclimatic and palaeoenvironmental evolution in this critical transition, chemical weathering indexes (chemical index of alteration [CIA], plagioclase index of alteration [PIA], and chemical index of weathering (CIW)) are analysed in high resolution across the Permian–Triassic Boundary. Results show that the declining trend of the CIA, PIA, and CIW was related to the continuous decrease of the chemical weathering in the latest Permian. The climate in the mid‐latitude NE Pangea was becoming increasingly arid in a generally greenhouse warm climate, causing widespread wildfire and turnover of the fauna and biota, coupled with the environmental deterioration expressed by the anomalies of carbon and mercury. Climatic conditions oscillated in the Early Triassic with possible intermittent rainfall and was likely affected by the strengthening of the megamonsoon. In the latest Permian–earliest Triassic, whether chemical weathering strengthened or weakened, as well as whether the climate was increasingly arid or humid, varied in the different places. The possible reasons inducing this need to be further explored. [ABSTRACT FROM AUTHOR]

Aims: The fairy circles along the Namib Desert in southern Africa are round grassland gaps that have puzzled scientists for about 50 years. With the discovery of fairy circles in Australia in 2016, the debate on the origin of the circles has been extended to a new continent. Research interest on the topic has since then risen strongly but so has the use of the term "fairy circle". This term has become more imprecise and, by analogy, has been applied to circular vegetation gaps or plant rings that are largely unrelated to fairy circles. For this reason, we define the concept of fairy circles by identifying their three main characteristics based on in situ field observations and soil excavations to larger‐scale spatial patterns, and regional‐scale distribution. Results: Following this approach, fairy circles are defined by: (a) being "empty gaps" in grassland without a central insect‐nest structure; (b) their ability to form spatially periodic patterns, which are regular hexagonal patterns with an extraordinary degree of spatial ordering; and (c) their strongly regional distribution confined within a narrow arid climatic envelope. In these combined traits, fairy circles differ from other common vegetation gaps which, for example, always have a central insect‐nest structure and may occur across broad climatic gradients on continents. Also plant rings have their own specific characteristics that largely differ from the combined attributes of genuine fairy circles. Conclusions: There are many other vegetation‐gap patterns in arid lands but if such gaps cannot jointly show the three characteristics defining the fairy circles, they should be carefully discussed on their own, rather than mixing them up with fairy circles. Our synthesis provides a new etymology for the different types of vegetation gaps and rings, aiming to guide the reader through various classes of circular plant patterns. [ABSTRACT FROM AUTHOR]