Macroecological Analyses Research Articles

A macroecological analysis of ecological uniqueness of freshwater macrophyte assemblages across Europe and North America

Abstract Understanding spatial variation of species composition at different scales is essential for efficient conservation planning. Here, we investigate ecological uniqueness patterns of freshwater macrophyte assemblages at continental extents. We explored the similarities and differences in the patterns of ecological uniqueness between Europe and North America in relation to species richness and environmental variables using macrophyte presence–absence data in 50 × 50 km grid cells. To describe the ecological uniqueness of macrophyte assemblages, we used an index called ‘local contribution to beta diversity’ (LCBD). First, we used linear regression to evaluate the relationship between ecological uniqueness and species richness. Second, the variation of ecological uniqueness was modelled using environmental variables in generalized additive modelling (GAM). Third, boosted regression tree (BRT) analysis was performed with the same environmental variables to compare BRT results with the results from GAM. The results revealed relatively similar patterns of ecological uniqueness in both continents. The relationship between species richness and ecological uniqueness was overall negative but showed differences in the form and degree of the relationship between Europe and North America. The main driver of ecological uniqueness in both continents was mean annual temperature, with further effects associated with annual precipitation, elevation range, alkalinity and the proportion of freshwaters in a grid cell. Synthesis. Our results showed that species richness and ecological uniqueness may be negatively correlated at large spatial extents, and that the form of the relationship is likely to depend on the species richness profile of the area. The significant influence of climate on the ecological uniqueness of macrophyte assemblages suggests that changes in climate and land use may shape unique macrophyte assemblages. Thus, conservation strategies should consider protection measures, especially in the northern areas with unique macrophyte species assemblages, as they are expected to face many changes in the future. Identifying areas with high ecological uniqueness at different scales is important for efficient implementation of biodiversity conservation practices.

Island biogeography of the megadiverse plant family Asteraceae

The megadiverse plant family Asteraceae forms an iconic component of island floras including many spectacular radiations, but a global picture of its insular diversity is lacking. Here, we uncover the global biogeographical and evolutionary patterns of Asteraceae on islands to reveal the magnitude and potential causes of their evolutionary success. We compile a global checklist of Asteraceae species native and endemic to islands and combine it with macroecological analyses and a phylogenetic review of island radiations. Asteraceae have a global distribution on islands, comprising approximately 6,000 native island species, with 58% endemics. While diversity of the family on islands is lower than expected given its overall diversity, Asteraceae are the most diverse family on oceanic islands, suggesting an exceptional ability to thrive in isolation. In agreement with island biogeography predictions, native Asteraceae diversity increases with area and decreases with isolation, while endemism increases with both. We identify 39 confirmed island radiations and 69 putative radiations, exceeding numbers for other iconic insular groups. Our results reveal Asteraceae offer immense potential for research in ecology and evolution, given their close tracking of island biogeography expectations, large number of both species and radiations, cosmopolitan distribution, and numerous undiscovered radiations.

Integrating host biological and ecological variables to predict probability of haemosporidian infection in raptors

Variations in host traits that influence their exposure and susceptibility may impact probability of vector-transmitted diseases. Therefore, identifying the predictors of infection probability is necessary to understand the risk of disease outbreaks during expanding environmental perturbation. Here, we conducted a large survey based on microscopic examination and molecular analysis of haemosporidian parasite infection in raptors rescued at the Beijing Raptor Rescue Centre. Combining these data with biological and ecological variables of the raptors, we determined predictors that affect the probability of haemosporidian infection using generalized linear mixed models and multimodel inference. Our results showed that infection probability exhibited considerable variation across host species in raptors, and body mass, sex, and evolutionary history played relatively weaker roles in driving infection probability. Instead, activity pattern, age, geographic range size, migration distance, and nest type were important predictors of the probability of haemosporidian infection, and the role of each predictor differed in the three main haemosporidian genera (Plasmodium, Haemoproteus, and Leucocytozoon). This macro-ecological analysis will add to our understanding of host traits that influence the probability of avian haemosporidian infection and will help inform risk of emerging diseases.

ToTE: A global database on trees of the treeline ecotone.

Globally, treelines form a transition zone between tree-dominated forest downslope and treeless alpine vegetation upslope. Treelines represent the highest boundary of "tree" life form in high-elevation mountains and at high latitudes. Recently, treelines have been shifting upslope in response to climate warming, so it has become important to understand global tree diversity and treeline distributions. However, to the best of our knowledge, no global database on tree flora of treelines exists, which limits our capacity to undertake macroecological analyses. Here, for the first time, we present a global data set on the trees of the treeline ecotone, supported by an online ToTE database. We synthesized the database from 1202 studies published over the last 60 years (1962 to 2022) following the Preferred Reporting Items in Systematic Reviews and Meta-Analysis (PRISMA) protocol. We classified the tree species in the database into three categories: treeline tree (TL) species, near to treeline (NTL) tree species, and tree species with an upper montane range limit (TUMR). The ToTE Version-1 presents a total of 208 tree taxa, including 189 species, five subspecies, and 14 varieties, belonging to 54 genera and 26 families distributed across 34 mountain regions worldwide that either grow exactly at the treeline or have a range limit below the treeline. Of the total taxa, 155, 14, and 39 belong to TL, NTL, and TUMR, respectively. Genera such as Abies, Picea, Pinus, Larix, and Juniperus are more represented in the treeline tree category. On the other hand, Acer, Prunus, Populus, and Quercus have more representatives in the near to treeline category, whereas Erica, Nothofagus, and Polylepis contribute more tree species with an upper montane range limit. Furthermore, families such as Rosaceae and Pinaceae include trees that occur both at the treeline and with an upper montane range limit, whereas Sapindaceae includes trees that occur exclusively near to treeline. Our database also includes information on the global distribution patterns of treeline tree species richness across mountains and biomes. The mountains with the highest number of tree species are the Andes (39) followed by the Himalaya (37). Close to 67% of tree species show restricted distributions in different mountains, with the highest endemism in the Andes and the Himalaya. In terms of tree species distribution, Pinus sylvestris was widespread, with a distribution across nine mountain regions, followed by Picea glauca and Fagus sylvatica, both distributed across five mountain regions. In terms of species' distribution across biomes, the temperate biome harbors the highest treeline tree species richness (152 species), which may reflect the fact that the majority of studies are available from the temperate regions of the world. The remaining 56 species are distributed within five other biomes, with the least in dry tropical and subarctic (four species each). Furthermore, currently 40 treeline tree species fall under different International Union for Conservation of Nature threat categories. We anticipate that our database will help advance research on macroecological, biogeographic, evolutionary, climate-change, and conservation aspects of the treeline on a global scale. The data are released under a Creative Commons Attribution 4.0 international license. Please cite this data paper when the data are reused.

RE: Expert range maps of global mammal distributions harmonised to three taxonomic authorities

Abstract In a recent paper titled Expert range maps of global mammal distributions harmonised to three taxonomic authorities, Marsh et al. (2022) introduced a series of new geographic range maps for all extant species of mammals and made these maps available on the Map of Life (MoL) website (www.mol.org). The title of the paper and inclusion of over 140 prominent mammalogists and biogeographers as coauthors strongly suggested that these new range maps were carefully vetted. However, when examining the maps of Marsh et al. (2022) on the MoL web platform, we found a variety of serious problems, including, but not limited to: range exaggerations (inclusion of substantial geographic areas not represented by specimen records or verified observations); range maps that are geographically shifted so that species are shown as occurring in areas in which they do not, and not occurring in areas in which they do (and in some cases, these new maps do not even encompass the type locality of a species); range maps that simply omit peripheral populations of conservation concern; and range maps for fully marine mammals (i.e., those that do not spend any time on land) that include large swaths of both insular and continental landmasses. Overall, we evaluated the new “expert” mammal range maps on the MoL platform for 78 species (retrieved between 31 March 2022 and 1 April 2023) and show that there are serious, systemic problems with these maps, and that these problems are both geographically and taxonomically widespread. As such, we caution researchers to carefully review and evaluate the range maps of Marsh et al. (2022) on the MoL before using them for any research purpose—including conservation, biogeographical, and macroecological analyses of mammals.

Relatively large wings facilitate life at higher elevations among Nearctic dragonflies.

Determining which traits allow species to live at higher elevations is essential to understanding the forces that shape montane biodiversity. For the many animals that rely on flight for locomotion, a long-standing hypothesis is that species with relatively large wings should better persist in high-elevation environments because wings that are large relative to the body generate more lift and decrease the aerobic costs of remaining aloft. Although these biomechanical and physiological predictions have received some support in birds, other flying taxa often possess smaller wings at high elevations or no wings at all. To test if predictions about the requirements for relative wing size at high elevations are generalizable beyond birds, we conducted macroecological analyses on the altitudinal characteristics of 302 Nearctic dragonfly species. Consistent with the biomechanical and aerobic hypotheses, species with relatively larger wings live at higher elevations and have wider elevation breadths-even after controlling for a species' body size, mean thermal conditions, and range size. Moreover, a species' relative wing size had nearly as large of an impact on its maximum elevation as being adapted to the cold. Relatively large wings may be essential to high-elevation life in species that completely depend on flight for locomotion, like dragonflies or birds. With climate change forcing taxa to disperse upslope, our findings further suggest that relatively large wings could be a requirement for completely volant taxa to persist in montane habitats.

Global patterns and predictors of avian population density

AbstractAimHow population density varies across animal species in the context of environmental gradients, and associated migratory strategies, remains poorly understood. The recent influx of avian trait data and population density estimates allows these patterns to be described and explored in unprecedented detail. This study aims to identify the main macroecological drivers of population density in birds.LocationGlobal.Time period1970–2021.Major taxa studiedBirds (Aves).MethodsWe collated a dataset of 5072 local population density estimates for 1853 species and modelled population density as a function of trait and environmental predictors in a Bayesian framework accounting for phylogenetic and spatial autocorrelation. We explored the influence of body mass, diet, primary lifestyle, mating system, nesting behaviour, territoriality, and migratory behaviour on population density, accounting for a range of environmental variables, including preferred habitat type, primary productivity, precipitation and temperature. Based on this empirical baseline, we then predicted the mean population density for 9089 species of birds and estimated global geographic patterns of bird population density.ResultsPopulation density was lower in species with larger body mass and higher trophic levels, and also declined in territorial species, migratory species, brood parasites and species inhabiting resource‐poor habitat types (e.g., deserts). Conversely, population density increased in cooperative breeders. Environmental drivers were most influential for migratory birds, with precipitation and temperature both associated with higher population density. Overall, bird population densities were higher at lower latitudes.Main conclusionsOur results support previous findings on the role of body mass, diet and environmental gradients, but also reveal novel species‐specific drivers of avian densities related to reproduction, migration and resource‐holding behaviour. Substantial fine‐scale variation remains unexplained. We provide a global dataset of population density predictions for use in macroecological analyses and conservation assessments.

A biome-dependent distribution gradient of tree species range edges is strongly dictated by climate spatial heterogeneity.

Understanding the causes of the arrest of species distributions has been a fundamental question in ecology and evolution. These questions are of particular interest for trees owing to their long lifespan and sessile nature. A surge in data availability evokes a macro-ecological analysis to determine the underlying forces limiting distributions. Here we analyse the spatial distribution of >3,600 major tree species to determine geographical areas of range-edge hotspots and find drivers for their arrest. We confirmed biome edges to be strong delineators of distributions. Importantly, we identified a stronger contribution of temperate than tropical biomes to range edges, adding strength to the notion that tropical areas are centres of radiation. We subsequently identified a strong association of range-edge hotspots with steep spatial climatic gradients. We linked spatial and temporal homogeneity and high potential evapotranspiration in the tropics as the strongest predictors of this phenomenon. We propose that the poleward migration of species in light of climate change might be hindered because of steep climatic gradients.

High-throughput micro-CT scanning and deep learning segmentation workflow for analyses of shelly invertebrates and their fossils: Examples from marine Bivalvia

The largest source of empirical data on the history of life largely derives from the marine invertebrates. Their rich fossil record is an important testing ground for macroecological and macroevolutionary theory, but much of this historical biodiversity remains locked away in consolidated sediments. Manually preparing invertebrate fossils out of their matrix can require weeks to months of careful excavation and cannot guarantee the recovery of important features on specimens. Micro-CT is greatly improving our access to the morphologies of these fossils, but it remains difficult to digitally separate specimens from sediments of similar compositions, e.g., calcareous shells in a carbonate rich matrix. Here we provide a workflow for using deep learning—a subset of machine learning based on artificial neural networks—to augment the segmentation of these difficult fossils. We also provide a guide for bulk scanning fossil and Recent shells, with sizes ranging from 1 mm to 20 cm, enabling the rapid acquisition of large-scale 3D datasets for macroevolutionary and macroecological analyses (300–500 shells in 8 hours of scanning). We then illustrate how these approaches have been used to access new dimensions of morphology, allowing rigorous statistical testing of spatial and temporal patterns in morphological evolution, which open novel research directions in the history of life.

Ecological Indicator Values for Europe (EIVE) 1.0

Aims: To develop a consistent ecological indicator value system for Europe for five of the main plant niche dimensions: soil moisture (M), soil nitrogen (N), soil reaction (R), light (L) and temperature (T). Study area: Europe (and closely adjacent regions). Methods: We identified 31 indicator value systems for vascular plants in Europe that contained assessments on at least one of the five aforementioned niche dimensions. We rescaled the indicator values of each dimension to a continuous scale, in which 0 represents the minimum and 10 the maximum value present in Europe. Taxon names were harmonised to the Euro+Med Plantbase. For each of the five dimensions, we calculated European values for niche position and niche width by combining the values from the individual EIV systems. Using T values as an example, we externally validated our European indicator values against the median of bioclimatic conditions for global occurrence data of the taxa. Results: In total, we derived European indicator values of niche position and niche width for 14,835 taxa (14,714 for M, 13,748 for N, 14,254 for R, 14,054 for L, 14,496 for T). Relating the obtained values for temperature niche position to the bioclimatic data of species yielded a higher correlation than any of the original EIV systems (r = 0.859). The database: The newly developed Ecological Indicator Values for Europe (EIVE) 1.0, together with all source systems, is available in a flexible, harmonised open access database. Conclusions: EIVE is the most comprehensive ecological indicator value system for European vascular plants to date. The uniform interval scales for niche position and niche width provide new possibilities for ecological and macroecological analyses of vegetation patterns. The developed workflow and documentation will facilitate the future release of updated and expanded versions of EIVE, which may for example include the addition of further taxonomic groups, additional niche dimensions, external validation or regionalisation. Abbreviations: EIV = Ecological indicator value; EIVE = Ecological Indicator Values for Europe; EVA = European Vegetation Archive; GBIF = Global Biodiversity Information Facility; i = index for taxa; j = index for EIV systems; L = ecological indicator for light; M = ecological indicator for moisture; N = ecological indicator for nitrogen availability; R = ecological indicator for reaction; T = ecological indicator for temperature.

Occupancy–detection models with museum specimen data: Promise and pitfalls

Abstract Historical museum records provide potentially useful data for identifying drivers of change in species occupancy. However, because museum records are typically obtained via many collection methods, methodological developments are needed to enable robust inferences. Occupancy–detection models, a relatively new and powerful suite of statistical methods, are a potentially promising avenue because they can account for changes in collection effort through space and time. We use simulated datasets to identify how and when patterns in data and/or modelling decisions can bias inference. We focus primarily on the consequences of contrasting methodological approaches for dealing with species' ranges and inferring species' non‐detections in both space and time. We find that not all datasets are suitable for occupancy–detection analysis but, under the right conditions (namely, datasets that are broken into more time periods for occupancy inference and that contain a high fraction of community‐wide collections, or collection events that focus on communities of organisms), models can accurately estimate trends. Finally, we present a case study on eastern North American odonates where we calculate long‐term trends of occupancy using our most robust workflow. These results indicate that occupancy–detection models are a suitable framework for some research cases and expand the suite of available tools for macroecological analysis available to researchers, especially where structured datasets are unavailable.

Toward a Unified TreeTalker Data Curation Process

The Internet of Things (IoT) development is revolutionizing environmental monitoring and research in macroecology. This technology allows for the deployment of sizeable diffuse sensing networks capable of continuous monitoring. Because of this property, the data collected from IoT networks can provide a testbed for scientific hypotheses across large spatial and temporal scales. Nevertheless, data curation is a necessary step to make large and heterogeneous datasets exploitable for synthesis analyses. This process includes data retrieval, quality assurance, standardized formatting, storage, and documentation. TreeTalkers are an excellent example of IoT applied to ecology. These are smart devices for synchronously measuring trees’ physiological and environmental parameters. A set of devices can be organized in a mesh and permit data collection from a single tree to plot or transect scale. The deployment of such devices over large-scale networks needs a standardized approach for data curation. For this reason, we developed a unified processing workflow according to the user manual. In this paper, we first introduce the concept of a unified TreeTalker data curation process. The idea was formalized into an R-package, and it is freely available as open software. Secondly, we present the different functions available in “ttalkR”, and, lastly, we illustrate the application with a demonstration dataset. With such a unified processing approach, we propose a necessary data curation step to establish a new environmental cyberinfrastructure and allow for synthesis activities across environmental monitoring networks. Our data curation concept is the first step for supporting the TreeTalker data life cycle by improving accessibility and thus creating unprecedented opportunities for TreeTalker-based macroecological analyses.

Barriers and bridges for sustaining functional habitat networks: A macroecological system analysis of wet grassland landscapes.

This study aims at supporting the maintenance of representative functional habitat networks as green infrastructure for biodiversity conservation through transdisciplinary macroecological analyses of wet grassland landscapes and their stewardship systems. We chose ten north European wet grassland case study landscapes from Iceland and the Netherlands in the west to Lithuania and Belarus in the east. We combine expert experiences for 20–30 years, comparative studies made 2011–2017, and longitudinal analyses spanning >70 years. Wader, or shorebird, (Charadrii) assemblages were chosen as a focal species group. We used evidence‐based knowledge and practical experience generated in three steps. (1) Experts from 8 wet grassland landscapes in northern Europe's west and east mapped factors linked to patterns and processes, and management and governance, in social‐ecological systems that affect states and trends of wet grasslands as green infrastructures for wader birds. (2) To understand wader conservation problems and their dynamic in wet grassland landscapes, and to identify key issues for successful conservation, we applied group modeling using causal loop diagram mapping. (3) Validation was made using the historic development in two additional wet grassland landscapes. Wader conservation was dependent on ten dynamically interacting ecological and social system factors as leverage points for management. Re‐wetting and grazing were common drivers for the ecological and social system, and long‐term economic support for securing farmers’ interest in wader bird conservation. Financial public incentives at higher levels of governance of wetland management are needed to stimulate private income loops. Systems analysis based on contrasting landscape case studies in space and over time can support (1) understanding of complex interactions in social‐ecological systems, (2) collaborative learning in individual wet grassland landscapes, and (3) formulation of priorities for conservation, management, and restoration.

The interface between Macroecology and Conservation: existing links and untapped opportunities

Human activities are altering the structure of ecosystems, compromising the benefits they provide to nature and people. Effective conservation actions and management under ongoing global change rely on a better understanding of socio-ecological patterns and processes across broad spatiotemporal scales. Both macroecology and conservation science contribute to this improved understanding and, while they have different scopes, these disciplines have become increasingly interconnected over time. Here we describe examples of how macroecology has contributed to conservation science, and how conservation science can motivate further macroecological developments and applications. We identify challenges and untapped potential to further strengthen the links between these two disciplines. Major macroecological contributions include developing ecological theory, providing methodologies useful for biodiversity assessments and projections, making data more accessible and addressing knowledge gaps. These contributions have played a major role in the development of conservation science, and have supported outreach to policy makers, media, and the public. Nonetheless, a pure macroecological lens is limited to inform conservation decisions, particularly in local contexts, which frequently leads to the misuse of macroecological analyses for conservation applications, misunderstandings of research outputs, and skepticism among conservation practitioners and scientists. We propose possible solutions to overcome these challenges and strengthen links between macroecology and conservation science, including a stronger focus on ecological mechanisms and predictive approaches, and the creation of hybrid journals and meetings. Finally, we suggest new avenues for macroecological research that would further benefit conservation science.

The changing role of natural and human agencies shaping the ecology of an African savanna ecosystem

AbstractReconstructing the historical interplay of wildlife and pastoralists in the African savannas is clouded in contemporary studies by the transformation of subsistence societies and land use changes. We draw on five decades of monitoring by the Amboseli Conservation Program to illustrate the rainfall–plant–herbivore linkages in a free‐ranging wildlife–livestock system transitioning to contemporary savanna landscapes. In half a century, the coupled interactions of wildlife and livestock in the Amboseli ecosystem driven by rainfall and water sources have been severed and reshaped by farming, land subdivision, sedentism, poaching, and intensified herbivory. Livestock ranges have expanded, wildlife ranges have contracted, and overlapping spatial use has fluctuated with population sizes. In contrast, wildlife and livestock herds have been sustained where the rangelands remain open. A decrease in the mean body size reflecting a shift to small stock among pastoralists has increased species dominance, decreased diversity, and elevated biomass turnover and the probability of extreme shortfalls. In recent droughts, pastoralists have been importing food supplements to reduce drought risk and purchased livestock to restock herds, further uncoupling the rainfall‐herbivore link. Our study reinforces the view that biomes worldwide are shaped at an accelerating pace by human agencies rather than endogenous environmental factors. Disputes over models of rangeland systems echo the wider debate over using natural ecosystems as benchmarks for conservation verses “gardening” nature. We argue that models of natural ecosystems fail to account for the dominant role of humans in contemporary ecosystem yet that it is possible to monitor the complex interplay of human and natural systems and interpret the changes in terms of ecological function using macroecological analysis. The key finding for conservation is the importance of space, landscape heterogeneity, social networks, and mobility in sustaining the large herbivore populations.

COMBINE: a coalesced mammal database of intrinsic and extrinsic traits.

The use of species' traits in macroecological analyses has gained popularity in the last decade, becoming an important tool to understand global biodiversity patterns. Currently, trait data can be found across a wide variety of data sets included in websites, articles, and books, each one with its own taxonomic classification, set of traits, and data management methodology. Mammals, in particular, are among the most studied taxa, with large sources of trait information readily available. To facilitate the use of these data, we did an extensive review of published mammal trait data sources between 1999 and May 2020 and produced COMBINE: a COalesced Mammal dataBase of INtrinsic and Extrinsic traits. Our aim was to create a taxonomically integrated database of mammal traits that maximized trait number and coverage without compromising data quality. COMBINE contains information on 54 traits for 6,234 extant and recently extinct mammal species, including information on morphology, reproduction, diet, biogeography, life habit, phenology, behavior, home range, and density. Additionally, we calculated other relevant traits such as habitat and altitudinal breadths for all species and dispersal for terrestrial non-volant species. All data are compatible with the taxonomies of the IUCN Red List v. 2020-2 and PHYLACINE v. 1.2. Missing data were adequately flagged and imputed for non-biogeographical traits with 20% or more data available. We obtained full data sets for 21 traits such as female maturity, litter size, maximum longevity, trophic level, and dispersal, providing imputation performance statistics for all. This data set will be especially useful for those interested in including species' traits in large-scale ecological and conservation analyses. There are no copyright or proprietary restrictions; we request citation of this publication and all relevant underlying data sources (found in Data S1: trait_data_sources.csv), upon using these data.

SIVIM Floodplain Forests – Database of riverine forests and scrubs from the Iberian Peninsula

“SIVIM Floodplain Forests“ (GIVD ID: EU-00-024) is a thematic database focused on vegetation plots of riverine forests and scrubs from the Iberian Peninsula and the Pyrenees (Spain, Portugal and southern France). It was registered in the GIVD in February 2016. The data are available both from EVA and sPlot in semi-restricted regime. The database includes both digitized relevés from the literature and unpublished data. Many digitized relevés were derived from SIVIM (GIVD ID EU-00-004) and BIOVEG (GIVD ID EU-00-011), with which SIVIM Floodplain Forests thus partly overlaps. Currently it contains 4,736 vegetation plots of floodplain forests, alder carrs, willow scrubs, and tamarisk and oleander thickets, 99% of them classified at association level. Plot size is available for 94.6% of the relevés. Plant taxonomy is standardized to Flora Iberica. The database has been used for studies on vegetation classification at Iberian and European level, as well as studies on plant invasion, fine-grain plant diversity and macroecological analyses, most of them via EVA. Abbreviations: BIOVEG = Vegetation-Plot Database of the University of the Basque Country; EVA = European Vegeation Archive; GIVD = Global Index of Vegetation-Plot Databases; SIVIM = Iberian and Macaronesian Vegetation Information System.

MAcroecological Framework for Invasive Aliens (MAFIA): disentangling large-scale context dependence in biological invasions

Macroecology is the study of patterns, and the processes that determine those patterns, in the distribution and abundance of organisms at large scales, whether they be spatial (from hundreds of kilometres to global), temporal (from decades to centuries), and organismal (numbers of species or higher taxa). In the context of invasion ecology, macroecological studies include, for example, analyses of the richness, diversity, distribution, and abundance of alien species in regional floras and faunas, spatio-temporal dynamics of alien species across regions, and cross-taxonomic analyses of species traits among comparable native and alien species pools. However, macroecological studies aiming to explain and predict plant and animal naturalisations and invasions, and the resulting impacts, have, to date, rarely considered the joint effects of species traits, environment, and socioeconomic characteristics. To address this, we present the MAcroecological Framework for Invasive Aliens (MAFIA). The MAFIA explains the invasion phenomenon using three interacting classes of factors – alien species traits, location characteristics, and factors related to introduction events – and explicitly maps these interactions onto the invasion sequence from transport to naturalisation to invasion. The framework therefore helps both to identify how anthropogenic effects interact with species traits and environmental characteristics to determine observed patterns in alien distribution, abundance, and richness; and to clarify why neglecting anthropogenic effects can generate spurious conclusions. Event-related factors include propagule pressure, colonisation pressure, and residence time that are important for mediating the outcome of invasion processes. However, because of context dependence, they can bias analyses, for example those that seek to elucidate the role of alien species traits. In the same vein, failure to recognise and explicitly incorporate interactions among the main factors impedes our understanding of which macroecological invasion patterns are shaped by the environment, and of the importance of interactions between the species and their environment. The MAFIA is based largely on insights from studies of plants and birds, but we believe it can be applied to all taxa, and hope that it will stimulate comparative research on other groups and environments. By making the biases in macroecological analyses of biological invasions explicit, the MAFIA offers an opportunity to guide assessments of the context dependence of invasions at broad geographical scales.

Macroevolutionary and macroecological approaches to understanding the evolution of stress tolerance in plants.

Environmental stress response in plants has been studied using a wide range of approaches, from lab-based investigation of biochemistry and genetics, to glasshouse studies of physiology and growth rates, to field-based trials and ecological surveys. It is also possible to investigate the evolution of environmental stress responses using macroevolutionary and macroecological analyses, analysing data from many different species, providing a new perspective on the way that environmental stress shapes the evolution and distribution of biodiversity. "Macroevoeco" approaches can produce intriguing results and new ways of looking at old problems. In this review, we focus on studies using phylogenetic analysis to illuminate macroevolutionary patterns in the evolution of environmental stress tolerance in plants. We follow a particular thread from our own research-evolution of salt tolerance-as a case study that illustrates a macroevolutionary way of thinking that opens up a range of broader questions on the evolution of environmental stress tolerances. We consider some potential future applications of macroevolutionary and macroecological analyses to understanding how diverse groups of plants evolve in response to environmental stress, which may allow better prediction of current stress tolerance and a way of predicting the capacity of species to adapt to changing environmental stresses over time.

Blind spots in global soil biodiversity and ecosystem function research

Soils harbor a substantial fraction of the world’s biodiversity, contributing to many crucial ecosystem functions. It is thus essential to identify general macroecological patterns related to the distribution and functioning of soil organisms to support their conservation and consideration by governance. These macroecological analyses need to represent the diversity of environmental conditions that can be found worldwide. Here we identify and characterize existing environmental gaps in soil taxa and ecosystem functioning data across soil macroecological studies and 17,186 sampling sites across the globe. These data gaps include important spatial, environmental, taxonomic, and functional gaps, and an almost complete absence of temporally explicit data. We also identify the limitations of soil macroecological studies to explore general patterns in soil biodiversity-ecosystem functioning relationships, with only 0.3% of all sampling sites having both information about biodiversity and function, although with different taxonomic groups and functions at each site. Based on this information, we provide clear priorities to support and expand soil macroecological research.