Population and community ecology: past progress and future directions.

Population and community ecology as a science are about 100 years old, and we discuss here our opinion of what approaches have progressed well and which point to possible future directions. The three major threads within population and community ecology are theoretical ecology, statistical tests and models, and experimental ecology. We suggest that our major objective is to understand what factors determine the distribution and abundance of organisms within populations and communities, and we evaluate these threads against this major objective. Theoretical ecology is elegant and compelling and has laid the groundwork for achieving our overall objectives with useful simple models. Statistics and statistical models have contributed informative methods to analyze quantitatively our understanding of distribution and abundance for future research. Population ecology is difficult to carry out in the field, even though we may have all the statistical methods and models needed to achieve results. Community ecology is growing rapidly with much description but less understanding of why changes occur. Biodiversity science cuts across all these subdivisions but rarely digs into the necessary population and community science that might solve conservation problems. Climate change affects all aspects of ecology but to assume that everything in population and community ecology is driven by climate change is oversimplified. We make recommendations on how to advance the field with advice for present and future generations of population and community ecologists.

Do community changes persist after irruptive population dynamics? A case study from an invasive species boom and bust.

Irruptive or boom-and-bust population dynamics, also known as 'outbreaks', are an important phenomenon that has been noted in biological invasions at least since Charles Elton's classic book was published in 1958. Community-level consequences of irruptive dynamics are poorly documented and invasive species provide excellent systems for their study. African Jewelfish (Rubricatochromis letourneuxi, "jewelfish") are omnivores that demonstrate opportunistic carnivory, first reported in Florida in the 1960s and in Everglades National Park (ENP) in 2000. Twelve years after invasion in ENP, jewelfish underwent a 25-fold increase in density in one year. By 2016, jewelfish represented 25-50% of fish biomass. Using a 43-year fish community dataset at two sites (1978-2021), and a 25-year dataset of fish and invertebrate communities from the same drainage (1996-2021), with additional spatial coverage, we quantified differences in fish and invertebrate communities during different phases of invasion. During jewelfish boom, abundant, native cyprinodontiform fishes decreased in density and drove changes in community structure as measured by similarity of relativized abundance. Density of two species declined by > 70%, while four declined by 50-62%. Following the jewelfish bust, some species recovered to pre-boom densities while others did not. Diversity of recovery times produced altered community structure that lagged for at least four years after the jewelfish population declined. Community structure is an index of ecological functions such as resilience, productivity, and species interaction webs; therefore, these results demonstrate that irruptive population dynamics can alter ecological functions of ecosystems mediated by community structure for years following that population's decline.

Patterns in parasite diversity and interactions with anurans from the Atlantic Forest.

Knowledge of parasite-host interactions is essential for understanding factors associated with the ecology and evolution of both groups. Some aspects, such as host size and phylogeny, as well as parasite specificity, are significant predictors that help unveil the parasite-host relationship. Thus, the goals of this study were: (1) to describe parasite diversity in regions of the Atlantic Forest; (2) to analyze which host characteristics can influence parasite richness of anuran's parasite component community; and (3) to investigate if the prevalence of parasite infection is related to specificity metrics (ecological and phylogenetic), number of infected hosts and parasite's abundance. We identified 49 parasite taxa, classified into three phyla: Nematoda, Acanthocephala, and Platyhelminthes. Supporting the existing literature, our findings corroborate the positive relationship between host size and parasite richness, further emphasizing the significance of this predictor. Parasite prevalence in the host community is related to the number of infected host species and parasite abundance, but not to phylogenetic and ecological specificity indices. This shows that parasite prevalence is strongly associated with infection opportunity, host sampling effort, and high parasite abundance.

Host control and species interactions jointly determine microbiome community structure.

The host microbiome can be considered an ecological community of microbes present inside a complex and dynamic host environment. The host is under selective pressure to ensure that its microbiome remains beneficial. The host can impose a range of ecological filters including the immune response that can influence the assembly and composition of the microbial community. How the host immune response interacts with the within-microbiome community dynamics to affect the assembly of the microbiome has been largely unexplored. We present here a mathematical framework to elucidate the role of host immune response and its interaction with the balance of ecological interactions types within the microbiome community. We find that highly mutualistic microbial communities characteristic of high community density are most susceptible to changes in immune control and become invasion prone as host immune control strength is increased. Whereas highly competitive communities remain relatively stable in resisting invasion to changing host immune control. Our model reveals that the host immune control can interact in unexpected ways with a microbial community depending on the prevalent ecological interactions types for that community. We stress the need to incorporate the role of host-control mechanisms to better understand microbiome community assembly and stability.

Structural dynamics of plant-pollinator mutualistic networks.

The discourse surrounding the structural organization of mutualistic interactions mostly revolves around modularity and nestedness. The former is known to enhance the stability of communities, while the latter is related to their feasibility, albeit compromising the stability. However, it has recently been shown that the joint emergence of these structures poses challenges that can eventually lead to limitations in the dynamic properties of mutualistic communities. We hypothesize that considering compound arrangements-modules with internal nested organization-can offer valuable insights in this debate. We analyze the temporal structural dynamics of 20 plant-pollinator interaction networks and observe large structural variability throughout the year. Compound structures are particularly prevalent during the peak of the pollination season, often coexisting with nested and modular arrangements in varying degrees. Motivated by these empirical findings, we synthetically investigate the dynamics of the structural patterns across two control parameters-community size and connectance levels-mimicking the progression of the pollination season. Our analysis reveals contrasting impacts on the stability and feasibility of these mutualistic communities. We characterize the consistent relationship between network structure and stability, which follows a monotonic pattern. But, in terms of feasibility, we observe nonlinear relationships. Compound structures exhibit a favorable balance between stability and feasibility, particularly in mid-sized ecological communities, suggesting they may effectively navigate the simultaneous requirements of stability and feasibility. These findings may indicate that the assembly process of mutualistic communities is driven by a delicate balance among multiple properties, rather than the dominance of a single one.

Rapid taxonomic categorization of short, abundant virus sequences for ecological analyses.

Public health concerns about recent viral epidemics have motivated researchers to seek novel ways to understand pathogen infection in native, wildlife hosts. With its deep history of tools and perspectives for understanding the abundance and distribution of organisms, ecology can shed new light on viral infection dynamics. However, datasets allowing deep explorations of viral communities from an ecological perspective are lacking. We sampled 1086 bats from two, adjacent Puerto Rican caves and tested them for infection by herpesviruses, resulting in 3131 short, viral sequences. Using percent identity of nucleotides and a machine learning algorithm (affinity propagation), we categorized herpesviruses into 43 operational taxonomic units (OTUs) to be used in place of species in subsequent ecological analyses. Herpesvirus metacommunities demonstrated long-tailed rank frequency distributions at all analyzed levels of host organization (i.e., individual, population, and community). Although 13 herpesvirus OTUs were detected in more than one host species, OTUs generally exhibited host specificity by infecting a single core host species at a significantly higher prevalence than in all satellite species combined. We describe the natural history of herpesvirus metacommunities in Puerto Rican bats and suggest that viruses follow the general law that communities comprise few common and many rare species. To guide future efforts in the field of viral ecology, hypotheses are presented regarding mechanisms that contribute to these patterns.

Disturbance-mediated changes to boreal mammal spatial networks in industrializing landscapes.

Compound effects of anthropogenic disturbances on wildlife emerge through a complex network of direct responses and species interactions. Land-use changes driven by energy and forestry industries are known to disrupt predator-prey dynamics in boreal ecosystems, yet how these disturbance effects propagate across mammal communities remains uncertain. Using structural equation modeling, we tested disturbance-mediated pathways governing the spatial structure of multipredator multiprey boreal mammal networks across a landscape-scale disturbance gradient within Canada's Athabasca oil sands region. Linear disturbances had pervasive direct effects, increasing site use for all focal species, except black bears and threatened caribou, in at least one landscape. Conversely, block (polygonal) disturbance effects were negative but less common. Indirect disturbance effects were widespread and mediated by caribou avoidance of wolves, tracking of primary prey by subordinate predators, and intraguild dependencies among predators and large prey. Context-dependent responses to linear disturbances were most common among prey and within the landscape with intermediate disturbance. Our research suggests that industrial disturbances directly affect a suite of boreal mammals by altering forage availability and movement, leading to indirect effects across a range of interacting predators and prey, including the keystone snowshoe hare. The complexity of network-level direct and indirect disturbance effects reinforces calls for increased investment in addressing habitat degradation as the root cause of threatened species declines and broader ecosystem change.

Dispersal limitation and environmental filtering effects: The taxonomic and functional beta diversity of ground beetles along the altitudinal gradient in Chinese warm-temperature forests.

Beta diversity patterns along environmental gradients and underlying mechanisms constitute key research inquiries in biogeography. However, ecological processes often also influence the functional traits of biological communities, making the assessment of functional ß-diversity crucial. Ground beetles (Coleoptera: Carabidae) are one of the most species-rich groups in the insect community, displaying strong habitat specificity and morphological differences. In this study, we explored the patterns of taxonomic and functional beta diversity in ground beetle communities along the altitudinal gradient of warm-temperature forests. By partitioning beta diversity into turnover and nestedness components, we evaluated their relationship with spatial distance. Our findings indicate a decline in species and functional trait similarity with increasing elevation and geographic distance. Further analysis attributed both types of beta diversity in carabids to a combination of dispersal limitation and environmental filtering, with elevation and geographic distance emerging as significant factors. Interestingly, forest-type variations were found to have no impact on the beta diversity of these communities. Our study reveals the impact of environmental filtering and dispersal limitation on both taxonomic and functional beta-diversity, shedding light on carabid community assembly in localized warm-temperature forest areas in eastern China.

Interspecific selection in a diverse mycorrhizal symbiosis.

Coevolution describes evolutionary change in which two or more interacting species reciprocally drive each other's evolution, potentially resulting in trait diversification and ecological speciation. Much progress has been made in analysis of its dynamics and consequences, but relatively little is understood about how coevolution works in multispecies interactions, i.e., those with diverse suites of species on one or both sides of an interaction. Interactions among plant hosts and their mutualistic ectomycorrhizal fungi (ECM) may provide an ecologically unique arena to examine the nature of selection in multispecies interactions. Using native genotypes of Monterey pine (Pinus radiata), we performed a common garden experiment at a field site that contains native stands to investigate selection from ECM fungi on pine traits. We planted seedlings from all five native populations, as well as inter-population crosses to represent intermediate phenotypes/genotypes, and measured seedling traits and ECM fungal traits to evaluate the potential for evolution in the symbiosis. We then combined field estimates of selection gradients with estimates of heritability and genetic variance-covariance matrices for multiple traits of the mutualism to determine which fungal traits drive plant fitness variation. We found evidence that certain fungal operational taxonomic units, families and species-level morphological traits by which ECM fungi acquire and transport nutrients exert selection on plant traits related to growth and allocation patterns. This work represents the first field-based, community-level study measuring multispecific coevolutionary selection in nutritional symbioses.

Sediment DNA metabarcoding and morphology provide complementary insight into macrofauna and meiobenthos response to environmental gradients in an Arctic glacial fjord.

Arctic fjords ecosystems are highly dynamic, with organisms exposed to various natural stressors along with productivity clines driven by advection of water masses from shelves. The benthic response to these environmental clines has been extensively studied using traditional, morphology-based approaches mostly focusing on macroinvertebrates. In this study we analyse the effects of glacially mediated disturbance on the biodiversity of benthic macrofauna and meiobenthos (meiofauna and Foraminifera) in a Svalbard fjord by comparing morphology and eDNA metabarcoding. Three genetic markers targeting metazoans (COI), meiofauna (18S V1V2) and Foraminifera (18S 37f) were analyzed. Univariate measures of alpha diversity and multivariate compositional dissimilarities were calculated and tested for similarities in response to environmental gradients using correlation analysis. Our study showed different taxonomic composition of morphological and molecular datasets for both macrofauna and meiobenthos. Some taxonomic groups while abundant in metabarcoding data were almost absent in morphology-based inventory and vice versa. In general, species richness and diversity measures in macrofauna morphological data were higher than in metabarcoding, and similar for the meiofauna. Both methodological approaches showed different patterns of response to the glacially mediated disturbance for the macrofauna and the meiobenthos. Macrofauna showed an evident distinction in taxonomic composition and a dramatic cline in alpha diversity indices between the outer and inner parts of fjord, while the meiobenthos showed a gradual change and more subtle responses to environmental changes along the fjord axis. The two methods can be seen as complementing rather than replacing each other. Morphological approach provides more accurate inventory of larger size species and more reliable quantitative data, while metabarcoding allows identification of inconspicuous taxa that are overlooked in morphology-based studies. As different taxa may show different sensitivities to environmental changes, both methods shall be used to monitor marine biodiversity in Arctic ecosystems and its response to dramatically changing environmental conditions.

Taxonomic accuracy and complementarity between bulk and eDNA metabarcoding provides an alternative to morphology for biological assessment of freshwater macroinvertebrates.

Determining biological status of freshwater ecosystems is critical for ensuring ecosystem health and maintaining associated services to such ecosystems. Freshwater macroinvertebrates respond predictably to environmental disturbances and are widely used in biomonitoring programs. However, many freshwater species are difficult to capture and sort from debris or substrate and morphological identification is challenging, especially larval stages, damaged specimens, or hyperdiverse groups such as Diptera. The advent of high throughput sequencing technologies has enhanced DNA barcoding tools to automatise species identification for whole communities, as metabarcoding is increasingly used to monitor biodiversity. However, recent comparisons have revealed little congruence between morphological and molecular-based identifications. Using broad range universal primers for DNA barcode marker cox1, we compare community composition captured between morphological and molecular-based approaches from different sources - tissue-based (bulk benthic and bulk drift samples) and environmental DNA (eDNA, filtered water) metabarcoding - for samples collected along a gradient of anthropogenic disturbances. For comparability, metabarcoding taxonomic assignments were filtered by taxa included in the standardised national biological metric IBMWP. At the family level, bulk benthic metabarcoding showed the highest congruence with morphology, and the most abundant taxa were captured by all techniques. Richness captured by morphology and bulk benthic metabarcoding decreased along the gradient, whereas richness recorded by eDNA remained constant and increased downstream when sequencing bulk drift. Estimates of biological metrics were higher using molecular than morphological identification. At species level, diversity captured by bulk benthic samples were higher than the other techniques. Importantly, bulk benthic and eDNA metabarcoding captured different and complementary portions of the community - benthic versus water column, respectively - and their combined use is recommended. While bulk benthic metabarcoding can likely replace morphology using similar benthic biological indices, water eDNA will require new metrics because this technique sequences a different portion of the community.

Diet-driven differential response of Akkermansia muciniphila modulates pathogen susceptibility.

The erosion of the colonic mucus layer by a dietary fiber-deprived gut microbiota results in heightened susceptibility to an attaching and effacing pathogen, Citrobacter rodentium. Nevertheless, the questions of whether and how specific mucolytic bacteria aid in the increased pathogen susceptibility remain unexplored. Here, we leverage a functionally characterized, 14-member synthetic human microbiota in gnotobiotic mice to deduce which bacteria and functions are responsible for the pathogen susceptibility. Using strain dropouts of mucolytic bacteria from the community, we show that Akkermansia muciniphila renders the host more vulnerable to the mucosal pathogen during fiber deprivation. However, the presence of A. muciniphila reduces pathogen load on a fiber-sufficient diet, highlighting the context-dependent beneficial effects of this mucin specialist. The enhanced pathogen susceptibility is not owing to altered host immune or pathogen responses, but is driven by a combination of increased mucus penetrability and altered activities of A. muciniphila and other community members. Our study provides novel insights into the mechanisms of how discrete functional responses of the same mucolytic bacterium either resist or enhance enteric pathogen susceptibility.

Environmental filtering mediates desert ant community assembly at two spatial scales.

Understanding the mechanisms that maintain species coexistence and determine patterns of community assembly are fundamental goals of ecology. Quantifying the relationship between species traits and stress gradients is a necessary step to disentangle assembly processes and to be able to predict the outcome of environmental change. We examined the hypothesis that desert ant communities are assembled by niche-based processes i.e., environmental filtering and limiting similarity. First, we used population-level morphological trait measurements to study the functional structure of ant communities along a dryland environmental stress gradient. Second, we developed species distribution models for each species to quantify large-scale climatic niche overlap between species. Body, femur, antennal scape, and head lengths were correlated with environmental gradients. Regionally, the ant community was significantly and functionally overdispersed in terms of morphological traits which suggests the importance of competition to ant community structure. Ant community assembly was also strongly influenced by environmental factors as the degree of functional trait divergence, but not phylogenetic divergence, decreased with increasing environmental stress. Thus, environmental stress likely mediates limiting similarity in these desert ecosystems. Species with lower climatic niche overlap were more dissimilar in morphological traits. This suggests that environmental filtering on ant functional traits is important at the scale of species distributions in addition to regional scales. This study shows that environmental and biotic filtering (i.e., niche-based assembly mechanisms) are jointly and non-independently structuring the ant community.

Effect of a generalist mesopredator on modular and unitary sessile prey associated with a foundation species.

Unitary and modular sessile organisms both dominate in marine benthic communities, commonly preyed upon by the same generalist predators. The differences between unitary and modular defensive strategies may underlie the ways generalist predators control community structure, but this has never been empirically examined. We hypothesize that the individual size of an omnivorous mesopredatory shrimp affects the relative vulnerability of unitary and modular prey and hence translates into community structure. In a short-term laboratory microcosm experiment, we assessed the effect of the shrimp individual size on an epibiotic assemblage of red algae blades initially dominated by three species of modular bryozoans and a unitary serpulid tubeworm. We found that the individual size of a shrimp determines its effect on the prey community composition. Large shrimp stronger than small shrimp increased the proportion of unitary tubeworms among the epibionts surviving predation. While large shrimp reduced the proportions of all the three dominant bryozoan species, small shrimp, in contrast, mostly increased the proportion of a bryozoan species with the smallest modules and largest colonies. This bryozoan, like the tubeworms, demonstrated a higher survival rate with larger individual (colony) size. Yet, against large shrimp this bryozoan was outperformed by the largest tubeworms almost immune to predation. Partial predation by small shrimp modestly improved survival of the largest bryozoan colonies. Thus, relative vulnerability of unitary and modular prey is determined by the predator individual size. Our findings clarify the complex way the size structures of generalist consumers and their prey shape communities by affecting the species-specific relative performance of modular and unitary organisms. The demography of a foundation species and the competitive hierarchy can have additional effects by altering the balance of predation and competition.

Cooperative interactions between invader and resident microbial community members weaken the negative diversity-invasion relationship.

The negative diversity-invasion relationship observed in microbial invasion studies is commonly explained by competition between the invader and resident populations. However, whether this relationship is affected by invader-resident cooperative interactions is unknown. Using ecological and mathematical approaches, we examined the survival and functionality of Aminobacter niigataensis MSH1 to mineralize 2,6-dichlorobenzamide (BAM), a groundwater micropollutant affecting drinking water production, in sand microcosms when inoculated together with synthetic assemblies of resident bacteria. The assemblies varied in richness and in strains that interacted pairwise with MSH1, including cooperative and competitive interactions. While overall, the negative diversity-invasion relationship was retained, residents engaging in cooperative interactions with the invader had a positive impact on MSH1 survival and functionality, highlighting the dependency of invasion success on community composition. No correlation existed between community richness and the delay in BAM mineralization by MSH1. The findings suggest that the presence of cooperative residents can alleviate the negative diversity-invasion relationship.

Vegetation structure drives mosquito community composition in UK's largest managed lowland wetland.

PURPOSE: The rising burden of mosquito-borne diseases in Europe extends beyond urban areas, encompassing rural and semi-urban regions near managed and natural wetlands evidenced by recent outbreaks of Usutu and West Nile viruses. While wetland management policies focus on biodiversity and ecosystem services, few studies explore the impact on mosquito vectors. METHODS: Our research addresses this gap, examining juvenile mosquito and aquatic predator communities in 67 ditch sites within a South England coastal marsh subjected to different wetland management tiers. Using joint distribution models, we analyse how mosquito communities respond to abiotic and biotic factors influenced by wetland management. RESULTS: Of the 12 mosquito species identified, Culiseta annulata (Usutu virus vector) and Culex pipiens (Usutu and West Nile virus vector) constitute 47% of 6825 larval mosquitoes. Abundant predators include Coleoptera (water beetles) adults, Corixidae (water boatmen) and Zygoptera (Damselfy) larvae. Models reveal that tier 3 management sites (higher winter water levels, lower agricultural intensity) associated with shade and less floating vegetation are preferred by specific mosquito species. All mosquito species except Anopheles maculipennis s.l., are negatively impacted by potential predators. Culiseta annulata shows positive associations with shaded and turbid water, contrary to preferences of Corixidae predators. CONCLUSIONS: Tier 3 areas managed for biodiversity, characterised by higher seasonal water levels and reduced livestock grazing intensity, provide favourable habitats for key mosquito species that are known vectors of arboviruses, such as Usutu and West Nile. Our findings emphasise the impact of biodiversity-focused wetland management, altering mosquito breeding site vegetation to enhance vector suitability. Further exploration of these trade-offs is crucial for comprehending the broader implications of wetland management.

Birds of Berlin: Changes in communities and guilds in the urban park "Tiergarten" since 1850.

Urbanization has far-reaching consequences on birds, and knowledge of the impacts on taxonomic and functional diversity is necessary to make cities as compatible as possible for species. Avian diversity in parks in urban centers has been investigated multiple times, but rarely so in long-term studies due to lacking data. The Tiergarten in Berlin is a large-scale park in the city center of great value for people and many species including birds. We compiled bird species lists since 1850 and from monitoring in 2022 in one dataset to investigate how bird communities and guilds have changed over time and how these alterations were influenced by the eventful history of the park's vegetation conditions. Long-term changes in species assemblages were analyzed with an ordination analysis, and changes in guild presence and functional richness were discussed with regard to landscape transitions. A gradual development of species assemblages yet only small changes in guild composition since 1850 was detected, whereas the 1950 community stands out with a drop in species richness and replacement of forest species with an open land community, which reflects the deforestation of the park during World War II. Consideration of habitat, lifestyle, trophic, and migration guilds revealed no sign of functional homogenization over the last 172 years (1850-2022). Despite the high frequentation of the park by humans it still allows for a high bird diversity due to the Tiergarten's sheer size and heterogeneity of vegetation and habitats. We recommend that the park is maintained and managed accordingly to preserve this condition and advise other urban parks to strive for these beneficial features.

Climate-driven shifts in the diversity of plants in the Neotropical seasonally dry forest: Evaluating the effectiveness of protected areas.

Given the current environmental crisis, biodiversity protection is one of the most urgent socio-environmental priorities. However, the effectiveness of protected areas (PAs), the primary strategy for safeguarding ecosystems, is challenged by global climate change (GCC), with evidence showing that species are shifting their distributions into new areas, causing novel species assemblages. Therefore, there is a need to evaluate PAs' present and future effectiveness for biodiversity under the GCC. Here, we analyzed changes in the spatiotemporal patterns of taxonomic and phylogenetic diversity (PD) of plants associated with the Neotropical seasonally dry forest (NSDF) under GCC scenarios. We modeled the climatic niche of over 1000 plant species in five representative families (in terms of abundance, dominance, and endemism) of the NSDF. We predicted their potential distributions in the present and future years (2040, 2060, and 2080) based on an intermediate scenario of shared socio-economic pathways (SSP 3.70), allowing species to disperse to new sites or constrained to the current distribution. Then, we tested if the current PAs network represents the taxonomic and phylogenetic diversities. Our results suggest that GCC could promote novel species assemblages with local responses (communities' modifications) across the biome. In general, models predicted losses in the taxonomic and phylogenetic diversities of all the five plant families analyzed across the distribution of the NSDF. However, in the northern floristic groups (i.e., Antilles and Mesoamerica) of the NSDF, taxonomic and PD will be stable in GCC projections. In contrast, across the NSDF in South America, some cores will lose diversity while others will gain diversity under GCC scenarios. PAs in some NSDF regions appeared insufficient to protect the NSDF diversity. Thus, there is an urgent need to assess how the PA system could be better reconfigured to warrant the protection of the NSDF.

Dada la actual crisis ambiental, la protección de la biodiversidad se presenta como una de las prioridades socio ambientales más urgentes. Sin embargo, la efectividad de las áreas protegidas (AP), la estrategia principal para salvaguardar los ecosistemas, se ve desafiada por el cambio climático global (CCG), con evidencia que muestra que las especies están desplazando sus distribuciones hacia nuevas áreas, provocando conjuntos de especies novedosos. Por lo tanto, es necesario evaluar la efectividad actual y futura de las AP para la biodiversidad bajo el CCG. En este contexto, analizamos cambios en los patrones espacio­temporales de diversidad taxonómica y filogenética de plantas asociadas al bosque estacionalmente seco neotropical (BES) bajo escenarios de CCG. Modelamos el nicho climático de más de 1,000 especies de plantas en cinco familias representativas (en términos de abundancia, dominancia y endemismo) del BES. Pronosticamos sus distribuciones potenciales en los años actuales y futuros (2040, 2060 y 2080) basándonos en un escenario intermedio de trayectorias socioeconómicas compartidas (SSP 3.70), permitiendo que las especies se dispersen a nuevos sitios o estén limitadas a la distribución actual. Luego, evaluamos si la red actual de AP representa las diversidades taxonómicas y filogenéticas. Nuestros resultados sugieren que el CCG podría promover conjuntos de especies novedosos con respuestas locales (modificaciones en las comunidades) en todo el bioma. En general, los modelos pronosticaron pérdidas en las diversidades taxonómicas y filogenéticas de las cinco familias de plantas analizadas en la distribución del BES. Sin embargo, en los grupos florísticos del norte (es decir, Antillas y Mesoamérica) del BSDN, la diversidad taxonómica y filogenética se mantendrá estable en las proyecciones de CCG. En cambio, en toda la región del BES en América del Sur, algunos núcleos perderán diversidad mientras que otros ganarán diversidad bajo escenarios de CCG. Algunas AP en regiones del BES parecen ser insuficientes para proteger la diversidad del bioma. Por lo tanto, es urgente evaluar cómo se podría reconfigurar mejor el sistema de AP para garantizar la protección del BES.

A nature-positive future with biological invasions: theory, decision support and research needs.

In 2050, most areas of biodiversity significance will be heavily influenced by multiple drivers of environmental change. This includes overlap with the introduced ranges of many alien species that negatively impact biodiversity. With the decline in biodiversity and increase in all forms of global change, the need to envision the desired qualities of natural systems in the Anthropocene is growing, as is the need to actively maintain their natural values. Here, we draw on community ecology and invasion biology to (i) better understand trajectories of change in communities with a mix of native and alien populations, and (ii) to frame approaches to the stewardship of these mixed-species communities. We provide a set of premises and actions upon which a nature-positive future with biological invasions (NPF-BI) could be based, and a decision framework for dealing with uncertain species movements under climate change. A series of alternative management approaches become apparent when framed by scale-sensitive, spatially explicit, context relevant and risk-consequence considerations. Evidence of the properties of mixed-species communities together with predictive frameworks for the relative importance of the ecological processes at play provide actionable pathways to a NPF in which the reality of mixed-species communities are accommodated and managed. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.

Predicting the responses of European grassland communities to climate and land cover change.

European grasslands are among the most species-rich ecosystems on small spatial scales. However, human-induced activities like land use and climate change pose significant threats to this diversity. To explore how climate and land cover change will affect biodiversity and community composition in grassland ecosystems, we conducted joint species distribution models (SDMs) on the extensive vegetation-plot database sPlotOpen to project distributions of 1178 grassland species across Europe under current conditions and three future scenarios. We further compared model accuracy and computational efficiency between joint SDMs (JSDMs) and stacked SDMs, especially for rare species. Our results show that: (i) grassland communities in the mountain ranges are expected to suffer high rates of species loss, while those in western, northern and eastern Europe will experience substantial turnover; (ii) scaling anomalies were observed in the predicted species richness, reflecting regional differences in the dominant drivers of assembly processes; (iii) JSDMs did not outperform stacked SDMs in predictive power but demonstrated superior efficiency in model fitting and predicting; and (iv) incorporating co-occurrence datasets improved the model performance in predicting the distribution of rare species. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.