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Phytoplankton has been used as a paradigm for studies of coexistence of species since the publication of the "paradox of the plankton." Although there are a wealth of studies about phytoplankton assemblages of lakes, reservoirs and rivers, our knowledge about phytoplankton biodiversity and its underlying mechanisms in mountain headwater stream ecosystems is limited, especially across regional scales with broad environmental gradients. In this study, we collected 144 phytoplankton samples from the Xijiang headwater streams of the Pearl River across low altitude (< 1,000 m) located in Guangxi province, intermediate altitude (1,000 m < altitude <2,000 m) in Guizhou province and high altitude (> 2,000 m) in Yunnan province of China. Our study revealed high phytoplankton diversity in these streams. Freshwater phytoplankton, including cyanobacteria, Bacillariophyta, Chlorophyta, Rhodophyta, Chrysophyta, Euglenophyta, Glaucophyta, Phaeophyta and Cryptophyta, were all detected. However, phytoplankton alpha diversity exhibited a monotonic decreasing relationship with increasing altitude. High altitudes amplified the "isolated island" effect of headwater streams on phytoplankton assemblages, which were characterized by lower homogeneous selection and higher dispersal limitation. Variability and network vulnerability of phytoplankton assemblages increased with increasing altitudes. Our findings demonstrated diversity, variability and co-occurrence patterns of phytoplankton assemblages linked to environmental factors co-varying with altitude across regional scales. [ABSTRACT FROM AUTHOR]

Ungulate herbivores shape grassland plant communities at multiple scales, ultimately affecting ecosystem function. However, ungulates have complex effects on grasslands, including defoliation, trampling, excreta return and their interactions. Moreover, the effects of ungulate density on grasslands are regulated by these three mechanisms. Nevertheless, how these three mechanisms affect biodiversity at multiple scales and community assembly remains poorly understood.Here, we conducted a 4‐year novel field experiment to disentangle the effects of defoliation, trampling, and excreta return by ungulates on plant community assembly in a temperate grassland in Inner Mongolia, China. This experiment set two different scenarios: moderate ungulate density (Moderate, characterised by selective defoliation and moderate trampling) and high ungulate density (Intense, characterised by non‐selective defoliation and heavy trampling), including different combinations of defoliation, trampling and excreta return in each scenario.We found that defoliation and trampling increased stochasticity in community assembly and promoted alpha and beta diversity under both scenarios. Specifically, defoliation promoted the coexistence of species with multiple resource acquisition strategies (higher functional trait diversity) by reducing interspecific competition; trampling tended to facilitate random species colonisation. Conversely, excreta return favoured grasses, promoting deterministic assembly and impacting species coexistence. Notably, selective defoliation in the Moderate scenario led to a dominance of stochastic processes during community assembly, whereas non‐selective defoliation still did not change the dominance of deterministic processes. Further, communities subject to selective defoliation were insensitive to changes in soil properties caused by trampling and excreta return, maintaining a high‐level beta diversity and the stochastic of community assembly.Synthesis: Our study provides important insights into the mechanisms by which ungulate herbivores influence plant community assembly, suggesting that defoliation and trampling have the potential to drive stochastic processes, while excreta return plays the opposite role. Our study also suggests that selective foraging by ungulates acts as stronger stochastic forces during community assembly compared to non‐selective defoliation. These results imply that considering ungulate feeding preferences and foraging behaviour in grassland management will help prevent biodiversity loss and biotic homogenisation. [ABSTRACT FROM AUTHOR]

This paper concerns a discrete diffusive predator–prey system involving two competing predators and one prey in a shifting habitat induced by the climate change. By assuming that both predators can increase when the prey is at the maximal capacity and the prey can still survive under optimal climatic conditions when these two predators have their maximal densities, we investigate the existence and non-existence for different types of forced traveling waves which describe the conversion from the state of a saturated aboriginal prey with two invading alien predators, an aboriginal co-existent predator–prey with an invading alien predator, and the coexistence of three species to the extinction state, respectively. The existence of supercritical and critical forced waves is showed by applying Schauder's fixed point theorem on various invariant cones via constructing different types of generalized super- and sub-solutions while the non-existence of subcritical forced waves is obtained by contradiction. [ABSTRACT FROM AUTHOR]

In this paper, we incorporate stoichiometry into a competition model in chemostat culture. We first discuss the dynamics of this stoichiometric chemostat model for single algae species. We obtain the uniform persistence and find that an increase of phosphorus input or a slow dilution rate facilitates the algal persistence. Then, we consider a stoichiometric chemostat model in which two species competing for single nutrient, investigate how stoichiometry, dilution rate and concentration of phosphorus input affect the result of competition between algae species. Competitive exclusion and coexistence of two competing algae species are explored by discussing the existence, local stability of all feasible equilibria. Previous studies suggested that competitive exclusion holds in general chemostat models with two species competing for one limiting nutrient. Our theoretical and numerical results demonstrate that stoichiometry brings the coexistence of two competing algae species. Moreover, under low phosphorus input or fast dilution rate, competitive exclusion still holds. High phosphorus input or slow dilution rate facilitates the coexistence of multiple species. [ABSTRACT FROM AUTHOR]

Species‐specific phenological responses to changing climate are reshuffling the timing of species interactions, however we do not fully understand the consequences of these changes for species' population dynamics and community composition. In this study, we experimentally manipulated the timing of germination for five annual plant species from southern California and used pairwise competition experiments and coexistence theory to quantify how phenological shifts may impact species interactions and coexistence. We found that phenological shifts may help promote coexistence when they confer an advantage for competitively inferior species, but in other cases promote dominance by competitively superior species. Earlier germination generally increased species' performance relative to competitors, but the relative changes in intra‐and inter‐specific interactions caused more complex effects on niche and fitness differences. Phenological differences tended to reduce stabilising niche differences for many species pairs and reduced overall coexistence probabilities. Synthesis. While phenological differences among species have typically been considered a form of niche partitioning, it seems increasingly likely that phenological offsets could destabilise species coexistence. The net effects of changing phenology on species coexistence will depend on the complex combinations of effects on intra‐ and inter‐specific interactions, which remain challenging to predict. [ABSTRACT FROM AUTHOR]

A fundamental question of ecology is why species coexist in the same habitat. Coexistence can be enabled through niche differentiation, mediated by trait differentiation. Here, behaviour constitutes an often-overlooked set of traits. However, behaviours such as aggression and exploration drive intra- and interspecific competition, especially so in ants, where community structure is usually shaped by aggressive interactions. We studied behavioural variation in three ant species, which often co-occur in close proximity and occupy similar dominance ranks. We analysed how intra- and allospecific aggression, exploration and foraging activity vary under field conditions, namely with temperature and over time. Behaviours were assessed for 12 colonies per species, and four times each during several months. All behavioural traits consistently differed among colonies, but also varied over time and with temperature. These temperature-dependent and seasonal responses were highly species-specific. For example, foraging activity decreased at high temperatures in Formica rufibarbis, but not in Lasius niger; over time, it declined strongly in L. niger but much less in F. rufibarbis. Our results suggest that, owing to these species-specific responses, no species is always competitively superior. Thus, environmental and temporal variation effects a dynamic dominance hierarchy among the species, facilitating coexistence via the storage effect. [ABSTRACT FROM AUTHOR]

Three new populations of the invasive New Zealand mud snail, Potamopyrgus antipodarum, have been discovered in central Chile, increasing the documented records in the country to 23. Only females were observed in the present study. Significant differences in shell length and fecundity were found among populations. The size of the snails was less than 6 mm, while fecundity varied from 0 to 45 offspring per snail. A significant correlation was found between adult shell length and brood size in one of the three populations discovered. In these localities, Potamopyrgus antipodarum coexists with native and possibly other invasive gastropods. [ABSTRACT FROM AUTHOR]

Negative density dependence (NDD) in biotic interactions of interference such as plant–plant competition, granivory and herbivory are well-documented mechanisms that promote species' coexistence in diverse plant communities worldwide. Here, we investigated the generality of a novel type of NDD mechanism that operates through the mutualistic interactions of frugivory and seed dispersal among fruit-eating birds and plants. By sampling community-wide frugivory interactions at high spatial and temporal resolution in Pennsylvania, Puerto Rico, Peru, Brazil and Argentina, we evaluated whether interaction frequencies between birds and fruit resources occurred more often (selection), as expected, or below expectations (under-utilization) set by the relative fruit abundance of the fruit resources of each plant species. Our models considered the influence of temporal scales of fruit availability and bird phylogeny and diets, revealing that NDD characterizes frugivory across communities. Irrespective of taxa or dietary guild, birds tended to select fruits of plant species that were proportionally rare in their communities, or that became rare following phenological fluctuations, while they mostly under-utilized abundant fruit resources. Our results demonstrate that negative density-dependence in frugivore–plant interactions provides a strong equalizing mechanism for the dispersal processes of fleshy-fruited plant species in temperate and tropical communities, likely contributing to building and sustaining plant diversity. This article is part of the theme issue 'Diversitydependence of dispersal: interspecific interactions determine spatial dynamics'. [ABSTRACT FROM AUTHOR]

Dispersal plays a pivotal role in the eco-evolutionary dynamics of spatially structured populations, communities and ecosystems. As an individual-based trait, dispersal is subject to both plasticity and evolution. Its dependence on conditions and context is well understood within single-species metapopulations. However, species do not exist in isolation; they interact locally through various horizontal and vertical interactions. While the significance of species interactions is recognized for species coexistence and food web functioning, our understanding of their influence on regional dynamics, such as their impact on spatial dynamics in metacommunities and meta-food webs, remains limited. Building upon insights from behavioural and community ecology, we aim to elucidate biodiversity as both a driver and an outcome of connectivity. By synthesizing conceptual, theoretical and empirical contributions from global experts in the field, we seek to explore how a more mechanistic understanding of diversity–dispersal relationships influences the distribution of species in spatially and temporally changing environments. Our findings highlight the importance of explicitly considering interspecific interactions as drivers of dispersal, thus reshaping our understanding of fundamental dynamics including species coexistence and the emergent dynamics of metacommunities and meta-ecosystems. We envision that this initiative will pave the way for advanced forecasting approaches to understanding biodiversity dynamics under the pressures of global change. This article is part of the theme issue 'Diversity-dependence of dispersal: interspecific interactions determine spatial dynamics'. [ABSTRACT FROM AUTHOR]

Due of the potential of species to determine ecosystem properties, it is important to understand how species abundance influences community assembly. Using vegetation surveys on 35 dry grasslands in north-east Slovenia, we defined dominant (8) and subordinate (61) plant species. They were compared on 14 traits to test for differences in community-weighted mean (CWM) and functional diversity (FD). We found that dominants and subordinates differed strongly in their functional traits. Dominants showed higher leaf dry matter content and a more pronounced stress tolerance strategy and were all clonal with a large proportion of species with rhizomes and a rich bud bank, while other species showed a higher specific leaf area, a longer flowering period and more ruderals. For most traits, FD was higher in subordinates. Our results suggest that dominants drive community structure by limited susceptibility to non-competitive processes. Dominants may have positive effects on subordinates by mitigating environmental stressors. Subordinates are able to assemble together by being dissimilar and use different fine-scale niches that are engineered and homogenised by dominants. Our results show that there are fundamental differences in the relative importance of ecological processes between dominant and subordinate plants in species-rich grasslands, which is also important for their conservational management. [ABSTRACT FROM AUTHOR]

Filtering processes across environmental gradients can structure patterns of trait variation within communities. The community‐weighted mean (CWM) is a metric that is commonly used to indicate the directionality of such filtering processes and the optimal adaptive strategy of taxa within community. Proximity to the CWM indicates higher fitness, and deviations from this optimal value result in changes in the relative abundances of coexisting species. We investigated patterns of intraspecific trait variation in four coexisting carrion beetle species (Coleoptera: Silphidae) across elevational gradients. The study was conducted in temperate forest ecosystems with distinct natural vegetation zones ranging from 950 m to 1700 m above sea level. Of the 12 traits measured, we found that intraspecific variation ranged from 34% (body length) to 100% (ratio of elytra length, head length and head width to body length) and accounted for a larger proportion of variation than interspecific variation in 7 traits. For most traits, trait range, which indicates the niche breadth of species at a given elevation, was positively correlated with relative abundance. The CWMs of traits associated with long‐distance dispersal decreased with elevation, whereas those associated with microhabitat use showed the opposite trend. Soil temperature influenced tibia length after controlling for the effects of species identity, but soil water content had no effect on trait variation. Patterns of variation in body width and thorax width of two beetle species supported the CWM‐optimality hypothesis; however, patterns of trait variation in body width and thorax length of another species showed an opposite trend. Our study identifies several traits that can be highly variable within carrion beetle species. Such high levels of intraspecific trait variation may enable populations to adapt across a wide range of elevations and vegetation types. [ABSTRACT FROM AUTHOR]

Species' traits and interactions are products of evolutionary history. Despite the long‐standing hypothesis that closely related species possess similar traits, and thus experience stronger competition, measuring the effect of evolutionary history on the ecology of natural communities remains challenging. We propose a novel framework to test whether phylogeny influences patterns of coexistence and abundance of species assemblages. In our approach, phylogenetic trees are used to parameterize species' interactions, which in turn determine the abundance of species in a given assemblage. We use likelihoods to score models parameterized with a given phylogeny, and contrast them with models built using random trees, allowing us to test whether phylogenetic information helps to predict species' abundances. Our statistical framework reveals that interactions are indeed structured by phylogeny in a large set of experimental plant communities. Our results confirm that evolutionary history can help predict, and potentially manage or conserve, the structure and function of complex ecological communities. [ABSTRACT FROM AUTHOR]

Rarely do we observe competitive exclusion within plant communities, even though plants compete for a limited pool of resources. Thus, our understanding of the mechanisms sustaining plant biodiversity might be limited. In this study, we explore two common ecological strategies, species sorting and character displacement, that promote coexistence by reducing competition. We assess the degree to which woody plants may implement these two strategies to lower belowground competition for nutrients which occurs via nutritional (mostly mycorrhizal) mutualisms. First, we compile data on plant traits and the mycorrhizal association state of woody angiosperms using a global inventory of indigenous flora. Our analysis reveals that species in locations with high mycorrhizal diversity exhibit distinct mean values in leaf area and wood density based on their mycorrhizal type, indicating species sorting. Second, we reanalyse a large dataset on leaf area to demonstrate that in areas with high mycorrhizal diversity, trees maintain divergent leaf area values, showcasing character displacement. Character displacement among plants is considered rare, making our observation significant. In summary, our study uncovers a rare occurrence of character displacement and identifies a common mechanism employed by plants to alleviate competition, shedding light on the complexities of plant coexistence in diverse ecosystems. [ABSTRACT FROM AUTHOR]

Simple Summary: We used the line transect method and infrared camera traps to research the sable and yellow-throated marten in Taipinggou National Nature Reserve, Heilongjiang, China, to understand the distribution and overlap of their habitats and niches. In our study, the results showed that the habitat suitable for sables was larger than that for yellow-throated martens and that there is a partial overlap in terms of the suitable habitat for both species. There was a high degree of niche overlap between the sable and yellow-throated marten, primarily influenced by four environmental variables, i.e., "Distance from Settlements", "Distance from Roads", "Slope", and "Distance from Coniferous and Broadleaved Mixed Forest". This study can offer valuable insights for the development of policies aimed at conserving and managing sables and yellow-throated martens. The global focus on fostering harmonious interactions and promoting rational coexistence among wildlife species to uphold or reinstate biodiversity remains a prominent area of interest. We conducted a study on the sable and yellow-throated marten in Taipinggou National Nature Reserve, Heilongjiang, China, using the line transect method and infrared camera traps from 2022 to 2023. We then analyzed the overlap of their suitable habitats and niches with the aim of gaining insight into the interspecific competition between these two species. We found that the suitable habitat areas for the sable and yellow-throated marten were 55.20 km2 and 23.28 km2, accounting for 24.86% and 10.48% of the total area of this study, respectively. The overlap between the suitable habitats for the sable and yellow-throated marten was 15.73 km2, accounting for 28.5% and 67.6% of their suitable habitat, supporting our Hypothesis 1. The first principal component (Dim1) of the niche explained 35.4% of the overall variability, which is mainly related to the environmental variables "Distance from Settlements" and "Distance from Roads". Overall, 25.5% of the total variability was explained by the second principal component (Dim2), associated with "Slope" and "Distance from Coniferous and Broadleaved Mixed Forest". The niches occupied by the sable and yellow-throated marten were both off-center of the environmental background space, with the niches of the sable being larger than those of the yellow-throated marten. Schoener's D index was 0.56, indicating a high degree of niche overlap between the sable and yellow-throated marten, supporting our Hypothesis 2. Our study is helpful in terms of formulating conservation and management policies for the sable and yellow-throated marten. [ABSTRACT FROM AUTHOR]

Summary: Differences in demographic and environmental niches facilitate plant species coexistence in tropical forests. However, the adaptations that enable species to achieve higher demographic rates (e.g. growth or survival) or occupy unique environmental niches (e.g. waterlogged conditions) remain poorly understood. Anatomical traits may better predict plant environmental and demographic strategies because they are direct measurements of structures involved in these adaptations.We collected 18 leaf and twig traits from 29 tree species in a tropical freshwater swamp forest in Singapore. We estimated demographic parameters of the 29 species from growth and survival models, and degree of association toward swamp habitats. We examined pairwise trait–trait, trait–demography and trait–environment links while controlling for phylogeny.Leaf and twig anatomical traits were better predictors of all demographic parameters than other commonly measured leaf and wood traits. Plants with wider vessels had faster growth rates but lower survival rates. Leaf and spongy mesophyll thickness predicted swamp association.These findings demonstrate the utility of anatomical traits as indicators of plant hydraulic strategies and their links to growth–mortality trade‐offs and waterlogging stress tolerance that underlie species coexistence mechanisms in tropical forest trees. [ABSTRACT FROM AUTHOR]

While the presence of morphologically cryptic species is increasingly recognized, we still lack a useful understanding of what causes and maintains co‐occurring cryptic species and its consequences for the ecology, evolution, and conservation of communities. We sampled 724 Pocillopora corals from five habitat zones (the fringing reef, back reef, and fore reef at 5, 10, and 20 m) at four sites around the island of Moorea, French Polynesia. Using validated genetic markers, we identified six sympatric species of Pocillopora, most of which cannot be reliably identified based on morphology: P. meandrina (42.9%), P. tuahiniensis (25.1%), P. verrucosa (12.2%), P. acuta (10.4%), P. grandis (7.73%), and P. cf. effusa (2.76%). For 423 colonies (58% of the genetically identified hosts), we also used psbAncr or ITS2 markers to identify symbiont species (Symbiodiniaceae). The relative abundance of Pocillopora species differed across habitats within the reef. Sister taxa P. verrucosa and P. tuahiniensis had similar niche breadths and hosted the same specialist symbiont species (mostly Cladocopium pacificum) but the former was more common in the back reef and the latter more common deeper on the fore reef. In contrast, sister taxa P. meandrina and P. grandis had the highest niche breadths and overlaps and tended to host the same specialist symbiont species (mostly C. latusorum). Pocillopora acuta had the narrowest niche breadth and hosted the generalist, and more thermally tolerant, Durusdinium gynnii. Overall, there was a positive correlation between reef habitat niche breadth and symbiont niche breadth—Pocillopora species with a broader habitat niche also had a broader symbiont niche. Our results show how fine‐scale variation within reefs plays an important role in the generation and coexistence of cryptic species. The results also have important implications for how niche differences affect community resilience, and for the success of coral restoration practices, in ways not previously appreciated. [ABSTRACT FROM AUTHOR]

Plant nutrient composition is a reliable tool to identify plant ecological strategies and niche differentiation. Here, we aimed to (i) reveal the potential physiological mechanisms governing distinct foliar nutrient compositions among coexisting grassland species and (ii) clarify the role of taxonomy and environmental conditions in these compositions. At the local (grassland) scale, we measured root morphological and physiological traits, photosynthetic parameters and foliar concentrations of six macronutrients (N, P, S, K, Ca and Mg) and four micronutrients (Fe, Mn, Zn and Cu) across 18 coexisting species. At the regional scale, foliar macro‐ and micronutrient concentrations of 76 site‐species combinations of grasses and forbs across temperate meadow, typical, desert and saline grasslands were measured in Inner Mongolia. At the national scale, we collected the data on foliar macronutrient concentrations of 513 site‐species combinations across grasslands in Xinjiang, Qinghai‐Tibet and Inner Mongolia of China. Compared with forbs, grasses had 3.9 times higher root branching intensity, but 58% and 48% lower root carboxylate exudation and leaf transpiration rate. These distinct nutrient acquisition and transport strategies led to lower foliar nutrient (N, P, Ca, Mg and Mn) concentrations in grasses than forbs at the local scale. Most foliar micronutrient concentrations did not differ between grasses and forbs at the regional scale, whereas macronutrient concentrations were higher in forbs than grasses regardless of the grassland type at both the regional and national scales. All macronutrient concentrations exhibited stronger phylogenetic conservatism and less environmental control than micronutrients. The biogeochemical niche segregation (Euclidean distance based on PCA score of foliar macronutrient concentrations) between sympatric grasses and forbs was lower in meadow grassland than in the typical, desert and saline grasslands. Our results suggest that diverse nutrient acquisition and transport strategies can underlie the distinct foliar nutrient compositions between grasses and forbs. The linkage between potential physiological mechanisms and biogeochemical niche differentiation of grasses and forbs will advance our understanding of plant species coexistence and adaptive strategy. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Background and aims: The differences in multi-elemental concentrations among plant species provide insightful information for understanding species coexistence in forest ecosystems, known as the biogeochemical niche separation. As most of the studies focused on leaf elemental concentrations, it is unclear whether belowground fine roots exhibit biogeochemical niche separation and whether there are close linkages of elemental concentrations among leaves, fine roots and rhizosphere soils. Methods: Nine element (N, P, K, Ca, Mg, Mn, Zn, Cu, and Fe) concentrations in leaves, fine roots and rhizosphere soils were measured for three tree species, three woody shrub species, and three herbaceous species in three subtropical plantations. Results: Elemental concentrations in leaves and fine roots were significantly different between woody and herbaceous species. Notably, the elemental concentrations differed more significantly for leaves than for fine roots, which indicated that leaves, as the most metabolically active tissues, tended to maintain their unique elemental concentrations within a particular functional type. Despite the different elemental needs between leaves and fine roots, most elemental concentrations of leaves were closely associated with those of the fine roots, highlighting the relationship between leaf and root ecological processes. Elemental concentrations in leaves or fine roots were not significantly correlated with those of the rhizospheres. Conclusions: There is evidence for biogeochemical niche separation between coexisting woody and herbaceous species to avoid competition. Our results generalized the biogeochemical niche hypothesis to belowground tissues, which offered new insights into a better understanding of species evolution and coexistence in ecosystems. [ABSTRACT FROM AUTHOR]

Invasive species are a major threat to freshwater conservation. The coexistence of species in invaded habitats depends on the relative strength of intra‐ versus inter‐specific competition, where inter‐specific competition from invasive to native species is often stronger than intra‐specific competition, jeopardising their coexistence.In this study, we conducted a laboratory experiment to test for the relative strength of interference competition between native plains topminnow (Fundulus sciadicus) and invasive western mosquitofish (Gambusia affinis) at three experimental temperatures. Intra‐ and inter‐specific competition was quantified using an isodar approach, which assumes that animals are ideally distributed to maximise their fitness. Thus, their distributions measure the quality and quantity of habitat patches. This was supplemented by behavioural observations of intra‐ and inter‐specific competition.Contrary to our predictions, we did not find evidence that competition was asymmetrical from the invasive mosquitofish to the native plains topminnow. Instead, more individuals occupied their shared preferred habitat (a slow‐moving pool) in sympatry compared to allopatry, and the isodar analysis demonstrated that intra‐specific interference competition was significantly stronger than inter‐specific competition at all temperature levels. Behavioural observations corroborated this analysis of habitat selection that aggression was most frequent among plains topminnow in sympatry.This study shows that the widely perceived aggression of adults might not be the only key mechanism of global invasion success by mosquitofish. Other ecological traits, such as rapid reproduction, environmental tolerance, and interactions with early life stages of native species, might also be responsible for their invasion success. Additional investigations are warranted to determine whether their invasions directly affect native species or they invade degraded ecosystems opportunistically. [ABSTRACT FROM AUTHOR]

Simple Summary: Alpine musk deer, red serow, and white-lipped deer coexist in the Nyenchen Tanglha Mountains of Tibet. We aimed to understand the mechanisms of their coexistence by studying their dietary preferences using DNA barcoding. All of the species exhibited broad dietary ranges with distinct food preferences. Furthermore, our findings revealed genus-level dietary specializations and the mechanisms facilitating their coexistence. The results of this study provide valuable insights for the development and implementation of effective conservation strategies and management measures in the local area. Wild ungulates play crucial roles in maintaining the structure and function of local ecosystems. The alpine musk deer (Moschus chrysogaste), white-lipped deer (Przewalskium albirostris), and red serow (Capricornis rubidus) are widely distributed throughout the Nyenchen Tanglha Mountains of Tibet. However, research on the mechanisms underlying their coexistence in the same habitat remains lacking. This study aimed to investigate the mechanisms underlying the coexistence of these species based on their dietary preferences through DNA barcoding using the fecal samples of these animals collected from the study area. These species consume a wide variety of food types. Alpine musk deer, white-lipped deer, and red serow consume plants belonging to 74 families and 114 genera, 62 families and 122 genera, and 63 families and 113 genera, respectively. Furthermore, significant differences were observed in the nutritional ecological niche among these species, primarily manifested in the differentiation of food types and selection of food at the genus level. Owing to differences in social behavior, body size, and habitat selection, these three species further expand their differentiation in resource selection, thereby making more efficient use of environmental resources. Our findings indicate these factors are the primary reasons for the stable coexistence of these species. [ABSTRACT FROM AUTHOR]

Evaluating the factors that promote coexistence between ecologically similar species is crucial to understanding the evolution and assembly of herbivore communities. The Jarman–Bell principle presents a trade-off between diet quality and quantity as an axis for dietary niche segregation and has been suggested as a mechanism facilitating species coexistence. This idea holds that larger-bodied herbivores consume greater amounts of relatively low-quality plant resources, while smaller-bodied herbivores typically feed selectively on higher-quality resources. Most studies investigating the Jarman–Bell principle have examined free-living ungulates in African savannas. The diverse ungulate community in Yellowstone National Park, USA offers an opportunity to investigate the applicability of this principle in a temperate North American ecosystem. In this study we use fecal nitrogen (FN) and stable carbon isotope values (δ13C) to examine the relationship between body size and seasonal patterns of dietary niche segregation among five species of wild ungulates. Specifically, we test the predictions that: (1) diet quality decreases with increasing body mass, (2) interspecific differences in diet are greatest between the largest- and smallest-bodied species, and (3) smaller-bodied species have narrower dietary breadth than larger-bodied species. Diet quality, as indicated by digestibility, declined significantly with body mass, consistent with the empirical pattern predicted by the Jarman–Bell hypothesis. Significant interspecific differences in diet quality generally aligned with variation in body mass. When resources were limited during the winter, the relationship between body mass and diet quality was more pronounced, suggesting increased dietary niche segregation during the lean season. The results showed little evidence indicating that dietary breadth scaled allometrically with body mass, as the two species most similar in body mass displayed the greatest and least range of seasonal variation in both FN and δ13C. This study adds to the weight and breadth of evidence that diet quality is negatively correlated with body size in wild ungulate assemblages. Our findings underscore the importance of body size as a factor facilitating dietary niche segregation and promoting coexistence among ecologically similar ungulate species. [ABSTRACT FROM AUTHOR]

Sympatric species reduce competitive interactions by segregating their ecological niche as a strategy that promotes coexistence. The main dimensions in which niche differentiation occurs are spatial, trophic, and temporal axes. Thus, describing the spatiotemporal patterns of sympatric species help us better grasp how species coexist. In Mexico, coyotes (Canis latrans) and gray foxes (Urocyon cinereoargenteus) are sympatric and widely distributed, and information about their temporal and spatiotemporal interactions is still needed to explain their coexistence throughout their distribution. The evaluation of the ecological niche in temperate forests where both species coexist has shown high spatial and trophic overlap. Therefore, more pronounced segregation must occur in other niche dimensions, such as temporal and spatiotemporal axes, to maintain the coexistence between coyotes and gray foxes. As an approach to exploring the coexistence between these species in temperate forests, we pose the following question: Is there temporal or spatiotemporal segregation between sympatric coyotes and gray foxes? We hypothesized that both species maintain coexistence due to differences in their daily activity patterns (temporal segregation) and the presence of avoidance behaviors at the spatiotemporal level (spatiotemporal segregation), thereby reducing agonistic interactions. We aimed to evaluate indicators of niche segregation through two approaches: (i) temporal niche partitioning, measuring the overlap of the daily activity patterns and activity levels; and (ii) spatiotemporal niche partitioning, through temporal co-occurrence analysis and time to encounter analysis. In 2018, we used a camera-trap array (n = 43) to evaluate spatiotemporal interactions of coyotes and gray foxes in temperate forests of northern Mexico. We found that coyotes exhibited a diurnal daily activity pattern, whereas gray foxes were nocturnal, showing low overlap between daily activity patterns. Temporal co-occurrence and time to encounter analysis showed that coyotes and gray foxes occurred independently of each other. Therefore, we demonstrated that the spatiotemporal interactions between both species is a result of random species associations. In conclusion, here we provide evidence that ecological segregation occurred in the temporal niche and not in the spatiotemporal niche of the species. Thus, the temporal niche segregation represents one of the ecological strategies that facilitates the coexistence between coyotes and gray foxes and therefore promotes their sympatry in the temperate forests of northern Mexico. [ABSTRACT FROM AUTHOR]

Background and Aims The deceptive strategies by which orchids are pollinated and how these are capable of attracting pollinators remain understudied with regard to their implications for plant fitness. Despite their ecological importance, limited investigations have been conducted on sexual deception and shelter mimicry in orchid species, making this a compelling avenue in orchid biology research. To expand the knowledge of these reproductive mechanisms, we studied the pollination of Serapias lingua and S. parviflora in co-occurring and isolated sites in the Balearic Islands (Spain), further accentuated by the presence of a hybrid, indicating shared pollinators. Methods We employed bagging and hand pollination experiments to examine the reproductive biology of the two species. Furthermore, we evaluated the influence of phenotypical and ecological factors on reproductive success, including biometric measurements, reproductive performance and neighbourhood diversity (co-flowering and pollinator communities). Key Results Reproductive mechanisms between these two orchid species exhibit substantial disparities. Serapias lingua relies primarily on insect-mediated pollination, while S. parviflora demonstrates self-reproduction capacity. Although events of open pollination are rare, hybridization occurs predominantly when S. lingua is the pollen donor. Fruit set in S. parviflora was positively correlated with plant height, while in S. lingua it was negatively associated with flower size. The coexistence of the two species positively affected pollinium removal in S. parviflora , but did not exert an influence on reproductive traits in S. lingua. Overall, biometric parameters were diminished in isolated compared with co-occurring sites. At the community level, the increased diversity of co-flowering species in the vicinity exhibited an inhibitory effect on pollinium removal in S. parviflora. Conclusions Under a context of pollinator loss or phenological mismatch between pollinator presence and flowering, the selfing capacity of S. parviflora would guarantee reproduction whereas S. lingua survival would be compromised. Furthers studies are needed to assess the effects of phenotypical and ecological factors on reproductive success of S. lingua in pollinator-decline scenarios. [ABSTRACT FROM AUTHOR]

Climate and land use changes drive shifts in species distributions, causing variations in species richness. Yet the influence of shifts in species distributions on functional diversity at broad spatial scales remains uncertain. Here, we explored the potential effect of climate and land use changes on the functional diversity of European amphibian assemblages from the present to 2050, along with their effect on species richness. We performed species distribution modelling using a scenario of climate and land use change to estimate current and future potential distributions of 73 species. We estimated functional diversity using morphological and ecological functional traits. Our results highlight the intricate effects of climate and land use changes on taxonomic and functional diversity of amphibians. A climate-induced northward expansion of amphibians is anticipated, with temperature, precipitation, and forest cover prominently shaping future assemblages. Species expected to have shrinking ranges (n = 35) tend to mature sexually at a later age, produce fewer offspring per reproductive event, and live at higher maximum altitudes compared to species expected to expand (n = 38). Furthermore, trait composition changes are expected to exceed predictions based solely on species richness. These changes will vary geographically, with northern regions likely experiencing substantial increases in functional richness and functional redundancy, i.e., the coexistence of species with similar functional roles. Our findings underscore that functional diversity changes might serve as an early warning signal to assess human impacts on biodiversity. [ABSTRACT FROM AUTHOR]

This document explores the multi-dimensionality of root traits in plants and the challenges in understanding them. It emphasizes the importance of considering various factors such as root biomass, physiological traits, and exudation in assessing root foraging capacity. The document also suggests the need to study community-level patterns and include other dimensions like root depth and chemical defense. Additionally, it highlights the significance of studying the relationship between root and leaf traits. The research was supported by the National Natural Science Foundation of China. [Extracted from the article]

Soils in forested ecosystems are extremely heterogeneous and represent a critical component of terrestrial ecosystems. Despite their substantial ecological value, the geographic characteristics, ecological processes, and coexistence of microbial communities in forest soils remain poorly understood. Here, we investigated the biodiversity dynamics, environmental influences, community assembly, and co‐occurrence patterns of bacterial and fungal communities in surface and subsurface soils across 47 Chinese forest sites. The biogeographic characteristics determined using high‐throughput sequencing data sets revealed evident spatial patterns of bacterial and fungal α and β diversity, assembly processes, and co‐occurrence relationship, with greater variation in the bacterial than in fungal communities. Both fungal and bacterial communities showed significant spatial separations regulated by community assembly processes, co‐occurrence patterns, and soil variables. The microbial dissimilarity was lower in high latitudes than in low latitudes, which was consistent with the lower deterministic processes and relatively higher co‐occurrence associations in high latitudes than in low latitudes. Additionally, there were significant associations of soil dissolved organic matter (DOM) characteristics (e.g., its content, aromaticity, and molecular weight) with biodiversity dissimilarities, microbial assembly process balances, and microbial co‐occurrence relationships in bacterial and fungal communities; they clearly indicate the key role of DOM in regulating microbial biogeographic patterns in forest soil ecosystems. Collectively, our study enhances the understanding of biogeographic patterns and coexistence theories in forest soil microbial ecosystems. Plain Language Summary: Our study revealed an intrinsic link between microbial spatial variation, environmental impacts, community assembly processes, and species coexistence patterns. Understanding the mechanisms of microbial community diversity is a prerequisite for recognizing the environmental functions of microbes in forest soil ecosystems. To sum up, this study illustrates the critical influence of DOM in microbial spatial variation, assembly processes, and species coexistence of microbial communities in Chinese forest soils. Our study contributes to management strategies for microbial communities in forest ecosystems to better adapt to habitat fragmentation and climate change. Key Points: The spatial dissimilarities of bacterial and fungal communities associated with soil DOMBacterial and fungal community assembly and co‐occurrence relationships shaped microbial biogeographyBacterial and fungal community assembly and species coexistence correlated with DOM [ABSTRACT FROM AUTHOR]

Summary Polyploidy is widely recognized as an important speciation mechanism because it isolates tetraploids from their diploid progenitors. Polyploidy also provides new genetic material that may facilitate adaptive evolution. However, new mutations are more likely to arise after a neopolyploid already has successfully invaded a population. Thus, the role of adaptive forces in establishing a polyploid remains unclear. One solution to this apparent paradox may lie in the capacity of polyploids to suppress recombination among preexisting locally adapted alleles. The local adaptation mechanism requires that spatially heterogeneous selection acts on multiple loci and that gene flow introduces maladapted alleles to the population where the polyploid forms. The mechanism requires neither strong genetic drift nor any intrinsic benefit of genome doubling and can accommodate any mode of gene action. A unique prediction of the mechanism is that adaptive alleles should predate polyploidization, a pattern consistent with observations from a few well‐studied polyploids. The mechanism is also consistent with the coexistence of both diploid and tetraploid cytotypes, fitness heterogeneity among independently derived polyploids, and the prevalence of outcrossing among older polyploids. The local adaptation mechanism also makes novel predictions about circumstances favoring polyploid invasions that can be tested using molecular genetic or comparative approaches. [ABSTRACT FROM AUTHOR]

Background: Numerous bacteria are involved in the etiology of bacterial vaginosis (BV). Yet, current tests only focus on a select few. We therefore designed a new test targeting 22 BV-relevant species. Methods: Using 946 stored vaginal samples, a new qPCR test that quantitatively identifies 22 bacterial species was designed. The distribution and relative abundance of each species, a- and b-diversities, correlation, and species coexistence were determined per sample. A diagnostic index was modeled from the data, trained, and tested to classify samples into BV-positive, BV-negative, or transitional BV. Results: The qPCR test identified all 22 targeted species with 95 - 100% sensitivity and specificity within 8 hours (from sample reception). Across most samples, Lactobacillus iners, Lactobacillus crispatus, Lactobacillus jensenii, Gardnerella vaginalis, Fannyhessea (Atopobium) vaginae, Prevotella bivia, and Megasphaera sp. type 1 were relatively abundant. BVAB-1 was more abundant and distributed than BVAB-2 and BVAB-3. No Mycoplasma genitalium was found. The inter-sample similarity was very low, and correlations existed between key species, which were used to model, train, and test a diagnostic index: MDL-BV index. The MDL-BV index, using both species and relative abundance markers, classified samples into three vaginal microbiome states. Testing this index on our samples, 491 were BV-positive, 318 were BV-negative, and 137 were transitional BV. Although important differences in BV status were observed between different age groups, races, and pregnancy status, they were statistically insignificant. Conclusion: Using a diverse and large number of vaginal samples from different races and age groups, including pregnant women, the new qRT-PCR test and MDL-BV index efficiently diagnosed BV within 8 hours (from sample reception), using 22 BV-associated species. [ABSTRACT FROM AUTHOR]

Exploring the relationship between soil properties and species diversity in typical forest stands in Liaoning Xianrendong National Nature Reserve will help maintain the stability of forest communities in the transition zone between flora in Changbai and North China. Based on the plant-soil feedback theory, community sample data from nine typical forest stands in the study area and experimental test data from 54 soil samples, we selected indexes of soil physical and chemical properties based on the minimum data set (temperature, compactness, capillary pore space, bulk weight, capillary water holding capacity, drainage capacity, soil water storage, conductivity, pH, organic matter, Ca, Fe, K, N and P). We adopt the research method of classical statistical analysis. The soil properties of nine typical stands in Xianrendong National Nature Reserve of Liaoning Province were systematically analyzed. The relationship between soil properties and forest stands' species diversity was quantified using correlation and redundancy analyses. The Pearson correlation analysis results showed significant positive correlations between the Gleason abundance index (arbors) with conductivity, pH, organic matter, Ca, N and P; Pielou's evenness index (arbors) with bulk weight and Fe. Significant negative correlations between the Gleason abundance index (arbors) with capillary pore space, bulk weight, drainage capacity, soil water storage and capillary water holding capacity; Simpson dominance index and Shannon–Wiener diversity index with capillary water holding capacity, drainage capacity and soil water storage; Pielou's evenness index (arbors) with Ca and N. The natural moisture content and clay particles are neutral feedback. The results showed that the feedback mechanism of soil physicochemical properties on stand species diversity was complex, which was conducive to species coexistence and community stability. [ABSTRACT FROM AUTHOR]

Density dependence and habitat filtering have been proposed to aid in understanding community assembly and species coexistence. Phylogenetic relatedness between neighbors was used as a proxy for assessing the degree of ecological similarity among species. There are different conclusions regarding the neighborhood effect in previous studies with different phylogenetic indices or at different spatiotemporal scales. However, the effects of density dependence, neighbor phylogenetic relatedness, and habitat filtering on seedling survival with different phylogenetic indices or at different temporal and spatial scales are poorly understood. We monitored 916 seedlings representing 56 woody plant species within a 4‐ha forest dynamics plot for 4 years (from 2020 to 2023) in a subtropical mid‐mountain moist evergreen broad‐leaved forest in the Gaoligong Mountains, Southwestern China. Using generalized linear mixed models, we tested whether and how four phylogenetic indices: total phylogenetic distance (TOTPd), average phylogenetic distance (AVEPd), relative average phylogenetic distance (APd′), and relative nearest taxon phylogenetic distance (NTPd′), three temporals (1, 2, and 3 years), and spatial scales (1, 2, and 4 ha) affect the effect of density dependence, phylogenetic density dependence, and habitat filtering on seedling survival. We found evidence of the effect of phylogenetic density dependence in the 4‐ha forest dynamics plot. The effects of density dependence, phylogenetic density dependence, and habitat filtering on seedling survival were influenced by phylogenetic indices and temporal and spatial scales. The effects of phylogenetic density dependence and habitat filtering on seedling survival were more conspicuous only at 1‐year intervals, compared with those at 2‐ and 3‐year intervals. We did not detect any effects of neighborhood or habitat factors on seedling survival at small scales (1 and 2 ha), although these effects were more evident at the largest spatial scale (4 ha). These findings highlight that the effects of local neighborhoods and habitats on seedling survival are affected by phylogenetic indices as well as temporal and spatial scales. Our study suggested that phylogenetic index APd′, shortest time scale (1 year), and largest spatial scales (4 ha) were suitable for neighborhood studies in a mid‐mountain moist evergreen broad‐leaved forest in Gaoligong Mountains. Phylogenetic indices and spatiotemporal scales have important impacts on the results of the neighborhood studies. [ABSTRACT FROM AUTHOR]

Inundations in Amazonian black‐water river floodplain result in the selection of different tree lineages, thus promoting coexistence between species. We investigated whether Amazonian tree communities are phylogenetically structured and distributed along a flooding gradient from irregularly flooded forests along streams embedded within upland (terra‐firme) forest to seasonally flooded floodplains of large rivers (igapós). Floristic inventories and hydrological monitoring were performed along the Falsino River, a black‐water river in the eastern Amazon within the Amapá National Forest. We constructed a presence‐and‐absence matrix and generated a phylogeny using the vascular plant database available in GenBank. We calculated the standardized values of the metrics of phylogenetic diversity (ses.PD), average phylogenetic distance (ses.MPD), and average nearest‐neighbor distance (ses.MNTD) to test whether the history of relationships between species in the community is influenced by inundation. We used the phylogenetic endemism (PE) metric to verify the existence of taxa with restricted distribution. Linear regressions were used to test whether phylogenetic metrics have a significant relationship with the variables: maximum flood height, maximum water table depth, and maximum flood amplitude. The results show that forests subject to prolonged seasonal flooding have reduced taxon richness, low phylogenetic diversity, and random distribution of lineages within communities. On the other hand, terra‐firme riparian forests showed higher rates of taxon richness, diversity, and phylogenetic dispersion, in addition to greater phylogenetic endemism. These results indicate that seasonal and predictable soil flooding filters tree lineages along the hydrographic gradient. Different adaptations to root waterlogging are likely requirements for colonization in these environments and may represent an important factor in the diversification of tree lineages in the Amazon biome. [ABSTRACT FROM AUTHOR]

Intransitive competition has received much attention over the past decade. Indeed, these cyclic arrangements of species interactions have the potential to promote and stabilize species coexistence. However, the importance of intransitive interactions in real-world species-rich communities containing a mixture of hierarchic and intransitive interactions remains unknown. Here, using simulations, we explore the behavior of intransitive loops when they interact with outer competitors, as would be expected in real-world communities. Our results show that dominant competitors often cancel the beneficial effects of intransitive loops of inferior competitors. These results call for caution when inferring beneficial effects of intransitivity on species coexistence. Although intransitive loops are a frequent motif in competition networks, their positive effects on species coexistence may be less important than previously thought. The specific properties of a subnetwork—such as stabilization by intransitive loops—should thus not be interpreted independently of the global network. [ABSTRACT FROM AUTHOR]

Understanding the links between causes and consequences of biodiversity is key to achieving conservation of both biodiversity and its functions, yet previous studies have mostly studied them independently. Ecologists have developed bipartite frameworks of high-level processes to understand mechanisms of species coexistence (niche and fitness differences) and biodiversity effects on ecosystem functioning (complementarity and selection effects) and stability (species stability and asynchrony). These high-level processes represent combined effects of low-level processes, which mediate either positive or negative associations between coexistence and biodiversity effects on functioning or stability. Our synthesis, based on high-level processes, provides a first step towards an integrative framework of biodiversity science. Future research needs to address low-level processes using more mechanistic approaches across broader contexts and scales. The global biodiversity crisis has stimulated decades of research on three themes: species coexistence, biodiversity–ecosystem functioning relationships (BEF), and biodiversity–ecosystem functional stability relationships (BEFS). However, studies on these themes are largely independent, creating barriers to an integrative understanding of the causes and consequences of biodiversity. Here we review recent progress towards mechanistic integration of coexistence, BEF, and BEFS. Mechanisms underlying the three themes can be linked in various ways, potentially creating either positive or negative relationships between them. That said, we generally expect positive associations between coexistence and BEF, and between BEF and BEFS. Our synthesis represents an initial step towards integrating causes and consequences of biodiversity; future developments should include more mechanistic approaches and broader ecological contexts. [ABSTRACT FROM AUTHOR]

Plant enemies can influence plant community assembly and structure. However, it is unclear how insect herbivores and fungal pathogens affect seedling recruitment. Complex interactions with competition and resource availability make it difficult to isolate the effect of enemies. This uncertainty can impede understanding of community assembly drivers, species coexistence and trophic interactions; and limits hypothesis testing such as of the enemy release hypothesis, a key hypothesis in invasion biology. Using a novel species‐specific approach, we examine how enemies affect seedling survival and recruitment of 16 grassland species.We planted seedlings of 16 native species from two functional groups (C4 grasses and non‐legume forbs) into two grassland sites (early and mid‐succession). We hand‐painted 1512 individual seedlings with pesticides (insecticide and fungicide) over the course of one growing season to enforce aboveground species‐specific release from enemies and tested whether it enhanced survival relative to untreated controls. Applying treatments to individuals allowed us to test for the effect of enemies on plant performance while controlling for contexts such as competition from the resident community and resource levels.Release from insects increased seedling survival by 56% on average, with no additional benefit of release from fungal pathogens. This effect was observed for both forbs and C4 grasses across both sites and was strongest in resource‐acquisitive species. There was no effect of the mean phylogenetic distance between our target species and the resident plant community, or of light availability or soil moisture.Synthesis. The significant positive effect of release from insect herbivores on survival early in colonisation—a trend that held across functional groups and types of resident community—suggests insects play an important regulatory role in community assembly, especially for resource‐acquisitive species. As variation between species could be explained by traits but not by phylogeny, we emphasise the importance of trait‐based approaches to plant community ecology. Our results also support the key mechanism (increased performance following release from enemies) underlying the enemy release hypothesis. Enemy release may therefore aid initial recruitment of plants during the invasion process. [ABSTRACT FROM AUTHOR]

Understanding species coexistence requires information about how species interact and partition their ecological niche. Niches of closely related species tend to be quite similar and thereby, when syntopic, overlap can result in competition when shared resources are limiting. Brocket deer of tropical forests are ecologically similar species due to convergence or relatedness. As a group, what little is known about their ecology suggests spatial and temporal niche separation while dietary differences among species remain largely unknown. The possibility of competition has been suggested, as it is rare for more than two species to co‐occur. If competition is important, then it may limit syntopy of more species and its importance should increase with relatedness between species. Based on analyses of faecal samples, camera traps, and stable isotopes and multidimensional analysis of niche space, we test spatial, temporal and dietary niche differences and compare niche breadth in two syntopic species pairs: Mazama rufa with M. nana (both of subtribe Odocoileina) and M. jucunda (Odocoileina) with Subulo gouazoubira (Blastocerina). In 2007–2008 and 2017–2019, 240 faecal samples and 375 records were collected in the Brazilian Atlantic Forest. Spatial partitioning among both species pairs was found, with S. gouazoubira and M. nana having greater niche breadth, which may permit or facilitate coexistence. Odocoileina tend to be nocturnal, while Blastocerina tend to be diurnal, which suggests that phylogeny may influence species coexistence. Furthermore, the species tended to overlap with respect to diet. These results suggest interference competition avoidance by niche partitioning at the level of habitat and time, allowing coexistence. Thereby, despite the morphological similarities, brocket deer species of evolutionarily convergent subtribes preserve differences in ecological niche dimensions that facilitate the coexistence of their populations. [ABSTRACT FROM AUTHOR]

One of the key goals of ecology is to understand how communities are assembled. The species co‐existence theory suggests that community β‐diversity is influenced by species pool and community assembly processes, such as environmental filtering, dispersal events, ecological drift and biotic interactions. However, it remains unclear whether there are similar β‐diversity patterns among different soil microbial groups and whether all these mechanisms play significant roles in mediating β‐diversity patterns. By conducting a broad survey across Chinese deserts, we aimed to address these questions by investing biological soil crusts (biocrusts). Through amplicon‐sequencing, we acquired β‐diversity data for multiple microbial groups, that is, soil total bacteria, diazotrophs, phoD‐harbouring taxa, and fungi. Our results have shown varying distance decay rates of β‐diversity across microbial groups, with soil total bacteria showing a weaker distance‐decay relationship than other groups. The impact of the species pool on community β‐diversity varied across microbial groups, with soil total bacteria and diazotrophs being significantly influenced. While the contributions of specific assembly processes to community β‐diversity patterns varied among different microbial groups, significant effects of local community assembly processes on β‐diversity patterns were consistently observed across all groups. Homogenous selection and dispersal limitation emerged as crucial processes for all groups. Precipitation and soil C:P were the key factors mediating β‐diversity for all groups. This study has substantially advanced our understanding of how the communities of multiple microbial groups are structured in desert biocrust systems. [ABSTRACT FROM AUTHOR]

Simple Summary: The invasive woodwasp Sirex noctilio occasionally shares hosts with the native S. nitobei and other colonizers. The coexistence of these species may significantly impact individual species. We compared coexistence patterns among several colonizers at both stand and tree scales. Spatial scales revealed negative associations (e.g., Asemum striatum, Phaenops sp.) and neutral ones (Ips acuminatus) between woodwasps and other co-colonizing insects. A positive correlation was found between the frequency of woodwasp attacks and the density of trees damaged by Sirex in the current and previous years. At the tree scale, S. noctilio is more abundant in sections where it occurs alone than in sections where it co-occurs with S. nitobei. The distribution and body size of S. noctilio within the tree are unaffected by the presence of S. nitobei. However, S. nitobei was more prevalent in bottom sections when S. noctilio was present and larger in bottom sections where it occurred alone. This result can be attributed to early S. noctilio attacks enhancing the micro-environment of S. nitobei, which provides nutrients for larval development. Sirex noctilio, a European woodwasp, occasionally shares resources with the native S. nitobei and other colonizers in northeast China. The impact of its coexistence on individual species remains unclear. Random sampling was conducted to assess the patterns and extent of insect co-colonization across various spatial scales. Additionally, we analyzed wood sections to determine the density, adult size, and distribution of the two Sirex species. Spatial scales revealed negative associations (Asemum striatum and Phaenops sp.) and neutral ones (Ips acuminatus) between woodwasps and other co-colonizers. Clustering of woodwasps and Phaenops sp. occurred at a small scale (0–7.3 m). Regression analysis showed a positive correlation between the chance of woodwasp attacks and past attacks on the same host, with little impact from other colonization factors. The distribution and body size of S. noctilio within the tree appeared unaffected by S. nitobei's presence. In the presence of S. noctilio, S. nitobei tended to lay eggs in damaged sections. At the stand level, the overall impact of S. noctilio on S. nitobei population density is likely positive because S. nitobei prefer weaker trees, a preference potentially influenced by initial attacks from S. noctilio on healthier hosts. [ABSTRACT FROM AUTHOR]

Wildlife plays significant roles in many societies that go beyond its ecological importance and economic rationale associated with conservation. This article examines the meanings of antelopes for the Khwe people in Bwabwata National Park in north-eastern Namibia. It underlines the importance that indigenous communities attach to wildlife and advocates for a more comprehensive understanding of human-wildlife relationships beyond ecological and economic values and the usual framing of conflicting relationships. The article explores how antelopes go beyond being merely "wild animals" to being intertwined in the lives and spaces of the Khwe. Drawing from secondary data, lived experiences and empirical data collected through qualitative methods of semi-structured interviews and focus group discussions, we engage Khwe residents in Bwabwata National Park, including elders, traditional leaders and the management committee of the Kyaramacan Association. Our fundamental question is: what lessons can we draw from the relations of the Khwe with certain antelope species to foster coexistence in Namibia's community conservation landscapes? Conceptually, we adopt the concept of mechanical solidarity, which emphasises a collective conscience based on shared knowledge, norms and values. We propose that integrating this approach into community conservation practices could enhance conservation outcomes. [ABSTRACT FROM AUTHOR]

This article concludes a special issue on multispecies relations in Southern Africa, focusing on Namibia, South Africa, and Zambia. The authors emphasize the importance of understanding the historical and political contexts that shape these relationships, including precolonial, colonial, and postcolonial histories. They discuss the significance of including marginalized species in the analysis and explore the cultural aspects of these relationships. The article also examines the politics of nature conservation, including the effects of global capitalist markets and the displacement of indigenous communities. Overall, it provides insights into the complex and evolving nature of multispecies relations in Southern Africa, highlighting the need to address inequalities and include neglected narratives in contemporary discourses. [Extracted from the article]

Niche partitioning is a common strategy species use to avoid competition for limited resources, allowing them to coexist. Rodent species often reduce competition by spatial segregation and trophic differentiation, but behavioural differences, particularly related to foraging, can also be important. Therefore, temporal segregation can also be an important mechanism for species coexistence, as it helps them avoid sub‐optimal habitats. We found three rodent species (the native Octodon degus and O. lunatus, and the exotic Rattus rattus) foraging on endemic palm Jubaea chilensis seeds, a highly valuable but limited resource. We hypothesized that these rodent species could coexist by segregating foraging in time, showing behavioural differences. To test this, we used camera traps to monitor the fate of J. chilensis seeds and rodent activity at 25 feeding stations. From 596 photographic records, we identified 128 as O. degus, 232 as O. lunatus and 236 as R. rattus. Octodon degus had a diurnal activity, while O. lunatus and R. rattus were nocturnal, showing significant temporal segregation. However, we found no spatial association among these rodents. We found significant behavioural differences in decision and handling times and seed removal rates, with O. degus having the greatest seed removal rate. Nevertheless, we found some nocturnal O. degus records in which the three rodent species were co‐foraging, which may suggest that the resource is limited but valuable enough to shift from exploitation to interference competition. Our results suggest that temporal and behavioural differentiation are more important than spatial segregation and trophic differentiation. Thus, niche partition over multiple dimensions might allow for species coexistence. [ABSTRACT FROM AUTHOR]

The outcome of species competition strongly depends on the traits of the competitors and associated trade‐offs, as well as on environmental variability. Here, we investigate the relevance of consumer trait variation for species coexistence in a ciliate consumer–microalgal prey system under fluctuating regimes of resource supply. We focus on consumer competition and feeding traits, and specifically on the consumer's ability to overcome periods of resource limitation by mixotrophy, that is, the ability of photosynthetic carbon fixation via algal symbionts in addition to phagotrophy. In a 48‐day chemostat experiment, we investigated competitive interactions of different heterotrophic and mixotrophic ciliates of the genera Euplotes and Coleps under different resource regimes, providing prey either continuously or in pulses under constant or fluctuating light, entailing periods of resource depletion in fluctuating environments, but overall providing the same amount of prey and light. Although ultimate competition results remained unaffected, population dynamics of mixotrophic and heterotrophic ciliates were significantly altered by resource supply mode. However, the effects differed among species combinations and changed over time. Whether mixotrophs or heterotrophs dominated in competition strongly depended on the genera of the competing species and thus, species‐specific differences in the minimum resource requirements that are associated with feeding on shared prey, nutrient uptake, light harvesting, and access to additional resources such as bacteria. Potential differences in the curvature of the species' resource‐dependent growth functions may have further mediated the species‐specific responses to the different resource supply modes. Overall, our study demonstrates that genus‐ or species‐specific traits other than that related to nutritional mode may override the relevance of acquired phototrophy by heterotrophs in competitive interactions, and that the potential advantage of photosynthetic carbon fixation of symbiont‐bearing mixotrophs in competition with pure heterotrophs may differ greatly among different mixotrophs, playing out under different environmental conditions and depending on the specific requirements of the species. Complex trophic interactions determine the outcome of competition, which can only be understood by taking on a multidimensional trait perspective. [ABSTRACT FROM AUTHOR]

The article explores how dominant theories in ecology can limit our understanding of nature and emphasizes the importance of reflecting on the narratives and metaphors we use to describe natural phenomena. It presents case studies on sexual behavior, community assembly, plant-soil microbe interactions, and the impact of plants on microclimates to highlight the limitations of current theory and the need for pluralistic approaches in ecological research. The article encourages scientists to interrogate their values and politics and consider the cultural and societal influences on our understanding of nature. The first article discusses factors that drive plant community assemblage on islands, the second article explores the persistence of genetic polymorphism, and the third article discusses the importance of rethinking the way ecology is taught and the role of models in understanding nature. The summary of the panel discussion highlights the importance of understanding the limitations and assumptions of models in ecology. [Extracted from the article]

Bacteria and archaea are foundational life forms on Earth and play crucial roles in the development of our planet's biological hierarchy. Their interactions influence various aspects of life, including eukaryotic cell biology, molecular biology, and ecological dynamics. However, the coexistence network patterns of these microorganisms within natural river ecosystems, vital for nutrient cycling and environmental health, are not well understood. To address this knowledge gap, we systematically explored the non-random coexistence patterns of planktonic bacteria and archaea in the 6000-km stretch of the Yangtze River by using high-throughput sequencing technology. By analyzing the O/R ratio, representing the divergence between observed (O%) and random (R%) co-existence incidences, and the module composition, we found a preference of both bacteria and archaea for intradomain associations over interdomain associations. Seasons notably influenced the co-existence of bacteria and archaea, and archaea played a more crucial role in spring as evidenced by their predominant presence of interphyla co-existence and more species as keystone ones. The autumn network was characterized by a higher node or edge number, greater graph density, node degree, degree centralization, and nearest neighbor degree, indicating a more complex and interconnected structure. Landforms markedly affected microbial associations, with more complex networks and more core species found in plain and non-source areas. Distance-decay analysis suggested the importance of geographical distance in shaping bacteria and archaea co-existence patterns (more pronounced in spring). Natural, nutrient, and metal factors, including water temperature, NH4+-N, Fe, Al, and Ni were identified as crucial determinants shaping the co-occurrence patterns. Overall, these findings revealed the dynamics of prokaryotic taxa coexistence patterns in response to varying environmental conditions and further contributed to a broader understanding of microbial ecology in freshwater biogeochemical cycling. [ABSTRACT FROM AUTHOR]

This paper is concerned with existence, non-existence and uniqueness of positive (coexistence) steady states to a predator-prey system with prey-dependent dispersal. To overcome the analytical obstacle caused by the cross-diffusion structure embedded in the prey-dependent dispersal, we use a variable transformation to convert the problem into an elliptic system without cross-diffusion structure. The transformed system and pre-transformed system are equivalent in terms of the existence or non-existence of positive solutions. Then we employ the index theory alongside the method of the principle eigenvalue to give a nearly complete classification for the existence and non-existence of positive solutions. Furthermore we show the uniqueness of positive solutions and characterize the asymptotic profile of solutions for small or large diffusion rates of species. Our results pinpoint the positive role of prey-dependent dispersal on the population dynamics for the first time by showing that the prey-dependent dispersal in the predator-prey system is a beneficial strategy increasing the chance of predator's survival and hence promoting the coexistence of species. [ABSTRACT FROM AUTHOR]

[Display omitted] Single-atom catalysts (SACs) have been widely studied in Fenton-like reactions, wherein their catalytic performance could be further enhanced by adjusting electronic structure and regulating coordination environment, although relevant research is rarely reported. This text elucidates fabrication of dual atom catalyst systems aimed at augmenting their catalytic efficiency. Herein, atomically dispersed copper-zinc (Cu-Zn) dual sites anchored on nitrogen (N)-doped porous carbon (NC), referred to as CuZn-NC, were synthesized using cage-encapsulated pyrolysis and host–guest strategies. The CuZn-NC catalyst exhibited high activity in activation of peroxymonosulfate (PMS) for degradation of organic pollutants. Based on synergistic effects of adjacent Cu and Zn atom pairs, CuZn-NC (PMS) system achieved 94.44 % bisphenol A (BPA) degradation in 24 min. The radical pathway predominated, and coexistence of non-radical species was demonstrated for BPA degradation in CuZn-NC/PMS system. More importantly, CuZn-NC/PMS system showed generality for degradation of various refractory contaminants. Our experiments indicate that CuZn-N sites on CuZn-NC act as active sites for bonding PMS molecules with optimal binding energy, while pyrrolic N sites are considered as adsorption sites for organic molecules. Overall, this research designs diatomic site catalysts (DACs), with promising implications for wastewater treatment. [ABSTRACT FROM AUTHOR]

This paper concerns an age-structured juvenile-adult model incorporating harvesting pulse and moving boundaries in a heterogeneous environment, in which harvesting reflects human periodic pulse intervention on adults and the moving boundaries describe the natural expanding front of species. The principal eigenvalue is firstly defined and its properties involving the intensity of harvesting and length of habitat sizes are analyzed. Then the criteria to determine whether the species spread or vanish is discussed, and some relevant sufficient conditions characterized by pulse are established. Our results reveal that the co-extinction or coexistence of species is influenced by internal expanding capacity from species itself and external harvesting pulse from human intervention, in which the intensity and timing of harvesting play key roles. Our numerical simulations validate that the larger the harvesting rate and the shorter the harvesting period, the worse the survival of the species due to the cooperation among juveniles and adults, and such harvesting pulse can even alter the situation of species from persistence to extinction. In addition, expanding capacities also affect or alter the outcomes of spreading and vanishing. [ABSTRACT FROM AUTHOR]

The emergence of bacterial species is rooted in their inherent potential for continuous evolution and adaptation to an ever-changing ecological landscape. The adaptive capacity of most species frequently resides within the repertoire of genes encoding the secreted proteome (SP), as it serves as a primary interface used to regulate survival/reproduction strategies. Here, by applying evolutionary genomics approaches to metagenomics data, we show that abundant freshwater bacteria exhibit biphasic adaptation states linked to the eco-evolutionary processes governing their genome sizes. While species with average to large genomes adhere to the dominant paradigm of evolution through niche adaptation by reducing the evolutionary pressure on their SPs (via the augmentation of functionally redundant genes that buffer mutational fitness loss) and increasing the phylogenetic distance of recombination events, most of the genome-reduced species exhibit a nonconforming state. In contrast, their SPs reflect a combination of low functional redundancy and high selection pressure, resulting in significantly higher levels of conservation and invariance. Our findings indicate that although niche adaptation is the principal mechanism driving speciation, freshwater genome-reduced bacteria often experience extended periods of adaptive stasis. Understanding the adaptive state of microbial species will lead to a better comprehension of their spatiotemporal dynamics, biogeography, and resilience to global change. Here, by applying evolutionary genomics approaches to metagenomics data of lake microbiomes, the authors reveal that freshwater species with small genomes face extended periods with their niche adaptation capabilities frozen. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The grazing impacts of two Acartia species (Acartia omorii and A. steueri) on size-fractionated phytoplankton biomass were measured in Jangmok Bay, Korea (34°59′37.8" N, 128°40′28.2'' E) from January to May 2015. Total chlorophyll (Chl-a) concentrations ranged from 0.66 to 5.18 µg L−1, and micro-phytoplankton (> 20 µm) comprised up to 66% (range, 10.5–65.6%) of the total pigment. The total abundance of Acartia species ranged from 267 to 5931 ind. m−3, and these copepods accounted for 20.8 to 88.0% of the total copepod abundance. The ingestion rates of A. steueri (r2 = 0.904, P = 0.013) and A. omorii (r2 = 0.239, P = 0.046) showed a high correlation with micro-phytoplankton. The average grazing impact of Acartia species on phytoplankton biomass was approximately 6.8 ± 11.8% (range, 0.1–69.0%). Temperature–salinity (T–S) diagram analysis revealed distinct environmental preferences for each species; A. omorii preferred a broader temperature range of 6.2 to 17.1 °C and a salinity range of 31.8 to 33.5, whereas A. steueri was more restricted, preferring temperatures between 6.5 and 12.8 °C and a salinity range of 32.2 to 33.5. These findings not only contribute to our understanding of the ecological roles of these copepod species in marine ecosystems but also highlight the importance of continuous research regarding the mechanisms driving their coexistence and interaction with the coastal food web. [ABSTRACT FROM AUTHOR]

Patterns of species distributions and abundance are driven by a combination of species abiotic niches and biotic interactions between members of a community. Joint-species distribution models extend traditional modeling of occurrence or abundance to quantify species corelationships that may result from interspecific interactions. In the southern Appalachian Mountains, stream-associated salamander communities are thought to be structured by competitive and predatory interactions; therefore, spatial patterns in occurrence and abundance and temporal patterns in activity may reflect species associations. To evaluate the role of interspecific interactions in salamander community occurrence and abundance patterns, we conducted repeated point-count and leaf-bag surveys for adult and larval communities, respectively. We estimated adult and larval community occurrence and abundance by using the hierarchical modeling of species communities framework to identify the extent to which residual co-occurrence and correlation in abundance was present within these communities. For both adult and larval communities, we found no evidence that residual co-occurrence or correlation in abundance was present. Instead, results indicated that environmental covariates characterizing both plot- and landscape-level habitat conditions were responsible for observed patterns. In addition, we found no evidence for temporal niche partitioning, suggesting competition does not play a significant role in inter- or intraday activity patterns. Our results contrast with the accepted paradigm that extant biotic interactions drive community composition among stream-associated salamanders. Instead, our findings suggest that the effects of biotic interactions are not evident at the spatial or temporal scales associated with occurrence or abundance. [ABSTRACT FROM AUTHOR]