Outbreaks of zoonotic diseases are accelerating at an unprecedented rate in the current era of globalization, with substantial impacts on the global economy, public health, and sustainability. Alien species invasions have been hypothesized to be important to zoonotic diseases by introducing both existing and novel pathogens to invaded ranges. However, few studies have evaluated the generality of alien species facilitating zoonoses across multiple host and parasite taxa worldwide. Here, we simultaneously quantify the role of 795 established alien hosts on the 10,473 zoonosis events across the globe since the 14th century. We observe an average of ~5.9 zoonoses per alien zoonotic host. After accounting for species-, disease-, and geographic-level sampling biases, spatial autocorrelation, and the lack of independence of zoonosis events, we find that the number of zoonosis events increase with the richness of alien zoonotic hosts, both across space and through time. We also detect positive associations between the number of zoonosis events per unit space and climate change, land-use change, biodiversity loss, human population density, and PubMed citations. These findings suggest that alien host introductions have likely contributed to zoonosis emergences throughout recent history and that minimizing future zoonotic host species introductions could have global health benefits.

The observed patterns and underlying mechanisms of elevational beta-diversity have been explored intensively, but multi-dimensional comparative studies remain scarce. Herein, across distinct beta-diversity components, dimensions and species groups, we designed a multi-faceted comparative framework aiming to reveal the general rules in the observed patterns and underlying causes of elevational beta-diversity. We have found that: first, the turnover process dominated altitudinal patterns of species beta-diversity ( β sim > β sne ), whereas the nestedness process appeared relatively more important for elevational trait dissimilarity ( β funcsim < β funcsne ); second, the taxonomic turnover was relative higher than its phylogenetic and functional analogues ( β sim > β phylosim / β funcsim ), conversely, nestedness-resultant trait dissimilarity tended to be higher than the taxonomic and phylogenetic measures ( β funcsne > β sne / β phylosne ); and third, as elevational distance increased, the contradicting dynamics of environmental filtering and limiting similarity have jointly led the elevational patterns of beta-diversity, especially at taxonomic dimension. Based on these findings, we infer that the species turnover among phylogenetic relatives sharing similar functional attributes appears to be the main cause of shaping the altitudinal patterns of multi-dimensional beta-diversity. Owing to the methodological limitation in the randomization approach, currently, it remains extremely challenging to distinguish the influence of the neutral process from the offset between opposing niche-based processes. Despite the complexities and uncertainties during species assembling, with a multi-dimensional comparative perspective, this work offers us several important commonalities of elevational beta-diversity dynamics.

The recently described trait‐based approach is becoming widely popular for a mechanistic understanding of species coexistence. However, the greatest challenge in functional analyses is decomposing the contributions of different ecological and evolutionary processes (e.g., niche‐based process, neutral process, and evolutionary process) in determining trait structure. Taking rodents (Rodentia) in the Hengduan Mountains as our study model, we aim to (1) quantify the vertical patterns of functional structure for head–body length (HL), tail/body ratio (TR), animal component in diet (ACD), and all traits; (2) disentangle the relative importance of different assembly processes (environment, space, and phylogeny) in structuring trait dispersion; and (3) assess the feasibility of Bergmann's rule and Allen's rule along elevational gradient. Our results have suggested that the vertical functional structure pattern varied across these three traits, indicating distinct functional roles in the community assembly process. These nonrandom vertical patterns of HL, TR, and terminal ACD have demonstrated these traits were dominated by different ecological process along environmental gradient. In variance partitioning, high proportion of the spatial variations in trait dispersion was explained by environmental and spatial models, which have provided supporting strong evidence for niche‐based and neutral processes in leading species coexistence. Although the three traits all exhibited apparent phylogenetic signals, phylogenetic relationship within community failed to predict the spatial variations of functional dispersion, confirming the enormous inference of phylogenetic signals in predicting trait structure. By assessing the vertical patterns of HL and TR at order and family levels, we argued that functional adaptation along an environmental gradient is a surrogate of series of complex processes (e.g., environmental filtering, interspecific interaction, and neutral dispersal) acting on multiple functional axes, which results in inconsistence with the empirical rules along elevational gradient.

The idea that a positive abundance-range size relationship (ARR) is pervasive in nature has been challenged by recent studies focused on montane and island vertebrate assemblages. However, because some of these studies used species' local abundance and regional or global range size in examining the ARRs, the negative and neutral trends reported are questionable. Here, by relating species' mean abundance along elevational gradients to elevational range size, we examined the ARRs of non-flying small mammals on three subtropical mountains of southwest China. We also examined the relationship between mean abundance and elevational range centre (reflecting species' elevational distribution) on each mountain, and compared the elevational range centre and mean abundance between endemic and non-endemic species as they may have been subjected to different intensities of historical (e.g. geographical isolation and colonization) and ecological (e.g. ecological specialization) processes. The results show significantly positive relationship between mean abundance and elevational range size on each mountain. We also observed a consistent positive relationship between mean abundance and elevational range centre, probably due to the stronger local specialization of mid-and high-elevation species, lower species richness at higher elevations, and increasing extinction rate of small-ranged less abundant species towards higher elevations. A novel finding of our study is that endemic species show higher elevational range centres and higher mean abundance than non-endemic species on each mountain, which is most likely driven by the increasing geographical isolation with elevation and the higher degree of ecological specialization for endemic species. Measuring abundance and range size at the same spatial scale is a key prerequisite to evaluate the ARRs of montane small mammals.

Understanding the mechanisms that govern the spatial patterns of species turnover (beta diversity) has been one of the fundamental issues in biogeography. Species turnover is generally recognized as strong in mountainous regions, but the way in which different processes (dispersal, niche, and isolation) have shaped the spatial turnover patterns in mountainous regions remains largely unexplored. Here, we explore the directional and elevational patterns of species turnover for nonvolant small mammals in the Hengduan Mountains of southwest China and distinguish the relative roles of geographic distance, environmental distance, and geographic isolation on the patterns. The spatial turnover was assessed using the halving distance (km), which was the geographic distance that halved the similarity (Jaccard similarity) from its initial value. The halving distance was calculated for the linear, logarithmic, and exponential regression models between Jaccard similarity and geographic distance. We found that the east–west turnover is generally faster than the south–north turnover for high‐latitudinal regions in the Hengduan Mountains and that this pattern corresponds to the geographic structure of the major mountain ranges and rivers that mainly extend in a south–north direction. There is an increasing trend of turnover toward the higher‐elevation zones. Most of the variation in the Jaccard similarity could be explained by the pure effect of geographic distance and the joint effects of geographic distance, environmental distance, and average elevation difference. Our study indicates that dispersal, niche, and isolation processes are all important determinants of the spatial turnover patterns of nonvolant small mammals in the Hengduan Mountains. The spatial configuration of the landscape and geographic isolation can strongly influence the rate of species turnover in mountainous regions at multiple spatial scales.

Hexagonal boron nitride (hBN) shows huge promise for metallic corrosion protection due to its excellent impermeability. However, the exfoliation and dispersion of hBN have proven to be very challenging, owing to the strong "lip−lip" interactions and inherent hydrophobic features. Herein, ultrathin IL-BN nanosheets were synthesized and simultaneously noncovalent functionalized by ionic liquid (IL) through a liquid ball milling strategy to achieve the good compatibility with epoxy (EP), which was characterized by scanning electron microscope (SEM), transmittance electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectronic spectroscopy (XPS), and UV−vis absorbance spectroscopy. Electrochemical measurements confirmed that the addition of 0.5 wt % IL-BN into the EP matrix significantly enhanced the anticorrosion capability of coatings. After 4 weeks of immersion in 3.5 wt % NaCl solution, the IL-BN-EP coating remained with a high coating resistance R c of 5.6 × 10 9 Ω cm 2 , 4 orders of magnitude higher than EP (4.9 × 10 5 Ω cm 2 ). SEM and Raman measurements also corroborated that the steel protected by IL-BN-EP was hardly corroded. Moreover, the passivation effect of IL-BN-EP coating was confirmed by potential polarization curve (PPC) tests at the coating defects. The superior anticorrosion performance of IL-BN-EP coating was mainly attributed to the synergistic effect of physical barrier and self-healing property endowed by the well-dispersed IL-BN hybrids.

No abstract

Our understanding of geographic patterns of species diversity and the underlying mechanisms is increasing rapidly, whereas the temporal variation in these patterns remains poorly understood. We examined the seasonal species richness and species turnover patterns of nonvolant small mammals along three subtropical elevational gradients in southwest China. Small mammal diversity was surveyed in two seasons (early wet season and late wet season) using a standardized sampling protocol. The comparison of species richness patterns between two seasons indicated a temporal component in magnitude and shape, with species richness at high elevations clearly increased during the late wet season. Species richness demonstrated weak correlations with modelled temperature and precipitation. The elevational pattern of species turnover measured by Chao-Sørenson similarity index also changed seasonally, even though the temporal pattern varied with scale. Species turnover between neighboring elevations at high elevations was slower in the late wet season. Meanwhile, there was an acceleration of species turnover along the whole range of the gradient. The seasonal change in species diversity patterns may be due to population-level increases in abundance and elevational migration, whereas seasonal variation in factors other than temperature and precipitation may play a greater role in driving seasonal diversity patterns. Our study strongly supports the seasonality in elevational patterns of small mammal diversity in subtropical montane forests. Thus it is recommended that subsequent field surveys consider temporal sampling replicate for elevational diversity studies.Abstract in Chinese is available in the online version of this article.