Effect Of Geographic Distance Research Articles

Do geographic distance, cultural distance, and political hazards equally matter for Japanese firms' outbound mergers and acquisitions? A firm‐ and deal‐level empirical analysis

Several studies on cultural clusters classify Japan as independent, meaning that wherever Japanese firms go abroad, they must adapt to very different environments. This study examines how Japanese firms treat deterrent effects of geographic distance, cultural distance, and political hazards and whether the deterrent effects may vary with firm size, firm age, and ownership solution. Results using data on Japanese firms' outbound mergers and acquisitions (M&A) from 2010 to 2019 reveal that (1) only the deterrent effect of geographic distance is absolute. (2) Larger firms with larger slack resources in their home country are less concerned about geographic distances and political hazards. (3) Older firms, exposed to typical practices and norms for a long time, are less adaptable to cultural distances. (4) The deterrent effect of geographic distance is weaker for complete control mode on the one hand, on the other hand, the moderating effect of complete control mode on political hazards hinges on firm size and age due to trade‐offs between integration benefits and resource/experience constraints.

Coupling and decoupling of ancestral linkages and current cross-border economic activities: Genetics and policy

This paper studies the potential link between the biological evolution of populations and present-day economic interactions by estimating the correlation of shared ancestry among populations with cross-border capital and human flows. To this end, we employ the new concept of genetic distance, based on (dis)similarity of neutral gene alleles, to quantify shared ancestry. We then incorporate the genetic distance measure into an augmented gravity model, traditionally used to analyze the effect of geographical distance on bilateral exchange. Our analysis focuses on bilateral foreign direct investment (FDI) and migration across 135 countries and we use both linear regression techniques as well as the Poisson Pseudo-Maximum Likelihood Estimator to account for any non-linearities in the model. Our results show that a 1% increase in genetic distance reduces FDI flows by 0.08% while controlling for other distance constructs and factors associated with global capital and human movement. Genetic distance also has a negative effect on migration, where a 1% increase in genetic distance reduces migration flows by 0.22%, with all other things remaining constant. Our study, therefore, links shared ancestry with economic behavior, showing how historical connections are associated with current economic exchanges among nations. Additionally, recognizing that ancestral ties are outside human control, we examine policy measures that help nations overcome such distance barriers. Our findings show that strengthening a nation’s institutional quality and adherence to the rule of law can effectively mitigate any negative correlation of distance constructs with economic exchanges. These insights suggest that prudent policies to foster a stable business environment are essential for any nation to attract FDI and human capital, even from geographically or genetically distant nations.

Patterns and processes underlying understory songbird communities in southern China

AbstractUnderstory bird communities, especially those comprising insectivores, are highly sensitive to forest loss and fragmentation. Currently, there is little knowledge regarding the large‐scale diversity patterns of understory bird communities, particularly in Eastern Asia. Consequently, we aimed to identify the distribution patterns of understory birds in southern China and the factors underlying these patterns. We analysed the diversity distribution patterns of taxonomic and functional α and β diversity for understory Passeriformes birds in southern China utilising cluster and ordination analyses. Subsequently, we analysed the effects of geographic distance, annual mean temperature, annual temperature range, annual mean precipitation, and annual precipitation range on diversity distribution patterns. In total, 9282 individuals belonging to 11 orders, 48 families, and 297 species were captured over 98,544 net hours, with Alcippeidae being the most abundant family in southern China. The understory bird communities of the 25 sites were categorised into six sub‐regions of the Oriental Realm (Indo‐Malayan Realm). The pattern in the distribution of taxonomic and functional β‐diversity of understory birds in southern China was consistent with zoogeographical regionalisation. Three distinct geographical groups were identified: Group 1 was located in the Min‐Guang Coast and Hainan sub‐regions; Group 2 was located in the East Hilly Plain, Southwest Mountains, and Western Mountains and Plateaus sub‐regions; and Group 3 was located in the Southern Yunnan Mountain subregion. The most critical factors related to the distribution patterns of β‐diversity were geographical distance, annual mean temperature, and annual temperature range. Our results showed that the understory bird communities of the Southwest Mountain, East Hilly Plain, and Western Mountains, and Plateaus sub‐regions were similar, as were those of the Min‐Guang Coast and Hainan sub‐regions. Our results underscore the joint roles of distance, temperature, and historical evolution in understory bird communities.

Assessing the Efficiency and Potential of China’s Apple Exports

This study elucidates the factors impacting China’s apple trade, its efficiency, and opportunities for increased revenue. This study adopts a stochastic frontier gravity model on China’s apple exports data, covering the period from 1997 to 2022 across 38 significant trading partners. The finding demonstrates that the economic growth of China and its trading partners substantially boosts apple export volumes, with a positive correlation between GDP growth and export flows. The research also highlights the deterrent effect of geographical distance on exports and reveals a complex negative relationship between the per capita GDP of importing nations and export efficiency, shedding light on the nuanced nature of trade dynamics. Furthermore, the study finds that the appreciation of China’s currency plays a crucial role in enhancing export efficiency by lowering transaction costs. Meanwhile, increased agricultural land in importing countries presents competitive challenges, impacting export performance negatively. Geographical proximity and infrastructural features, such as shared borders and lack of access to seaport, are identified as significant factors in export efficiency. The analysis unveils considerable untapped export potential in various countries, suggesting a strategic avenue for market expansion. To optimize China’s apple export strategy, policymakers are advised to consider currency management, negotiate trade agreements that mitigate distance and per capita GDP effects, and target markets with high untapped potential, thereby facilitating sustainable growth in China’s apple export sector.

Advertisement call variation is related to environmental and geographic distances in two anuran species inhabiting highland forests in northeastern Brazil

AbstractHighlands are of paramount importance to the study of evolution as they are frequently implicated in historical and ecological processes that generate and maintain biological diversity. In northeastern Brazil, sparse rainforest remnants located in highlands north of the São Francisco River are surrounded by the dry and open landscape of the Caatinga biome. Earlier studies suggested that these forests were historical refuges to the rainforest fauna and flora during Pleistocene's climatic cycles. However, it is still unclear whether populations in distinct highlands experienced phenotypic differentiation as a result of adaptation to environmental conditions of each forest remnant. Herein, we used two frog species widely distributed and ecologically different, Dendropsophus oliveirai, a habitat specialist, and Physalaemus cuvieri, a habitat generalist, to investigate the relationships between environmental variation, geographic, genetic, and body size distance with advertisement call variation among populations inhabiting different highlands. Our results indicated that acoustic variation among P. cuvieri populations is strongly influenced by environmental variation, but also by the geographic distance among populations. In D. oliveirai, environment is also the most influent factor on acoustic variation, followed by a lower influence of genetic and morphological variation. Associations between environmental and geographic factors suggest indirect effects of geographic distance on acoustic variation in both species through an environmental gradient. We believe that selective processes and isolation by distance possibly act together in driving interpopulational acoustic variation with habitat‐specific species being more affected by geographic isolation in suitable habitats.Abstract in Portuguese is available with online material.

Research on the impact of geographic distance on corporate technology for social good: From the perspective of institutional environment and regional innovation capability

Corporate technology for social good is an important philosophy and action for enterprises to incorporate social issues and social needs into their core business activities, provide goodwill products/services based on technology innovation, and promote the integrated development of social and commercial values, which has become a heated topic in academia. Moreover, a better understanding of the relationship between corporate technology for social good and its predictors has significant implications for enterprise managers. The aim of this study is to explore the causal link between geographic distance and corporate technology for social good, and to investigate the moderating roles of institutional environment and regional innovation capability. Using available data for A-share listed companies in the Shanghai and Shenzhen stock markets of China between 2015 and 2020, this study adopts Ordinary Least Squares regression to empirically test the effect of geographic distance on corporate technology for social good, including the moderating roles of institutional environment and regional innovation capability in the geographic distance-corporate technology for social good link. The results show that geographic distance has a significant negative impact on corporate technology for social good. In other words, the shorter the geographic distance between enterprises and central cities, the better is the performance of corporate technology for social good. Besides, institutional environment and regional innovation capability can moderate the negative impact of geographic distance on corporate technology for social good. These obtained findings promote the extension of mature theoretical achievements such as stakeholder theory and institutional theory to the research field of corporate technology for social good, and expand the boundaries of existing theoretical applications. The results of the study also open the “black box” of the relationship between geographic distance and corporate technology for social good, which offer insights into geographic location and institutional factors influencing corporate technology for social good engagement. Moreover, the study is a useful supplement to the existing exploration of the drivers of corporate technology for social good from theoretical perspectives, and provides practical references for enterprises to actively participate in corporate technology for social good and the government to strengthen ethical governance of science and technology in the process of achieving sustainable development.

Superior medical resources or geographic proximity? The joint effects of regional medical resource disparity, geographic distance, and cultural differences on online medical consultation

Online medical consultation platforms enable patients to seek health advice from physicians across geographic regions. In this study, we analyze patterns of online consultation between patients and physicians. We examine the joint effects of regional medical resource disparity, geographic distance, and cultural differences between patients and physicians on patients' decisions about which physicians they consult online. Using a unique dataset of city-to-city tuples based on 813,684 online consultation records and combining it with region-level data from multiple external sources, we find that while regional medical resource disparity drives patients from medically disadvantaged regions to seek online consultations with physicians from medically advantaged regions, geographic distance and cultural differences tend to constrain these consultations. We also find that cultural differences can amplify the impact of regional medical resource disparity, whereas geographic distance may lessen this effect. Further, we discover that the constraining effect of geographic distance is partly due to the online-to-offline nature of online medical consultations. Moreover, additional analyses suggest that physicians' online reputation and information about physicians’ participation on the platform can help alleviate the negative effects of geographic distance and cultural differences. These findings hold significant implications for the allocation of medical resources and the formulation of healthcare policies.

Combining population genomics and biophysical modelling to assess connectivity patterns in an Antarctic fish.

Connectivity is a fundamental process of population dynamics in marine ecosystems. In the last decade, with the emergence of new methods, combining different approaches to understand the patterns of connectivity among populations and their regulation has become increasingly feasible. The Western Antarctic Peninsula (WAP) is characterized by complex oceanographic dynamics, where local conditions could act as barriers to population connectivity. Here, the notothenioid fish Harpagifer antarcticus, a demersal species with a complex life cycle (adults with poor swim capabilities and pelagic larvae), was used to assess connectivity along the WAP by combining biophysical modelling and population genomics methods. Both approaches showed congruent patterns. Areas of larvae retention and low potential connectivity, observed in the biophysical model output, coincide with four genetic groups within the WAP: (1) South Shetland Islands, (2) Bransfield Strait, (3) the central and (4) the southern area of WAP (Marguerite Bay). These genetic groups exhibited limited gene flow between them, consistent with local oceanographic conditions, which would represent barriers to larval dispersal. The joint effect of geographic distance and larval dispersal by ocean currents had a greater influence on the observed population structure than each variable evaluated separately. The combined effect of geographic distance and a complex oceanographic dynamic would be generating limited levels of population connectivity in the fish H. antarcticus along the WAP. Based on this, population connectivity estimations and priority areas for conservation were discussed, considering the marine protected area proposed for this threatened region of the Southern Ocean.

Linking landscape and genetic variation in the heterogeneous Yungas Andean forest' hotspot: a multi taxa approach

AbstractAimThe factors that influence the diversity of Yungas Andean forest remain unexplored. Our study seeks to investigate the impact of key isolating factors on the genetic structure of multiple taxa, testing for four hypotheses: isolation by distance (IBD), isolation by resistance due to topography (IBRtopo), isolation by resistance due to habitat suitability (IBRsuit) and isolation by environmental dissimilarity (IBE).LocationYungas Andean forest.TaxonTetrapoda.MethodsWe analysed a dataset consisting of 477 Cyt‐b sequences from 138 localities, encompassing 13 species. Through multiple matrix regression, Moran Spectral Randomization of Mantel and GDM analyses, we tested the impact of each extrinsic predictor on observed genetic variation and determined the effect size of environmental variation on genetic divergence. Additionally, we investigated the spatial distribution of lineages within the study species.ResultsThe genetic variation within the Yungas exhibited varied responses that correspond to the regional landscape heterogeneity. We identified different isolating factors as the main predictor for specific species: IBD for Akodon spegazzinii; IBRtopo for certain small mammals' species; IBE for Thylamys cinderella and Oligoryzomys brendae; and IBRsuit for Calomys fecundus, Oreobates barituensis and Melanophryniscus rubriventris with some considerations. Furthermore, our results support the presence of a latitudinal pattern in the distribution of genetic lineages.Main ConclusionsThe heterogeneous landscape of the Yungas Andean forest posed varied effects on genetic variation. The effect of topography and continuity of suitable habitats over vertebrate dispersal shapes the genetic diversity, in particular topography acts either as a barrier or as corridor, while habitat suitability resistance mainly shapes endemism genetic structure; local climate represents a strong genetic promoter in transition zones; and the effect of geographic distance is less evident when considering other landscape promoter of genetic divergence. This reinforces the understanding that the complex interplay of environmental and historical factors contributes to the observed patterns of genetic diversity in this region.

Research on the relationship between CEO career variety, digital knowledge base extension, and digital transformation in the context of digital merger and acquisition: The case of China's new generation of information technology firms.

This study examines the relationship between CEO career variety, digital knowledge base extension, and digital transformation in a digital M&A context. An empirical test was conducted using regression analysis with the digital M&A events of the new generation of information technology firms in China as the research sample. The results reveal that CEO career variety has a positive effect on digital transformation in the digital M&A context and that digital knowledge-base extension plays a mediating role. Moreover, the heterogeneity impact analysis indicated that the moderating effects of geographical distance, knowledge disparity, and cultural difference between target and acquirer firms on the above relationships vary greatly: geographical distance has a negative moderating effect, cultural difference has a positive moderating effect, and the moderating effects of both geographical distance and cultural difference are realized through mediating effects, but none of the moderating effects of knowledge disparity are significant.

Restricted dispersal and inbreeding in a high‐elevation bird across the ‘sky islands’ of the European Alps

AbstractAimHigh‐elevation specialist species are threatened by climate change and habitat loss, and their distributions are becoming increasingly reduced and fragmented. In such a context, dispersal ability is crucial to maintain gene flow among patches of suitable habitat. However, information about dispersal is often lacking for these species, especially for those taxa that are usually considered as good dispersers such as birds. We adopted a landscape genomics approach to investigate dispersal in a climate‐sensitive high‐elevation specialist bird. Our aims were to assess the levels of gene flow within a wide mountain area, and to assess the effects of geographic distance and landscape characteristics on dispersal, by testing the isolation by distance (IBD) hypothesis against the isolation by resistance (IBR) hypothesis.LocationEuropean Alps.Taxon Montifringilla nivalis. MethodsWe sampled individuals from several breeding areas and obtained single nucleotide polymorphism (SNP) data by ddRAD sequencing. We then calculated site‐ and individual level genetic distances and individual inbreeding coefficients. To test IBD versus IBR, we related genetic distances to both geographic distances and different measures of landscape resistance by using maximum likelihood population effects models.ResultsGene flow among breeding areas was partly restricted, and we found support for IBD, indicating that geographic distance limits snowfinch dispersal. Spatial patterns of genetic distances suggested that philopatry strongly contributed to determine the observed IBD. High inbreeding coefficients in several individuals indicated frequent mating among relatives.Main ConclusionsRestricted dispersal and frequent inbreeding within ‘sky island’ systems can also occur in highly mobile species, because their potential ability to cover very large distances can be counteracted by high philopatry levels that are likely related to high dispersal costs. IBD and philopatry will increasingly hinder snowfinch dispersal among suitable areas within the future more restricted and fragmented breeding range, increasing the risks of local extinctions.

Intercity asymmetrical linkages influenced by Spring Festival migration and its multivariate distance determinants: a case study of the Yangtze River Delta Region in China

Understanding intercity linkage patterns is of great importance to understanding urbanization. With advancements in transportation, communication technology, and the availability of big data, the “death of distance” concept has gained significant attention. This paper analyzes the asymmetric spatial intercity linkage network in China’s economically developed YRDR based on big data derived from Spring Festival (SF) migration. The aim is to explore the determinants of these linkages considering multivariate distance factors. The findings indicate a notable pattern of asymmetry in the intercity linkage network of the YRDR between core and non-core cities. The spatial decay effect of geographic distance on intercity asymmetry linkage is observed. Despite technological advancements, geographic distance remains the most influential and decisive factor in determining intercity asymmetric linkages. While other attribute distances also play a positive role, their effects become complex when controlling for geographic distance. Understanding these attribute distances is essential in comprehending the decay effect. This study contributes to the empirical investigation of the “death of distance” debate and provides a practical analytical framework for analyzing the drivers of intercity linkage patterns. It enhances our understanding of intercity spatial linkages within the context of urbanization in China and offers valuable insights for formulating development policies in the YRDR.

Host habitat rather than evolutionary history explains gut microbiome diversity in sympatric stickleback species.

Host-associated microbiota can influence host phenotypic variation, fitness and potential to adapt to local environmental conditions. In turn, both host evolutionary history and the abiotic and biotic environment can influence the diversity and composition of microbiota. Yet, to what extent environmental and host-specific factors drive microbial diversity remains largely unknown, limiting our understanding of host-microbiome interactions in natural populations. Here, we compared the intestinal microbiota between two phylogenetically related fishes, the three-spined stickleback (Gasterosteus aculeatus) and the nine-spined stickleback (Pungitius pungitius) in a common landscape. Using amplicon sequencing of the V3-V4 region of the bacterial 16S rRNA gene, we characterised the α and β diversity of the microbial communities in these two fish species from both brackish water and freshwater habitats. Across eight locations, α diversity was higher in the nine-spined stickleback, suggesting a broader niche use in this host species. Habitat was a strong determinant of β diversity in both host species, while host species only explained a small fraction of the variation in gut microbial composition. Strong habitat-specific effects overruled effects of geographic distance and historical freshwater colonisation, suggesting that the gut microbiome correlates primarily with local environmental conditions. Interestingly, the effect of habitat divergence on gut microbial communities was stronger in three-spined stickleback than in nine-spined stickleback, possibly mirroring the stronger level of adaptive divergence in this host species. Overall, our results show that microbial communities reflect habitat divergence rather than colonisation history or dispersal limitation of host species.

Geographic Distance and State's Grip: Information Asymmetry, State Inattention, and Firm Implementation of State Policy

In this study, we develop the argument that geographic distance between the state and local governments undermines the state's capacity to influence the implementation of state policies by local organizations. Drawing from information economics and the attention-based view, we propose that physical distance reduces the state's monitoring effectiveness through two interrelated mechanisms: information asymmetry and state leaders’ inattention to distant issues. Using data of Chinese public firms’ implementation of environmental activities between 2008 and 2016, we find that firms conduct fewer environmental activities required by the state when they are regulated by local governments that are more geographically distant to Beijing. This distance effect is, however, attenuated in regions with higher levels of gross domestic product growth and Internet activism. Furthermore, firm characteristics that draw the direct attention of state leaders and provide alternative information channels—namely, firm visibility and government subsidy received—negatively moderate the effect of geographic distance. This study contributes to the literatures by identifying a geography-based view of state capacity in shaping organizational behaviors and its underlying mechanisms.

Effect of geographical distance on repeat pleural procedures in patients managed by indwelling pleural catheters: A retrospective cohort study

INTRODUCTION Malignant pleural effusions are typically initially managed with thoracentesis or chest tubes prior to indwelling pleural catheter insertion. We sought to examine whether geographical distance from a specialized pleural effusion clinic affected the number of pleural procedures prior to the insertion of a definitive indwelling pleural catheter. METHODS This retrospective single-center cohort study included adult patients from Alberta with malignant pleural effusions who underwent indwelling catheter insertion at an outpatient pleural effusion clinic in Edmonton from November 1, 2012, to December 31, 2018. We collected data on demographic and indwelling pleural catheter characteristics. We computed a multivariable logistic analysis adjusting for age, sex, and malignancy type. RESULTS A total of 515 indwelling pleural catheters were inserted during the study period. Patients living in communities over 300 km away from the clinic were more likely to have undergone 3 or more pleural procedures prior to their indwelling pleural catheter insertion compared with patients living within 50 km of the clinic (OR 2.67; 95%CI 1.23 to 5.81; p = 0.0130). This association was also significant if their travel time was over 90 min when compared to 45 min or less (OR 1.98; 95%CI 1.10 to 3.56; p = 0.0232). CONCLUSION Patients residing in distant communities were more likely to have had multiple pleural procedures prior to the insertion of their indwelling pleural catheter for their malignant pleural effusion. This study highlights the impact of distance and limited access on how Canadians with refractory pleural effusions are treated.

Interlibrary loan in Türkiye: interlibrary loan tracking system (KITS)

PurposeThis study aims to evaluate the current situation of the interlibrary loan in Türkiye using interlibrary loan tracking system raw data (2008–2019). Data was analyzed geographically to reveal the effect of geographical distance on the collaboration and thematically to identify the prominent areas/topics in the requests. In addition, the requests were evaluated in terms of the type and age of the university, the size of the collection and the number of library users.Design/methodology/approachThe effect of geographical distance on the collaboration was revealed using VOSviewer. The place numbers and titles of the requests were used for thematic analysis, which was performed using Flourish and VOSviewer. Statistical tests were conducted with SPSS to investigate the effects of factors such as university age and type.FindingsGeographic analysis revealed that the prominent regions are Marmara, Central Anatolia and Aegean Regions, respectively. The fact that these regions host Türkiye’s largest cities with the highest number of universities has been effective in achieving this result. The results of the thematic analysis are in accordance with the literature. Almost half of the requests are from Social Sciences, Language and Literature, History and Law. While the effects of collection size and the number of library users have relatively insignificant effects on requests, age and university type were found to be more relevant.Originality/valueInterlibrary loan data of this size has not been the subject of an evaluation before in Türkiye. Hence, the results obtained have the potential to influence relevant policies and decisions on the subject. On the other hand, to the best of the authors’ knowledge, bibliographic mapping was used for the first time on interlibrary loan data.

Corridor-based approach with spatial cross-validation reveals scale-dependent effects of geographic distance, human footprint and canopy cover on grizzly bear genetic connectivity.

Understanding how human infrastructure and other landscape attributes affect genetic differentiation in animals is an important step for identifying and maintaining dispersal corridors for these species. We built upon recent advances in the field of landscape genetics by using an individual-based and multiscale approach to predict landscape-level genetic connectivity for grizzly bears (Ursus arctos) across ~100,000 km2 in Canada's southern Rocky Mountains. We used a genetic dataset with 1156 unique individuals genotyped at nine microsatellite loci to identify landscape characteristics that influence grizzly bear gene flow at multiple spatial scales and map predicted genetic connectivity through a matrix of rugged terrain, large protected areas, highways and a growing human footprint. Our corridor-based modelling approach used a machine learning algorithm that objectively parameterized landscape resistance, incorporated spatial cross validation and variable selection and explicitly accounted for isolation by distance. This approach avoided overfitting, discarded variables that did not improve model performance across withheld test datasets and spatial predictive capacity compared to random cross-validation. We found that across all spatial scales, geographic distance explained more variation in genetic differentiation in grizzly bears than landscape variables. Human footprint inhibited connectivity across all spatial scales, while open canopies inhibited connectivity at the broadest spatial scale. Our results highlight the negative effect of human footprint on genetic connectivity, provide strong evidence for using spatial cross-validation in landscape genetics analyses and show that multiscale analyses provide additional information on how landscape variables affect genetic differentiation.

Food Trade Network and Food Security: From the Perspective of Belt and Road Initiative

In recent times, there has been a growing interest in the role of food trade in achieving food security. This study presents a comprehensive analysis of the relationship between food trade and food security within the context of the Belt and Road Initiative (BRI). This study employs complex networks alongside the quadratic assignment procedure (QAP) regression method on trade data of 46 countries under BRI for the period 2008 to 2018. The resulting complex network showed an enhancement in the food trade relationships and food security levels after BRI, indicating a mutually positive effect. In addition, the closeness centrality measure showed a strong correlation with food security, indicating that food trade has positive spillovers on food security in the proximate countries. Using geographical distance as an instrumental variable, the QAP regression model proved the positive effects of food trade on food security. More investment in trade infrastructure is recommended to reduce the negative effect of geographical distance on food security.

Out of sight, out of mind: Effect of geographical environment on consumer’s representations

The objective of this article is to evaluate the effects of geographical distance and age on the representations of traditional products using Maroilles cheese as a case study. To test the effect of these factors, we used a free word association task with nine groups of participants from different places in France, at three different distances from the Maroilles production area (Thiérache - 0 km, Lille - 80 km and Angers - 500 km) and three different ages (18–34, 35–54, >55 years old). Our study highlights that geographic proximity promotes information sharing by consumers and constitute a building block of knowledge acquisition. Finally, our study shows that geographical distance also plays a role on the valence of the terms associated with Maroilles cheeses suggesting the importance of the concept of local identity and ethnocentrism for artisanal products.

Environmental distances are more important than geographic distances for predicting earthworm gut bacterial community composition

Distance-decay of similarity is one of the most widely studied patterns in biogeography. Both geographic distance and environmental distance can cause distance-decay of similarity in ecological communities. Here, we studied distance-decay relationships of bacteria in the gut of an earthworm species, Eisenia nordenskioldi, which is widely distributed in Eurasian boreal region. Using high-throughput sequencing, we investigated bacterial community composition in different gut sections, together with the surrounding soil. We specifically quantified the effects of geographic distance and environmental distance on distance-decay pattern of both soil and earthworm gut bacteria. Environmental distance significantly affected soil bacteria, and bacteria in the foregut and midgut of earthworms, with those in the foregut changing most, whereas geographic distance only significantly affected bacteria in the foregut of earthworms. Both, environmental and geographic distance explained bacterial community composition in the gut of earthworms and in surrounding soil, with environmental distance being more important than geographic distance. The results indicate that bacteria in the foregut of earthworms are most sensitive to environmental changes than those in the other sections. Overall, the results suggest that homogenization processes during gut passage of earthworms contribute to similarity of soil microbial communities in space due to the production of casts of similar bacterial community composition.