The impact of free-roaming pigs on arthropod diversity: a field survey in four European countries

The impact of free-roaming pigs on arthropod diversity: a field survey in four European countries | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The impact of free-roaming pigs on arthropod diversity: a field survey in four European countries Atle Wibe, Massimo Pindo, Davide Bochicchio, Jan Plut, Marina Štukelj, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8310948/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The diversity and composition of arthropod communities are influenced by a broad range of environmental factors, including local livestock management practices. Free-roaming domestic pigs, through activities such as, wallowing, exploration, foraging at and below the soil surface, and defaecation can substantially alter arthropod habitats. While these behaviours may reduce populations of soil-associated arthropods, they can also create novel microhabitats that support other species. In this study, arthropods were sampled using Malaise traps positioned both in proximity to free-roaming pigs and at distances from them across five locations in four European countries—Norway, Denmark, Italy, and Slovenia—during 2022 and 2023. DNA metabarcoding of the Cytochrome Oxidase I (COI) gene was used to identify the collected bulk samples. The results revealed significant differences in arthropod order composition between areas with or without pigs at sites in Norway and Italy in 2022. Moreover, free-roaming pigs significantly modified the relative distribution of arthropod orders across all investigated locations. The analysis further demonstrated a strong positive relationship between α- and β-diversity and the total site γ-diversity across all sites and study years. Implications for insect conservation: These findings indicate that free-roaming domestic pigs enhance arthropod diversity. Accordingly, agricultural management practices that integrate free-roaming pigs may contribute to strengthening arthropod biodiversity within managed ecosystems. Arthropods diversity DNA metabarcoding free-roaming pigs Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Insects support a wide range of ecosystem services whereof pollination, biological control, food supply, and recycling of organic matter are the most studied (Noriega et al. 2018 ). Insects are therefore often categorised by their functional groups as pollinators, predators, parasitoids, herbivores and decomposers while the most studied taxa are Hymenoptera, Coleoptera and Diptera. Through their function, insects can provide services to achieve the sustainable development goals (Dangles and Casas 2019 ). However, in recent decades a decline of up to 75% in insect biomass has been observed in Central Europa (Hallmann et al. 2017 ) and in places in the tropics (Janzen and Hallwachs 2019 ). Evidence suggests agricultural intensification and climate change are directly linked to these losses (Raven and Wagner 2021 ; Rumohr et al. 2023 ). For the agricultural impact crop monocultures and the decrease in landscape diversity have been associated with a decline of e.g. bumble bee species (Hemberger et al. 2021 ), but no studies have been published on the impact of free-roaming domestic pigs ( Sus scrofa domesticus ) on insect diversity and abundance in natural or cultural pastures. The closest comparison is the impact of wild boar ( Sus scrofa scrofa ) that is now present on all continents except Antarctica (Barrios-Garcia and Ballari 2012 ). Domesticated pigs and wild boar belong to the same species and thus share many behavioural patterns such as wallowing, exploration, foraging at and below soil surface in out-door systems and defaecation. By rooting extensive areas of soil, vegetation is overturned in the search for belowground plant parts, fungi, and invertebrates as earthworms and insects (larvae and/or imagines) (Baubet et al. 2003 ; Schley and Roper 2003 ). This behaviour may potentially reduce soil-associated arthropods while, on the other hand, it can create habitats for other species. Tuinder et al. ( 2025 ) showed that wild boars supported Orthoptera diversity by creating habitats for specialists with different life cycles, thereby increasing species richness. Electrophysiological studies have indicated that Volatile Organic Compounds (VOCs) from pig manure elicit responses in the antenna of female houseflies (Cossé and Baker 1996 ), and mixtures of these volatiles attracted the flies in a behaviour study. Also, some mosquito species are attracted to pigs by means of olfaction (Takken 1991 ). These blood sucking insects may also carry pathogens that affect pigs (Stelder et al. 2023 ), thereby posing a potential threat to pig health and wellbeing. In monitoring species composition of populations several expressions, such as diversity and evenness are widely used. Species diversity, or richness, is used to describe all species living in a particular area, while species evenness is the relative abundance with which each species is represented in a sample (DeJong 1975 ). The diversity can be divided into a-, b- and g-diversity as described by Whittaker ( 1972 ). This concept was later elaborated in the book Ecosystem Management: adaptive, community-based conservation by Meffe et al. ( 2002 ) (Fig. 1 ). According to their description, a-diversity is defined as equivalent to species richness which is the number of species within a particular area or ecosystem. b- diversity is defined as the change in species diversity between areas or ecosystems and is measured by counting the total number of species unique to each area under comparison. The g-diversity of a landscape or location is determined by number of species shared between its communities and the degree of b-differentiation among them, making it a measure of the total ecosystem diversity. In this study, we aimed to investigate whether free-roaming pigs on forest/pasturelands influence arthropod biodiversity compared to nearby areas without the presence of pigs. In many countries, free-roaming or out-door pigs, make up only a very small share of total pig production, with stable-based management being far more common, e.g. in Denmark, pigs produced in organic farming systems constituted less than 1.7% of the total national pig production in 2023 (Neergaard 2023 ). However, with growing emphasis on animal welfare and product quality, free-roaming pigs may become a more significant part of meat production. Yet little is known about their environmental impact or their effects on insect fauna. In our study, we focused on all kinds of flying insects and other arthropods that could be trapped within a restricted period. Identification of the collected bulk samples was performed through COI-based DNA metabarcoding. The study therefore investigates whether the taxonomic composition of arthropods differs significantly between treatments—specifically, areas with pigs and non-pig areas—at sites located in Norway, Denmark, Italy, and Slovenia, using Pearson’s Chi-square test of independence. The impact of a- and b-diversity on the g-diversity was tested by linear regression analysis. Material and methods Arthropod sampling To sample flying insect, we used black Malaise traps (Malaise, 1937 ) (Uhler et al. 2022 ) manufactured by Watkins & Doncaster, UK ( www.watdon.co.uk ) (Fig. 2 ). These traps have a tent-like structure made of insect net. The side walls are left open to allow insects to enter the trap. Inside these traps, a vertical net acts as a barrier, intercepting insects that fly into it. Most insects attempted to escape upwards, however, they were led to a capture bottle containing ethanol (70–96%). In addition, other non-flying arthropods as spiders (Araneae) and harvestmen (Opiliones) crawling into the trap were also caught. At each sampling site one trap was positioned next to the fence of the roaming pigs and another trap was placed 100–410 m away of the pigs, at a location with the same type of vegetation in the same successional stage as the first trap (Table 1 ). The sampling site in Norway was located roughly 100 km north of Oslo; in Denmark, the sampling sites were situated in Central Jutland; in Italy, it was in the Tuscany region; and in Slovenia, in the Littoral–Inner Carniola region. More detailed information about the sampling sites is provided in Supplementary Table 1. In Norway, Italy and Slovenia same trap locations were used in both 2022 and 2023. In Denmark, however, two different locations were used for 2023. The sampling periods began in late May/early June and lasted for 26–36 days. Table 1 Trap locations and sampling periods Pig area Non-pig area MASL Distance between traps Sampling period Sampling days Trap location latitude longitude latitude longitude Start Stop Norway 60°52'03.2"N 11° 10'52.6"E 60°51'50.2"N 11° 10'56.8"E 320 410 m 24.05.2022 24.06.2022 31 03.06.2023 01.07.2023 28 Denmark DK1 56°23'20.0"N 9° 01'07.2"E 56°23'15.5"N 9° 01'21.4"E 22 280 m 06.06.2023 11.07.2023 36 Denmark DK2 55°34'39.6"N 9° 00'02.9"E 55°34'32.2"N 9° 00'00.9"E 54 220 m 31.05.2023 27.06.2023 26 Italy 43°36'41.8"N 12° 07'06.2"E 43°36'46.9"N 12°07'11.1"E 544 200 m 01.06.2022 29.06.2022 28 27.05.2023 27.06.2023 31 Slovenia 45°41'44.6"N 14°02'32.5"E 45°41'44.6"N 14°02'32.5"E 835 100 m 01.06.2022 29.06.2022 28 06.06.2023 04.07.2023 28 MASL: Meter Above Sea Level Arthropod identification For identifying the arthropod species in the capture bottles, DNA metabarcoding analysis based on Cytochrome c oxidase I gene ( COI ) was used. The samples from Norway and Denmark were analysed by the Centre for Biodiversity Genetics (NINAGEN) at the Norwegian Institute for Nature Research (NINA), Trondheim, Norway (Åström et al. 2023 ). In this analysis, NINAGEN followed the non-destructive metabarcoding protocol for bulk insect analysis of as described by Iwaszkiewicz Eggebrecht et al. (2023) (See Supplementary Material). To assess the taxonomic composition of the arthropods in the capture bottles, identifications assigned low or poor confidence were excluded, retaining only those classified with moderate or high confidence for subsequent analysis. The samples from Italy and Slovenia were analysed by the Sequencing Platform of the Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010 San Michele all'Adige, Italy. Total DNA was extracted using the Macherey-Nagel NucleoSpin Soil kit, following the manufacturer’s instructions. The metabarcoding and bioinformatic workflows used for the analysis of the bulk insect samples are described in the Supplementary Material. Identifications assigned only to family or genus were excluded, retaining exclusively those classified to species. Statistical analysis In the analysis of the results, Microsoft Excel was used to categorize the identified species by order and grouped according to the treatment, “Pig area” or “Non-pig area”. This analysis provided the total number of unique species at each site, along with the number of species shared between the two areas. It also enabled a comparison of the number of species in each order and the relative taxonomic composition of insect biodiversity between the pig and non-pig areas at each location for each year. For each location × year, a Pearson’s Chi-square test of independence was used in R (R Core Team 2025 ) to test whether insect order composition differed between treatments, and to examine whether the relative distribution of insect orders differed between “pig area” and “non-pig area.” To explore how local a-diversities and between-treatment b-diversity components contribute to total regional g-diversity, a linear regression model was fitted with γ-diversity as the dependent variable and α₁, α₂, and β as predictors in separate models with a significance level of p < 0.05. To support workflow efficiency, ChatGPT (OpenAI, GPT-5.1, accessed November 2025) was used to generate draft R code for statistical analyses for the Pearson’s Chi-square tests. All code was verified, adapted, and executed by the authors, and all statistical interpretations and decisions were made solely by the authors. The codes are found in the Supplementary material. Results Significant differences in the composition of insect orders between treatments were found for Norway 2022 and Italy 2022 (Table 2 ). Table 2 Differences in the composition of arthropod orders between treatments. Significant differences in the composition of arthropod orders between treatments were found for Norway 2022 and Italy 2022 (p < 0.5) Location Year χ² df p -value Taxa contributing most to treatment differences Norway 2022 41.66 16 0.0004 Hymenoptera, Coleoptera, Diptera, Lepidoptera, Norway 2023 24.96 18 0.126 Hymenoptera, Diptera, Neuroptera, Ephemeroptera, Denmark DK1 2023 10.18 17 0.896 Hymenoptera, Orthoptera, Lepidoptera, Odonata, Denmark DK2 2023 17.47 13 0.179 Diptera, Lepidoptera, Araneae, Mecoptera, Italy 2022 12.87 6 0.045 Diptera, Coleoptera, Orthoptera, Lepidoptera, Italy 2023 13.47 7 0.062 Coleoptera, Diptera, Hymenoptera, Lepidoptera, Slovenia 2022 0.02 10 1 Coleoptera, Araneae, Blattodea, Hemiptera, Slovenia 2023 3.23 7 0.863 Trichoptera, Hemiptera, Diptera, Lepidoptera, These differences are illustrated for Norway in Fig. 3 and for Italy in Fig. 4 . No significant differences were detected in Norway 2023, Denmark 2023, Italy 2023, or Slovenia 2022–2023. All measured values are found in Supplementary Table 2. In Norway 2022, Hymenoptera showed strong positive residuals in non-pig areas, indicating higher relative abundance, whereas Diptera and Coleoptera were over-represented in pig areas. Similar but weaker patterns for Diptera and Coleoptera were observed in Italy 2022. When analysing the sequence “reads” (the individual DNA sequence fragments produced by the sequencer during the metabarcoding), significant differences in insect taxonomic composition were detected between “pig area” and “non-pig area” across all locations and years ( p < 0.001) (Table 3). For instance, at DK2 2023, Hymenoptera were markedly over-represented in “non-pig area” (standardized residual (SR) = + 86.2) (Fig. 5 ), while Diptera were over-represented in pig area (SR = + 45.1). In Slovenia 2023, Lepidoptera, Hymenoptera and Hemiptera were over-represented in the “non-pig area” (SR = + 27.7, + 27.2 and + 26.5) (Fig. 6 ). All “reads” are presented in Supplementary Table 3. Tabel 3 Differences in relative taxonomic composition at order level of between “pig area” and “non-pig area. Significant differences for all locations and years ( p < 0.001) Location Year χ² df p -value Taxa contributing most to treatment differences Norway 2022 145 921.79 16 < 0.001 Hemiptera, Diptera, Mecoptera, Plecoptera, Norway 2023 9 333.62 18 < 0.001 Opiliones, Mecoptera, Hymenoptera, Coleoptera, Denmark DK1 2023 21 401.50 17 < 0.001 Opiliones, Diptera, Odonata, Entomobryomorpha, Denmark DK2 2023 30 492.36 13 < 0.001 Hymenoptera, Diptera, Trichoptera, Araneae, Italy 2022 31 743.95 8 < 0.001 Lepidoptera, Diptera, Coleoptera, Hymenoptera, Italy 2023 22 140.45 8 < 0.001 Diptera, Araneae, Coleoptera, Trichoptera, Slovenia 2022 1 680.86 8 < 0.001 Lepidoptera, Hymenoptera, Coleoptera, Diptera, Slovenia 2023 5 243.97 7 < 0.001 Lepidoptera, Hymenoptera, Hemiptera, Diptera, The highest proportions of unique arthropod species identified for each treatment (b/g-diversity) were observed in Norway 2022 at 76% and in DK2 2023 at 74% (Table 4 ). Table 4 Number and relative proportion (%) of unique and shared arthropod species; α 1 -diversity (pig area); α 2 -diversity (non-pig area); and β- and γ-diversity values (b % of g) in areas under the “pig area” and “non-pig area” treatments across different locations in 2022 and 2023 Location Year Unique pig area Shared Unique non-pig area Type of diversities a 1 a 2 b g Norway 2022 431 (40%) 264 (24%) 390 (36%) 695 654 821 (76%) 1085 Norway 2023 420 (35%) 344 (28%) 443 (37%) 764 787 863 (71%) 1207 Denmark DK1 2023 261 (23%) 433 (37%) 465 (40%) 694 898 726 (63%) 1159 Denmark DK2 2023 263 (48%) 143 (26%) 145 (26%) 406 288 408 (74%) 551 Italy 2022 78 (24%) 156 (48%) 90 (28%) 234 246 168 (52%) 324 Italy 2023 53 (26%) 78 (39%) 71 (35%) 131 149 124 (61%) 202 Slovenia 2022 59 (18%) 225 (67%) 49 (15%) 284 274 108 (32%) 333 Slovenia 2023 43 (20%) 111 (52%) 58 (28%) 154 169 101 (48%) 212 In all other locations and years, except Slovenia, more than half of the identified arthropod species were unique to either the “pig area” or the “non-pig area.” In Slovenia 2022, 67% of the identified species were shared between treatments, indicating low α-diversity in both areas. The total γ-diversity ranged from 202 (Italy 2023) to 1207 (Norway 2023). β-diversity also showed strong variation among locations, from 101 (Slovenia 2023) to 863 (Norway 2023), indicating substantial differences in species composition between pig and non-pig areas across regions. The linear regression model revealed a strong positive relationship between α- and b-diversity and total site γ-diversity across all study locations and years (Table 5 ). However, the estimates indicate that the a 1 -diversity (1.68) may contribute more to the g-diversity than the a 2 (1.45) and the b-diversity (1.28). Table 5 Linear regression values of the contribution of a 1 -, a 2 and b diversity on the g -diversity that is the total number of arthropod species in the region. a 1 -diversity represent the number of species at the “pig area” and a 2 -diversity the number of species at the “non-pig area”. b diversity is the sum of unique species at both treatments Diversity Estimate Std. Error t-value p -value R² (Intercept) -72.913 37.041 -1.968 0.097 α₁ 1.682 0.0762 22.074 5.65E-07 0.99 (Intercept) 3.946 70.032 0.056 0.957 α₂ 1.451 0.136 10.679 3.98E-05 0.95 (Intercept) 100.090 46.828 2.137 0.076 β 1.287 0.090 14.342 7.19E-06 0.97 Discussion Our findings reveal that free-roaming pigs can significantly alter the composition of insect order, although the magnitude and direction of effects vary by region and year. In both Norway and Italy in 2022, areas near pigs exhibited a higher proportion of Dipteran species, whereas Hymenopteran and Lepidopteran species were more prevalent in areas without pigs. This pattern suggests that pig activity can promote the relative abundance of taxa adapted to habitat disturbance. Although not all site-year combinations showed significant effects, the consistent taxonomic trends indicate that roaming pigs influence insect community composition beyond simple abundance differences. Furthermore, the Chi-square analyses demonstrate that free-roaming pigs significantly modify the relative distribution of arthropod orders across all studied European locations. Pig activity increased the relative abundance of Diptera and Hymenoptera—orders typically associated with nutrient-rich or disturbed habitats—while orders such as Hemiptera and Lepidoptera were more prevalent in undisturbed non-pig areas. These results indicate that free-roaming pigs alter local habitat structure and resource availability, driving shifts in community composition rather than simple changes in total abundance. The diversity patterns observed here align with Whittaker’s ( 1972 ) concept of hierarchical partitioning, where γ-diversity is the sum of unique local richness’s (β) and the shared species. Furthermore, strong α–γ and b–γ relationships indicates that local habitat richness is a major driver of total arthropod diversity, while also revealing differentiation among sites. However, the different diversities indicates that a 1 (local diversity by pig area) has the strongest contribution to the total g-diversity. This finding implies that managing free roaming pigs in an open area has a positive contribution on the overall diversity. The g-diversity is found by total identified species at each location. For Norway, Italy, and Slovenia, gamma diversity remains within a similar range across years. Italy and Slovenia show comparable g-diversity, whereas Norway’s g-diversity is three to six times higher than the other two countries. In Italy, an estimated of 38,500 insect species are present (Chiarucci et al. 2024 ), while in Norway, the number is estimated to be around 23,000 species (Ottesen et al. 2025). These figures suggest that one would expect to encounter a greater diversity of species in Italy than in Norway. The results of the present study may be explained by the fact that g-diversity is highly variable nationally, the trapping locations in Italy and Slovenia were situated in areas with low g-diversity, despite the countries’ overall high national g-diversity. This explanation is supported by the results from Denmark where the g-diversity at DK1 was twice as high as at DK2, being only 100 km apart. This shows that choice of location has a strong impact on the results when measuring insect biodiversity. It may also be noted that the trap locations in Slovenia and Italy were situated at higher altitudes compared to those in Norway and Denmark. This difference in elevation may have contributed to the lower arthropod diversity observed at the Slovenian and Italian sites. An important factor influencing the outcome of the DNA metabarcoding analysis is that the two laboratories in Norway and Italy used different extraction methods, COI target primers, databases, and data-analysis pipelines. Consequently, the results from Norway and Denmark cannot be directly compared with those from Italy and Slovenia. However, when assessing the impact of the treatments at each location, the choice of DNA metabarcoding protocols does not affect the conclusions. If all samples had been analysed by the same laboratory, the result would likely have been more comparable. The implications of using different analytical protocols are discussed by Iwaszkiewicz Eggebrecht et al. (2023). For all countries, the order with most numerous species was Diptera, and there was a tendency for more species to be present at areas with pigs than the non-pig areas. There can be several reasons for flies and mosquitos are attracted or find suitable areas to live next to the roaming pigs. Flies may feed directly of the pig skin or use pig manure for feed and egg deposition, while blood sucking mosquitos may be attracted to the warm-blooded mammals to find a meal (Takken 1991 ). The relative taxonomic composition can be strongly influenced by local weather conditions that affect a single species. If insects are sampled during the swarming period of a particular species, the resulting high catch rate may cause the relative composition to differ significantly from that observed in other areas or years. In other words, species evenness is reduced. For instance, in Norway 2022, the total number of reads identified as the jumping plant lice Cacopsylla brunneipennis was 70,419 out of 79,816 for the order Hemiptera in the non-pig area. In contrast, at the pig area, this species accounted for 6,202 out of 8,739 reads. This more than tenfold difference suggests a local incidence in the non-pig area, which increased the relative taxonomic representation of Hemiptera. Such a difference was not observed in Norway 2023. Integrating such analyses across sites helps clarify the ecological footprint of free-roaming pig systems and supports management strategies that balance animal welfare with biodiversity conservation in agricultural landscapes. Future studies including species-level identification and habitat parameters will help clarify the ecological mechanisms underlying these patterns. In conclusion, just as wild boars can enhance Orthoptera biodiversity in calcareous grasslands (Tuinder et al. 2025 ), free-roaming domestic pigs also influence arthropod diversity. Their presence enhances arthropod biodiversity compared to areas without pigs. Therefore, agricultural management practices that include free-roaming pigs can strengthen arthropod fauna at a time when insect biomass is in decline. Declarations Supplementary Information The online version contains supplementary material available at - - - - - - - - - - - - Declarations The authors have no competing interests to declare that are relevant to the content of this article. Funding This study was funded by the ERA-NET CORE Organic Cofund (Grant agreement ID: 727495), Project title: RObust Animals in sustainable Mixed FREE-range systems (ROAM-FREE). Author Contribution All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Atle Wibe, Massimo Pindo, Davide Bochicchio, Jan Plut, Marina Štukelj, Amalie Camilla Pedersen, Helena Mejer and Stig Milan Thamsborg. The first draft of the manuscript was written by Atle Wibe and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Acknowledgement We are grateful to the pig farmers in all four countries for granting us access to their farms and allowing us to collect arthropods. In Norway, Guri Sveberg welcomed us onto her farm and assisted with the sampling. In Denmark, Bertel Hestbjeg and Dennis Lauritsen kindly allowed us to set up our traps on their farms. In Slovenia, Andrej Škibin took excellent care of the pigs involved in the study. We are also grateful to the pig organization in Italy for granting us access to one of their farms. We thank Erling Meisingset (PhD) at NIBIO, Norway, for his support with the statistical analysis, and Line Dinesen Jensen, Denmark, for assisting in collecting data. 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Mammal Rev 33(1):43–56. https://doi.org/https://doi.org/10.1046/j.1365-2907.2003.00010.x Stelder JJ, Mihalca AD, Olesen AS, Kjær LJ, Boklund AE, Rasmussen TB, Marinov M, Alexe V, Balmoş OM, Bødker R (2023) Potential mosquito vector attraction to- and feeding preferences for pigs in Romanian backyard farms [Original Research]. Front Vet Sci 9:11. pp https://doi.org/10.3389/fvets.2022.1046263 Takken W (1991) The Role of Olfaction in Host-Seeking of Mosquitoes: A Review. Int J Trop Insect Sci 12(1):287–295. https://doi.org/10.1017/S1742758400020816 Tuinder QAM, van Leeuwen BO, Vergeer P, Scherer G, Fartmann T, Jansen PA (2025) Impact of wild boar (Sus scrofa) rooting succession on grasshoppers (Orthoptera) in abandoned calcareous grasslands. J Insect Conserv 29:78. https://doi.org/10.1007/s10841-025-00715-2 Uhler J, Haase P, Hoffmann L, Hothorn T, Schmidl J, Stoll S, Welti EAR, Buse J, Müller J (2022) A comparison of different Malaise trap types. Insect Conserv Divers 15(6):666–672. https://doi.org/10.1111/icad.12604 Whittaker RH (1972) Evolution and Measurement of Species Diversity. Taxon 21(2/3):213–251. https://doi.org/10.2307/1218190 Additional Declarations No competing interests reported. Supplementary Files WIBEetalSupplementarymaterial.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8310948","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":573282242,"identity":"ea4f8d34-4afa-40d6-bf4b-35a02d7d1303","order_by":0,"name":"Atle Wibe","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA10lEQVRIiWNgGAWjYFAC5gYgIZHAwN4A5hoQ1sHGCNXCc4A0LQwJIF3EaeGf39j4gLHNIo9f8u3BxxV/bIwZpJsP4NUicYyx2YCxTaJYcnZesuHZtjQzBpljCfitOQZUz7hNInHD7RwzycaGwzYMEjn4HSd/jLH9B0jL/ptnzCQb/hChxQBoCwPYFgkeoBa2w2YEtRgeS2yWSPwnUSxxJsfYsLEtzZhNIg2/X+QOHz744cOZujz+9jOGDxv+2Bj2SyQfwKsFDFBMZSOsfhSMglEwCkYBIQAAIIhCJ5qek34AAAAASUVORK5CYII=","orcid":"","institution":"Norwegian Centre for Organic Agriculture","correspondingAuthor":true,"prefix":"","firstName":"Atle","middleName":"","lastName":"Wibe","suffix":""},{"id":573282243,"identity":"8af6becd-b948-4333-91e2-928d1c5d3900","order_by":1,"name":"Massimo Pindo","email":"","orcid":"","institution":"Fondazione Edmund Mach","correspondingAuthor":false,"prefix":"","firstName":"Massimo","middleName":"","lastName":"Pindo","suffix":""},{"id":573282244,"identity":"4181e5a8-b636-49c0-a4d0-9b18f840c2a0","order_by":2,"name":"Davide Bochicchio","email":"","orcid":"","institution":"Council for Agricultural Research and Economics – Research Centre for Animal Production and Aquaculture","correspondingAuthor":false,"prefix":"","firstName":"Davide","middleName":"","lastName":"Bochicchio","suffix":""},{"id":573282245,"identity":"17f468d3-b915-412b-99c5-f17e93b496c6","order_by":3,"name":"Jan Plut","email":"","orcid":"","institution":"University of Ljubljana, Clinic for Reproduction and Large Animals / Clinic for Ruminants and Pigs","correspondingAuthor":false,"prefix":"","firstName":"Jan","middleName":"","lastName":"Plut","suffix":""},{"id":573282246,"identity":"8836e7fc-4701-4e33-a245-5af2d11ac81f","order_by":4,"name":"Marina Štukelj","email":"","orcid":"","institution":"University of Ljubljana, Clinic for Reproduction and Large Animals / Clinic for Ruminants and 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08:09:06","extension":"xml","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":107146,"visible":true,"origin":"","legend":"","description":"","filename":"59b494824ef44a489a84ea57a11bed5b1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/7f93c63e45e8faf0c10c118e.xml"},{"id":100244667,"identity":"11731b74-4f7a-4347-a168-16e9a69e196d","added_by":"auto","created_at":"2026-01-14 14:04:16","extension":"html","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":117424,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/b7cbb43518528f2b5ce32d6b.html"},{"id":100371972,"identity":"62ffcbe4-ba38-4900-8544-4b015848c668","added_by":"auto","created_at":"2026-01-16 08:11:19","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":47101,"visible":true,"origin":"","legend":"\u003cp\u003eEach circle represents a distinct habitat type. a: the number of species within small areas of fairly uniform habitats, b: the total of the non-overlapping species in the two a habitats, g: the total number of species within a region (after Meffe et al. 2002, with permission)\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/19d950c4a2ac387020e3c981.png"},{"id":100371934,"identity":"e20ffb3e-3403-46af-893c-ab75900ca0e6","added_by":"auto","created_at":"2026-01-16 08:11:15","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":428013,"visible":true,"origin":"","legend":"\u003cp\u003eMalaise trap mounted next to pig enclosure in Norway (Photo: A. Wibe)\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/d0b82165b7206c5d8e7a3584.jpg"},{"id":100244650,"identity":"71a106ab-166a-469d-95dc-d0073f36fb65","added_by":"auto","created_at":"2026-01-14 14:04:16","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":73161,"visible":true,"origin":"","legend":"\u003cp\u003eNumber of species in each order of arthropods, found in Norway, 2022. Significant differences (p\u0026lt;0.5) in the composition of insect orders between treatments, “Pig area” and “Non-pig area”, were found by using Pearson’s Chi-square test of independence (χ² = 41.66, df = 16, p = 0.0004)\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/ad1c0a0e180993fc5164cf2f.png"},{"id":100372053,"identity":"18a53927-a4b6-4ca4-82f0-b79560aaeecb","added_by":"auto","created_at":"2026-01-16 08:11:29","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":76743,"visible":true,"origin":"","legend":"\u003cp\u003eNumber of species in each order of arthropods, found in Italy, 2022. Significant differences (p\u0026lt;0.5) in the composition of insect orders between treatments, “Pig area” and “Non-pig area”, were found by using Pearson’s Chi-square test of independence (χ² = 12.87, df = 6, p = 0.045)\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/11c72bfe20f8d0b57279015f.png"},{"id":100244658,"identity":"c371ade4-4b2e-49b5-b8cf-dd44dc79cfac","added_by":"auto","created_at":"2026-01-14 14:04:16","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":97787,"visible":true,"origin":"","legend":"\u003cp\u003eRelative taxonomic composition at the order level, found in Denmark 2023. Significant differences in insect taxonomic composition were detected between “Pig area” and “Non-pig area” (p\u0026lt;0.001) at both locations, DK1 and DK2, by using Pearson’s Chi-square test of independence.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/2d66391717b625ce04f4cfd3.png"},{"id":100244652,"identity":"1394b45f-d187-4cef-950e-851e74495b10","added_by":"auto","created_at":"2026-01-14 14:04:16","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":93372,"visible":true,"origin":"","legend":"\u003cp\u003eRelative taxonomic composition at the order level, found in Slovenia 2022- 2023. Significant differences in insect taxonomic composition were detected between “Pig area” and “Non-pig area” (p\u0026lt;0.001) both years, by using Pearson’s Chi-square test of independence\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/2911c5059d9678b28bca21e9.png"},{"id":103739222,"identity":"15a7c1a3-978e-4355-bb9f-25eea37af060","added_by":"auto","created_at":"2026-03-02 10:38:35","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1858416,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/13d99dc2-440b-41b2-ad24-a496a4201d8a.pdf"},{"id":100371956,"identity":"a698638f-e9a8-46af-9097-cb4ca796b53b","added_by":"auto","created_at":"2026-01-16 08:11:17","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":63529,"visible":true,"origin":"","legend":"","description":"","filename":"WIBEetalSupplementarymaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-8310948/v1/3c40e21b460c7321ae0c1589.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The impact of free-roaming pigs on arthropod diversity: a field survey in four European countries","fulltext":[{"header":"Introduction","content":"\u003cp\u003eInsects support a wide range of ecosystem services whereof pollination, biological control, food supply, and recycling of organic matter are the most studied (Noriega et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Insects are therefore often categorised by their functional groups as pollinators, predators, parasitoids, herbivores and decomposers while the most studied taxa are Hymenoptera, Coleoptera and Diptera. Through their function, insects can provide services to achieve the sustainable development goals (Dangles and Casas \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2019\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHowever, in recent decades a decline of up to 75% in insect biomass has been observed in Central Europa (Hallmann et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) and in places in the tropics (Janzen and Hallwachs \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Evidence suggests agricultural intensification and climate change are directly linked to these losses (Raven and Wagner \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Rumohr et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). For the agricultural impact crop monocultures and the decrease in landscape diversity have been associated with a decline of e.g. bumble bee species (Hemberger et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), but no studies have been published on the impact of free-roaming domestic pigs (\u003cem\u003eSus scrofa domesticus\u003c/em\u003e) on insect diversity and abundance in natural or cultural pastures. The closest comparison is the impact of wild boar (\u003cem\u003eSus scrofa scrofa\u003c/em\u003e) that is now present on all continents except Antarctica (Barrios-Garcia and Ballari \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Domesticated pigs and wild boar belong to the same species and thus share many behavioural patterns such as wallowing, exploration, foraging at and below soil surface in out-door systems and defaecation. By rooting extensive areas of soil, vegetation is overturned in the search for belowground plant parts, fungi, and invertebrates as earthworms and insects (larvae and/or imagines) (Baubet et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2003\u003c/span\u003e; Schley and Roper \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). This behaviour may potentially reduce soil-associated arthropods while, on the other hand, it can create habitats for other species. Tuinder et al. (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2025\u003c/span\u003e) showed that wild boars supported Orthoptera diversity by creating habitats for specialists with different life cycles, thereby increasing species richness.\u003c/p\u003e \u003cp\u003eElectrophysiological studies have indicated that Volatile Organic Compounds (VOCs) from pig manure elicit responses in the antenna of female houseflies (Coss\u0026eacute; and Baker \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1996\u003c/span\u003e), and mixtures of these volatiles attracted the flies in a behaviour study. Also, some mosquito species are attracted to pigs by means of olfaction (Takken \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e1991\u003c/span\u003e). These blood sucking insects may also carry pathogens that affect pigs (Stelder et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2023\u003c/span\u003e), thereby posing a potential threat to pig health and wellbeing.\u003c/p\u003e \u003cp\u003eIn monitoring species composition of populations several expressions, such as diversity and evenness are widely used. Species diversity, or richness, is used to describe all species living in a particular area, while species evenness is the relative abundance with which each species is represented in a sample (DeJong \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e1975\u003c/span\u003e). The diversity can be divided into a-, b- and g-diversity as described by Whittaker (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e1972\u003c/span\u003e). This concept was later elaborated in the book \u003cem\u003eEcosystem Management: adaptive, community-based conservation\u003c/em\u003e by Meffe et al. (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2002\u003c/span\u003e) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). According to their description, a-diversity is defined as equivalent to species richness which is the number of species within a particular area or ecosystem. b- diversity is defined as the change in species diversity between areas or ecosystems and is measured by counting the total number of species unique to each area under comparison. The g-diversity of a landscape or location is determined by number of species shared between its communities and the degree of b-differentiation among them, making it a measure of the total ecosystem diversity.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn this study, we aimed to investigate whether free-roaming pigs on forest/pasturelands influence arthropod biodiversity compared to nearby areas without the presence of pigs. In many countries, free-roaming or out-door pigs, make up only a very small share of total pig production, with stable-based management being far more common, e.g. in Denmark, pigs produced in organic farming systems constituted less than 1.7% of the total national pig production in 2023 (Neergaard \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). However, with growing emphasis on animal welfare and product quality, free-roaming pigs may become a more significant part of meat production. Yet little is known about their environmental impact or their effects on insect fauna. In our study, we focused on all kinds of flying insects and other arthropods that could be trapped within a restricted period. Identification of the collected bulk samples was performed through COI-based DNA metabarcoding. The study therefore investigates whether the taxonomic composition of arthropods differs significantly between treatments\u0026mdash;specifically, areas with pigs and non-pig areas\u0026mdash;at sites located in Norway, Denmark, Italy, and Slovenia, using Pearson\u0026rsquo;s Chi-square test of independence. The impact of a- and b-diversity on the g-diversity was tested by linear regression analysis.\u003c/p\u003e"},{"header":"Material and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eArthropod sampling\u003c/h2\u003e \u003cp\u003eTo sample flying insect, we used black Malaise traps (Malaise, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e1937\u003c/span\u003e) (Uhler et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) manufactured by Watkins \u0026amp; Doncaster, UK (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ewww.watdon.co.uk\u003c/span\u003e\u003cspan address=\"http://www.watdon.co.uk\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThese traps have a tent-like structure made of insect net. The side walls are left open to allow insects to enter the trap. Inside these traps, a vertical net acts as a barrier, intercepting insects that fly into it. Most insects attempted to escape upwards, however, they were led to a capture bottle containing ethanol (70\u0026ndash;96%). In addition, other non-flying arthropods as spiders (Araneae) and harvestmen (Opiliones) crawling into the trap were also caught. At each sampling site one trap was positioned next to the fence of the roaming pigs and another trap was placed 100\u0026ndash;410 m away of the pigs, at a location with the same type of vegetation in the same successional stage as the first trap (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The sampling site in Norway was located roughly 100 km north of Oslo; in Denmark, the sampling sites were situated in Central Jutland; in Italy, it was in the Tuscany region; and in Slovenia, in the Littoral\u0026ndash;Inner Carniola\u003c/p\u003e \u003cp\u003eregion. More detailed information about the sampling sites is provided in Supplementary Table\u0026nbsp;1. In Norway, Italy and Slovenia same trap locations were used in both 2022 and 2023. In Denmark, however, two different locations were used for 2023. The sampling periods began in late May/early June and lasted for 26\u0026ndash;36 days.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTrap locations and sampling periods\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"11\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003ePig area\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003eNon-pig area\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMASL\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eDistance between traps\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003eSampling period\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSampling days\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrap location\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003elatitude\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003elongitude\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003elatitude\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003elongitude\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eStart\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eStop\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNorway\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e60\u0026deg;52'03.2\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11\u0026deg; 10'52.6\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e60\u0026deg;51'50.2\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e11\u0026deg; 10'56.8\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e320\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e410 m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e24.05.2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e24.06.2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e03.06.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e01.07.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDenmark DK1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e56\u0026deg;23'20.0\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9\u0026deg; 01'07.2\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e56\u0026deg;23'15.5\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e9\u0026deg; 01'21.4\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e280 m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e06.06.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e11.07.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDenmark DK2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e55\u0026deg;34'39.6\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9\u0026deg; 00'02.9\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e55\u0026deg;34'32.2\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e9\u0026deg; 00'00.9\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e220 m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e31.05.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e27.06.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItaly\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e43\u0026deg;36'41.8\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12\u0026deg; 07'06.2\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e43\u0026deg;36'46.9\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e12\u0026deg;07'11.1\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e544\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e200 m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e01.06.2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e29.06.2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e27.05.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e27.06.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSlovenia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e45\u0026deg;41'44.6\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14\u0026deg;02'32.5\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e45\u0026deg;41'44.6\"N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e14\u0026deg;02'32.5\"E\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e835\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e100 m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e01.06.2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e29.06.2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e06.06.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e04.07.2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"11\"\u003eMASL: Meter Above Sea Level\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eArthropod identification\u003c/h3\u003e\n\u003cp\u003eFor identifying the arthropod species in the capture bottles, DNA metabarcoding analysis based on Cytochrome c oxidase I gene (\u003cem\u003eCOI\u003c/em\u003e) was used.\u003c/p\u003e \u003cp\u003eThe samples from Norway and Denmark were analysed by the Centre for Biodiversity Genetics (NINAGEN) at the Norwegian Institute for Nature Research (NINA), Trondheim, Norway (\u0026Aring;str\u0026ouml;m et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). In this analysis, NINAGEN followed the non-destructive metabarcoding protocol for bulk insect analysis of as described by Iwaszkiewicz Eggebrecht et al. (2023) (See Supplementary Material). To assess the taxonomic composition of the arthropods in the capture bottles, identifications assigned low or poor confidence were excluded, retaining only those classified with moderate or high confidence for subsequent analysis.\u003c/p\u003e \u003cp\u003eThe samples from Italy and Slovenia were analysed by the Sequencing Platform of the Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010 San Michele all'Adige, Italy. Total DNA was extracted using the Macherey-Nagel NucleoSpin Soil kit, following the manufacturer\u0026rsquo;s instructions. The metabarcoding and bioinformatic workflows used for the analysis of the bulk insect samples are described in the Supplementary Material. Identifications assigned only to family or genus were excluded, retaining exclusively those classified to species.\u003c/p\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eIn the analysis of the results, Microsoft Excel was used to categorize the identified species by order and grouped according to the treatment, \u0026ldquo;Pig area\u0026rdquo; or \u0026ldquo;Non-pig area\u0026rdquo;. This analysis provided the total number of unique species at each site, along with the number of species shared between the two areas. It also enabled a comparison of the number of species in each order and the relative taxonomic composition of insect biodiversity between the pig and non-pig areas at each location for each year.\u003c/p\u003e \u003cp\u003eFor each location \u0026times; year, a Pearson\u0026rsquo;s Chi-square test of independence was used in R (R Core Team \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2025\u003c/span\u003e) to test whether insect order composition differed between treatments, and to examine whether the relative distribution of insect orders differed between \u0026ldquo;pig area\u0026rdquo; and \u0026ldquo;non-pig area.\u0026rdquo;\u003c/p\u003e \u003cp\u003eTo explore how local a-diversities and between-treatment b-diversity components contribute to total regional g-diversity, a linear regression model was fitted with γ-diversity as the dependent variable and α₁, α₂, and β as predictors in separate models with a significance level of p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003cp\u003eTo support workflow efficiency, ChatGPT (OpenAI, GPT-5.1, accessed November 2025) was used to generate draft R code for statistical analyses for the Pearson\u0026rsquo;s Chi-square tests. All code was verified, adapted, and executed by the authors, and all statistical interpretations and decisions were made solely by the authors. The codes are found in the Supplementary material.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eSignificant differences in the composition of insect orders between treatments were found for Norway 2022 and Italy 2022 (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDifferences in the composition of arthropod orders between treatments. Significant differences in the composition of arthropod orders between treatments were found for Norway 2022 and Italy 2022 (p\u0026thinsp;\u0026lt;\u0026thinsp;0.5)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLocation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYear\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eχ\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003edf\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTaxa contributing most to treatment differences\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNorway\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e41.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.0004\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHymenoptera, Coleoptera, Diptera, Lepidoptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNorway\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHymenoptera, Diptera, Neuroptera, Ephemeroptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDenmark DK1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.896\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHymenoptera, Orthoptera, Lepidoptera, Odonata,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDenmark DK2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.179\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eDiptera, Lepidoptera, Araneae, Mecoptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItaly\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.045\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eDiptera, Coleoptera, Orthoptera, Lepidoptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItaly\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.062\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eColeoptera, Diptera, Hymenoptera, Lepidoptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSlovenia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eColeoptera, Araneae, Blattodea, Hemiptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSlovenia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.863\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTrichoptera, Hemiptera, Diptera, Lepidoptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThese differences are illustrated for Norway in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and for Italy in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eNo significant differences were detected in Norway 2023, Denmark 2023, Italy 2023, or Slovenia 2022\u0026ndash;2023. All measured values are found in Supplementary Table\u0026nbsp;2. In Norway 2022, Hymenoptera showed strong positive residuals in non-pig areas, indicating higher relative abundance, whereas Diptera and Coleoptera were over-represented in pig areas. Similar but weaker patterns for Diptera and Coleoptera were observed in Italy 2022.\u003c/p\u003e \u003cp\u003eWhen analysing the sequence \u0026ldquo;reads\u0026rdquo; (the individual DNA sequence fragments produced by the sequencer during the metabarcoding), significant differences in insect taxonomic composition were detected between \u0026ldquo;pig area\u0026rdquo; and \u0026ldquo;non-pig area\u0026rdquo; across all locations and years (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;3). For instance, at DK2 2023, Hymenoptera were markedly over-represented in \u0026ldquo;non-pig area\u0026rdquo; (standardized residual (SR)\u0026thinsp;=\u0026thinsp;+\u0026thinsp;86.2) (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e), while Diptera were over-represented in pig area (SR\u0026thinsp;=\u0026thinsp;+\u0026thinsp;45.1). In Slovenia 2023, Lepidoptera, Hymenoptera and Hemiptera were over-represented in the \u0026ldquo;non-pig area\u0026rdquo; (SR\u0026thinsp;=\u0026thinsp;+\u0026thinsp;27.7, + 27.2 and +\u0026thinsp;26.5) (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). All \u0026ldquo;reads\u0026rdquo; are presented in Supplementary Table\u0026nbsp;3.\u003c/p\u003e \u003cp\u003e \u003cb\u003eTabel 3\u003c/b\u003e Differences in relative taxonomic composition at order level of between \u0026ldquo;pig area\u0026rdquo; and \u0026ldquo;non-pig area. Significant differences for all locations and years (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001)\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLocation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYear\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eχ\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003edf\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTaxa contributing most to treatment differences\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNorway\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e145 921.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHemiptera, Diptera, Mecoptera, Plecoptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNorway\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9 333.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eOpiliones, Mecoptera, Hymenoptera, Coleoptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDenmark DK1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21 401.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eOpiliones, Diptera, Odonata, Entomobryomorpha,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDenmark DK2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30 492.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHymenoptera, Diptera, Trichoptera, Araneae,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItaly\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31 743.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLepidoptera, Diptera, Coleoptera, Hymenoptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItaly\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22 140.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eDiptera, Araneae, Coleoptera, Trichoptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSlovenia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 680.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLepidoptera, Hymenoptera, Coleoptera, Diptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSlovenia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 243.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLepidoptera, Hymenoptera, Hemiptera, Diptera,\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe highest proportions of unique arthropod species identified for each treatment (b/g-diversity) were observed in Norway 2022 at 76% and in DK2 2023 at 74% (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eNumber and relative proportion (%) of unique and shared arthropod species; α\u003csub\u003e1\u003c/sub\u003e-diversity (pig area); α\u003csub\u003e2\u003c/sub\u003e-diversity (non-pig area); and β- and γ-diversity values (b % of g) in areas under the \u0026ldquo;pig area\u0026rdquo; and \u0026ldquo;non-pig area\u0026rdquo; treatments across different locations in 2022 and 2023\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLocation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYear\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eUnique\u003c/p\u003e \u003cp\u003epig area\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eShared\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eUnique\u003c/p\u003e \u003cp\u003enon-pig area\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003eType of diversities a\u003csub\u003e1\u003c/sub\u003e a\u003csub\u003e2\u003c/sub\u003e b g\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNorway\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e431 (40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e264 (24%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e390 (36%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e695\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e654\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e821 (76%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1085\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNorway\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e420 (35%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e344 (28%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e443 (37%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e764\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e787\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e863 (71%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1207\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDenmark DK1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e261 (23%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e433 (37%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e465 (40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e694\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e898\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e726 (63%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1159\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDenmark DK2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e263 (48%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e143 (26%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e145 (26%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e406\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e288\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e408 (74%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e551\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItaly\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e78 (24%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e156 (48%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e90 (28%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e234\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e246\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e168 (52%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e324\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItaly\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e53 (26%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e78 (39%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e71 (35%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e131\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e149\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e124 (61%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e202\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSlovenia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e59 (18%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e225 (67%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e49 (15%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e284\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e274\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e108 (32%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e333\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSlovenia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43 (20%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e111 (52%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e58 (28%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e154\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e169\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e101 (48%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e212\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIn all other locations and years, except Slovenia, more than half of the identified arthropod species were unique to either the \u0026ldquo;pig area\u0026rdquo; or the \u0026ldquo;non-pig area.\u0026rdquo; In Slovenia 2022, 67% of the identified species were shared between treatments, indicating low α-diversity in both areas.\u003c/p\u003e \u003cp\u003eThe total γ-diversity ranged from 202 (Italy 2023) to 1207 (Norway 2023). β-diversity also showed strong variation among locations, from 101 (Slovenia 2023) to 863 (Norway 2023), indicating substantial differences in species composition between pig and non-pig areas across regions.\u003c/p\u003e \u003cp\u003eThe linear regression model revealed a strong positive relationship between α- and b-diversity and total site γ-diversity across all study locations and years (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e5\u003c/span\u003e). However, the estimates indicate that the a\u003csub\u003e1\u003c/sub\u003e-diversity (1.68) may contribute more to the g-diversity than the a\u003csub\u003e2\u003c/sub\u003e (1.45) and the b-diversity (1.28).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eLinear regression values of the contribution of a\u003csub\u003e1\u003c/sub\u003e-, a\u003csub\u003e2\u003c/sub\u003e and b diversity on the g -diversity that is the total number of arthropod species in the region. a\u003csub\u003e1\u003c/sub\u003e-diversity represent the number of species at the \u0026ldquo;pig area\u0026rdquo; and a\u003csub\u003e2\u003c/sub\u003e-diversity the number of species at the \u0026ldquo;non-pig area\u0026rdquo;. b diversity is the sum of unique species at both treatments\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiversity\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEstimate\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStd. Error\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003et-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eR\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(Intercept)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-72.913\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37.041\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-1.968\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.097\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eα₁\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.682\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0762\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.074\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.65E-07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(Intercept)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.946\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.056\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.957\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eα₂\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.451\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.136\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10.679\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.98E-05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(Intercept)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100.090\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e46.828\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.137\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.076\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eβ\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.287\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.090\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.342\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.19E-06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.97\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur findings reveal that free-roaming pigs can significantly alter the composition of insect order, although the magnitude and direction of effects vary by region and year.\u003c/p\u003e \u003cp\u003eIn both Norway and Italy in 2022, areas near pigs exhibited a higher proportion of Dipteran species, whereas Hymenopteran and Lepidopteran species were more prevalent in areas without pigs. This pattern suggests that pig activity can promote the relative abundance of taxa adapted to habitat disturbance.\u003c/p\u003e \u003cp\u003eAlthough not all site-year combinations showed significant effects, the consistent taxonomic trends indicate that roaming pigs influence insect community composition beyond simple abundance differences.\u003c/p\u003e \u003cp\u003eFurthermore, the Chi-square analyses demonstrate that free-roaming pigs significantly modify the relative distribution of arthropod orders across all studied European locations. Pig activity increased the relative abundance of Diptera and Hymenoptera\u0026mdash;orders typically associated with nutrient-rich or disturbed habitats\u0026mdash;while orders such as Hemiptera and Lepidoptera were more prevalent in undisturbed non-pig areas. These results indicate that free-roaming pigs alter local habitat structure and resource availability, driving shifts in community composition rather than simple changes in total abundance.\u003c/p\u003e \u003cp\u003eThe diversity patterns observed here align with Whittaker\u0026rsquo;s (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e1972\u003c/span\u003e) concept of hierarchical partitioning, where γ-diversity is the sum of unique local richness\u0026rsquo;s (β) and the shared species. Furthermore, strong α\u0026ndash;γ and b\u0026ndash;γ relationships indicates that local habitat richness is a major driver of total arthropod diversity, while also revealing differentiation among sites. However, the different diversities indicates that a\u003csub\u003e1\u003c/sub\u003e (local diversity by pig area) has the strongest contribution to the total g-diversity. This finding implies that managing free roaming pigs in an open area has a positive contribution on the overall diversity.\u003c/p\u003e \u003cp\u003eThe g-diversity is found by total identified species at each location. For Norway, Italy, and Slovenia, gamma diversity remains within a similar range across years. Italy and Slovenia show comparable g-diversity, whereas Norway\u0026rsquo;s g-diversity is three to six times higher than the other two countries. In Italy, an estimated of 38,500 insect species are present (Chiarucci et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2024\u003c/span\u003e), while in Norway, the number is estimated to be around 23,000 species (Ottesen et al. 2025). These figures suggest that one would expect to encounter a greater diversity of species in Italy than in Norway. The results of the present study may be explained by the fact that g-diversity is highly variable nationally, the trapping locations in Italy and Slovenia were situated in areas with low g-diversity, despite the countries\u0026rsquo; overall high national g-diversity. This explanation is supported by the results from Denmark where the g-diversity at DK1 was twice as high as at DK2, being only 100 km apart. This shows that choice of location has a strong impact on the results when measuring insect biodiversity. It may also be noted that the trap locations in Slovenia and Italy were situated at higher altitudes compared to those in Norway and Denmark. This difference in elevation may have contributed to the lower arthropod diversity observed at the Slovenian and Italian sites.\u003c/p\u003e \u003cp\u003eAn important factor influencing the outcome of the DNA metabarcoding analysis is that the two laboratories in Norway and Italy used different extraction methods, COI target primers, databases, and data-analysis pipelines. Consequently, the results from Norway and Denmark cannot be directly compared with those from Italy and Slovenia. However, when assessing the impact of the treatments at each location, the choice of DNA metabarcoding protocols does not affect the conclusions. If all samples had been analysed by the same laboratory, the result would likely have been more comparable. The implications of using different analytical protocols are discussed by Iwaszkiewicz Eggebrecht et al. (2023).\u003c/p\u003e \u003cp\u003eFor all countries, the order with most numerous species was Diptera, and there was a tendency for more species to be present at areas with pigs than the non-pig areas. There can be several reasons for flies and mosquitos are attracted or find suitable areas to live next to the roaming pigs. Flies may feed directly of the pig skin or use pig manure for feed and egg deposition, while blood sucking mosquitos may be attracted to the warm-blooded mammals to find a meal (Takken \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e1991\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe relative taxonomic composition can be strongly influenced by local weather conditions that affect a single species. If insects are sampled during the swarming period of a particular species, the resulting high catch rate may cause the relative composition to differ significantly from that observed in other areas or years. In other words, species evenness is reduced. For instance, in Norway 2022, the total number of reads identified as the jumping plant lice \u003cem\u003eCacopsylla brunneipennis\u003c/em\u003e was 70,419 out of 79,816 for the order Hemiptera in the non-pig area. In contrast, at the pig area, this species accounted for 6,202 out of 8,739 reads. This more than tenfold difference suggests a local incidence in the non-pig area, which increased the relative taxonomic representation of Hemiptera. Such a difference was not observed in Norway 2023.\u003c/p\u003e \u003cp\u003eIntegrating such analyses across sites helps clarify the ecological footprint of free-roaming pig systems and supports management strategies that balance animal welfare with biodiversity conservation in agricultural landscapes. Future studies including species-level identification and habitat parameters will help clarify the ecological mechanisms underlying these patterns.\u003c/p\u003e \u003cp\u003eIn conclusion, just as wild boars can enhance Orthoptera biodiversity in calcareous grasslands (Tuinder et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2025\u003c/span\u003e), free-roaming domestic pigs also influence arthropod diversity. Their presence enhances arthropod biodiversity compared to areas without pigs. Therefore, agricultural management practices that include free-roaming pigs can strengthen arthropod fauna at a time when insect biomass is in decline.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eSupplementary Information\u003c/h2\u003e \u003cp\u003eThe online version contains supplementary material available at - - - - - - - - - - - -\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eDeclarations\u003c/h2\u003e \u003cp\u003eThe authors have no competing interests to declare that are relevant to the content of this article.\u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis study was funded by the ERA-NET CORE Organic Cofund (Grant agreement ID: 727495), Project title: RObust Animals in sustainable Mixed FREE-range systems (ROAM-FREE).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Atle Wibe, Massimo Pindo, Davide Bochicchio, Jan Plut, Marina Štukelj, Amalie Camilla Pedersen, Helena Mejer and Stig Milan Thamsborg. The first draft of the manuscript was written by Atle Wibe and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eWe are grateful to the pig farmers in all four countries for granting us access to their farms and allowing us to collect arthropods. In Norway, Guri Sveberg welcomed us onto her farm and assisted with the sampling. In Denmark, Bertel Hestbjeg and Dennis Lauritsen kindly allowed us to set up our traps on their farms. In Slovenia, Andrej Škibin took excellent care of the pigs involved in the study. We are also grateful to the pig organization in Italy for granting us access to one of their farms. We thank Erling Meisingset (PhD) at NIBIO, Norway, for his support with the statistical analysis, and Line Dinesen Jensen, Denmark, for assisting in collecting data.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe data that support the findings of this study are openly available in Wibe, Atle (2025), \u0026ldquo;ROAM-FREE\u0026rdquo;, Mendeley Data, V1, doi: 10.17632/gjyxccywf6.1\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003e\u0026Aring;str\u0026ouml;m J, Birkemoe T, Brandsegg H, Dahle S, Davey M, Ekrem T, Foss\u0026oslash;y F, Hanssen O, Laugsand A, Majaneva M, Staverl\u0026oslash;kk A, Sverdrup-Thygeson A, \u0026Oslash;degaard F (2023) Insektoverv\u0026aring;king p\u0026aring; \u0026Oslash;stlandet, S\u0026oslash;rlandet og Tr\u0026oslash;ndelag. 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Taxon 21(2/3):213\u0026ndash;251. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2307/1218190\u003c/span\u003e\u003cspan address=\"10.2307/1218190\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Arthropods, diversity, DNA metabarcoding, free-roaming pigs","lastPublishedDoi":"10.21203/rs.3.rs-8310948/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8310948/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe diversity and composition of arthropod communities are influenced by a broad range of environmental factors, including local livestock management practices. Free-roaming domestic pigs, through activities such as, wallowing, exploration, foraging at and below the soil surface, and defaecation can substantially alter arthropod habitats. While these behaviours may reduce populations of soil-associated arthropods, they can also create novel microhabitats that support other species. In this study, arthropods were sampled using Malaise traps positioned both in proximity to free-roaming pigs and at distances from them across five locations in four European countries\u0026mdash;Norway, Denmark, Italy, and Slovenia\u0026mdash;during 2022 and 2023. DNA metabarcoding of the Cytochrome Oxidase I (COI) gene was used to identify the collected bulk samples. The results revealed significant differences in arthropod order composition between areas with or without pigs at sites in Norway and Italy in 2022. Moreover, free-roaming pigs significantly modified the relative distribution of arthropod orders across all investigated locations. The analysis further demonstrated a strong positive relationship between α- and β-diversity and the total site γ-diversity across all sites and study years.\u003c/p\u003e \u003cp\u003eImplications for insect conservation: These findings indicate that free-roaming domestic pigs enhance arthropod diversity. Accordingly, agricultural management practices that integrate free-roaming pigs may contribute to strengthening arthropod biodiversity within managed ecosystems.\u003c/p\u003e","manuscriptTitle":"The impact of free-roaming pigs on arthropod diversity: a field survey in four European countries","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-14 14:04:11","doi":"10.21203/rs.3.rs-8310948/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"fce84797-f9f8-4ff6-b198-6756e0da73a5","owner":[],"postedDate":"January 14th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-02T10:38:08+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-14 14:04:11","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8310948","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8310948","identity":"rs-8310948","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}