Anthropic Factors Research Articles

Assessing coastal habitats with Juniperus sp. pl. in the Iberian Peninsula and on the Balearic Islands

Coastal habitats with Juniperus sp. pl. represent the mature stage in the ecological succession of dune ecosystems. Maritime junipers (Juniperus macrocarpa), prickly junipers (J. navicularis) and caudate junipers (J. turbinata subsp. turbinata) are dominant in the Iberian Peninsula and Balearic Islands communities. This study analyses the biogeographical distribution of 12 habitats, the biotopes they occupy (stabilised sands, coastal cliffs), their biological value, natural and anthropogenic threats and the risk category, according to the IUCN scale, which varies from vulnerable habitats to those in danger of extinction. Half the studied habitats are classified as vulnerable and others endangered. The latter corresponds to small populations located in southeast and east Spain and on the Balearic Islands. Isolation, together with poor seed viability and several anthropic factors, contribute to these communities’ vulnerability.

VEGETATION PYRAMIDS APPLIED TO THE ANALYSIS OF DENSE FOREST UNITS IN THE PANTANAL OF ABOBRAL

The Pantanal of Abobral consists of units of heterogeneous landscapes, in which some dense vegetation, popularly known as cordilheiras and capões , stand out and survive amidst the floodplain. Such formations are of great importance for local biodiversity, but are continually exploited by livestock without adequate management. The aim of this study is to graphically demonstrate the process by which a cordilheira has been going through and discuss the possible causes of environment degradation related to the composition of each vegetal stratum. Biogeographic data sheets were filled with information from the herbaceous, shrubby and arboreal strata, collected in three plots, two at the edges and one at the center of the cordilheira . Strata information were graphically compiled in three vegetation pyramids, visually demonstrating the dynamics of the strata, providing a comparative analysis of the plots from aspects related to dynamics and sociability. Nineteen species, of various strata, were recorded in the central plot, compared to 13 and 15 species in the edges. The most frequent species in all plots was Attalea phalerata . The species composition of the cordilheira , indicated the occurrence of adaptive processes in response to biotic, abiotic and anthropic factors such as laminar erosion, burnings and presence of cattle. An analysis of the vegetation pyramids corroborated the field observations, due to the progression of the arboreal stratum and low representativeness of the other strata.

Performance parameters of ETICS: Correlating water resistance, bio-susceptibility and surface properties

The use of External Thermal Insulation Composite Systems (ETICS) significantly increased in the last decades due to their enhanced thermal properties, low installation cost and ease of application, not only in new constructions but also for thermal retrofitting of building facades. These multilayer rendering systems are constantly exposed to weathering agents and anthropic factors which can lead to physical-mechanical and aesthetical anomalies and thus affect their durability. However, possible synergetic effects among these agents are often neglected by international technical documents on the evaluation of the effectiveness and durability of ETICS. With the aim of filling this gap, moisture transport properties (capillary water absorption, water vapor permeability, water absorption under low pressure, and drying kinetics), thermal conductivity, mould susceptibility and surface properties (color, gloss, and roughness) of twelve commercially available ETICS were assessed and discussed. Possible links between these factors were analyzed and ETICS performance parameters were defined. Results demonstrate that a deeper knowledge of the correlation among ETICS properties can effectively contribute to the evaluation of the efficiency and long-term durability of these systems.

Confirmed cases of dengue in Brazil between the years 2008 to 2012

Dengue is caused by an RNA virus, which has 4 identified variations present in the human environment. Its main symptomatological manifestations include fever, muscle pain (myalgia), retro ocular pain, joint pain (arthralgia), headache (headache), nausea, vomiting and others, such as rash. This article aims to show the number of confirmed dengue cases in Brazil between 2008 and 2012. In Brazil, dengue is characterized as a major public health problem, being one of the diseases of an infectious nature that is very present. Some factors, such as the climate (predominantly tropical), deficient infrastructure of the urban environment, in addition to demographic expansion, which occurs in a disorderly manner, can provoke and possibly justify this national scenario. It represents a major public health problem, since the control of the disease depends on the fight against its vector, which spreads very easily in the country, due to climatic and anthropic factors. For the disease to be tackled efficiently in the country, the most effective method is to combat the vector. Garbage and materials must be efficiently separated and stored in suitable locations for further recycling, so that they do not accumulate water and become mosquito breeding sites.

Determining the effects of socioeconomic and environmental determinants on chronic obstructive pulmonary disease (COPD) mortality using geographically and temporally weighted regression model across Xi'an during 2014–2016

Numerous methods have been implemented to evaluate the relationship between environmental factors and respiratory mortality. However, the previous epidemiological studies seldom considered the spatial and temporal variation of the independent variables. The present study aims to detect the relations between respiratory mortality and related affecting factors across Xi'an during 2014–2016 based on a novel geographically and temporally weighted regression model (GTWR). Meanwhile, the ordinary least square (OLS) and the geographically weighted regression (GWR) models were developed for cross-comparison. Additionally, the spatial autocorrelation and Hot Spot analysis methods were conducted to detect the spatiotemporal dynamic of respiratory mortality. Some important outcomes were obtained. Socioeconomic and environmental determinants represented significant effects on respiratory diseases. The respiratory mortality exhibited an obvious spatial correlation feature, and the respiratory diseases tend to occur in winter and rural areas of the study area. The GTWR model outperformed OLS and GWR for determining the relations between respiratory mortality and socioeconomic as well as environmental determinants. The influence degree of anthropic factors on COPD mortality was higher than natural factors, and the effects of independent variables on COPD varied timely and locally. The results can supply a scientific basis for respiratory disease controlling and health facilities planning.

‘Waging war against the parasites’: critiquing women’s narrative identities through feminist ecocritical reflections on women and the Holocaust

ABSTRACT The existence of parasites and insects in Nazi internment centres during the Holocaust, and how it has latterly featured in the memoirs of women who survived, is largely overlooked by historians focused on anthropic and socio-political factors of the event. Yet, as this article illustrates, for many survivors life in these institutions is characterised, at least in its retelling, by turbulent relationships with parasitic creatures. This article explores, through critical reading and the lens of feminist ecocritical theory, how recurring patterns of entomological and parasitological imagery work in many women’s Holocaust testimonies to reinforce the authors’ identities as resistant, resilient survivors; how for women narrativising their ecological experiences, resistance and survival are often portrayed as reliant upon asserting traditional female identity. In so doing, this article works to allow us, using a non-traditional critical approach, to garner a deeper understanding of women’s accounts of incarceration and of the Holocaust more widely.

Groundwater damages on the historic buildings of Cairo: the case of the medieval walls of Mokattam limestone.

The conservation of historical buildings in Cairo represents a complex matter, influenced by several key factors such as the cultural context, the intrinsic features of a vast and heterogeneous architectural heritage and the environmental conditions. An Italian-Egyptian research group is working on the peculiarities of the monument conservation in old Cairo, concerning the material decay in relation to the anthropic and climatic factors and the pollution levels. Monument vulnerability levels strongly need to be identified and systematized to delineate adequate programs of control, management and intervention. One of the main topics developed is the study of the deterioration mechanisms of stone materials in medieval walls, connected to the capillary damp rising from the ground, common in Egypt, always accentuated by the combination with other factors. The research examines some historic buildings in different areas (El-Gamaleya, El Darb El Ahmar, Al Qarafah). The variety of materials has led to limiting the first phases of the study to the masonry materials, with special attention to the limestone blocks. The intersection of data collected on the field with those relating to underground water and environmental factors has allowed us to focus on some aspects of the problem. Some syntheses have been proposed on the main mechanisms affecting the studied material in situ and the necessary directions for further investigation have been identified. Our first results highlight the relationship existing between the environmental thermo-hygrometric excursions and the capillary water rising from the ground, which affect the evaporation speed, the imbibition levels and the crystallization of salts inside and on the rock surface. The studied rocks display intense weathering (decohesion, dissolution) due to a number of chemical and physical phenomena, responsible for a generalized decay of the mechanical properties of the original material. The observed widespread phenomena of carbonate sulphation also suggest the atmospheric contribution of particulate matter and polluting compounds. The mineralogical and physical characterization of the limestone allowed us to estimate its resistance to the decay processes.

Sustainable rehabilitation of neglected and marginal landscapes: the San Lorenzo valley in Sardinia

This paper describes a proposal for the sustainable rehabilitation of a neglected and marginal fluvial landscape. It situates the experience into a broader debate about sustainability and spatial design, and then draws from it some general conclusion. The study subject is a fluvial valley characterised by thirty-six mills, which once served the agriculture of the surroundings. The decline of water as power source let to the decline of the valley. The mills became eventually farms, houses, or were left empty. The proposal envisions multiple forms of interaction with the different contextual issues related to the context, turning the design of the water course in a way to cope with erosion and floods, to produce clean energy, and finally as attractor for tourism. The result is a series of integrated actions that offers new opportunities to the community, designing a new sustainable landscape drawing from the specific natural and historical aspects of the site. Every action is linked with one of the anthropic and natural factors that characterise the valley, or that can be beneficially introduced, so that the proposal can be further adjusted in accordance with the relative importance of each factor over time.

Вплив метеорологічних чинників на ослаблення в’язових деревостанів за умов розвитку комах-ксилофагів

The biological resistance of species of the genus Ulmus L. is interrelated with various biotic, abiotic and anthropic factors, in particular, abrupt changes in the hydrothermal regime, failure to comply with the rules of intermediate cutting management in the stands with these species, damage by leaf and stem insect pests that transmit and spread the infection, infectious agents, agents of undetermined etiology, etc.It has been discovered that the uneven distribution of rainfall over the years (the least rain in the research area fell in 2007, 2009 and 2015) induced deterioration of the sanitary state of elm woody plants, which caused them being affected by pathogens of mushroom and bacterial etiology and their settlement by xylophagous insects. On the basis of the analysis of changes in the population parameters in the phases of the development of the hotbeds of these pests it was shown that the studied plantations in the dynamics during the period from 2004 to 2006 were in a state of dispersion or the so-called crisis, but, starting from 2007, transformed into a state of the actual outbreak of the hotbed. Detected hotbeds of stem pests are characterized by high, medium and low degree of settlement of trees. At the same time, it was recorded that chronic hotbeds are characterized by a long period of existence, relatively low, although elevated (in comparison with healthy plantings), the number of insects and the size of the current dead trees; for episodic hotbeds, or hotbeds of mass reproduction, - a relatively short (3 to 5 years) period of development, a great number and size of the current dead trees. It has also been found that in both cases there are possible inverse and irreversible reactions of tree stands, although in the second scenario of the development of the population of pests, in the conditions of their mass reproduction, the full destruction of the forest plantation is most often observed. It was recorded that, near the hotbeds of mass reproduction, which are characterized by excessive population density, migration centers usually appear, where harmful insects migrate in search of new settlements.

Use of sound to guide the movement of eels and other fishes within rivers: a critical review

Downstream movements of some freshwater fishes, including eels, are adversely affected by the presence of hydroelectric structures and other anthropic factors. It is important to consider ways of influencing the movements of such fishes to ensure that their populations are protected and their abundance not detrimentally affected. It is especially important to divert migrating fishes to locations where they can be safely moved downstream. Guidance through exposure to underwater sound may effectively attract or deter fish in order to influence their movement to avoid in-water hazards and improve survival during downstream migration. This paper examines the available literature on the use of sound to control the movements of fishes, with an emphasis on pre-reproductive anguillid eels whose populations have been declining and which also must survive downstream passage in order to continue towards the spawning grounds in the Sargasso Sea. Information is provided on underwater acoustics, the detection of sounds by fishes, their responses to sound, the use of sound to guide fishes, and the generation of guiding underwater sounds. Information gaps are considered, and the paper explores the need to develop guidance systems that use acoustic cues, and perhaps other stimuli, to influence the behaviour of fishes. It is concluded that while it is premature to implement a full-scale acoustic guidance system to affect fish behaviour, with additional research it may be possible to develop acoustic and/or multisensory systems that could affect fish behaviour. It is also concluded that efforts to develop acoustic control systems have numerous advantages over other stimuli that do not propagate as well under widely diverse environmental conditions.

Recurring damages on earthen heritage. Diagnosis and possible interventions in the highlands of Jujuy (Argentina)

A significant number of the existing National Historical Monuments in the highlands of northwestern Argentina are built with different earthen constructive techniques. These architecures, which correspond mostly to colonial and republican times, have presented damage of different severity over time, associated with both environmental and anthropic factors, including conservation actions. Since the first half of the twentieth century, different institutions carried out systematic conservation projects on this heritage using foreign techniques and materials, which instead of favoring their consolidation caused new damages. This paper sets out to recognize which are the usual damages in this architectural heritage, considering their mechanisms of degradation, and observing the implications of the interventions carried. Finally, based on the working experience in the area, the recommendations from different researches and international standards, it will be possible to recognize potential forms of intervention consistent with these technologies and with the corpus of local knowledge. This paper will focus in different case studies in the Puna and Quebrada de Humahuaca, based on field and laboratory research carried out in recent years, specifically focused on the study of current and historical earthen constructive technologies. As part of these researches, there were made various diagnoses and intervention proposals that will also be included in this article.

Structural health assessment of Puente del Inca natural monument using the integration of instruments and technologies

Puente del Inca is a natural monument standing over the Cuevas river in Mendoza, Argentina. The bridge currently exhibits structural deterioration due to natural and anthropic factors. This article seeks to offer a contribution to the conservation and restoration works of Puente del Inca by integrating instruments and technologies that allow the assessment of the health state of the natural bridge. The study relied on visual inspection, accretion-erosion rate measurements, hydrothermal flow characterization, ground-penetrating radar, soil dielectric sensor, Global Navigation Satellite System, laboratory testing, Structure from Motion, the Finite Element Method and ambient vibration testing. The results show that the morphology and health of the natural bridge depend on the dynamic balance between the erosion and the geobiological system intervening in the formation of the travertine constituting the natural bridge. The computational structural modeling demonstrates that there is a controversy between the benefit of irrigating the geological formation with thermal water and the loss of stability of the bridge under saturation conditions. Nevertheless, a continuous monitoring and an efficient administration of thermal water may ensure the deceleration of most of the erosive processes as well as the improvement of the geobiological system health.

Regression Analysis of Subsidence in the Como Basin (Northern Italy): New Insights on Natural and Anthropic Drivers from InSAR Data

Natural and anthropogenic subsidence such as that in the Como urban area (northern Italy) can cause significant damage to structures and infrastructure, and expose the city’s lakefront to an increasing risk of inundation from Lake Como. This phenomenon affecting the Como basin has been studied by several researchers, and the major drivers of subsidence are known. However, the availability of historical InSAR data allowed us to reconsider the relationship between subsidence predisposing factors (i.e., the thicknesses of reworked and compressible layers, overburden stress, and the piezometric level) and ground surface displacements with higher precision over the entire basin. Benefiting from the deep knowledge of the hydromechanical setting of the Como basin and the availability of InSAR measurements from 1992 to 2010, in this paper we model subsidence-related movements using linear and nonlinear regression methods in order to determine the combination of natural and anthropic factors that have caused subsidence in the Como basin over the past decades. The results of this study highlight peculiar patterns of subsidence that suggest the influence of two further causes, namely tectonic control of the sedimentary architecture and diversion of local streams, which have never been considered before. This analysis aims to assess the spatial distribution of subsidence through InSAR analysis in order to enhance the knowledge and understanding of the phenomenon in the Como urban area. The interferometric data could be used to better plan urban risk management strategies.

Restoring a glacier‐fed river: Past and present morphodynamics of a degraded channel in the Italian Alps

AbstractThe present study explores the evolutionary trajectory of the glacier‐fed Mareit River (South Tyrol, Italian Alps), where a large restoration programme was implemented in 2008–2009. River corridor changes before and after the restoration works were assessed using historical maps, recent field observations, topographic surveys and topographic differencing. Trends of anthropic (forest cover, channel works, gravel mining) and natural (glacial cover, precipitation, flow regime) factors controlling channel morphology – at both catchment and reach scales – were reconstructed. From the mid‐19th century, the evolutionary trajectory of the Mareit River followed a degradational trend, characterized by channel narrowing, bed incision and planform simplification. Direct, in‐channel human alterations – mainly in the form of bank protections (in the late 19th century), gravel mining (mostly in the 1970s) and grade‐control works (since the 1980s) – dominated the historical adjustments before the restoration. In 2008–2009, a segment of the Mareit was restored by widening the channel, partly removing the check‐dams and shaping a braided pattern within a laterally constrained corridor. Post‐work monitoring shows that the restoration improved both the morphological quality and the geomorphic diversity. At present, the channel is subject to narrowing and slight bed level incision, with islands and floodplains progressively expanding at the expenses of the active channel. This trend is likely to continue in the next decades based on the expected future flow regime, and indeed the Mareit River seems to be attaining a ‘miniaturized’ version of the anabranching pattern of the mid‐19th century. Overall, this restoration approach and the associated evolutionary trajectory is considered positive, because it leads to a complex mosaic of geomorphic units, dynamically self‐adjusting to the time‐varying driving variables. The formation of a morphodynamically active corridor, while keeping artificially non‐erodible boundaries, represents an optimal strategy to integrate ecological improvements with flood risk mitigation in the densely populated Alpine valleys. © 2020 John Wiley & Sons, Ltd.

Influence of Anthropic and Topographic Factors on the Physicochemical Properties of the Soil around Temporary Pools in Ferlo, North Senegal

The temporary ponds at Ferlo constitute wetlands whose pastoral activity is of paramount importance in the economy of Senegal. These zones are characterized by a fairly specific microclimate (soft and humid), a shallow depth of the water table, alternating phases of submersion and exudation whose functioning is linked to the soil. Thus the restoration and conservation of these wetlands requires a good knowledge of the soil factors.
 The objective of this study is to compare the physico-chemical parameters of the soil around temporary pools in grazed and ungrazed areas and different topographical units in order to determine their relative similarities.
 The samples taken at different horizons from seven soil pits (P1, P2, P3, P4, P5, P6 and P7) opened in the different morpho-pedological facies of two grazed ponds and one ungrazed pond were analyzed in the laboratory.
 The results obtained show that the soils of Ferlo have a sandy texture and low fertility in the slopes and plateaus. However, they have a balanced texture and average fertility in ponds and ungrazed areas. The factorial analysis made it possible to highlight three distinct soil classes. A class of sandy texture soil with very low chemical fertility comes from the plateau. A class of soil with a balanced texture which is rich in cation and calcium exchange capacity found in the low zones of strong mineralization. A last class rich in chemical element with a silty texture which is found in wooded areas.
 These results thus reveal the predominant influence of anthropic and topographic factors on the evolution and physico-chemical composition of the soil.

Análise das chuvas na Região Metropolitana do Cariri e a influência do fenômeno climático El Niño - Oscilação do Sul

O estudo do clima é essencial para compreender e monitorar as atividades atmosféricas, como exemplo as mudanças climáticas. O clima de uma região sofre variadas modificações devido a fatores naturais ou antrópicos, destaca-se o El Niño - Oscilação Sul, anomalia esta que podem causar prejuízos financeiros na produção agrícolas, enchentes e secas severas. Destaca-se a Climatologia e a Meteorologia no estudo das precipitações históricas e os fenômenos de ordem climática, que corroboram no controle e compreensão das atividades atmosféricas que influenciam nas chuvas do Nordeste. Nesse sentido, o presente trabalho objetiva analisar o comportamento das precipitações pluviométricas na Região Metropolitana do Cariri e relacionar o comportamento das chuvas com os anos de influência do fenômeno climático El Niño-Oscilação do Sul, no período de 1980 a 2019, enfocando na identificação dos períodos mais secos do regime pluviométrico e os anos de chuvas intensas. Para a realização desse estudo, os dados foram disponibilizados pela Fundação Cearense de Meteorologia e Recursos Hídricos por meio das séries históricas. A tabulação e organização dos dados, como também os cálculos estatísticos, utilizou-se o software Excel. Foi possível identificar a variabilidade e irregularidades nas chuvas da Região e a influência do El Niño, intervindo nas chuvas da Região estudada.

Spatiotemporal variation and determinants of population's PM2.5 exposure risk in China, 1998-2017: a case study of the Beijing-Tianjin-Hebei region.

PM2.5 pollution has emerged as a global human health risk. The best measure of its impact is a population's PM2.5 exposure (PPM2.5E), an index that simultaneously considers PM2.5 concentrations and population spatial density. The spatiotemporal variation of PPM2.5E over the Beijing-Tianjin-Hebei (BTH) region, which is the national capital region of China, was investigated using a Bayesian space-time model, and the influence patterns of the anthropic and geographical factors were identified using the GeoDetector model and Pearson correlation analysis. The spatial pattern of PPM2.5E maintained a stable structure over the BTH region's distinct terrain, which has been described as "high in the northwest, low in the southeast". The spatial difference of PPM2.5E intensified annually. An overall increase of 6.192 (95% CI 6.186, 6.203) ×103 μg/m3 ∙ persons/km2 peryear occurred over the BTH region from 1998 to 2017. The evolution of PPM2.5E in the region can be described as "high value, high increase" and "low value, low increase", since human activities related to gross domestic product (GDP) and energy consumption (EC) were the main factors in its occurrence. GDP had the strongest explanatory power of 76% (P < 0.01), followed by EC and elevation (EL), which accounted for 61% (P < 0.01) and 40% (P < 0.01), respectively. There were four factors, proportion of secondary industry (PSI), normalized differential vegetation index (NDVI), relief amplitude (RA), and EL, associated negatively with PPM2.5E and four factors, GDP, EC, annual precipitation (AP), and annual average temperature (AAT), associated positively with PPM2.5E. Remarkably, the interaction of GDP and NDVI, which was 90%, had the greatest explanatory power for PPM2.5E ' s diffusion and impact on the BTH region.

Impact of Cultural Practice, Socio-economic Level and Environment on the Profitability of the Date Palm (Phoenix dactylifera L.) in Niger (West Africa)

Phoeniciculture, or date palm cultivation plays a major socio-economic and ecological role. However, few studies have quantified the drivers of date palm cultivation and its socio-economic and environmental benefits in West African Sahel. Therefore, this study assessed the effect of anthropic and environmental factors on quantitative and qualitative production of dates palm in Niger. We conducted an ethnobotanical survey to collect data in the Sahelian and Saharian zones of Niger. We used permutation regression test to assess the influence of climatic conditions, fidelity of cultural practices implementation and the socio-economic level of producers on the date palm profitability. The Spearman rank correlation coefficients between the economic parameters and the geographical position of palm groves were also estimated based on the Spearman rank permutation test. A total of 60 producers were surveyed in ten villages of Sahelian and Saharian zones known as two main phoenicicultural areas in Niger. This analysis showed that date palm production varies quantitatively and qualitatively across agro-ecological zones. The study revealed also that ethnic groups influence the quantitative aspect of date palm production (P = 0.023), by socioeconomic parameters (P = 0.005) and by the index of fidelity to the cultural practice implementation (P = 0.035). The date palm production varies quantitatively (P = 0.001) and qualitatively (P = 0.033) according to the agro-climatic zones. The Spearman rank test shows a significant correlation between the quantitative and qualitative production, the geographical position of the palm groves and the depth of the water table. The profitability of the date palm seems not to be up to the phoenicicultural potential that can be the consequence of the poor implementation of the cultural practices, the socio-economic level of the producers and the environmental conditions.

Meteorological Variability and Groundwater Quality: Examples in Different Hydrogeological Settings

Rainfall and temperature variability causes changes in groundwater recharge that can also influence groundwater quality by different processes. The aim of this study is the analysis of the hydrogeochemical variations over time due to meteorological variability in two different study areas in Italy: an alluvial aquifer in the Piedmont Po plain and an alluvial-pyroclastic aquifer in the Campanian plain. The examined plains show groundwater with natural quality not satisfying the European drinking water standards, or anthropogenic contamination. The peculiar natural quality is due, in the Campanian plain, to the closeness of volcanic areas, and to the presence of reducing conditions. In Piedmont plain a test site is characterized by a point-source contamination by heavy metals, due to the presence of past industrial activities. In all the examined areas there is a diffuse nitrate contamination. The fluctuations of the ions As, F, Fe, Mn, Cr VI, NO3, and Cl were analyzed and compared, using statistical methods, with the variations over time in precipitation, temperature, and piezometric levels, sometimes significant. Results highlight the importance of the groundwater and meteorological monitoring and the key role of the recharge variation in the hydrogeochemical processes. The linking degree between rainfall/temperature variability and hydrogeochemistry is variable, in function of the typology of chemical species, their origin, and of the aquifer characteristics. The fluctuation of climate variables determines sudden changes in the geochemistry of shallow unconfined aquifers (e.g., in the Piedmont plain), while semiconfined or confined aquifers (e.g., in the Volturno-Regi Lagni plain) react with a greater delay to these variations. Moreover, natural quality is more affected by climatic variations than anthropogenic contamination, which is the result of multiple environmental and anthropic factors.

Phylodynamic analysis and evaluation of the balance between anthropic and environmental factors affecting IBV spreading among Italian poultry farms

Infectious bronchitis virus (IBV) control is mainly based on wide vaccine administration. Although effective, its efficacy is not absolute, the viral circulation is not prevented and some side effects cannot be denied. Despite this, the determinants of IBV epidemiology and the factors affecting its circulation are still largely unknown and poorly investigated. In the present study, 361 IBV QX (the most relevant field genotype in Italy) sequences were obtained between 2012 and 2016 from the two main Italian integrated poultry companies. Several biostatistical and bioinformatics approaches were used to reconstruct the history of the QX genotype in Italy and to assess the effect of different environmental, climatic and social factors on its spreading patterns. Moreover, two structured coalescent models were considered in order to investigate if an actual compartmentalization occurs between the two integrated poultry companies and the role of a third “ghost” deme, representative of minor industrial poultry companies and the rural sector. The obtained results suggest that the integration of the poultry companies is an effective barrier against IBV spreading, since the strains sampled from the two companies formed two essentially-independent clades. Remarkably, the only exceptions were represented by farms located in the high densely populated poultry area of Northern Italy. The inclusion of a third deme in the model revealed the likely role of other poultry companies and rural farms (particularly concentrated in Northern Italy) as sources of strain introduction into one of the major poultry companies, whose farms are mainly located in the high densely populated poultry area of Northern Italy. Accordingly, when the effect of different environmental and urban parameters on IBV geographic spreading was investigated, no factor seems to contribute to IBV dispersal velocity, being poultry population density the only exception. Finally, the different viral population pattern observed in the two companies over the same time period supports the pivotal role of management and control strategies on IBV epidemiology. Overall, the present study results stress the crucial relevance of human action rather than environmental factors, highlighting the direct benefits that could derive from improved management and organization of the poultry sector on a larger scale.