The ecological roles of the European rabbit in the Magellanic/Fuegian ecosystem of southernmost Chile.

The European rabbit has invaded numerous ecosystems worldwide, but rarely steppes. Since its various introduction attempts into the ecosystems of the Magallanes/Fuegian region, the rabbit has become a key player, interacting with species at different trophic levels and generating impacts on ecosystems. To better understand the role of the rabbit in steppe and scrub ecosystems, we characterised the food web in the Magallanes/Fuegian region to understand the identity of their interacting species, the mechanisms and complexities of their interactions to demonstrate that rabbit management may become more complex than just controlling a single species. Based on a bibliographic review and wildlife specialists' opinions, we built the Magellanic/Fuegian food web, evaluated their topological properties and performed a rabbit extinction simulation to assess the possible short-term ecological mechanisms operating in the community. We found that the network had 206 nodes (64% native, 13% exotic, and 22% mixed) and 535 links among nodes. The European rabbit was the most connected node of the food web, had the second largest dietary breadth, and ranked as the seventh prey item with more predators. A rabbit extinction simulation shows a possible release of herbivory pressure on plants, including that on several native plants (e.g., Gunnera tinctoria, Pratia repens, Gavilea lutea, Tetroncium magellanicus), and a possible release of competition for some herbivores that share resources with the rabbit (e.g., Ovis aries, Lama guanicoe, Bos taurus). Although rabbit predators have a broad and generalist diet, some such as the native Galicitis cuja, could face a 20% reduction in their trophic width and could intensify predation on alternative prey. These results show that the European rabbit is strongly embedded in the Magellanic/Fuegian ecosystem and linked to several native species. Therefore, rabbit management should consider ecosystem approaches accompanied by monitoring programs on native fauna and experimental pilot studies on native flora to conserve the Chilean Patagonia community.

First Detection of Benign Rabbit Caliciviruses in Chile.

Pathogenic lagoviruses (Rabbit hemorrhagic disease virus, RHDV) are widely spread across the world and are used in Australia and New Zealand to control populations of feral European rabbits. The spread of the non-pathogenic lagoviruses, e.g., rabbit calicivirus (RCV), is less well studied as the infection results in no clinical signs. Nonetheless, RCV has important implications for the spread of RHDV and rabbit biocontrol as it can provide varying levels of cross-protection against fatal infection with pathogenic lagoviruses. In Chile, where European rabbits are also an introduced species, myxoma virus was used for localised biocontrol of rabbits in the 1950s. To date, there have been no studies investigating the presence of lagoviruses in the Chilean feral rabbit population. In this study, liver and duodenum rabbit samples from central Chile were tested for the presence of lagoviruses and positive samples were subject to whole RNA sequencing and subsequent data analysis. Phylogenetic analysis revealed a novel RCV variant in duodenal samples that likely originated from European RCVs. Sequencing analysis also detected the presence of a rabbit astrovirus in one of the lagovirus-positive samples.

Exploring the influence of density-dependence and weather on the spatial and temporal variation in common vole (Microtus arvalis) abundance in Castilla y León, NW Spain.

BACKGROUND: The common vole has invaded the agroecosystems of northwestern Spain, where outbreaks cause important crop damage and management costs. Little is yet known about the factors causing or modulating vole fluctuations. Here, we used 11 years of vole abundance monitoring data in 40 sites to study density-dependence and weather influence on vole dynamics. Our objective was to identify the population dynamics structure and determine whether there is direct or delayed density-dependence. An evaluation of climatic variables followed, to determine whether they influenced vole population peaks. RESULTS: First- and second-order outbreak dynamics were detected at 7 and 33 study sites, respectively, together with second-order variability in periodicity (2-3 to 4-5-year cycles). Vole population growth was explained by previous year abundance (mainly numbers in summer and spring) at 21 of the sites (52.5%), by weather variables at 11 sites (27.5%; precipitation or temperature in six and five sites, respectively), and by a combination of previous abundance and weather variables in eight sites (20%). CONCLUSIONS: We detected variability in vole spatiotemporal abundance dynamics, which differs in cyclicity and period. We also found regional variation in the relative importance of previous abundances and weather as factors modulating vole fluctuations. Most vole populations were cyclical, with variable periodicity across the region. Our study is a first step towards the development of predictive modeling, by disclosing relevant factors that might trigger vole outbreaks. It improves decision-making processes within integrated management dealing with mitigation of the agricultural impacts caused by voles. © 2023 Society of Chemical Industry.

European Rabbit Invasion in a Semi-Arid Ecosystem of Chile: How Relevant Is Its Role in Food Webs?

The European rabbit (Oryctolagus cuniculus) is one of the main invasive species in Chile, where it became naturalized ca. 150 years ago. Their high reproductive capacity, lack of specialist predators, and great adaptability favored the settlement of rabbits in diverse mainland and island ecosystems of the country. Recently, rabbits have become central players in semi-arid ecosystems, such as those represented in Las Chinchillas National Reserve in north-central Chile. We undertook to analyze the place and role of rabbits in the food web of that Reserve, based on a bibliographic review and long-term annual data gathered from 1987 until 2022 (36 years). Results showed that the network comprised 77 species, where 69% were primary producers (plants), 18% were mid-level consumers (herbivores), and 13% were top-level consumers (predators). The most connected species in the food web was the rabbit, which positively or negatively affected the species interacting with it. Predators such as Galictis cuja, Geranoaetus polyosoma, Leopardus colocolo, and Puma concolor, and the scavenger Vultur gryphus, could be negatively affected by an eventual decrease (natural or human-caused) in the rabbit population of the Reserve. To the contrary, primary producers such as Oxalis perdicaria, Plantago hispidula, Schizanthus parvulus, Senna cumminggi, and Tropaeolum azureum could be positively affected by an increase in their biomass in response to a decrease in rabbits, favoring native rodents. We consider that analyzing the rabbit-centered food web and its impacts on native interacting species allows a better understanding of the relevance of invasive species in the local community, providing conceptual tools for rabbit management.

Chemical and microbiological comparison of biodeterioration inColombian heritage constructions / Comparación química y microbiológica del biodeterioro en construcciones patrimoniales en Colombia

Se compararon química y microbiológicamente morterosde Bogotá, Villa de Leyva y Barichara. Las muestras seanalizaron por espectrometría de absorción y emisión atómica,espectroscopia infrarroja con transformada de Fourier,difracción de Rayos X, microscopía electrónica de barrido yespectroscopia por dispersión de energía. Se encontraron óxidosde silicio, aluminio, calcio, hierro, magnesio, yeso, weddellita,despuljosita, cuarzo, berlinita, carbonatos, mica, feldespatos,silicatos, sales de nitratos, sulfitos y compuestos orgánicos.A su vez, se hallaron partículas irregulares entre 10, 50 y 100µm y fibras de tipo orgánico de 20 µm. Se realizó el conteo deunidades formadoras de colonias por el método de dilucionespara identificar microorganismos fúngicos. Se identificaron lossiguientes géneros Aspergillus, Penicillium, Alternaria, Fusarium,Mucor y Syncephalastrum. La muestra de Bogotá presentó el mayornúmero de UFC/mL y el mayor porcentaje de humedad relativa.La concentración de hongos en esta muestra, a diferencia delas de Villa de Leyva y de Barichara, causó la degradación de lamayoría de los metales identificados. Esta comparación químicay microbiológica propone un plan eficaz de intervención paraeliminar y prevenir el biodeterioro en apoyo a la conservación deobras patrimoniales...

Mortars from Bogotá, Villa de Leyvaand Barichara were compared chemically andmicrobiologically. We analyzed the samples using atomicabsorption and emission spectrometry, Fourier-transforminfrared spectroscopy, X-ray diffraction, scanningelectron microscopy and energy dispersive spectroscopy.Oxides of silicon, aluminum, calcium, iron, magnesium,gypsum, weddellite, despujolsite, quartz, berlinite,carbonate, mica, feldspars, silicates, nitrate salts, sulfites,and organic compounds were identified. In addition,irregular particles between 10, 50 an 100 µm werefound, as well organic fibers of 20 µm. Was performeda CFU count using a dilution method to identify fungalmicroorganisms and found following genera Aspergillus,Penicillium, Alternaria, Fusarium, Mucor and Syncephalastrum.The mortar sample taken in Bogotá presented thehighest number of CFU/mL and the highest percentageof relative humidity. The concentration of fungi in thissample, unlike those from Villa de Leyva and Barichara,caused degradation in most of the metals identified.This chemical and microbiological comparison proposesan effective plan of action to eliminate and preventbiodeterioration in support of the conservation ofheritage constructions...

As amostras foram analisadas por espectrometria deemissão e espectroscopia de absorção atômica, infravermelhocom transformada de Fourier, difração de raios X, microscopiaeletrônica de varredura e espectroscopia de energia dispersiva.Foram identificados óxidos de silício, alumínio, cálcio, ferro,magnésio, gesso, weddellita, despuljosita, quartzo, berlinita,carbonato, mica, feldspato, silicatos, sais de nitratos, sulfitos, ecompostos orgânicos. Partículas irregulares entre os 10, 50 e 100µm foram encontradas bem como fibras de tipo orgânico de20 µm. Realizou-se uma contagem CFU usando um método dediluição para identificar microorganismos fúngicos e encontrousefungos dos gêneros Aspergillus, Penicillium, Alternaria, Fusarium,Mucor e Syncephalastrum. A amostra de Bogotá apresentou o maiornúmero de UFC/mL e umidade relativa do ar. A maior presençade fungos desta amostra, ao contrário das amostras da Villa deLeyva e Barichara, causou degradação na maioria dos metaisidentificados. Esta comparação química e microbiológica podesugerir um plano de ação eficaz para a eliminação e prevenção dabiodegradação e assim preservar obras patrimoniais.Departamento de Química, Facultad de Ciencias. PontificiaUniversidad Javeriana. Bogotá, D.C., Colombia.Departamento de Microbiología, Facultad de Ciencias. PontificiaUniversidad Javeriana. Bogotá, D.C., Colombia.Departamento de Biología, Facultad de Ciencias. PontificiaUniversidad Javeriana. Bogotá, D.C., Colombia.Departamento de Arquitectura, Facultad de Arquitectura y Diseño.Pontificia Javeriana. Bogotá, D.C., Colombia.Received: 15-12-2012 Accepted: 02-02-2013 Published on line: 28-02-2013 Edited by Alberto Acosta mUniversitas Scientiarum, Journal of the Faculty of Sciences, Pontificia Universidad Javeriana, is licensed under the Creative Commons 2.5 of Colombia: Attribution - Noncommercial - No Derivative...