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The evolutionary dynamics of the ecoregions of southern South America and the species that inhabit them have been poorly studied, and few biogeographic hypotheses have been proposed and tested. Quaternary climatic oscillations are among the most important processes that have led to the current distribution of genetic variation in different regions of the world. In this work, we studied the evolutionary history and distribution of the Córdoba vesper mouse (Calomys venustus), a characteristic rodent of the region of which little is known about its natural history. Since the population dynamics of this species are influenced by climatic factors, this rodent is a suitable model to study the effects of Quaternary climatic oscillations in central Argentina. The mitochondrial cytochrome b gene was sequenced to analyze the phylogeography of C. venustus, and ecological niche modeling tools were used to map its potential distributions. The results of these approaches were combined to provide additional spatially explicit information about this species' past. Our results suggest that the Espinal was the area of origin of this species, which expanded demographically and spatially during the last glacial period. A close relationship was found between the Espinal and the Mountain Chaco. These results are consistent with previous studies and emphasize the role of the Espinal in the biogeographic history of southern South America as an area of origin of several species. [ABSTRACT FROM AUTHOR]

Background and aims: In the course of floristic dry forest sampling, specimens of Venturiella acrifolia were collected in Santiago del Estero and Santa Fe provinces. This record constitutes the first report in Argentina and the second in South America. M&M: Specimens collected in 2019 and 2023 were analyzed morphologically using conventional techniques for bryophytes and housed in DTE, LIL, MFA and SDE. Results: The species is described and illustrated. Conclusions: This work confirms the presence of Venturiella acrifolia in Argentina. The species is found in North America, Mexico, Bolivia and Argentina. [ABSTRACT FROM AUTHOR]

Aim of study: To examine the transferability of G-SSR (genomic simple sequence repeats) and EST-SSR (expressed sequence tag simple sequence repeats) markers developed for several Neltuma species to N. affinis, a species with no genomic data. Area of study: West-Center of Entre Ríos province, Argentina. The set of molecular markers here proposed can be used to analyze samples from the entire species’ distribution range. Material and methods: Twenty-five genomic G-SSRs and eleven EST-SSRs from multiple species were amplified in thirty N. affinis genotypes. Polymorphism, discrimination power and possible deviations from Hardy-Weinberg equilibrium were assessed. Main results: Seventeen highly polymorphic G-SSRs were successfully transferred to N. affinis, with a PIC (polymorphic information content) average value of 0.811 and a He (expected heterozygosity) average value of 0.694; thirteen were validated, showing very low frequencies of null alleles and no linkage disequilibrium. Additionally, seven polymorphic EST-SSRs were transferred. As expected, PIC and He average values were low. Six out of seven markers were validated, and very low frequencies of null alleles and no linkage disequilibrium were observed. Research highlights: This work provides information on the levels of microsatellites’ cross transferability to N. affinis, and its polymorphism degree. Two sets of polymorphic SSRs (genomic and expressed) to study the genetic status of the species are proposed.

Arbuscular mycorrhizal fungi (AMF) are mutualistic symbionts associated with most terrestrial plants. HMA communities vary in composition and life histories and are affected by land use and management. The caldén forests (Prosopis caldenia Burkart) in the province of San Luis have suffered a considerable reduction in their area. Currently, its relics are part of a landscape made up of forests and lands cultivated with Medicago sativa L. (alfalfa) and Eragrostis curvula (Schrad.) Nees (weeping lovegrass), key forage species for livestock production in the region. Considering the ecological and economic importance that these land uses have for the region, the objective of this work was to analyze whether the diversity of AMF is affected by the change in land use from caldén forest to alfalfa or weeping lovegrass plots and whether there are indicator species for each use. Four plots of permanent forest were established, 4 of alfalfa and 4 of weeping lovegrass. Soil samples were taken from each plot, the physicochemical characteristics were determined and the AMF spores were extracted. The composition of the spore communities was different in each land use. The AMF morphospecies richness did not showed differences between forest and alfalfa but show differences with weeping lovegrass. Total abundance, spore abundance of ruderal and stress-tolerant species were significantly higher in alfalfa. In addition, 2 indicator species were identified in alfalfa, 1 in forests, and 2 in weeping love grass. This study provides evidence suggesting that land-use change in Caldenal significantly alters the composition of AMF spore communities and may have a negative effect on this endemic forest. [ABSTRACT FROM AUTHOR]

Forest vegetation is key for buffering microclimatic factors and regulating atmospheric deposition. Epiphytic lichens are sensitive to these factors and can indicate the overall health status of the ecosystem. Specifically, the analysis of morpho-anatomical variations allows us to understand the degree of tolerance or sensitivity of these organisms exposed to agricultural crops and how vegetation might buffer this response. We analyzed variations in vegetative and reproductive characters and injuries in thalli of Parmotrema pilosum as a response to distance to crops and forest cover. The study was conducted in forest patches of the Espinal in central Argentina, an ecosystem threatened by agricultural activity. We selected 10 sites with different forest cover areas and two collection points differing in distance to crops: sites adjacent to (0 m) and far from (150 m) crops. We collected five thalli from each collection point and analyzed variations in morpho-anatomical characters at macro- and microscopic levels. We found a lower number of algae and a higher proportion of simple cilia in individuals at points adjacent to crops. At points with low forest cover, a thinner upper cortex was observed, whereas at points with greater forest cover, an increase of necrosis and greater presence of apothecia were detected. Bleaching was the most frequent injury at sites adjacent to crops, decreasing with increasing forest cover. Conservation and reforestation of Espinal forest patches would promote the propagation of lichens affected by agricultural practices. [ABSTRACT FROM AUTHOR]

Many South American dry woodlands lack good historical or paleoecological baseline data to inform restoration and conservation. However, functionalist approaches such as those popularized by rewilding suggest that functional interactions producing target ecosystem processes are valid even without data confirming compositionalist values such as a long coevolutionary histories or known historical range overlaps of target species. In central Chile, the guanaco (Lama guanicoe) has been extirpated but is known to browse trees in other regions of South America, and the tree Vachellia [Acacia] caven shows adaptations to browsing but has no extant browsers within its Chilean range. Both species are native to Chile but there are no data to assess their historical levels of interaction. Here we test the hypothesis that they can act as mutual "Eltonian proxy" species: interacting species for which we lack sufficient data (the Eltonian shortfall) to prove they are not proxies. Specifically we predict that they have complementary adaptations such that guanacos will browse Vachellia [Acacia] caven and the latter will show adaptive responses to their browsing. We introduced five guanacos into an enclosure of Vachellia [Acacia] caven "espinal" woodland, and over two years measured the growth responses of individual branches, compared to branches of trees in an area without browsing. We predicted that Vachellia [Acacia] caven would show compensatory growth in response to guanaco browsing resulting in an increase in branching. Guanacos browsed throughout the two years. In the presence of guanaco browsing, Vachellia [Acacia] caven branches grew longer, grew more sub-branches, and showed more densely streamlined branch architectures. These results indicate that guanacos could be used to substitute anthropogenic pruning as a restoration and management technique in Vachellia [Acacia] caven "espinal" woodlands. However, other extinct megaherbivores or extirpated deer may also be key components of a past herbivore community to which Vachellia [Acacia] caven was adapted. Further attention to a network of multiple interacting browsers, and their indirect and nontrophic effects, is an area for further research. • Native trees (Vachellia (Acacia) caven) in open woodlands show compensatory growth, a potential adaptation to browsing. • We tested whether V. caven and regionally extirpated guanacos Lama guanicoe show reciprocal browsing adaptations. • Naïve guanacos spontaneously browsed Acacia caven branches and leaves. • Browsed Acacia caven grew longer branches, with more sub-branches and in a more tightly bunched shape compared to controls. • Guanacos could be used as a natural restoration method to mimic known positive impacts of pollarding on open woodlands. [ABSTRACT FROM AUTHOR]

Animal populations that require tree cavities can be either limited or structured depending on the quality and availability of tree cavities in their ecosystems. Over the last century, the Caldén forest of Argentina has experienced severe habitat degradation due to anthropogenic activities. Here, we report the density and characteristics of cavities and their vertebrate users in areas of the Caldén forest with two different types of management: a protected area and an area with cattle ranching. The average density of cavities was 16.1 cavities/ha. However, the reserve's cavity density was four times higher than the ranch's (19.5 vs. 5.8 cavities/ha). The characteristics of the cavities and their support trees showed significant variations, but they were generally similar between sites. Forty-four vertebrate species use or may use tree cavities. The proportion of recorded species using cavities in the reserve was higher (30/41 vs. 6/32; p < 0.01). While most cavity users in the semi-arid forest are not threatened, this ecosystem has been dramatically fragmented, with only 11% of its original area remaining. If anthropogenic activities continue to alter this fragile ecosystem, it is possible that in the future, many species, including tree cavity nesters, will suffer a decline in their populations. [Display omitted] • Forest management is important for conserving tree cavity user communities. • We found 44 potential users of tree cavities in the Caldén forest. • Natural areas have a greater density of cavities and users. • Forests with livestock management could negatively influence tree cavity users. [ABSTRACT FROM AUTHOR]

Los hongos micorrícicos arbusculares (HMA) son simbiontes mutualistas asociados a la mayoría de las plantas terrestres. Las comunidades de HMA varían en composición y en historias de vida, y son afectadas por el uso y el manejo del suelo. Los bosques de caldén (Prosopis caldenia Burkart) de la provincia de San Luis han sufrido una reducción considerable de su superficie. Actualmente, sus relictos integran un paisaje compuesto por bosques y tierras cultivadas con Medicago sativa L. (alfalfa) y Eragrostis curvula (Schrad.) Nees (pasto llorón), dos especies forrajeras clave para la producción ganadera de la región. Dada la importancia ecológica y económica que tienen estos usos de suelo en la región, el objetivo de este trabajo fue analizar si la diversidad de los HMA es afectada por el cambio de uso de suelo del bosque de caldén a parcelas agrícolas de alfalfa o de pasto llorón, y si existen especies indicadoras para cada uso. Se establecieron 4 parcelas permanentes de bosques, 4 de alfalfa y 4 de pasto llorón. De cada parcela se recolectaron muestras de suelo, se les determinaron características fisicoquímicas y se les extrajeron las esporas de HMA. La composición de las comunidades de esporas fue diferente en cada uso de suelo. La riqueza de morfoespecies de esporas de HMA no mostró diferencias entre bosque y alfalfa, pero sí con pasto llorón. La abundancia total, la abundancia de esporas de especies ruderales y de estrés tolerantes fue significativamente mayor en alfalfas. Además, se identificaron 2 especies indicadoras en alfalfa, 1 en bosques y 2 en llorones. Este estudio provee evidencia que sugiere que el cambio de uso de suelo en el Caldenal altera de manera significativa la composición de las comunidades de esporas de HMA, lo cual puede afectar negativamente este bosque endémico.

Copyright of Medicina (Buenos Aires) is the property of Medicina (Buenos Aires) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The transformation of forests to treeless landscapes as a result of disturbances (deforestation transitions) is an ongoing process in many regions of the world. Here we first revise the historical context of these transformations and then, we focus on its consequences for litter decomposition. We also present a case study, based on four ecosystems of central Argentina (Sub-Andean, Mountain Chaco, Espinal and Arid Chaco), evaluating how deforestation transitions can modify ecosystem decomposition by altering its main controls. Although there is evidence of consequences of deforestation transitions on the local environment for decomposition and on leaf litter quality it is not clear how those changes would impact the decomposition of natural mixed litter in the field. In our study case, we show that the deforestation transitions evaluated across four ecosystems resulted in no consistent changes in standard substrate decomposition but a consistent increase in the litter mixtures' decomposability and quality. Likely as a consequence of this pattern, the loss of trees resulted in a consistent increase in the in situ mixtures decomposition across the ecosystems studied. Beyond our particular findings, our analysis highlights how the accurate prediction of the consequences of deforestation transition on changes in carbon and nutrient cycling needs to understand the behaviour of its controls. Only through this understanding, we will be able to interpret the patterns of in situ mixtures decomposition and predict the consequences of deforestation transitions adequately on carbon (C) and nutrient cycling. Additionally, the recent literature, in coincidence with our results, gives evidence that the presence of non-leafy plant debris and local-scale variation in the local environment may play a stronger role than previously thought in C and nutrient cycling. [ABSTRACT FROM AUTHOR]

La hidatidosis es una enfermedad causada por el estado larval del platelminto Echinococcus, siendo la especie más prevalente Echinococcus granulosus. Es endémica Eurasia, Africa, Australia y Sudamérica. En Chile tiene una incidencia notificada de 2,1 casos por 100.000 habitantes y a pesar de que está asociada a las zonas ganaderas del sur de Chile, se presenta a lo largo de todo el territorio debido al desplazamiento de la población y su largo período de incubación. Se caracteriza por la presencia de un quiste habitualmente a nivel hepático (75%) o pulmonar (15%). La afectación de otros territorios es menos frecuente y el compromiso óseo es una rareza que no supera el 1 a 2,5%, ya sea en el tejido trabecular o canal medular. El tratamiento por lo general es médico-quirúrgico con resultados clínicos dispares debido a alta tasa de recurrencias y secuelas. La experiencia en el manejo de pacientes afectados con hidatidosis intrarraquídea es limitada debido a su baja frecuencia. Por ello quisimos reportar 2 casos observados en nuestro centro y analizar su manejo.

Arid and semiarid environments dominate the Earth's surface and are very vulnerable to global change. Chañar (Geoffroea decorticans) and brea (Parkinsonia praecox) are two ubiquitous woody species of these environments. They grow in degraded forests, strongly modified areas and as a main component of secondary forests. Despite the value of both species, little is known about their growth dynamics and their relationship with climate. The objective of this research was to determine their dendrochronological potential and the connection between growth and climate variables. Anatomical and standard dendrochronological methods were applied. First of all, we stated the anatomical characteristics that allowed us to detect tree-ring boundaries (terminal parenchyma and variation in the shape of vessels). Further, after dating and measurement of tree rings we determined significant correlation between series, which means a common growth signal among trees as a result of environmental variable effects. Trees were not older than 40 years. Mean annual radial growth was 3.37 mm (SD±0.71) and 2.16 mm (SD±0.61) for chañar and brea, respectively. Finally, chañar and brea had a negative growth-mean temperature association. Rainfall affected chañar and brea growth in summer previous to the growing season. Southern Oscillation Index (SOI) had an inverse association with growth of brea. This means, in the case of brea, a significant association with local (temperature and rainfall) and global (SOI) climate variables. These results evidenced the growth dynamics of both species and their value for dendroclimatological studies for the first time. [ABSTRACT FROM AUTHOR]

During last decade we surveyed the richness of non-flying mammals of La Pampa Province using different methods that included 4 transects using motor vehicles, trappings (13 sites), bird pellets and carnivore feces analyses (5 sites), interviews with local farmers, and collected road-kill and other remains from locally consumed mammals. We calculated species richness through 0.25° x 0.25° (ca. 616 km2) quadrants, richness and number of records by Phytogeographic Province (PP). We generated 591 records comprising 31 native species included in 27 genera and 12 families, coming from 123 direct observations, 108 trapped specimens, 230 specimens from pellets and feces, and 103 recovered from locals, 21 records were generated from interviews and 6 specimens from the consultation of informal collections. The highest richness was found in the Espinal PP (23 species, with values between 14 and 1 per quadrant), in Monte PP (23 species, with values between 12 and 1 species per quadrant), and in the Pampa PP (16 species, with values between 10 and 1 per quadrant). Of the 30 species recorded, one is categorized for Argentina as Endangered, 2 Vulnerable, 2 Near Threatened, and 1 Data Deficient, while the remainder species are treated as Least Concern. The results updates the distribution of several taxa and are an important source of information to generate conservation measures aimed at resolving conflicts between the local fauna and local inhabitants, or to identify new zones for inclusion in the provincial protected area system. [ABSTRACT FROM AUTHOR]

Aims: Trithrinax campestris is one of the palm species with the southernmost distribution in the Neotropics. Despite that the vegetation types in which T. campestris occurs are nowadays heavily threatened by land use and land cover changes, their floristic composition and structure are still to be documented. In order to characterize T. campestris habitats, the aim of this study was to describe the floristic composition of the vegetation types in which this palm occurs and their relationships with different environmental factors. Study area: The survey was conducted in central Argentina in an area comprising the southern extreme of the distribution of T. campestris in the following phytogeographic areas: Espinal, Lowland and Mountain Chaco. Methods: Following the Braun-Blanquet approach we collected 92 floristic relevés recording a total of 601 vascular plant species. Vegetation was classified through the ISOPAM hierarchical analysis. Bioclimatic and elevation data were related to the floristic data through the ISOMAP ordination. Remote-sensed images (Landsat TM, ETM+ and OLI) were used to characterize the fire frequency in the 92 stands. Results: Four vegetation types that differed in floristic composition and in diagnostic species were discriminated: 1.1 Celtis tala/Sida rhombifolia closed forest; 1.2 Aspidosperma quebracho-blanco/Prosopis kuntzei open forest; 2.1 Jarava pseudoichu/Vachellia caven open savanna; and 2.2 Acalypha variabilis/Nassella cordobensis scrubland. The ISOMAP ordination showed that differences in floristic composition were related to elevation, topography and climatic variables. Out of the 92 stands, only 21 showed the occurrence of fires during the period 1999-2018. Conclusions: Our results evidenced that vegetation types (forests, savannas and scrublands) comprising T. campestris developed in a wide range of environmental conditions. This is the first study that focuses on all vegetation types in which T. campestris occurs in central Argentina and it is relevant for conservation and sustainable management of the only native palm species in the flora of this part of the country. [ABSTRACT FROM AUTHOR]

El tumor de células gigantes espinal es una neoplasia de estirpe benigna y comportamiento local agresivo, de presentación rara en la población pediátrica. El dolor asociado al compromiso neurológico es la presentación típica en niños. La resección amplia del tumor y la descompresión de los elementos neurales asociada a fusión instrumentada permiten obtener una columna estable, preservar o restaurar la función neural y evitar la recidiva tumoral. Se presentan dos pacientes con tumor de células gigantes espinal en esqueleto inmaduro, sometidos a resección y estabilización mediante artrodesis instrumentada, sin recidiva en el posoperatorio alejado. La presentación clínica, la edad de los pacientes y los resultados quirúrgicos a largo plazo hacen de extremo valor el reporte de estos casos en esqueletos inmaduros.

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We present the first record of Promops centralis Thomas, 1915 for Santa Fe province, Argentina. This species was previously known in Argentina only from Formosa province. This new record adds a second province to the distribution of this species in Argentina and a new ecoregion, the Espinal. Furthermore, this record extends the distribution area of P. centralis by almost 610 km to the south and increase to 24 the number of bats species in Santa Fe province. [ABSTRACT FROM AUTHOR]

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We examine the feasibility of improving connectivity between of two dryland woodland types (“espinal”, a savanna type habitat, and sclerophyllous forest) in the Mediterranean climate zone of Chile, for restoration purposes. The restoration approach we examine involves the reintroduction of guanacos (Lama guanicoe) in a “transhumant rewilding” model. The guanacos stimulate the growth of Acacia caven in espinal through browsing, and also provide seed and nutrient dispersal and connectivity between the two woodland types. As in many drylands, degradation is problematic in this region, but clear criteria or maps of degradation are lacking. Thus to assess where restoration is required, how degradation has varied with ENSO across years, and how degraded areas are distributed across the region, we construct an index of woodland condition from Normalized Difference Vegetation Index (NDVI), Net Primary Production (NPP) and evapotranspiration (ET), derived from MODIS data at 1 km resolution for each year between 2000 and 2013 inclusive. We construct a least-cost path for each year, which models the possible transhumant movements of herded guanacos between low and high quality woodlands each year. We find highly fragmented areas of espinal, sclerophyllous forest, and overlap between these, which we identified as sucessional habitat. We also found a fully-connected network linking low-quality and high-quality fragments of all types of woodland in each year. This shows that guanaco transhumant herding has the capacity to be used to create regional connectivity and restoration services.

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BACKGROUND: Extrapulmonary tuberculosis represents a public health problem in Mexico and the pediatric population is a particularly susceptible group. Establishing diagnosis and treatment is a complex process in this age group because only 5% of microscopic studies are positive. CLINICAL CASE: Patient 2 years 3 months with diagnosis of spinal tuberculosis at thoracic level (T7-T9). The evolution was torpid due to the clinical characteristics of the disease and the low response to the different treatments. As diagnostic options, multiple conditions were considered but, finally, the treatment was medical-surgical, with chemotherapy and surgical resection of the lesion, by means of anterior corpectomy, placement of a graft mesh and posterior instrumentation with Luque bar and sub-wiring laminate. CONCLUSION: The neurological deficit and the important evolution of kyphosis make surgical treatment added to chemotherapy the best option. The surgical treatment with double access allowed to stop the evolution of the neurological deficit, indispensable requirement to obtain favorable results. At present, the patient evolves satisfactorily without clinical or radiographic evidence of infection, remains neurologically intact, with adequate development according to their age. [ABSTRACT FROM AUTHOR]

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Highlights • Agriculture will continue to intensify if land users seek profit maximization. • Economic policies may affect land use change patterns less than often assumed. • Road improvement would provide strong incentives to expand agriculture into forest. • Low agricultural profits and higher yields could curb deforestation in marginal areas. • Land-use pressure on priority areas for conservation will stay high. Abstract Agricultural expansion and intensification drive the conversion of natural areas worldwide. Scenarios are powerful tools to explore possible future changes in agricultural land use, how these may affect the environment, and how policies may influence land-use patterns. Focusing on Argentina's prime agricultural areas, the Pampas, Espinal and Chaco, we developed spatially-explicit future land-use scenarios from 2010 to 2030, considering both agricultural expansion (i.e., conversions from woodland to either grazing land or cropland) and agricultural intensification (i.e., conversions from grazing land to cropland). Our simulations were based on an econometric model of net returns, which assumes economically rational land-use actors. Using this model, we assessed the rates and spatial patterns of future land-use change under current land zoning in our study region, and contrasted this with a forecast of future land use based on land-conversion rates from 2000–2010. We systematically tested the impact of economic policies (e.g., taxes or subsidies), infrastructure improvement (e.g., road paving), and technological innovation (i.e., yield increases) on the spatial patterns of land-use conversions. Our model suggests future land-use change will mainly happen along intensification pathways, with deforestation slowing down, if land-use actors would be profit-maximizing. This general pattern did not change even for policy interventions that impacted profits from agriculture in major ways, cautioning against overestimating the leverage that economic policies provide for halting deforestation. Improving the region's road network would create a strong incentive to expand cropland further into remaining woodlands and over grazing lands. However, low agricultural profits and higher yields could curb deforestation in marginal areas to some extent. We also highlight that priority areas for conservation are particularly likely to experience high land-use pressure in the future. Given the lower-than-expected power of economic policies to alter deforestation patterns in our models, zoning, if properly enforced, appears to be a more straightforward tool for avoiding unwanted environmental impacts in the Chaco. [ABSTRACT FROM AUTHOR]

Objetivo: Presentar en una serie de casos los posibles errores técnicos durante el bloqueo epidural, ya que se pueden prevenir y corregir durante el procedimiento. Materiales y métodos: Se evaluaron retrospectivamente, entre enero de 2013 y abril de 2014, 118 pacientes con dolor lumbar y/o radicular tratados con antiinflamatorio/analgésico mínimamente invasivo mediante una inyección selectiva guiada por tomografía computada (TC) en el espacio epidural. En todos los casos se utilizó una aguja espinal 21 G, y se inyectó esteroide de depósito (betametasona 3 mg) y anestésicos (lidocaína 1 ml al 2% + bupivacaína 0,5 ml al 0,5%) o solo esteroide en los pacientes con sospecha de duramadre perforada. Se seleccionaron únicamente aquellos casos en los que hubo errores de técnica durante el procedimiento. Resultados: Cinco pacientes (4,23%) tuvieron complicaciones técnicas durante el bloqueo epidural. Estas se observaron luego de una inadecuada posición del extremo de la aguja (perforación de la duramadre y falta de acceso al espacio epidural) y se objetivaron por la aspiración directa del líquido cefalorraquídeo (LCR) o por la disposición del aire, utilizado como trazador antes de la inyección del medicamento. Los errores se detectaron y corrigieron con rapidez, sin mayores inconvenientes ni necesidad de tratamientos complementarios. Conclusión: El bloqueo epidural es una práctica frecuentemente usada en el manejo del dolor lumbar crónico. Los errores técnicos y las complicaciones del procedimiento son poco comunes, pero para su manejo y posterior corrección es importante conocerlos y contar con un médico experimentado.

Understanding ecosystem processes is vital for developing dynamic adaptive management of human-dominated landscapes. We focus on conservation and management of the central Chilean silvopastoral savanna habitat called “espinal”, which often occurs near matorral, a shrub habitat. Although matorral, espinal and native sclerophyllous forest are linked successionally, they are not jointly managed and conserved. Management goals in “espinal” include increasing woody cover, particularly of the dominant tree Acacia caven, improving herbaceous forage quality, and increasing soil fertility. We asked whether adjacent matorral areas contribute to espinal ecosystem processes related to the three main espinal management goals. We examined input and outcome ecosystem processes related to these goals in matorral and espinal with and without shrub understory. We found that matorral had the largest sets of inputs to ecosystem processes, and espinal with shrub understory had the largest sets of outcomes. Moreover, we found that these outcomes were broadly in the directions preferred by management goals. This supports our prediction that matorral acts as an ecosystem process bank for espinal. We recommend that management plans for landscape resilience consider espinal and matorral as a single landscape cover class that should be maintained as a dynamic mosaic. Joint management of espinal and matorral could create new management and policy opportunities.

Here, we present the first record of Eptesicus brasiliensis argentinus Thomas, 1920 for the province of Entre Ríos, Argentina. This subspecies was originally described as a full species (E. argentinus) based on its morphological features that clearly separate it from all other species of the genus. However, it was later treated as a subspecies of E. brasiliensis by Cabrera (1957), a treatment that was followed by all authors until today. Our record raises the number of bat species for the province of Entre Ríos to 21. This locality represents the fourth record for this subspecies in Argentina, after 35 years since the last known record was obtained. Its geographic range is extended by approximately 130 km to the south, which represents the southernmost known record for this subspecies, and a new ecoregion, the Espinal, is added to its distribution. [ABSTRACT FROM AUTHOR]

Abstract: Question: What are the composition and spatial patterns of native woody plant communities in the southern Great Chaco and Espinal? Location: Córdoba Province, central Argentina, an area of ca. 161,000 km2. Methods: We collected 351 geo‐referenced relevés representative of the geographic, topographic and ecological variation of the Chaco and Espinal woody vegetation in central Argentina. The relevés were classified into vegetation types using the hierarchical ISOPAM method. Forest and shrubland types were described on the basis of diagnostic species occurrences and their distribution in relation to environmental factors. A map of the actual vegetation derived from remote‐sensed images (Landsat) and field data was used to describe the current distribution and abundance of the different vegetation types. Results: The classification of the 351 plots × 837 species matrix revealed two major clusters comprising seven woody vegetation types corresponding to Chaco lowland and mountain forests and shrublands, Espinal forests and edaphic vegetation. The most important gradients in woody vegetation types are related to elevation, temperature and rainfall variables. Conclusions: Subtropical seasonally dry woody plant communities from the southern extreme of the Great Chaco and Espinal forests were described for the first time based on complete floristic data. Our results show that lowland Chaco native forests, as well as replacement communities, are still present in its southern distribution range and are well distinguishable from other vegetation types such as the Espinal and mountain forests. Overall, extensive Espinal forests have almost disappeared while Chaco vegetation is highly fragmented and degraded. [ABSTRACT FROM AUTHOR]

El carpincho (Hydrochoerus hydrochaeris) es el roedor actual más grande del mundo y uno de los mamíferos típico de las Provincias Fitogeográficas Pampeana y del Espinal, habitando todo el sector Este de las mismas. Estas regiones han sido categorizadas por la World Wildlife Foundation (WWF) como áreas "en peligro crítico/ amenazada", y se les asigna el nivel de máxima prioridad de conservación como consecuencia de la destrucción de hábitat, la sobreexplotación, la contaminación y la introducción de especies exóticas. El carpincho presenta una preferencia marcada por los ambientes con abundancia de cuerpos de agua donde la vegetación palustre le proporciona alimento y refugio. De esta forma, tanto los cuerpos de agua como la vegetación asociada es determinante para la prevalescencia de poblaciones de carpinchos en un ambiente determinado. Para la provincia de Santa Fe los registros no son muy abundantes, registrándose hasta la actualidad unos 33 puntos de colecta/observación, la gran mayoría ubicados en el centro y norte de la provincia. El objetivo de la presente contribución es presentar nuevos registros de presencia de Hydrochoerus hydrochaeris en la cuenca del río Carcarañá (sur de la provincia de Santa Fe), y su asociación con algunas variables climático-ambientales y evaluar la distribución de esta especie. Finalmente, se discute la posible expansión o migración de este especie hacia el oeste de esta provincia y de la provincia de Buenos Aires.

Forest fragmentation in agroecosystems is linked to declines of avian species worldwide. Agriculture has greatly reduced native forest cover in east-central Argentina. Assessing the influence of fragmentation on forest bird populations is vital to inform reliable conservation and management strategies for the Espinal region of Argentina. We determined the relationships of vegetation structure within native forest patches, size and shape of these patches (patch scale), composition and spatial configuration (at landscape scale) to relative abundance of 17 forest bird species during austral fall-winter and spring-summer seasons. Birds were sampled from 2007-2009 in 45 forest patches within three landscape mosaics (30 x 30 km) representing a gradient of native forest fragmentation in east-central Argentina. We used an information-theoretic approach and approximated model inference to examine the effect of predictor environmental variables at two spatial scales on patterns of forest bird abundance. Density of trees within forest patches was the main predictor of bird abundance at the patch scale. Amount of forest and spatial configuration were also important. The abundance of several bird species was greater in patches with high density of trees and landscapes characterized by more forest cover and larger patches in close proximity. We found two main avian response patterns to forest fragmentation and patch characteristics. This information contributes reliable knowledge for the design of conservation measures of agricultural landscapes in the Espinal region of Argentina.

In Argentina approximately 280 odonate species have been recorded, which are chiefly found in the north-eastern and north-western regions. With only three previously recorded species, La Pampa province is one of most understudied parts of the country. In the present work we provide a check-list of 17 species from La Pampa, including 14 new records for the province. [ABSTRACT FROM AUTHOR]

Gleditsia triacanthos L. is a woody species native to North America that has invaded Uruguay, Spain, Australia, South Africa and several countries of Central and Eastern Europe. In Argentina, it has become one of the most important invasive woody species and has a high potential to continue spreading. In this study, we review different aspects of G. triacanthos invasion in Argentina that include descriptions of invaded ecoregions and environments, intrinsic characteristics of the species, invasion dynamics and impacts. In addition, we discuss mechanisms that potentially explain its success, control strategies and natural barriers to its invasion. We reviewed a total of 91 articles and book chapters, of which 62 were developed in Argentina. Studies reported that the invasion of G. triacanthos in different ecoregions was favoured by intrinsic characteristics of the species, together with the interaction with cattle and disturbances, which cause negative impacts on flora, fauna and ecosystem processes. Disturbances were proposed as the main mechanism to explain this species' invasion, but other hypotheses such as the release of natural enemies and/or propagule pressure might also be important. Further studies are required, mainly on the impacts on ecosystem processes and on the control, production of organic compounds and mutualistic interactions (with nitrogen-fixing bacteria and mycorrhizal fungi). [ABSTRACT FROM AUTHOR]

The successional pathways linking the Acacia caven-dominated savanna habitat “espinal” and the closed sclerophyllous forest of central Chile have long been debated. Previously, espinal was considered an invasive degradation of closed forest that tended toward desertification, could not be restored to forest, and had little ecological value. Recent GIS (Geographical Information System) research on land-use change has, however, detected apparent regeneration of sclerophyllous forest from espinal. This suggests that there is a successional path linking espinal and sclerophyllous forest. Here, we used surveys of transects in espinals and espinal–sclerophyllous forest transitions to ask whether (1) A. caven is an invasive species or a pioneer species, (2) forest regenerates by sclerophyllous trees “filling in” spaces between A. caven individuals, and then shading them out (plant–plant competition), or (3) forest regenerates by plant–plant facilitation between A. caven and other species, and (4) how current and historical management and condition affect these potential successional mechanisms. We find that A. caven establishes primarily in full sunlight and is unlikely to degrade forests via invasion. We also find, for the first time, evidence that A. caven is a nurse tree to several sclerophyllous forest tree-beneficiary species. Measurements of the under-canopy microhabitat of A. caven, compared to Lithraea caustica, another possible nurse species, suggest that it provides a balance between shade and soil moisture retention, making it a regeneration site not only for directed bird-dispersed seeds but also for undirected wind-dispersed ones. Conservation and restoration of espinals, especially in drier areas, could provide capacity for future dynamic successional pathways in central Chile. [ABSTRACT FROM AUTHOR]

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The diet of the Pampas fox (Lycalopex gymnocercus) in the Province of Buenos Aires. Studies of carnivore diets provide essential information on ecosystem dynamics. The Pampas fox (Lycalopex gymnocercus) is an opportunistic carnivore. From the analysis of stomach content of 70 foxes we described the diet of L. gymnocercus and compared males and females in two rural areas in Buenos Aires Province, one characterized by Espinal habitat (Villarino) and the other by Pampas grassland (Azul). Diet was described using the following indices: relative frequency, frequency of occurrence, biomass contribution and relative abundance. Sexes and locations were compared with indices of diversity and dietary overlap. Our results support the hypothesis of an opportunistic diet where murine rodents were the most frequent item, while the main biomass contribution corresponded to caviomorphs, lagomorphs and carrion. These results suggest that L. gymnocercus is well adapted to rural areas with high levels of disturbance. We recorded a high dietary overlap between males and females without significant differences in prey diversity. Finally, a greater dietary diversity was observed in the Espinal, but dietary overlap was high among foxes from both regions, suggesting incipient homogenization between ecoregions due to increased human activities in these environments. [ABSTRACT FROM AUTHOR]

Context: Amphibians are declining worldwide and land use change to agriculture is recognized as a leading cause. Argentina is undergoing an agriculturalization process with rapid changes in landscape structure. Objectives: We evaluated anuran response to landscape composition and configuration in two landscapes of east-central Argentina with different degrees of agriculturalization. We identified sensitive species and evaluated landscape influence on communities and individual species at two spatial scales. Methods: We compared anuran richness, frequency of occurrence, and activity between landscapes using call surveys data from 120 sampling points from 2007 to 2009. We evaluated anuran responses to landscape structure variables estimated within 250 and 500-m radius buffers using canonical correspondence analysis and multimodel inference from a set of candidate models. Results: Anuran richness was lower in the landscape with greater level of agriculturalization with reduced amount of forest cover and stream length. This pattern was driven by the lower occurrence and calling activity of seven out of the sixteen recorded species. Four species responded positively to the amount of forest cover and stream habitat. Three species responded positively to forest cohesion and negatively to rural housing. Two responded negatively to crop area and diversity of cover classes. Conclusions: Anurans within agricultural landscapes of east-central Argentina are responding to landscape structure. Responses varied depending on species and study scale. Life-history traits contribute to responses differences. Our study offers a better understanding of landscape effects on anurans and can be used for land management in other areas experiencing a similar agriculturalization process. [ABSTRACT FROM AUTHOR]

The replacement of natural vegetation by pastures and extensive crops is generally driven by economic incentives and supported by technology improvements and multiple subsidies. However, towards areas of increasing aridity the productive performance of these replacements may decline from all perspectives – ecological to agronomic to economic – due to intrinsic differences in the structural and physiological adjustment of natural and cultivated vegetation to reduced and fluctuating water availability. We compare natural woody vegetation, perennial C4 pastures and annual crops (maize, soybean and wheat) along a gradient of decreasing precipitation (900–400 mm of annual mean) encompassing the current agricultural frontier of the Dry Chaco and Western Espinal ecoregions of South America. We assess (i) aboveground net primary productivity (ANPP) (ii) yields of product dry mass, edible energy and protein outputs and, (iii) economic gross profits and return of investment. We linked climatic with yield data from national statistics, field trials and empiric models, together with productive parameters and market prices obtained from local consultants and economic bulletins. Maize achieved the highest ANPP of all vegetation covers (+ 42% in average compared to the rest) along the entire precipitation gradient, while the rest of the crops were very similar to natural vegetation. Pastures approached the ANPP of natural vegetation in the humid range, but had the lowest performance below 700 mm (− 15%). Along the entire precipitation gradient, maize was outstanding in mass and edible energy yield while soybean was so in protein production. Soybean had the highest gross profit per hectare (+ 50%) and total capital return of investment (+ 70%). Pastures offered the highest functional capital return of investment (+ 98%; without fixed capital, infrastructure and land value costs), explaining their relevance at the onset of the deforestation process and the gradual prevalence of crops afterwards. While agronomic and economic incentives for natural vegetation replacement remain strong along the whole aridity gradient, crop choice rather than land use system seem to shape the key ecological process of net primary productivity. [ABSTRACT FROM AUTHOR]

Food selection is a key aspect of a bird's life history strategy, so understanding how birds respond to variation in food abundance is relevant to evaluating their general ecology and survival, and also the potential consequences of the degradation of environments impacted by livestock. We studied the dietary ecology of Vermilion Flycatchers (VEFL) and Fork-tailed Flycatchers (FTFL), two insectivores and Neotropical austral migrants, during their breeding season. We worked in areas with and without cattle ranching in the Espinal biome of La Pampa, Argentina. We found different arthropod prey abundance for both flycatchers according to arthropod orders and/or study sites, suggesting that livestock may impact food abundance. Both consumed similar prey and positively selected for hymenopterans and coleopterans, and FTFL also positively selected for orthopterans. VEFL selected nest sites with a lower abundance of heteropterans and FTFL selected sites with a higher abundance of coleopterans. Additionally, VEFL nest survival was negatively related to the abundance of hemipterans and FTFL nest survival was positively related to the abundance of coleopterans. This study helps fill gaps on the general ecology of species that breed in rangelands, and highlights the importance of similar studies to formulate effective conservation planning for the Espinal biome. • We examined dietary ecology of Vermilion Flycatchers and Fork-tailed Flycatchers. • Abundance of some arthropod prey for both varied according to taxa and/or sites. • Cattle ranching may impact food abundance for both flycatchers. • Both species consumed and positively selected for similar arthropod prey. • Abundance of some prey influenced breeding success and nest site selection of both. [ABSTRACT FROM AUTHOR]

En esta contribución se presenta la riqueza específica y abundancia relativa de mamíferos en un remanente de bosque xerófilo en la cuenca media del río Carcarañá (32 ° 582 S – 61 ° 152 O), provincia de Santa Fe, Argentina. Las formaciones vegetales autócto- nas observadas, pertenecientes a la provincia fitogeográfica del Espinal, se caracterizan por presentar una fisonomía del paisaje marcada por variaciones notables en espacios relativa- mente reducidos, a diferencia de lo observado en el entorno predominante. La metodología uti- lizada consistió en el recorrido estandarizado de transectas lineales en busca de signos de actividad (heces, huellas y otras señales indirectas), observaciones directas, entrevistas y utilización de cámaras trampa. La información obtenida a partir de los datos colectados fue empleada para obtener la riqueza específica (S) del lugar. Se registró la presencia de ocho especies comprendidas en ocho familias y cuatro órdenes, siendo los registros indirectos la metodología más efectiva. De acuerdo a la abundancia relativa de las especies registradas, el zorro Pampa (Pseudalopex gymnocercus) es la especie con mayor valor de ocurrencia (0.48 ind/km) mientras que el menor valor está dado por dos especies, el zorrino común (Conepatus ching ) y el carpincho (Hydrochoerus hydrochaeris) con un índice de abundancia de 0.07 ind/km para cada una. Se proporcionan además datos sobre las especies Didelphis albiventris, Myocastor coypus, Chaetophractus villosus, Leopardus geoffroyi y Galictis cuja.