Since the first finding of Ehrlichia chaffeensis in the Argentinian marsh deer populations in 2018, we have conducted ongoing surveillance efforts to better understand the ecological and epidemiological dynamics of this zoonotic tick-borne pathogen in the region. Over a period of 7 years (2018–2024) we analyzed blood and tissue samples from 40 marsh deer (Blastocerus dichotomus) and 13 parasitic Amblyomma triste ticks in the Paraná River Delta, Argentina. We identified E. chaffeensis DNA in two deer blood samples and in the salivary glands of three A. triste ticks parasitizing one of those deer. The approach used for E. chaffeensis detection in the tick sample ensured that the identified DNA came from an active tick infection, not residual host blood in the gut. After sequencing generic genes (16S ribosomal RNA [rRNA], 23S rRNA and groEl) and the specific E. chaffeensis variable-length polymerase chain reaction target (VLPT) molecular marker, we identified a genotype previously reported in Argentina. This first-time contemporary detection of zoonotic E. chaffeensis in both a wild vertebrate host and its parasitic generalist ticks in a natural setting, provides direct evidence of a putative transmission cycle in Argentina, highlighting the need of implementing multidisciplinary surveillance systems.

Bats worldwide play significant roles in ecosystem functions, encompassing pollination, seed dispersal, and pest control while concurrently serving as diseases reservoirs. As part of a comprehensive wildlife health surveillance effort, bats were systematically sampled within two national protected areas in Argentina. During this study 67 bats were examined and samples were collected from eight Molossus spp. individuals exhibiting conspicuous yellowish or white lesions on their noses. All samples were cultured on Sabouraud dextrose agar and lactrimel agar for fungal growth evaluation. Fungal isolates were identified using morphologic and molecular taxonomic techniques, leading to the detection of Microascus sp. in three Molossus rufus from Ibera National Park and Cephalotheca sp. in five Molossus molossus from Marsh Deer National Park. No fungal growth was identified in samples collected from the healthy hairs of the bats displaying lesions on their noses. The two fungi, which have not previously been isolated from bats, should be considered potentially pathogenic, evidenced by diseased hairs in the affected individuals.

Monitoring wildlife health is essential for understanding global disease patterns, particularly as vector-borne infections extend the geographic ranges and thereby hosts due to environmental shifts. Anaplasma marginale, primarily impacting cattle, has economic implications and has been found in diverse hosts, yet its presence in capybaras (Hydrochoerus hydrochaeris), influential in tick-borne pathogen spread, lacks comprehensive understanding. From 2015 to 2022, 14 capybaras were surveyed across two different areas of northeastern Argentina. In 1 of 14 (7%) capybaras, the presence of A. marginale was confirmed through the amplification of specific genes, msp5 and msp1β. In addition, A. marginale DNA was detected in the capybara's blood sample through quantitative PCR, with a cycle threshold value of 30.81 (800 copies per reaction). Amplification of a fragment of the msp1α gene revealed PCR products of three different sizes, suggesting the presence of at least three coinfecting A. marginale variants in the capybara host. This study suggests that capybaras are wild hosts for A. marginale in the Ibera Wetlands in Argentina, potentially influencing the infection dynamics of both domestic and wild species. This finding highlights the necessity for thorough studies on the role of capybaras in disease dynamics, crucial for understanding wildlife health and the spread of disease.

Hantavirus Pulmonary Syndrome (HPS) is an emerging infectious disease caused by orthohantaviruses in the Americas. In Argentina, since 1995, several reservoirs and virus variants have been described, but the northeastern and central endemic zones in the country include an area without human or rodent infections, despite sharing rodent species with areas with that disease. The aim of this study was to search for orthohantavirus in rodent communities that inhabit this area, which borders two endemic areas of HPS. Small rodents were captured in June of 2022 through a total effort of 644 trap nights distributed in five grids located in the Iberá National Park, Corrientes, Northeastern Argentina. All rodents were sexed, weighed, and the species was recorded. Blood samples were extracted to detect ANDV-specific immunoglobulin G (IgG), and to extract the RNA virus. Trimmed sequences were mapped against reference sequences from GenBank. We captured a total of 36 Oligoryzomys flavescens and 15 Oxymycterus rufus. We detected the O. flavescens species infected with Lechiguanas orthohantavirus in the camping area of the National Park. A nucleotide comparison with previously published sequences shows a 98.34% similarity to the virus obtained from a human case of HPS reported in the adjacent Misiones province. This study demonstrated, for the first time, that O. flavescens is a host of the Lechiguanas orthohantavirus in this zone and contributes to closing information gaps on the distribution of orthohantavirus in Argentina. Additionally, the high similarity with the hantavirus found in the human case of Misiones suggests that the reservoir in that province would also be O. flavescens (not previously confirmed). This information permits us to focus on the preventive measurements to protect the human population.

Los cambios en la distribución geográfica de carnívoros son reportados cada vez con mayor frecuencia. En Argentina Cerdocyon thous habita el centro-este y norte del país. Recientemente, su distribución se ha extendido hacia el sur y fue reportado por primera vez hace 12 años en el delta del Paraná, provincia de Buenos Aires. Entre 2020 y 2022 realizamos un monitoreo de fauna en la Reserva Natural de Uso Múltiple Isla Martín García utilizando trampas cámara. Se informa el primer registro de C. thous en el área protegida, a unos 45 km del registro más austral reportado para la especie.

La contaminacion ambiental y la creciente presion antropica sobre los ecosistemas naturales han producido una disminucion significativa de numerosas poblaciones de fauna silvestre a nivel mundial. En los paises del Cono Sur, especialmente Paraguay, Brasil y Argentina, se practica una intensa actividad agricola asociada a la aplicacion de plaguicidas. Estas sustancias pueden movilizarse a traves de compartimentos ambientales, generando contaminacion e impactando negativamente a la fauna local. Este proyecto se enmarca en un estudio mas amplio que evalua, desde 2015, eventos de mortalidad de fauna en dos humedales de Argentina: los Esteros del Ibera y el Delta del Parana. Durante estos eventos, ciervos de los pantanos (Blastocerus dichotomus) y capibaras (Hydrochoerus hydrochaeris) han sido las especies mas frecuentemente afectadas. Estudios previos de los eventos de mortalidad revelaron su condicion multifactorial y una asociacion con condiciones ambientales desfavorables, altas cargas parasitarias y mala condicion corporal en los animales afectados. Dado que el efecto de los contaminantes ambientales aun no ha sido evaluado, el objetivo principal de este estudio es estudiar la contaminacion por plaguicidas en dos humedales de Argentina, analizando el efecto de bioconcentracion que estas sustancias producen en poblaciones animales que sufren episodios de mortalidad. Se utilizara una estrategia de vigilancia de sitios centinela basada en eventos de mortalidad previos y actuales, para determinar la variabilidad temporal y espacial de la contaminacion ambiental por plaguicidas. A campo, se tomaran muestras de agua, sedimentos, suelo y vegetacion con dragas Eckman, muestreadores Corer y equipos multiparametricos sobre las que se cuantificaran concentraciones de plaguicidas. Adicionalmente, se realizaran muestreos de animales rescatados y necropsias de animales encontrados muertos en cuyos tejidos se cuantificara la presencia de estos contaminantes junto con otros parametros sanitarios. En el laboratorio, los extractos seran analizados por cromatografia gaseosa o liquida, utilizando como detectores espectrometros de masas de cuadrupolo o de tiempo de vuelo. Los resultados obtenidos a futuro permitiran evaluar correlaciones entre la contaminacion ambiental, el estado sanitario de ciervos y capibaras y los eventos de mortalidad que afectan a sus poblaciones. Se espera encontrar concentraciones detectables de plaguicidas tanto en matrices ambientales como en tejidos de ciervos y capibaras, en correlacion negativa con parametros sanitarios como el score corporal de estos animales. Este trabajo tiene el potencial de iniciar esfuerzos pioneros para comprender y monitorear el rol de los plaguicidas en la salud de los ecosistemas y la fauna asociada, fortaleciendo la red de vigilancia establecida y generando indicadores que contribuyan al abordaje integral de los eventos de mortalidad, promoviendo acciones para la conservacion de la biodiversidad y la salud ecosistemica en los humedales de Argentina. Abstract Environmental pollution and increasing anthropic pressure on natural ecosystems have resulted in a significant decline in numerous wildlife populations worldwide. In the Southern Cone countries, especially Paraguay, Brazil and Argentina, there is an intense agricultural activity associated with the application of pesticides. These substances can be mobilized through environmental compartments, generating pollution and negatively impacting local fauna. This project is part of a broader study that assesses, since 2015, fauna mortality events in two wetlands in Argentina: the Ibera Wetlands and the Parana Delta. During these events, swamp deer (Blastocerus dichotomus) and capybaras (Hydrochoerus hydrochaeris) have been the most frequently affected species. Previous studies of mortality events revealed their multifactorial condition and an association with unfavorable environmental conditions, high parasite loads, and poor body condition in affected animals. Given that the effect of environmental pollutants has not yet been evaluated, the main objective of this study is to study pesticide contamination in two wetlands in Argentina, analyzing the bioconcentration effect that these substances produce in animal populations that suffer mortality episodes. A sentinel site surveillance strategy based on previous and current mortality events will be used to determine the temporal and spatial variability of environmental contamination by pesticides. In the field, samples of water, sediments, soil and vegetation will be taken with Eckman dredges, Corer samplers and multiparametric equipment on which pesticide concentrations will be quantified. Additionally, samples of rescued animals and necropsies of animals found dead will be carried out in whose tissues the presence of these contaminants will be quantified along with other health parameters. In the laboratory, the extracts will be analyzed by gas or liquid chromatography, using mass spectrometers of quadrupole or time of flight. The results obtained in the future will allow evaluating correlations between environmental pollution, the health status of deer and capybaras and the mortality events that affect their populations. It is expected to find detectable concentrations of pesticides both in environmental matrices and in tissues of deer and capybaras, in negative correlation with health parameters such as the body score of these animals. This work has the potential to initiate pioneering efforts to understand and monitor the role of pesticides in the health of ecosystems and associated fauna, strengthening the established surveillance network and generating indicators that contribute to the comprehensive approach to mortality events, promoting Actions for the Conservation of Biodiversity and Ecosystem Health in Wetlands of Argentina. Keywords: Environmental pollution - Wetlands - Pesticides - Fauna mortality surveillance network - Blastocerus dichotomus.

El cambio climatico asociado al calentamiento global y a multiples actividades antropicas tiene profundas implicancias en la transmision de las enfermedades vectoriales. En ambientes modificados pueden darse cambios en la ecologia de los vectores y hospedadores/reservorios silvestres, ocurriendo alteraciones del equilibrio hospedador-vector-parasito, y modificandose la dinamica de transmision y la distribucion geografica de algunas enfermedades. En Argentina, episodios graves de mortalidad han alterado a la fauna silvestre en los Esteros del Ibera y el Delta del Parana durante los ultimos anos, siendo los ciervos de los pantanos (Blastocerus dichotomus) y los capibaras (Hydrochoerus hydrochaeris) las especies mas afectadas. Uno de los hallazgos mas relevantes de estos eventos es la multifactorialidad, en la que se combinan condiciones ambientales adversas y coinfecciones por multiples agentes patogenos transmitidos por vectores, como Trypanosoma evansi, hallado infectando ciervos muertos. Este parasito es un protozoario transmitido por tabanos y murcielagos hematofagos, que causa una enfermedad mortal en algunas especies domesticas y silvestres, mientras que en otras especies, como los capibaras, podria hallarse de forma asintomatica con una alta frecuencia en poblaciones silvestres. El objetivo de este proyecto es investigar el ciclo de transmision de T. evansi en dos humedales de Argentina. Se propone determinar la frecuencia e intensidad de infeccion por T. evansi en capibaras y ciervos de los pantanos, su ocurrencia en vectores y su asociacion con variables ambientales. Tambien se analizan las coinfecciones y el rol de este agente en los episodios de mortalidad. A campo se realiza el muestreo de ciervos y capibaras muertos, y un muestreo simultaneo de tabanos, garrapatas y murcielagos. En el laboratorio, los tejidos y artropodos colectados se analizan mediante tecnicas parasitologicas y moleculares. Se realizan PCRs dirigidas a un fragmento del gen 18SrRNA para Trypanosoma sp., y en paralelo se evaluaran molecularmente las coinfecciones haciendo target en otros genes. La intensidad de infeccion por T. evansi y su variacion estacional y anual se analiza estadistica y espacialmente mediante el uso de un software especifico. Los resultados obtenidos permitiran profundizar los conocimientos sobre la eco-epidemiologia de T. evansi en ambientes silvestres de Argentina, complementando el abordaje integral de los episodios de mortalidad de fauna en el area. Abstract Climate change associated with global warming and multiple anthropic activities has profound implications for the transmission of vector diseases. In modified environments, there may be changes in the ecology of wild vectors and hosts/reservoirs, with alterations of host-vector-parasite balance occurring, and the dynamics of transmission and geographical distribution of some diseases may be modified. In Argentina, severe mortality episodes have altered wildlife in the Ibera Andean Esteros and the Parana Delta in recent years, with marsh deer (Blastocerus dichotomus) and capybaras (Hydrochoerus hydrochaeris) being the most affected species. One of the most relevant findings of these events is multifactorial that combine adverse environmental conditions and co-infections by multiple vector-borne pathogens, such as Trypanosoma evansi, found infecting dead deer. This parasite is a protozoan transmitted by tabanos and hematophageal bats, which causes a deadly disease in some domestic and wild species, while other species such as capybaras, it could be found asymptomatically with a high frequency in wild populations. The objective of this project is to investigate the transmission cycle of T. evansi in two wetlands in Argentina. It is proposed to determine the frequency and intensity of T. evansi infection in capybaras and deer in swamps, their occurrence in vectors, and their association with environmental variables. Co-infections and the role of this agent in mortality episodes are also discussed. In the field, deer and dead capybaras are sampled, and simultaneous sampling of brooms, ticks, and bats is performed. In the laboratory, collected tissues and arthropods will be analyze using parasitological and molecular techniques. PCRs targeting an 18SrRNA gene fragment for Trypanosoma sp. are performed, and in parallel, co-infections had molecularly evaluated by targeting other genes. The intensity of T. evansi infection and its seasonal and annual variation are analyzed statistically and spatially by using specific software. The results obtained will allow to deepen knowledge about the eco-epidemiology of T. evansi in wild environments of Argentina, complementing the comprehensive approach of wildlife mortality episodes in the area. Keywords: eco-epidemiology, vector-borne diseases, Hydrochoerus hydrochaeris, Blastocerus dichotomus, Trypanosoma evansi.

This chapter describes the main vegetation units of Peninsula Valdes at scale 1:250,000 with emphasis on relevant physiognomic and floristic characteristics. Based on photogrammetry (aerial photograph pairs 1:60,000) and ground check, 18 dominant singular plant species arrangements (vegetation units) were identified reflecting the variety of environmental conditions at a mesoscale (1:250,000) within Peninsula Valdes. At sites selected for ground check, floristic-physiognomic census including a complete floristic plant species list with the relative abundance of each species were performed. After that, censuses of species abundance were ordered by principal component analysis. The layer structure, the main life forms and the dominant species for each identified and mapped vegetation unit were described. Among them, we identified shrubby vegetation units at northern and central Peninsula Valdes and, grassy vegetation units at southern Peninsula Valdes. A map of vegetation units and some pictures of the most representative vegetation units complete the vegetation description. Moreover, this chapter includes a detailed description of the plant communities (resolution scale 1:1) characterizing four sites identified as priorities for ecosystem conservation. Priority sites for conservation are located in Salt marshes, Uplands and Plain Systems and Endorheic Basins. Some contrasts between conserved and degraded community states are also exemplified.

In semiarid rangelands where the anthropogenic impact is currently increasing, as occurs in the rangelands of the Peninsula Valdes, the detrimental impacts of soil degradation on land resources became really dramatic. This chapter presents a review on the current knowledge of soil degradation in the Peninsula Valdes rangelands. Section 1 introduces the chapter, Sect. 2 focuses on soil degradation main processes, factors and causes, and Sect. 3 presents a review of soil degradation assessment methods and several soil degradation studies carried out since 1990 in the Peninsula Valdes region. Water and wind erosion are the degradation processes that are most strongly evidenced. Major causes of soil degradation are attributed to a combination of climatic and anthropic factors, with overgrazing being perceived to be a major factor. Four key causes associated with overgrazing in the Peninsula Valdes region rangelands are described: (1) Poor range management with respect to flock distribution and overstocking, (2) Limited access to information, (3) Top-down and largely ineffective government policy, and (4) Overdependence on grazing systems for sustained livelihoods. Assessment methods for assessing soil degradation include: expert judgment, remote sensing, productivity changes, field monitoring, pilot studies at farm level based on field criteria and expert opinion, and modeling.

Fil: Pazos, Gustavo Enrique. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Centro Nacional Patagonico. Instituto Patagonico para el Estudio de los Ecosistemas Continentales; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina

This paper presents an approach to explicitly determinate optimal stocking rates based on trade-offs between guanaco density and livestock grazing intensity on rangelands of Patagonia, Argentina. As sheep farming becomes less profitable in this region, farmers and ranchers need to focus on sustainable wildlife harvesting as alternative income generation. We developed a methodology for spatially-explicit assessment and mapping of stocking rates based on tradeoffs and synergies between ecosystem services and livestock grazing intensity on rangelands. Forage use for livestock production, carbon sequestration, wildlife conservation and soil erosion are the ecosystem services and disservices evaluated over a gradient of grazing intensity. We show how rangelands stocking rate determination can be converted into a multi-objective optimization problem that can be solved using a Fuzzy Multi-Objective Linear Programing (MOLP).

Understanding spatial and temporal patterns of burned areas at regional scales, provides a long-term perspective of fire processes and its effects on ecosystems and vegetation recovery patterns, and it is a key factor to design prevention and post-fire restoration plans and strategies. Standard satellite burned area and active fire products derived from the 500-m MODIS and SPOT are avail - able to this end. However, prior research caution on the use of these global-scale products for regional and sub-regional applica - tions. Consequently, we propose a novel algorithm for automated identification and mapping of burned areas at regional scale in semi-arid shrublands. The algorithm uses a set of the Normalized Burned Ratio Index products derived from MODIS time series; using a two-phased cycle, it firstly detects potentially burned pixels while keeping a low commission error (false detection of burned areas), and subsequently labels them as seed patches. Region growing image segmentation algorithms are applied to the seed patches in the second-phase, to define the perimeter of fire affected areas while decreasing omission errors (missing real burned areas). Independently-derived Landsat ETM+ burned-area reference data was used for validation purposes. The correlation between the size of burnt areas detected by the global fire products and independently-derived Landsat reference data ranged from R 2 = 0.01 - 0.28, while our algorithm performed showed a stronger correlation coefficient (R 2 = 0.96). Our findings confirm prior research calling for caution when using the global fire products locally or regionally.

Ecological sites are the basic entity used in rangeland health assessment. This study evaluates the synergistic use of multi- and hyper-spectral satellite imagery for sub-pixel classification of ecological sites in semiarid rangelands. Hyperion and Landsat enhanced thematic mapper (ETM) data are included in a two-step procedure to mapping ecological sites in Patagonian rangelands of Argentina. Firstly, mixture tuned matched filtering and logistic regression analyses are used for Hyperion data processing to obtain ecological site probability images in the area covered by hyperspectral imagery. Secondly, artificial neural networks are applied to model the relationships between the spectral response patterns of Landsat and the probability images from Hyperion, and used to map ecological sites over the entire study area. Overall classification accuracy was 81% (kappa=0.77) with relatively high accuracies for all ecological sites demonstrating that their spectral signatures are sufficiently distinct to be detectable. Better accuracies were obtained for shrub steppes with desert pavement (producer's and user's accuracies of 89% and 84%, respectively), and shrub-grass steppes associated to tertiary calcareous outcrops (producer's and user's accuracies of 100% and 86%, respectively), while poorer accuracies resulted for shrub-grass steppes on old alluvial plains (producer's and user's accuracies of 75% and 56%, respectively). Fuzzy maps of ecological sites as presented in this research can provide rangeland managers with a tool to stratify the landscape and organize ecological information for rangeland health assessment and monitoring, prioritizing and selecting appropriate management actions, and promoting the recovery of areas degraded in these environments.

We focus on Shannon Entropy (SE) for the characterization of polarimetric Synthetic Aperture Radar (PolSAR) images. This approach analyzes the information contribution made by individual pixels to the whole image for assessment of land degradation in the information content of ALOS PALSAR images. Additionally, the performance of other polarization parameters, and polarization decomposition is illustrated and discussed. Dual-Pol and Quad-Pol scenes have been acquired under the SAOCOM (Satelite Argentino de Observacion con Microondas, Spanish for Argentine Microwaves Observation Satellite) project in 2010 and 2011, from northeastern Patagonian coastal desert, Argentina. The accuracy of the SE map was assessed using a set of ground observations based on remotely sensed data that have higher accuracy. The results show that the SE can describe and determine the image features more obviously in the study area, so that it represents an important reference value for land degradation detection and land status characteristics extraction.

Land cover maps at different resolutions and mapping extents contribute to modeling and support decision making processes. Because land cover affects and is affected by climate change, it is listed among the 13 terrestrial essential climate variables. This paper describes the generation of a land cover map for Latin America and the Caribbean (LAC) for the year 2008. It was developed in the framework of the project Latin American Network for Monitoring and Studying of Natural Resources (SERENA), which has been developed within the GOFC-GOLD Latin American network of remote sensing and forest fires (RedLaTIF). The SERENA land cover map for LAC integrates: 1) the local expertise of SERENA network members to generate the training and validation data, 2) a methodology for land cover mapping based on decision trees using MODIS time series, and 3) class membership estimates to account for pixel heterogeneity issues. The discrete SERENA land cover product, derived from class memberships, yields an overall accuracy of 84% and includes an additional layer representing the estimated per-pixel confidence. The study demonstrates in detail the use of class memberships to better estimate the area of scarce classes with a scattered spatial distribution. The land cover map is already available as a printed wall map and will be released in digital format in the near future. The SERENA land cover map was produced with a legend and classification strategy similar to that used by the North American Land Change Monitoring System (NALCMS) to generate a land cover map of the North American continent, that will allow to combine both maps to generate consistent data across America facilitating continental monitoring and modeling.

Los objetivos de este trabajo fueron estimar la distribucion geografica potencial de una especie invasora, la Lobesia botrana, a escala regional en Argentina y simular la distribucion temporal de la especie en el marco de un potencial escenario de establecimiento y dispersion de la misma en el pais. Se categorizaron y delimitaron cartograficamente areas de riesgo diferencial mediante la utilizacion de un enfoque ecologico deductivo. Utilizando estadisticas climaticas diarias, se simulo para Argentina un modelo fenologico de la especie, validado previamente en Grecia. Los resultados indican que L. botrana podria potencialmente establecerse y completar al menos tres generaciones anuales en las zonas vitivinicolas del este de Cuyo y el noroeste argentino, mientras que las zonas vitivinicolas del Alto Valle de la Patagonia presentaria un bajo riesgo de establecimiento. Este analisis de riesgo territorial permitiria optimizar la planificacion espacio-temporal de las actividades de monitoreo preventivo de la especie por parte de los organismos de fiscalizacion fitosanitaria de Argentina.

The objectives of this study were to estimate the potential geographical distribution of Lobesia botrana in Argentina at regional scale and to simulate the temporal distribution of the specie, through a phenology model, in the context of a potential scenario of dispersion of the species across the country. Differential risk areas were categorized and delimited cartographically using a deductive approach. A phenological model, previously validated for this species in Greece, was simulated using daily weather statistics for Argentina. Results suggested that L. botrana could potentially be established and complete annually at least three generations in the eastern Cuyo and NOA vineyard areas, while in the vineyard regions of the Patagonian High Valley, L. botrana could have a lower risk of establishment. This geographical risk analysis would optimize spatio-temporal planning of preventive monitoring activities of the species by the phytosanitary control agencies of Argentina.