Conservation and management of birds in agroecosystems in east-central Argentina

Tesis para obtener el grado de Doctor of Philosophy, de la University of Georgia, en 2014Bird conservation, and associated ecosystem services, is challenged by agricultural intensification and expansion. In Pampas grassland and Espinal forest ecoregions of east-central Argentina these processes have been ongoing and rapid, requiring the assessment of their impact on biodiversity so as to recommend management alternatives. The objective of this study was to gather evidence to inform decision-making for bird conservation in agroecosystems, focusing on foraging guilds and potential ecosystem services provided. I evaluated the effects of land use on birds at a regional scale in the Pampas and Espinal, using 10 years of a regional bird monitoring program, modeling occupancy with hierarchical multi-species dynamic models using a Bayesian approach. At a local scale, I evaluated factors influencing the use of soybean fields and borders by birds, using bird surveys and arthropod sampling in 78 borders and 20 soybean fields, in four crop stages for two years. I analyzed bird occupancy using multiple-groups single-season models, separating field interior and edges, and fitting Poisson mixed models for counts of the orders of arthropods consumed by birds. I used structured decision making (SDM) to find optimal management strategies to integrate bird conservation with soybean agriculture. I demonstrated how the regional scale results can be used as a tool for decision-making, mapping species-based spatial distributions over time. Although potential ecosystem services offered by birds were distributed throughout the study area, few species could provide them in crop dominated areas. Most raptors, unlike other guilds, were associated with soybean. Most insectivore gleaners seemed unaffected by crops, suggesting their perception of landscape at smaller scales. Birds in soybean fields are mainly those common in agroecosystems, some likely providing pest control service, while most guilds benefited from native trees in borders. Counts of arthropods preyed by birds remained mostly constant throughout the soybean cycle. Finally, I identified the objectives of the SDM process: maximizing insectivorous birds and farmers’ well-being, while minimizing management costs. Reducing insecticide applications in soybean, and either planting trees in borders or no management, were the best decisions dependent on constraints of cost allocation and percent of managed border.Instituto de Recursos BiológicosFil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentin

Density, habitat use, and opportunities for conservation of shorebirds in rice fields in southeastern South America

Worldwide, shorebirds are a major component of rice field avian biodiversity. Rice fields in Argentina and southern Brazil hold large numbers of shorebirds and have been recognized as important areas for migrating or wintering species. To develop successful shorebird conservation strategies, we need to understand geographic variation in shorebird abundance in rice fields as well as how bird use of rice fields varies over the rice growing cycle. We surveyed shorebirds in November and December in the main rice cultivation regions of interior Argentina and coastal Brazil to estimate shorebird densities using distance sampling and to evaluate densities of individual species at different stages of the rice cycle. We detected >7,000 shorebirds in rice fields, including a variety of Nearctic migrants. Density of resident species was generally low and showed no differences between countries. Densities of migratory taxa were higher and varied between Brazil and Argentina. Pectoral Sandpiper (Calidris melanotos) and Lesser Yellowlegs (Tringa flavipes) were the most common species in Argentina, but White-rumped Sandpiper (Calidris fuscicollis) and American Golden-Plover (Pluvialis dominica) were the most common species in Brazil. Pectoral Sandpiper density was nearly 8 times higher in Argentina than in Brazil; densities of the White-rumped Sandpiper and American Golden-Plover were 33 and 25 times higher in Brazil than in Argentina. Shorebird density was highest in lightly flooded paddies with rice height 7000 aves playeras en los campos de arroz, incluyendo una variedad de migrantes neárticos. La densidad de las especies residentes fue generalmente baja y no mostró diferencias entre países. Las densidades de los taxa migratorios fueron mayores y variaron entre Brasil y Argentina. Calidris melanotos y Tringa flavipes fueron las especies más comunes en Argentina, mientras que Calidris fuscicollis y Pluvialis dominica fueron las especies más comunes en Brasil. La densidad de C. melanotos fue casi ocho veces mayor en Argentina que en Brasil; las densidades de C. fuscicollis y P. dominica fueron 33 y 25 veces mayores en Brasil que en Argentina. La densidad de aves playeras fue mayor en los arrozales someramente inundados con alturas de arroz < 20 cm. Nuestros resultados confirman la importancia de los arrozales para las aves playeras en el sudeste de América del Sur y enfatizan la necesidad de evaluaciones detalladas para asegurar que las prácticas de manejo de los agroquímicos y del agua son amigables con la biodiversidad.Instituto de Recursos BiológicosFil: Dias, Rafael Antunes. Universidade Católica de Pelotas. Laboratório de Ecologia e Conservação; BrasilFil: Blanco, Daniel E. Fundación Humedales/Wetlands International; ArgentinaFil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Zaccagnini, Maria Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentin

Occupancy of avian foraging guilds in soybean fields and borders in Entre Ríos, Argentina: responses to vegetation structure and prey resources

Reconciling agriculture and biodiversity conservation is a challenge given the growing demand for agricultural products. In recent decades, Argentina has witnessed agricultural expansion and intensification affecting biodiversity and associated ecosystem services. Within agroecosystems, the level of habitat quality is critical for birds, and may depend on vegetation structure, availability of invertebrate prey, and the use of pesticides. Although the relationship between vegetation structure and avian occurrence has been widely studied, to our knowledge, there are no studies that also incorporate prey availability throughout the cycle of soybean crops in Argentina. We estimated and predicted the effects of land cover and temporal variation on the occurrence of avian foraging guilds in Entre Ríos, Argentina, in order to guide management related to potential ecosystem services provided by birds. We also estimated temporal effects of vegetation structure and insecticides on the main arthropod orders consumed by birds to evaluate prey availability. Methods: We conducted bird and arthropod surveys for 2 years along transects located in 20 randomly selected soybean fields (N = 60) and their adjacent borders (N = 78) throughout the crop growing season, in four seasons. We estimated avian occupancy, accounting for imperfect detection, and arthropod counts fitting generalized linear mixed models. Results: The number of native trees in field borders positively influenced the occurrence of most bird species, mainly insectivores. Granivore foliage gleaners, also were positively affected by grass height. Salliers and aerial foragers were weakly affected by distance to forest and native trees. In general, the availability of invertebrates to birds was highest during the third season. Arthropod counts in borders were greater during the last three crop stages than during the pre-sowing period. Conclusions: We found that with 10 to 15 native tree species in borders, coupled with a complex vegetation structure with shrubs and grasses, we could conserve a wide spectrum of insectivorous birds, and may contribute to the invertebrate pest control service. Vegetated field borders function as a refuge for arthropods, especially agriculturally beneficial taxa such as Hymenopterans. Finally, several groups of birds use the interior of the fields and could help control pests.Instituto de Recursos BiológicosFil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina. University of Georgia. D.B. Warnell School of Forestry and Natural Resources; Estados UnidosFil: Conroy, Michael J. University of Georgia. D.B. Warnell School of Forestry and Natural Resources; Estados UnidosFil: Varni, Vanina Delia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Thompson, Jeffrey. Guyra Paraguay – CONACYT; Paraguay. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina.Fil: Zaccagnini, Maria Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentin

Trade-offs between biodiversity and agriculture are moving targets in dynamic landscapes

1. Understanding how biodiversity responds to intensifying agriculture is critical to mitigating the trade-offs between them. These trade-offs are particularly strong in tropical and subtropical deforestation frontiers, yet it remains unclear how changing landscape context in such frontiers alters agriculture?biodiversity trade?offs.2. We focus on the Argentinean Chaco, a global deforestation hotspot, to explore how landscape context shapes trade-off curves between agricultural intensity and avian biodiversity. We use a space-for-time approach and integrate a large field dataset of bird communities (197 species, 234 survey plots), three agricultural intensity metrics (meat yield, energy yield and profit) and a range of environmental covariates in a hierarchical Bayesian occupancy framework.3. Woodland extent in the landscape consistently determines how individual bird species, and the bird community as a whole, respond to agricultural intensity.Many species switch in their fundamental response, from decreasing occupancy with increased agricultural intensity when woodland extent in the landscape is low (loser species), to increasing occupancy with increased agricultural intensity when woodland extent is high (winner species).4. This suggests that landscape context strongly mediates who wins and loses along agricultural intensity gradients. Likewise, where landscapes change, such as in deforestation frontiers, the very nature of the agriculture?biodiversity trade?offs can change as landscapes transformation progresses.5. Synthesis and applications. Schemes to mitigate agriculture?biodiversity trade?offs,such as land sparing or sharing, must consider landscape context. Strategies that are identified based on a snapshot of data risk failure in dynamic landscapes, particularly where agricultural expansion continues to reduce natural habitats. Rather than a single, fixed strategy, adaptive management of agriculture?biodiversity trade?offs is needed in such situations. Here we provide a toolset for considering changing landscape contexts when exploring such trade-offs. This can help to better align agriculture and biodiversity in tropical and subtropical deforestation frontiers.Fil: Macchi, Leandro. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Decarre, Julieta. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; ArgentinaFil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; ArgentinaFil: Mastrangelo, Matias Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Laboratorio de Agroecología; ArgentinaFil: Blendinger, Pedro Gerardo. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Gavier Pizarro, Gregorio. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Murray, Francisco. Instituto Nacional de Tecnología Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria San Luis. Agencia de Extensión Rural San Luis; ArgentinaFil: Piquer Rodríguez, María. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Semper Pascual, Asunción. Humboldt-universitat Zu Berlin. Geography Department.; AlemaniaFil: Kuemmerle, Tobias. Humboldt-universitat Zu Berlin. Geography Department.; Alemani

Herramienta para analizar la relación entre la toma de decisiones y el mantenimiento de los servicios ecosistémicos: Estudio de caso en bosque nativo de ñire de patagonia norte.

La toma de decisiones sobre el manejo de los sistemas socio-ecológicos que producen Servicios Ecosistémicos (SE) son complejas por los plazos, las interacciones de los factores intervinientes, y las percepciones de los actores. Este trabajo tiene como objetivo proponer una metodología que permita integrar los conocimientos sobre los procesos de cambio de los ecosistemas y los de toma de decisión, resaltando el rol de los SE. Mediante un taller de expertos, y basándonos en información preexistente y cálculos ad hoc, se integraron tres propuestas metodológicas: (1) los Modelos de Estados y Transiciones, que modelan el comportamiento del ecosistema, sus caminos de degradación y recuperación; (2) la definición y cuantificación de los SE provistos por cada uno de los estados del ecosistema, considerando los SE finales, los beneficios y el valor monetario de los mismos y (3) los modelos de Toma de Decisiones basado en estadística bayesiana, que considera los objetivos finales mediante una matriz de valoración; los objetivos intermedios, y las decisiones de manejo posibles que impactan sobre estos. La propuesta se ejemplifica con bosques de Nothofagus antárctica de Patagonia norte.Decision making about the management of socio-ecological systems that produce Ecosystem Services (ES) are complicated by the terms, number of factors involved in the processes and their interactions, and perceptions of the actors. This paper aims to propose a methodology to integrate knowledge about the processes of ecosystem change and decision making, highlighting the role of SE. Through a workshop of experts, and based on existing information and calculations ad hoc three methodological proposals were integrated: (1) Models States and Transitions, modelling ecosystem behaviour, its ways of degradation and recovery; (2) the definition and quantification of the ES provided by each of the states of the ecosystem, considering the final ES end, benefits and monetary value and (3) A Decision Making Models, based on Bayesian networks which considers the final objectives through a matrix of values; intermediate objectives and possible management decisions that impact on them. The proposal is exemplified by Nothofagus antarctica forests of northern Patagonia.EEA Santa CruzFil: Rusch, Verónica Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Forestal. Grupo de Ecología Forestal; Argentina.Fil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina.Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Lopez, Dardo Ruben. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Campo Anexo Villa Dolores; Argentina.Fil: Lopez, Dardo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Claps, Leonardo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina.Fil: Sarasola, Mauro Miguel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina.Fil: Cardozo, Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Agencia de Extensión Rural El Bolsón; Argentina.Fil: Rusch, Graciela Mónica. Norwegian Institute for Nature Research (NINA). Trondheim; Norueg

Primera aproximación a los daños por cotorras (Myiopsitta monachus) y su manejo en cultivos de pecán (Carya illinoinensis) en Argentina

Conocer las percepciones y experiencias sobre el daño por cotorras y su manejo en cultivos de pecán en nuestro país nos ayuda a orientar la investigación y el desarrollo de tecnologías de manejo adecuadas al contexto local de producción del cultivo.EEA ParanáFil: Canavelli, Sonia Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Paraná; ArgentinaFil: Cuatrin, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Paraná; ArgentinaFil: D´Alessio, Mariana. Asociación Civil Regional. Cluster de la Nuez Pecán; ArgentinaFil: Fracassi, Natalia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Gonzalez, Adrian Claudio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Grassi, Ana Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Ferrer, José Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concepción del Uruguay. Agencia de Extensión Rural Villaguay; ArgentinaFil: Frusso, Enrique Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Peyrou, Alejandro. Cámara Argentina de Productores de Pecán; ArgentinaFil: Poitevin, Adriana. Asociación Civil Regional. Cluster de la Nuez Pecán; ArgentinaFil: Zaccagnini, María Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Profesional Asociado; Argentin

Benznidazole biotransformation and multiple targets in <i>Trypanosoma</i> cruzi revealed by metabolomics

&lt;b&gt;Background&lt;/b&gt;&lt;p&gt;&lt;/p&gt; The first line treatment for Chagas disease, a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, involves administration of benznidazole (Bzn). Bzn is a 2-nitroimidazole pro-drug which requires nitroreduction to become active, although its mode of action is not fully understood. In the present work we used a non-targeted MS-based metabolomics approach to study the metabolic response of T. cruzi to Bzn.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methodology/Principal findings&lt;/b&gt;&lt;p&gt;&lt;/p&gt; Parasites treated with Bzn were minimally altered compared to untreated trypanosomes, although the redox active thiols trypanothione, homotrypanothione and cysteine were significantly diminished in abundance post-treatment. In addition, multiple Bzn-derived metabolites were detected after treatment. These metabolites included reduction products, fragments and covalent adducts of reduced Bzn linked to each of the major low molecular weight thiols: trypanothione, glutathione, γ-glutamylcysteine, glutathionylspermidine, cysteine and ovothiol A. Bzn products known to be generated in vitro by the unusual trypanosomal nitroreductase, TcNTRI, were found within the parasites, but low molecular weight adducts of glyoxal, a proposed toxic end-product of NTRI Bzn metabolism, were not detected.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions/significance&lt;/b&gt;&lt;p&gt;&lt;/p&gt; Our data is indicative of a major role of the thiol binding capacity of Bzn reduction products in the mechanism of Bzn toxicity against T. cruzi

First test for eradication of beavers (Castor canadensis) in Tierra del Fuego, Argentina

The North American beaver (Castor canadensis) was introduced in 1946 from Canada to Isla Grande de Tierra del Fuego to develop a fur industry. Their expansion to most of the habitats of Tierra del Fuego and their presence on the continent, moved Argentina and Chile to test their eradication. The objective of this paper is to analyse a pilot eradication test and determine which variables are associated with the capture success of beavers in a small area of the Fuegian forest. The pilot was conducted in the Corazón de la Isla reserve, Tierra del Fuego, Argentina, during April and May 2014, by three groups of trappers, using body-grip traps and snares. The capture success was modelled with different variables. A total of 115 individuals were captured after 590 and 265 body-grip and snare trapping-nights, respectively, with an overall efficiency of 13.5%. Using body-grip traps and placing traps in slides or burrows would increase trapping efficiency. This experience allowed us to evaluate techniques and generate recommendations for future beaver eradication trials on a larger scale: (a) the need to improve the data collection system through digital technology and georeferencing the location of operations, (b) the importance of the type of trap used according to the specific sites of the colony, (c) test alternative trapping strategies to reduce the eventual “learning” of animals, (d) drive the paradigm of hunters from yield oriented to eradication objectives and (e) ensure the political sustainability of the wider program.Instituto de Recursos BiológicosFil: Jusim, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Universidad Nacional de Tierra del Fuego. Instituto de Ciencias Polares, Ambiente y Recursos Naturales; ArgentinaFil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Escobar, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Carranza, María Luisa. Provincia de Tierra del Fuego. Dirección General de Áreas Protegidas y Biodiversidad; ArgentinaFil: Schiavini, Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego. Instituto de Ciencias Polares, Ambiente y Recursos Naturales; Argentina. Wildlife Conservation Society, Argentinian Representation; Argentin

Ecosystem services to support environmental and socially sustainable decision-making

The theory of ecosystem services (ES) needs to be operationalized to contribute to practices leading to sustainable use of ecosystems, which includes solving trade-offs between private and public benefits and incorporating monetary and non-monetary values to help inform decisions. We developed a framework to analyse the impacts of farmers’ management alternatives on Nothofagus antarctica (G. Forst.) Oerst. forest in northern Patagonia, and analysed synergies and trade-offs between private and public benefits based on three conceptual and methodological approaches: a) a state-and-transition model of ecosystem dynamics, and b) indicators of values of ecosystem service benefits based on the cascade model, implemented as c) a decision support tool based on a Bayesian network. We optimized a utility function for short (0-10 yr) and long (70-140 yr) term management decisions (levels of grazing, logging and tree planting) based on monetary and non-monetary indicators of benefits that fulfilled “farmer’s satisfaction” objectives. We then assessed the consequences of these decisions on the fulfilment of public benefits as defined by the National Forest Law when projected into short (0-10 yr), intermediate (10-40 yr) and long (70-140 yr) time horizons. We found that when short-term decisions are projected into a long-time horizon, they lead to high losses of benefits, mainly linked to “regulating and maintenance” ES. On the other hand, long-term decisions improved the level of benefits in degraded systems but resulted in the degradation of well-preserved forests. The decisions that optimize farmer’s satisfaction did not change with different weights of “farm income” in the utility function, indicating the absence of trade-offs between monetary and non-monetary benefits considered in the utility function. The tool developed helps to show long-term impacts of management, and discloses cause-effect relationships between levels of use and multiple benefits. It can therefore support measures aiming to raise awareness about degradation trends, and improve the functional understanding of the system wich can help to identify solutions for socio-economic and environmental sustainability.La teoría de los servicios ecosistémicos debe hacerse operativa para poder contribuir a la formulación de prácticas que conduzcan al manejo sustentable de los ecosistemas. Esto incluye contribuir a resolver los conflictos entre beneficios privados y públicos, e incorporar valores monetarios y no-monetarios para poder informar la toma de decisiones. Desarrollamos un modelo para analizar el impacto de las decisiones de manejo de los productores en el bosque de Nothofagus antarctica (G. Forst.) Oerst. del norte de la Patagonia y analizamos las sinergias y los conflictos entre los beneficios públicos y privados en base a tres marcos conceptuales y metodológicos: a) un modelo de estados y transiciones de la dinámica del ecosistema, y b) indicadores de los servicios ecosistémicos generados sobre la base del modelo de cascada, implementado como c) un sistema de apoyo a la toma de decisiones basado en redes Bayesianas. Optimizamos la función de utilidad sobre decisiones de manejo (niveles de pastoreo, extracción de madera y plantación de árboles), para lo cual nos apoyamos en indicadores de beneficios monetarios y no monetarios que satisfacen los objetivos del productor a corto (0-10 años) y largo (70-140 años) plazo. Luego, determinamos las consecuencias de las soluciones cercanas al óptimo en términos de satisfacción de beneficios públicos de acuerdo con su formulación en la Ley Nacional de Bosques. Encontramos que cuando las decisiones que optimizan los beneficios a corto plazo se proyectan en el tiempo (70-140 años), resultan en pérdidas altas de beneficios, especialmente, los ligados a servicios ecosistémicos de “regulación y mantenimiento”. Por otro lado, las decisiones que optimizan los beneficios a largo plazo mejoran el nivel de beneficios en los estados degradados, pero al mismo tiempo, desmejoran la condición del bosque en buen estado de conservación. Las decisiones que optimizan la satisfacción del productor no cambian con los distintos pesos de la variable ‘ingreso predial’, indicando que no existe conflicto entre los beneficios monetarios y no-monetarios en la función de utilidad. La herramienta desarrollada ayuda a visualizar los impactos a largo plazo y revela relaciones de causa-efecto entre los niveles de uso y los múltiples beneficios generados por el sistema. Por ello, puede asistir a formular medidas que generen conciencia sobre las tendencias de degradación y contribuir, de este modo, a identificar soluciones para lograr la sustentabilidad socioeconómica y ambiental.Estación Experimental Agropecuaria Bariloche. Área Sistemas Forestales. Grupo de Ecología ForestalFil: Rusch, Verónica Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Sistemas Forestales. Grupo de Ecología Forestal; ArgentinaFil: Rusch, Graciela Mónica. Norwegian Institute for Nature Research; NoruegaFil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Varela, Santiago Agustín. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barilohe. Área Sistemas Forestales. Grupo de Ecología Forestal; ArgentinaFil: Claps, Leonardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentin

Bird occupancy in intensively managed agroecosystems under large-scale organic and conventional farming in Argentina: A multi-species approach

Several studies in European and North American agroecosystems conclude that organic farming benefits birds compared to conventional farming. Nevertheless, there are some biases toward these geographic regions and farm size. Argentinian agroecosystems are particularly homogeneous with large arable fields and sparse uncultivated field margins (i.e. large-scale homogenous cropping systems). In Argentina only 0.55% of the total farmland is under organic farming. Thus, our aims were to assess differences in bird occupancy between organic versus conventional farming regimes, and whether bird occupancy varied in relation to annual crop proportion in both farming regimes in central Argentina agroecosystems. We surveyed 156 points in farms under conventional and 154 in organic farming regimes during two bird-breeding seasons. We used multi-species occupancy models with a Bayesian approach to estimate bird occupancy. We observed that the type of farming regime (organic in relation to conventional) had a weak effect on avian occupancy, varying by species and groups. Probability of occupancy was higher for a few insectivorous and omnivorous species but lower for carnivores in organic farms in relation to conventional ones. The proportion of annual crops was positively correlated with occupancy of an insectivore aerial forager, some insectivore foliage gleaners, a granivore, and some omnivorous species in organic farms, but not conventional farms. This work contributes to reducing geographic and small-scale heterogeneous cropping system biases in the avian agroecological literature. Our results, together with future studies needed to assess landscape configuration and composition, and resource availability for birds in each farming regime, will allow the evaluation of organic farming as a tool for the conservation of bird species in large-scale homogeneous cropping systems in temperate regions.Instituto de Recursos BiológicosFil: Contreras, Facundo. Universidad Nacional de Río Cuarto. Departamento de Ciencias Naturales. Grupo de Investigación en Ecología Comportamental y Poblacional; ArgentinaFil: Contreras, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Coda, José Antonio. Universidad Nacional de Río Cuarto. Departamento de Ciencias Naturales. Grupo de Investigación en Ecología Comportamental y Poblacional; ArgentinaFil: Coda, José Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Serafini, Vanesa. Universidad Nacional de Río Cuarto. Departamento de Ciencias Naturales. Grupo de Investigación en Ecología Comportamental y Poblacional; ArgentinaFil: Serafini, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Priotto, Jose Waldemar. Universidad Nacional de Río Cuarto. Departamento de Ciencias Naturales. Grupo de Investigación en Ecología Comportamental y Poblacional; ArgentinaFil: Priotto, Jose Waldemar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin