1,721,003 research outputs found
Caracterización de los nichos ecológicos y organización de las comunidades de roedores cricétidos en la región pampeana
Get PDFFil: Bilenca, David Norberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Caracterización de los nichos ecológicos y organización de las comunidades de roedores cricétidos en la región pampeana
No full textFil: Bilenca, David Norberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Can we produce more beef without increasing its environmental impact? Argentina as a case study
No full textWe analyse the current and future environmental impact of beef in Argentina, comparing four environmental dimensions (GHG, ecotoxicity, erosion and biodiversity) across 21 cow-calf systems and 47 finishing systems. The cow-calf and the finishing stages contributed equally to beef production, but impacts varied between stages (70 % of soil erosion and 75 % of GHG emissions occurred during the cow-calf stage, whereas 72 % of impact on biodiversity and 99 % of pesticide ecotoxicity occurred during the finishing stage). More intensive systems showed higher ecotoxicity and impact on biodiversity, and lower emissions and erosion per kg of beef than the more extensive systems. However, the intensity of this trade-off varied regionally, being more noticeable in the central regions of the Pampas and less so in the peripheric non-pampean regions. We also projected future beef production and environmental impacts under different production scenarios and found that it might be possible to increase beef production in Argentina by 15 % without a significant increase in the environmental impact of the sector (given a reduction of the ecotoxicological impact of crop production). We also showed that this could be achieved by adopting available practices and that the sector's self-set goals are compatible with this scenario.Fil: Gonzalez Fischer, Carlos Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Bilenca, David Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
Aves en rastrojos
No full textEl deficiente mantenimiento y la inadecuada operación de cosechadoras y medios de transporte de granos no solo producen en la agricultura pampeana la pérdida de unos 4 millones de toneladas anuales de granos de distintos cultivos que quedan en los rastrojos sin recolectar; contribuyen además a mantener significativas poblaciones de aves que pueden ser dañinas para dichos cultivos.Fil: Zufiaurre, Emmanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Codesido, Mariano. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; ArgentinaFil: Abba, Agustin Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Bilenca, David Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
Avian assemblages associated with different grasslands managements in cattle production systems in the pampas of Argentina
Get PDFModifications in the structure of grasslands have been responsible for the decline of several avian species due to a reduced quality in available habitat. Currently, applications of the herbicide glyphosate have been introduced to promote winter forage production in the Flooding Pampas of Argentina. Rotational grazing has been another technique used to promote winter forage production. Here, we evaluated different grasslands managements in cattle production systems on species richness, composition, and abundance of bird assemblages in grasslands Pampas. We put emphasis on responses of two neartic migratory shorebirds, the Buff-breasted Sandpiper (Calidris subruficollis) and the American Golden Plover (Pluvialis dominica). The three treatments on natural grassland were: (1) paddocks of Ryegrass growth promotion through the application of herbicide glyphosate; (2) paddocks managed with Rotational grazing, and 3) paddocks managed with Continuous grazing. We considered three periods of the breeding cycle of the birds (early, late, post-breeding) for two years (2011/2012, 2012/2013). Vegetation cover lower than 10 cm was greater in both Rotational and Continuous grazing sites in comparison to the ryegrass promotion sites. A NMDS analysis revealed a clear separation in structure of bird communities among the three grazing treatments. The abundance of total birds and of short grassland birds was lower in grasslands with Ryegrass promotion. An indicator species analysis revealed the associations of shorebirds with Rotational and Continuous grazing sites. Grassland management with glyphosate application had an effect on the structure of assemblages of grassland birds in the Flooding Pampas, which was negative particularly with Nearctic migrants of conservation importance.Fil: Codesido, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Bilenca, David Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
Responses of birds to planting of Lotus tenuis pasture in the Flooding Pampas, Argentina
Get PDFThe Flooding Pampas is the most important livestock region of Argentina, but is a region where replacement of originally natural, perennial tussock grasses by pasture species is changing the heterogeneity of the grassland system. We evaluated the response of grassland bird assemblages of the Flooding Pampas to planting of Lotus tenuis (Lotus) pasture, which mainly modifies vegetation structure by reducing vertical heterogeneity. Species richness and abundance of birds were compared between fields of Lotus pasture and semi-natural grasslands. Avian species richness and abundance were both greater in semi-natural grassland than in Lotus pasture. When grouped by nesting habits (grassland specialists, generalists), species richness and abundance of grassland specialists was greater in semi-natural grassland, whereas richness and abundance of generalist species was greater in Lotus pasture. An indicator-species analysis showed that five grassland birds were closely linked to semi-natural grassland vegetation, with two of those species – Hudson’s Canastero (Asthenes hudsoni) and Bay-capped Wren-Spinetail (Spartonoica maluroides) – of conservation concern In contrast, generalist species, such as Southern Lapwings (Vanellus chilensis) and Burrowing Owls (Athene cunicularia), were associated with Lotus pasture. Planting of Lotus pasture has negative effects on species that naturally occur in tussock grassland. Grassland management methods, such as intercropping and rotational grazing, could help reconcile the effects of livestock production and the conservation grassland bird conservation in the Flooding Pampas.Fil: Agra, Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Grupo de Estudios sobre Biodiversidad en Agroecosistemas; ArgentinaFil: Bilenca, David Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Grupo de Estudios sobre Biodiversidad en Agroecosistemas; ArgentinaFil: Codesido, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Grupo de Estudios sobre Biodiversidad en Agroecosistemas; Argentin
Spatial segregation among pampas deer and exotic ungulates: A comparative analysis at site and landscape scales
Get PDFThe pampas deer (Ozotoceros bezoarticus) is native to South America and is endangered in Argentina. In Buenos Aires province, Argentina, the last population of pampas deer is harbored in the Bahía Samborombón Wildlife Refuge (BSWR), which includes protected areas and numerous cattle ranches. This population has been declining and changing progressively in its distribution since 1985, and negative interactions between pampas deer and introduced ungulates (livestock and feral pigs) have been proposed among the main causes of its decline. We examined the abundance, distribution, and interactions among pampas deer, cattle, and feral pigs at site and landscape scales in the BSWR. At the site scale, coexistence between pampas deer and cattle at the same paddock was only possible at moderate stocking rates (0.2-0.4 AU/ha), and no deer were recorded at paddocks when stocking rates were above 0.6 AU/ha. Pampas deer and feral pigs co-occurred more frequently, but deer switched their behavior and increased levels of surveillance in response to proximity of feral pigs. At the landscape scale, a clear spatial segregation and differential distribution was detected among pampas deer, cattle, and feral pigs along the BSWR. Our results suggest that the current distribution of pampas deer at the study area is a consequence of avoiding contact with both livestock and feral pigs at the site scale. Thus, negative interactions recorded between pampas deer and introduced ungulates at the site scale were expressed at the landscape scale. Both in situ and ex situ conservation efforts are urgently needed to conserve pampas deer.Fil: Perez Carusi, Lorena Cynthia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Avellaneda; ArgentinaFil: Beade, Mario S.. Administración de Parques Nacionales; ArgentinaFil: Bilenca, David Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
Human attitudes as threats in amphibians: the case of the Ornate Horned Frog (Ceratophrys ornata)
No full textWe analyzed the characteristics of the human-animal conflict coming from the attitudes that local communities have toward Ceratophrys ornata, focusing on two threats: aversion and pet trade. Surveys conducted in Argentina, Brazil and Uruguay (n = 194) showed a strong aversion to this species (45% of respondents), causing the death of at least 364 individuals. This aversion was strongly linked to symbolism and folklore beliefs, and also influenced by gender and education level. Pet trade interviews (n = 30) showed that 77% of the specimens kept in captivity were wild-caught (≈178 individuals). The killing of specimens based on aversion might have impacts at local level, especially in populations occurring in recent urbanized areas. Our results also revealed that capture of specimens for pet trade is an ongoing process. Due to the context of illegality in which trade occurs, it is highly challenging to determine/predict the extent of impacts.Fil: Deutsch, Camila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Grisolia, Jimena. Universidad de Buenos Aires; ArgentinaFil: Bilenca, David Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Agostini, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
Grazing for biodiversity: Assessing the effects of cattle management practices on wetlands and amphibian communities in central Argentina
No full textArgentina is widely recognized as a key player in the production and consumption of beef, occupying a prominent position in the global context. However, there is a lack of comprehensive research on the environmental consequences of beef production, particularly concerning wetlands and aquatic biodiversity. We aim to assess the effects of cattle management practices (grazing types and stocking density) on wetland attributes and associated amphibian diversity in central Argentina. During two amphibian breeding seasons, we surveyed 117 wetland sites in paddocks with different cattle grazing types (continuous grazing, glyphosate-promoted pastures and rotational grazing) and stocking densities (low and high). We analyzed the effects of cattle management practices on wetland attributes, including water quality parameters, nutrient concentrations, wetland morphometry, and vegetation cover. Effects on amphibian communities were explored using richness, abundance, and species occurrence. General Mixed-effects Models revealed significant increases in nutrients (total solid dissolved, total nitrogen and soluble reactive phosphorous) and a significant decrease in vegetation cover in sites with high cattle stocking density. Likewise, we observed increased soluble reactive solids in wetlands associated with rotational grazing and decreased vegetation cover in those wetlands related to glyphosate-promoted pastures. Generalized Mixed-effects Models revealed that amphibian communities were negatively affected mainly by high stocking density, while abundance and species occurrence of hylids (Boana pulchella and Scinax squalirostris) were also affected by glyphosate-promoted pastures and rotational grazing treatments. Our results indicate that different types of grazing at low stocking density favor amphibian diversity and improve wetland water quality, therefore, reduced stocking density may result in improved wetland conditions and more diverse amphibian communities. Our results also suggest that glyphosate-promoted pastures and rotational grazing, although beneficial in terms of pasture management, may have unintended consequences on water quality in wetlands and amphibian communities. This study will contribute to our understanding of how cattle management practices influence wetland ecosystems and aquatic biodiversity in the most important cattle breeding area of South America, providing valuable insights for conservation efforts in cattle ranching landscapes.Fil: Agostini, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Bilenca, David Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
Influence of grazing intensity on avian assemblages in espartillares of Samborombon Bay, Argentina
Get PDFLas modificaciones en la estructura de los pastizales han sido responsables del declive de variasespecies de aves debido a la reducción de la calidad del hábitat disponible. En la Pampa Deprimida (Argentina) los espartillares de Spartina densiflora son marginalmente productivos para el ganado bovino y existe variación en la intensidad de su uso por los productores ganaderos. Aquí comparamos las respuestas de la abundancia y la riqueza de la avifauna en espartillares con diferentes cargas ganaderas en la Bahía de Samborombón. Los tratamientos fueron: 1) espartillares con carga baja (0.4 vacas/ha), y 2) espartillares con carga alta (0.8 vacas/ha). Se consideraron tres períodos del ciclo reproductivo de las aves (temprano, tardío, post-reproducción) durante dos años (2011/2012, 2012/2013). Los sitios con altas cargas tuvieron mayor cobertura de vegetación en el estrato menor a 11 cm y menor altura con respecto a los sitios con bajas cargas ganaderas. La riqueza y la abundancia total de las aves fueron 23% y 29.5% menores en pastizales con altas cargas, respectivamente. También la riqueza y la abundancia de las aves de pastizales altos fueron 60% y 61% menores en pastizales con altas cargas, respectivamente. Los pastoreos con alta carga afectan sustancialmente las abundancias deespecies del pasto alto como el Espartillero Enano (Spartonoica maluroides) y la Ratona Aperdizada (Cistothorus platensis). Se sugiere preservar espartillares con estructura alta (> 70 cm) y densa de la vegetación, manteniendo algunos potreros o zonas del potrero en escanso/exclusión, en lugar de un ajuste general de la carga para todo el establecimiento.Changes in the structure of grasslands have been responsible for the decline of several avian species due to the reduction in the quality of available habitat. In the Flooding Pampas (Argentina), espartillares of Spartina densiflora are marginally productive areas for cattle rearing and show great variation in the intensity of their use by ranchers as grazing areas. In this work we compare the responses in abundance and richness of avifauna in espartillares with different stocking rates in the Samborombón Bay area. Our treatments were: 1) plots with low stocking rate (0.4 cows/ha), and 2) plots with high stocking rate (0.8 cows/ha). Our study covered three periods of the birds’ breeding cycle (early, late, post-reproduction) over two years (2011/2012, 2012/2013). The sites with high livestock rate had greater vegetation coverage in the stratum lower than 11cm and lower height with respect to the sites with low livestock loads. Species richness and total abundance of birds were 23% and 29.5% lower, respectively, in grasslands with high livestock rates. Also, species richness and abundance of tall grassland species were 60% and 61% lower, respectively, in grasslands with high livestock rates. High stocking grazing substantially affects the abundances of tall grass specialist species such as the Bay-capped Wren-spinetail (Spartonoica maluroides) and the Sedge Wren (Cistothorus platensis). We encourage to preserve espartillares with high structure (> 70 cm) and dense vegetation, keeping some paddocks or paddock areas in rest/exclusion, instead of a general adjustment of the animal stocking rates for the entire establishment.Fil: Codesido, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Grupo de Estudios sobre Biodiversidad en Agroecosistemas; ArgentinaFil: Bilenca, David Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Grupo de Estudios sobre Biodiversidad en Agroecosistemas; Argentin
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