La basura y el ciclo de los materiales

La circulación de los materiales en los ecosistemas es un concepto algo abstracto y difícil de enseñar. En el ciclo natural de los materiales, sustancias como carbono, agua, nitrógeno o calcio se transfieren sucesivamente de vegetales a herbívoros, carnívoros, el suelo y la atmósfera. Durante ese pasaje también se transforman. Ese ciclo resume la vida.Fil: Semmartin, María Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomia; Argentin

Cuidado ambiental : manejo integral de residuos urbanos

Fil: Semmartin, María. Universidad de Buenos Aires. Facultad de Agronomía; Argentina.Fil: Omacini, Marina. Universidad de Buenos Aires; Facultad de Agronomía; Argentina.La enorme producción de residuos domésticos en las\ngrandes ciudades conforma una de las preocupaciones\nambientales más importantes de la sociedad actual.\nEn este contexto, la FAUBA creó en 2008 el programa\nManejo Integral de Residuos por el Ambiente (MIRA),\npara promover la conciencia y el cuidado del ambiente,\nla reducción del consumo de ciertos materiales y el\nmanejo racional de los residuos domésticos

Regional analysis of urban heat islands in Argentina

La urbanización es una de las formas más extremas de cambios en el uso de la tierra y tiene impactos sobre el clima, el agua y la biodiversidad en grandes áreas de todo el planeta. En este trabajo se cuantificaron las islas de calor urbano (ICU) y se relacionaron con características de las ciudades y su entorno a lo largo de gradientes ambientales de la Argentina. Analizamos 55 de las ciudades más grandes del país, ubicadas en 10 ecorregiones, mediante datos satelitales (MODIS) de temperatura de la superficie terrestre, albedo e índices de vegetación (NDVI), y de variables climáticas. La ICU diurna promedio anual de las ciudades argentinas para 2011-2015 fue 0.36±1.99 °C y la nocturna 1.68±0.61 °C. Los principales controles de la intensidad de la ICU fueron el NDVI rural, la precipitación media y la temperatura media durante el día y, en menor medida, la diferencia del albedo durante la noche. Durante el día, algunas ciudades se comportaron como islas de frío urbano (IFU) asociadas a climas áridos o a contextos agrícolas, mientras que durante la noche, todas las ciudades se comportaron como ICU. El efecto atemperador de la vegetación urbana se identificó a partir de la diferencia de NDVI urbano y rural, pero no se observó una relación directa negativa de ICU con NDVI urbano. Los resultados de este trabajo proveen nuevos conocimientos sobre los controles de las ICU y permitiría generar estrategias de desarrollo urbano para mitigar los efectos de la urbanización y mejorar la calidad de vida de la población urbana.Urbanization is one of the most extreme land use changes and has impacts on climate, water and biodiversity in large areas throughout the planet. In this paper, we quantified the urban heat islands (ICU, acronym in Spanish) and its relation to biophysical parameters of the surface of the earth along the main environmental gradients of Argentina. We analyzed 55 of the largest cities in the country, located in 10 ecoregions, using satellite data (MODIS) of land surface temperature, albedo and vegetation indexes (NDVI) and climatic variables. The average annual ICU in the cities for 2011-2015 was 0.36±1.99 °C for the day and 1.68±0.61 °C for the night. The main drivers of the ICU during the day were rural NDVI, mean precipitation and temperature. At night, the main driver was the difference between urban and rural blue albedo. During the day, some cities behaved like urban cold islands (IFU, acronym in Spanish) associated with arid climates or agricultural contexts, while at night, all cities behaved like ICU. The cooling effect of urban vegetation was identified from the difference of urban and rural NDVI, but no direct negative relationship between ICU and urban NDVI was observed. These results provide new insights on the drivers of the ICU and facilitate the generation of urban development strategies to mitigate the effects of urbanization and to improve the quality of life of urban populations.Fil: Casadei, Paula. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal. Cátedra de Forrajicultura; ArgentinaFil: Semmartin, María Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Garbulsky, Martín Fabio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal. Cátedra de Forrajicultura; Argentin

Hipertensión + Manejo sustentable de recursos : Programa 168

Fil: Vázquez, Marisa. Universidad de Buenos Aires. Facultad de Medicina. Escuela de Nutrición; ArgentinaFil: Semmartin, María. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Ecología; ArgentinaEn esta emisión, contamos con la participación de dos invitadas. Por un lado, conversamos con Marisa Vázquez, Dra. de la UBA en el área de Nutrición, docente e investigadora en la Escuela de Nutrición, acerca del consumo de sal y su impacto en la salud de estudiantes universitarios. Por el otro lado, dialogamos con María Semmartin, Prof. Adjunta en la Cátedra de Ecología (FAUBA) y Subdirectora de la Licenciatura en Ciencias Ambientales, sobre estrategias y el manejo sustentable de la energía, el agua y los residuos

Uncultivated margins are source of soil microbial diversity in an agricultural landscape

Agricultural intensification simplified environments, reduced their diversity, and hindered their ecosystem processes. Permanently vegetated areas (uncultivated margins) embedded in the cultivated matrix play a critical role in maintaining diversity and soil properties, and so mitigate the negative impact of intensification. We performed two studies aimed at evaluating the role of uncultivated margins on soil heterotrophic bacteria. In the first study, we sampled soybean fields and herbaceous and woody margins in three locations along a 100-kilometer transect. In a second study, in one location we sampled uncultivated margins and perpendicular 50-meter transects from each margin towards the centre of its adjacent soybean field. As control, we sampled similar transects in soybean fields that had cropped fields as margins. In both studies, we characterized the catabolic profiles and diversity of the heterotrophic bacterial community and soil properties. Soil microbial communities of uncultivated margins differed in composition and were more diverse than the cropped matrix. In turn, these differences positively correlated with soil pH. Woody margins also influenced the soil microbial composition, diversity and soil pH of neighbouring cultivated fields. In contrast, herbaceous margins did not influence their cultivated neighbours. These results broaden our understanding of soil heterotrophic bacterial community in agro-ecosystems and its implications for ecosystem functioning.Fil: D'acunto, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Semmartin, María Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Ghersa, Claudio Marco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

Broad-scale variation of fungal-endophyte incidence in temperate grasses

1.The strength of many interactions between plants and other organisms changes across regional gradients. For example, the relevance of plant-herbivore interactions increases with primary production. Likewise, biotic interactions collectively become more intense from the poles to the equator. Yet, the regional variation of the interaction between grasses and systemic fungal endophytes, which provide resistance to biotic and abiotic environmental factors (i.e. herbivory and drought), is poorly understood.2. We compiled 1008 records of the incidence level of fungal endophytes (Epichlo?e, Ascomycetes: Clavicipitaceae) on wild populations of 48 cool season grasses, encompassing 10 biomes across a broad latitudinal expanse and primary production gradient. Symbiosis incidence was analysed as a function of mean primary production, precipitation, temperature and latitude of each site, which in turn were obtained from climatic and satellital sources.3. Across a 30-fold variation of mean primary production, average symbiosis incidence increased from 20% to 70%. The pattern became stronger when the analysis was restricted to the single grass genus Festuca, which accounted for half of the total data.4. The number of grass populations showing no symbiosis incidence (0%) decreased as primary production increased, whereas those with 100% of incidence increased.5. Primary production at the regional scale was negatively correlated with latitude but positively with mean annual temperature and precipitation. Symbiosis incidence was similarly correlated with latitude and temperature, and it was not with mean annual precipitation. 6. Synthesis. Different descriptors of this grass-fungus symbiosis show that average incidence in wild populations world-wide increases with mean primary production. As at large spatial scales herbivory and temperature increase and aridity decreases with primary production, our results suggest that, at broad-scales, these biotic and abiotic factors may be important drivers of the symbiosis success.Fil: Semmartin, María Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Omacini, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Gundel, Pedro Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Hernández Agramonte, Ignacio M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

The role of grazing intensity and preference on grass-fungal endophyte symbiosis in a Patagonian steppe

The symbiosis between cool-season grasses and fungi of the genus Epichloë is widespread, but highly variable in natural ecosystems. Biotic and abiotic controls underlying its distribution patterns have been difficult to establish, but might be related to a greater capacity of infected plants to deal with drought and herbivory. In this study we examined the relationship between grazing intensity and symbiosis frequency in plant species differentially preferred by herbivores. In all the grass species found in the studied Patagonian steppe, we determined the infection frequency along a grazing gradient by sheep (ungrazed, moderate- and intense-grazing). Three out of five preferred species and one out of four non-preferred species presented the symbiosis. Within the group of species having the symbiosis, intense grazing decreased the infection frequency of the preferred species while the frequency of the non-preferred species remained constant. These changes of infection frequency were correlated with changes in tiller biomass of hosts suggesting that symbiosis frequency could depend on overall plant performance. Our results suggest that high grazing intensity could weaken the relationship between these endophytes and their palatable hosts, eventually making them even more vulnerable to further grazing.Fil: Hernandez Agramonte Caballero, Ignacio Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Semmartin, María Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

Uncropped field margins to mitigate soil carbon losses in agricultural landscapes

Agricultural intensification is a major cause of habitat transformation. Continuous cropping alters ecosystem services, such as biodiversity and carbon sequestration. Empirical evidence from agricultural lands in Argentina has shown that permanently vegetated areas imbedded in the agricultural matrix (uncropped margins) play a critical role in plant and animal communities compared to the usual situation of crops surrounded by other crops (cultivated margins). However, the potential impact of uncropped margins on their own carbon stocks and fluxes and on those of their neighbouring cropped fields remains unknown. We investigated the impact of uncropped (herbaceous and woody) and cropped margins (cultivated fields) on their own topsoil carbon stocks and fluxes and on those of their neighbouring croplands (soybean fields). We identified soybean fields adjacent to one of three possible margin types: herbaceous or woody permanent vegetation, and field crop, which acted as control because it is the most frequent situation in the region. In each of these margin?soybean pairs, we sampled transects from the margin towards the centre of the soybean field (50 m). Woody margins showed the greatest soil carbon content, the least decomposable plant litter and the greatest influence on the neighbouring crop. Conversely, herbaceous margins had the lowest litter accumulation and the most decomposable litter. Only woody margins influenced soil properties in the first metres of the cropped neighbourhood. Centres of soybean fields were similar, irrespective of margin type. The decomposition of common substrates was not affected by margin type. These findings suggest that woody margins are the unique element of the current landscape with a potential to mitigate soil carbon loss from agroecosystems, albeit spatially limited. In contrast, the low biomass and highly decomposable litter of herbaceous margins reveal the urgent need to re-think their current management strategies.Fil: D'acunto, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Semmartin, María Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Ghersa, Claudio Marco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

Seed science in the 21st century: its role in emerging economies

Emerging economies (Brazil, Russia, India, China and other countries) are expected to play a major role in the global economy during the 21st century. Some of these countries have exceptional soil and climate characteristics that determine evident advantages for food production. These features, combined with a rapid adoption of technologies generated by industrialized economies (i.e. transgenic crops and others), have been instrumental to fast expansion of agricultural production in recent years. For such reasons, some of these economies are strongly based on production of food commodities (agriculture represents 18.3, 12.6, 9.4 and 8.1% of the gross domestic product of India, China, Argentina and Brazil, respectively) and have a great share in global food production. Despite the mentioned characteristics that make agricultural activity so efficient in these countries, generation of new technologies in order to guarantee the systems’ sustainability and add value to agricultural production (by means of, for example, royalties or technologies generated with local criteria) relies on research carried out in areas such as crop science, biotechnology, ecology, plant breeding and, of course, seed science. However, the amount of local research carried out in these countries appears not to be in agreement with the importance that agricultural production has in their economies. For example, Argentina produces 16.20% of the soybean produced in the world but only 2% of the scientific literature related to this crop in its many aspects. This imbalance between the weight that agricultural production has on these economies and generation of knowledge in the related disciplines, threatens the sustainability of these economic models and, therefore, of global food production. Seed science, then, is called on to play a major role in these emerging economies, through the different approaches (i.e. ecological, physiological, agronomical and molecular) that the discipline has to offer. Here we provide four examples in which seed science (through any of the four approaches mentioned above): (1) has identified subtle but crucial components of newly adopted production systems; (2) has proposed means for their adjustment in order to secure the sustainability of those systems; and (3) might help to add value to agricultural production through the development of new germplasm displaying specific features (e.g. timing of dormancy release adjusted to industrial necessities).Fil: Benech Arnold, Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Semmartin, María Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Oesterheld, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin