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In recent decades, climate change has gained interest in the international scientific community due to the constant increase in the concentration of greenhouse gases (mainly CO2) and its consequences in various states in the economic, social, and environmental fields. Simultaneously, world energy demand has been growing hand in hand with economic and demographic development worldwide. In this sense, nations have been choosing to diversify their energy matrixes in order to reduce their dependence on fossil fuels, betting on different renewable energy alternatives. This review aims to describe the current state of the Latin American region in terms of the deployment of installation and use of renewable energy alternatives to carbon sources. Dualities stand out between nations such as Paraguay or Costa Rica which almost entirely consume their energy from renewable sources and others such as Trinidad and Tobago which still depend mainly on non-renewable sources and must invest efforts in energy diversification. Similarly, there is an organized group among Latin American states in favor of renewable energy development called "Renewables in Latin America and the Caribbean (RELAC)".

Se realizó el diagnóstico de los flujos nacionales de los envases rígidos de PET mediante un Análisis de Flujo de Materiales (AFM) y la validación de los resultados con los actores claves relacionados a la industria de este producto en el Perú. Se estimó una producción nacional de envases rígidos de PET de 237.5 mil toneladas, donde el 0.4% serían envases retornables, el 10.2% residuos reciclados, el 50.7% importaciones y el 38.7% corresponderían a los que ingresan conteniendo productos importados y al stock de períodos anteriores. Respecto a las salidas, se calcula que el 80.5% retornó o se dispuso como residuo en un periodo menor al año; y el 19.5% se exportó. Centrándonos en los residuos, alrededor del 78.1% se perdió en rellenos sanitarios y en botaderos, en tanto que el 21.9% se recicló; donde solo el 12.2% fue destinado para producir nuevos envases rígidos de PET. Respecto al AFM de los plásticos se estima que el 9.1% de la producción total de plásticos retorna a la economía y que la tasa de reciclaje asciende al 15% respecto a los residuos de plástico postconsumo generados, aunque solo el 13% se mantuvo en la economía nacional. A pesar de la promulgación de la Ley de Plásticos de un solo uso en diciembre de 2018 y la modificatoria de la Ley de Residuos aprobada en 2020, con lo que se esperaba un aumento en la valorización nacional del plástico de un solo uso, es posible que no se haya logrado debido a la pandemia del coronavirus. Abstract The diagnosis of the national flows of rigid PET containers was carried out by means of a Material Flow Analysis (AFM) and the validation of the results with the key players related to the industry of this product in Peru. A national production of rigid PET containers of 237.5 thousand tons was estimated, where 0.4% would be returnable containers, 10.2% recycled waste, 50.7% imports and 38.7% would correspond to those that enter containing imported products and the stock of periods previous. Regarding the exits, it is calculated that 80.5% returned or were disposed of as waste in a period of less than a year; and 19.5% was exported. Focusing on waste, around 78.1% was lost in landfills and dumps, while 21.9% was recycled; where only 12.2% was destined to produce new rigid PET containers. Regarding the AFM of plastics, it is estimated that 9.1% of the total production of plastics returns to the economy and that the recycling rate amounts to 15% with respect to the post-consumer plastic waste generated, although only 13% remained in the national economy. Despite the enactment of the Single-use Plastics Law in December 2018 and the amendment to the Waste Law approved in 2020, with which an increase in the national valorization of single-use plastic was expected, it is possible that has not been achieved due to the coronavirus pandemic. Keywords: Material Flow Analysis-plastics-recycling-Circular Economy.

Se realizó el diagnóstico de los flujos nacionales de los envases de vidrio mediante un Análisis de Flujo de Materiales, y la validación de los resultados con los actores clave relacionados a la industria de envases de vidrio en el Perú. Se identificó que, en 2018, circularon 632,5 mil toneladas de envases de vidrio, de las cuales el 52.1% (329.5 mil toneladas) correspondía a envases retornables, el 41,1% (259,7 mil toneladas) a envases de fabricación nacional, el 3,6% (22,9 mil toneladas) a importaciones, y el 3,2% (20,4 mil toneladas) al mercado ilegal. Respecto a las salidas, el 83,5% (528,0 mil toneladas) de los envases de vidrio fue retornado al productor o dispuesto como residuo en un periodo menor a un año; el 6,5% (41,1 mil toneladas) permaneció en uso por un periodo mayor a un año, y el 10% (63,4 mil toneladas) se exportó. Centrándonos en los residuos de envases de vidrio postconsumo del mercado nacional formal (178,1 mil toneladas), el 73,9% (131,5 mil toneladas) se perdió en rellenos sanitarios y en botaderos, en tanto que el 26,1% (46.5 mil toneladas) se valorizó. Esta última cifra desciende a 23,4% si también se considera el consumo de productos de procedencia ilegal. Se estima que alrededor de la mitad de los residuos de estos envases estaría en Lima.

Herbivory is one of the most globally distributed disturbances affecting carbon (C)-cycling in trees, yet our understanding of how it alters tree C-allocation to different functions such as storage, growth or rhizodeposition is still limited. Prioritized C-allocation to storage replenishment vs growth could explain the fast recovery of C-storage pools frequently observed in growth-reduced defoliated trees. We performed continuous 13C-labeling coupled to clipping to quantify the effects of simulated browsing on the growth, leaf morphology and relative allocation of stored vs recently assimilated C to the growth (bulk biomass) and non-structural carbohydrate (NSC) stores (soluble sugars and starch) of the different organs of two tree species: diffuse-porous (Betula pubescens Ehrh.) and ring-porous (Quercus petraea [Matt.] Liebl.). Carbon-transfers from plants to bulk and rhizosphere soil were also evaluated. Clipped birch and oak trees shifted their C-allocation patterns above-ground as a means to recover from defoliation. However, such increased allocation to current-year stems and leaves did not entail reductions in the allocation to the rhizosphere, which remained unchanged between clipped and control trees of both species. Betula pubescens and Q. petraea showed differences in their vulnerability and recovery strategies to clipping, the ring-porous species being less affected in terms of growth and architecture by clipping than the diffuse-porous. These contrasting patterns could be partly explained by differences in their C cycling after clipping. Defoliated oaks showed a faster recovery of their canopy biomass, which was supported by increased allocation of new C, but associated with large decreases in their fine root biomass. Following clipping, both species recovered NSC pools to a larger extent than growth, but the allocation of 13C-labeled photo-assimilates into storage compounds was not increased as compared with controls. Despite their different response to clipping, our results indicate no preventative allocation into storage occurred during the first year after clipping in either of the species.

Wheat is one of the most important cereal food crops in the world today. The productivity and quality of this crop is greatly affected by environmental conditions during grain filling. In this study, we have analyzed two genotypes of durum wheat, Blanqueta and Sula (traditional and a modern wheat respectively) in pre-industrial, current and future [CO2]. Plant growth and physiological parameters were analyzed during anthesis and grain filling in order to study the capacity of these plants to create new sinks and their role during the process of the acclimation of photosynthesis. It was observed that plants underwent photosynthetic acclimation at pre-industrial and future [CO2] (up and down-regulation respectively). However, the modern genotype averts the process of down-regulation by creating a new carbon sink (i.e. the spike). Here, we have shown the essential role that the spike plays as a new sink in order to avert the down-regulation of photosynthesis at future [CO2]. Moreover, we have demonstrated that at future [CO2] the growth response will depend on the ability of plants to develop new sinks or expand existing ones This study was supported by Ministerio de Educación y Ciencia de Espana˜ research project CGL2009-13079-C02-02. SA thanks the financial support of Ministerio de Educación y Ciencia de Espana˜ (BES-2010-032433)

Perennial rhizomatous grasses are regarded as leading energy crops due to their environmental benefits and their suitability to regions with adverse conditions. In this paper, two different experiments were carried out in order to study the salinity (S) and water stress (WS) effects on biomass production in giant reed (Arundo donax L.). In Experiment 1, eight clones of giant reed were subjected to four salinity (S) and water stress (WS) treatments: (1) well watered with non-saline solution, (2) water stress with non-saline solution, (3) well watered with saline solution and 4) water stress with saline solution. In Experiment 2, five clones of giant reed were subjected to increasing S levels in two locations: University of Catania (UNICT-Italy) (1) well watered with non-saline solution and (2) well watered with mild saline solution; and University of Barcelona (UB-Spain) (3) well watered with non-saline solution and (4) well watered with severe saline solution. Photosynthetic and physiological parameters as well as biomass production were measured in these plants. According to our data, giant reed seems to be more tolerant to S than WS. Both stresses mainly affected stomatal closure to prevent dehydration of the plant, eventually decreasing the photosynthetic rate. The differential performance of the giant reed clones was ranked according to their tolerance to S and WS by using the Stress Susceptibility Index. 'Agrigento' was the most WS resistant clone and 'Martinensis' was the most S resistant. 'Martinensis' and 'Piccoplant' were found to be the most suitable clones for growing under both stress conditions. Moreover, 'Fondachello', 'Cefalú' and 'Licata' were the most resistant clones to increasing S levels.