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66 Pag., 5 Fig. The definitive version is available at: http://www.sciencedirect.com/science/journal/00128252 Mediterranean areas of both southern Europe and North Africa are subject to dramatic changes that will affect the sustainability, quantity, quality, and management of water resources. Most climate models forecast an increase in temperature and a decrease in precipitation at the end of the 21st century. This will enhance stress on natural forests and shrubs, and will result in more water consumption, evapotranspiration, and probably interception, which will affect the surface water balance and the partitioning of precipitation between evapotranspiration, runoff, and groundwater flow. As a consequence, soil water content will decline, saturation conditions will be increasingly rare and restricted to periods in winter and spring, and snow accumulation and melting will change, especially in the mid-mountain areas. Future land management will be characterized by forest and shrub expansion in most Mediterranean mountain areas, as a consequence of farmland and grazing abandonment, with increasing human pressure localized only in some places (ski resort and urbanized of valley floors). In the lowlands, particularly in the coastal fringe, increasing water demand will occur as a consequence of expansion of irrigated lands, as well as the growth of urban and industrial areas, and tourist resorts. Future scenarios for water resources in the Mediterranean region suggest (1) a progressive decline in the average streamflow (already observed in many rivers since the 1980s), including a decline in the frequency and magnitude of the most frequent floods due to the expansion of forests; (2) changes in important river regime characteristics, including an earlier decline in high flows from snowmelt in spring, an intensification of low flows in summer, and more irregular discharges in winter; (3) changes in reservoir inputs and management, including lower available discharges from dams to meet the water demand from irrigated and urban areas. Most reservoirs in mountain areas will be subject to increasing water resource uncertainty, because of the reduced influence of snow accumulation and snowmelt processes. Besides, reservoir capacity is naturally reduced due to increasing sedimentation and, in some cases, is also decreased to improve the safety control of floods, leading to a reduction in efficiency for agriculture. And (4) hydrological and population changes in coastal areas, particularly in the delta zones, affected by water depletion, groundwater reduction and saline water intrusion. These scenarios enhance the necessity of improving water management, water prizing and water recycling policies, in order to ensure water supply and to reduce tensions among regions and countries. This work was supported by research projects CGL2006-11619/HID, CGL2008-01189/BTE, and CGL2008-1083/CLI, financed by the Spanish Commission of Science and Technology, and FEDER, EUROGEOSS (FP7-ENV-2008-1-226487) and ACQWA (FP7-ENV-2007-1-212250, financed by the European Commission, the VII Framework Programme financed by the European Commission, the project “Las sequías climáticas en la cuenca del Ebro y su respuesta hidrológica” and “La nieve en el Pirineo aragonés: Distribución espacial y su respuesta a las condiciones climáticas”, financed by “Obra Social La Caixa” and the Aragón Government, and “Programa de grupos de investigación de excelencia”, financed by the Aragón Government. Peer reviewed

The ambitious vision of off-grid renewable energy autonomy of remote regions has yet to come to fruition. The development of comprehensive energy production systems would be needed to achieve such a goal. This study consists of the simulation and exergetic evaluation of a novel hybrid power plant for stand-alone operation aiming to provide electricity autonomy of a Mediterranean island. The considered power plant is simulated dynamically over an annual cycle and accounts for both energy input fluctuations and electricity surplus. The plant combines a photovoltaic array with wind turbines for energy input, coupled with electricity storage and a hydrogen generation facility to stabilize the power output of the plant. Unlike other similar studies, the energy system presented here relies on real-case weather and demand data of a relatively large remote community and is optimized to ensure continuous operation even under extreme conditions. It is seen that this stand-alone hybrid power plant constitutes a robust and secure alternative to the current conventional energy situation; the combined renewable technologies succeed in complementing each other and offer stable performance throughout the year without the requirement of additional support by fossil fuels. The mean annual exergetic efficiency of the plant is found to be 17.9%, producing approximately 25,000 MWh of electricity per year, along with a secondary product (hydrogen) produced in the electrolyzer of the plant. Although this additional product is associated with additional investment cost, it offers the possibility to stabilize the power plant's performance and can be used as an additional source of financial income for the community. (C) 2015 Elsevier Ltd. All rights reserved. The authors would like to acknowledge the Marie Curie Actions PEOPLE-2012 IEFGENERGIS- 332028 and COFUND CONEX funded by FP7.

38 Pags.- 3 Figs. The definitive version is available at: http://link.springer.com/journal/13593 Dryland areas cover about 41 % of the Earth’s surface and sustain over 2 billion inhabitants. Soil carbon (C) in dryland areas is of crucial importance to maintain soil quality and productivity and a range of ecosystem services. Soil mismanagement has led to a significant loss of carbon in these areas, which in many of them entailed several land degradation processes such as soil erosion, reduction in crop productivity, lower soil water holding capacity, a decline in soil biodiversity, and, ultimately, desertification, hunger and poverty in developing countries. As a consequence, in dryland areas proper management practices and land use policies need to be implemented to increase the amount of C sequestered in the soil. When properly managed, dryland soils have a great potential to sequester carbon if financial incentives for implementation are provided. Dryland soils contain the largest pool of inorganic C. However, contrasting results are found in the literature on the magnitude of inorganic C sequestration under different management regimes. The rise of atmospheric carbon dioxide (CO2) levels will greatly affect dryland soils, since the positive effect of CO2 on crop productivity will be offset by a decrease of precipitation, thus increasing the susceptibility to soil erosion and crop failure. In dryland agriculture, any removal of crop residues implies a loss of soil organic carbon (SOC). Therefore, the adoption of no-tillage practices in field crops and growing cover crops in tree crops have a great potential in dryland areas due to the associated benefits of maintaining the soil surface covered by crop residues. Up to 80 % reduction in soil erosion has been reported when using no-tillage compared with conventional tillage. However, no-tillage must be maintained over the long term to enhance soil macroporosity and offset the emission of nitrous oxide (N2O) associated to the greater amount of water stored in the soil when no-tillage is used. Furthermore, the use of long fallow periods appears to be an inefficient practice for water conservation, since only 10–35 % of the rainfall received is available for the next crop when fallow is included in the rotation. Nevertheless, conservation agriculture practices are unlikely to be adopted in some developing countries where the need of crop residues for soil protection competes with other uses. Crop rotations, cover crops, crop residue retention, and conservation agriculture have a direct positive impact on biodiversity and other ecosystem services such as weed seed predation, abundance and distribution of a broad range of soil organisms, and bird nesting density and success. The objective of sequestering a significant amount of C in dryland soils is attainable and will result in social and environmental benefits. This work has been partially supported by the Spanish Ministry of Economy and Competitiveness (grants AGL 2013-49062-C4-1-R and AGL 2013-49062-C4-4-R). Peer reviewed

The study of electron transport system (ETS) in marine zooplankton provides potential respiration rates from measurements of the maximum activity of the enzymes involved in the respiratory electron transport chain. From these measurement we calculate the metabolic carbon demand to elucidate which group of zooplankton are most influential in the epipelagic zone carbon cycle. Here we present observations from a study of the zooplankton community in the upper 200 meters of the water column over the Balearic sub-basin and Algerian sub-basin, two areas in the oligotrophic Mediterranean with different oceanographic conditions. We compared the biomass, ETS activity and specific ETS activity of different fractions of size (53-200, 200-500, >500μm) in both areas. In the allometric exponential relationship between biomass and respiration, the coeficient b was less than 0.75 (Kleiber’s law). This supports the hypothesis of Gómez et al. (2008) that deviations from Kleiber’s law are influenced by nutritional state. When b 0.75 they are relatively well-fed. In both regions of this study the largest contribution to the ETS activity and to the potential respiration is by the larger sizes, while for the specific respiration (per unit biomass), smaller fractions are more important. This indicates that the small size fractions are, metabolically, more active. Both biomass and ETS activity increased in the region the Algerian sub-basin and for both regions the biomass and the ETS activity is greater in shallower water (200 m vs. 900m). 62 54 1,231 2,508 Q1 Q1 SCIE

[EN] Global change is expected to impact on the distribution and abundance of forests. Spain represents the southwestern limit of distribution for several types of deciduous forests and, as part of the Mediterranean Basin, it has all the characteristics to be affected by climate change. This study analyses the effects of climate change on habitat suitability and vulnerability in four categories of deciduous forests: Fagus sylvatica L., Quercus petraea (Matt.) Leibl., Quercus robur L. and Betula celtiberica Rothm. and Vasc. The approach combines an ensemble platform for species distribution models (SDMs) using three algorithms applied to four global circulation models (GCMs) driven by two representative concentration pathways (RCPs). Bioclimatic, biogeographic, soil and topographic variables were taken into consideration as predictors to build 320 single distribution models. Ensemble-forecasting models were then produced for each forest category and RCPs by computing a consensus of single-model projections. The adapted proposal of the Intergovernmental Panel on Climate Change (IPCC) was also applied to deal with the uncertainty and notify the likelihood of the outcomes. The results revealed generalized losses in habitat suitability compared to current conditions for all the forest categories, which were more drastic for the RCP 8.5 emission pathway. Exceptions worth noting are forests of Fagus sylvatica (likelihood 25%-50%) and Quercus robur (likelihood 75%-100%) in the Orocantabrian biogeographic subprovince, and Quercus petraea formations in the Cantabrian Atlantic subprovince (likelihood 25%-50%). Betula celtiberica would suffer the largest losses of habitat suitability under the climate change scenarios analysed. The vulnerability analysis confirmed that the deciduous formations least affected by climate change in future will be the Orocantabrian forests, while the Pyrenean and Oroiberian communities are the most vulnerable. The models developed in this study provide decision-makers with basic information and a useful tool for designing plans for the conservation and management of these forests in order to mitigate the impact of climate change. The study also highlights the importance and usefulness of conducting analyses at the biogeographic level, since the effects of climate change may be different and require management and conservation policies at local level SI

The traditional upscaling approach to greenhouse gas (GHG) emission estimates of inland waters is imprecise, but more precise methods based on environmental drivers are a longstanding challenge. Mexico lacks GHG emission estimates for its inland waters, and only sparse but scientifically validated information is available. This study provides the first GHG emission estimates from Mexican inland waters using 4275 GHG flux measurements from 26 distinctive waterbodies and one local and another global surface area dataset (INEGI and HydroLAKES). GHG emission factors were calculated and subsequently upscaled to estimate total national GHG emissions from the inland waters and compare to other emission measures based on mean global emission factors or size-productivity weighted (SPW) models. Mean (standard error) annual fluxes from all inland waters were 2.2 (5.3) kg CO2 m−2 yr−1, 0.6 (1.14) kg CH4 m−2 yr−1, and 1.0 × 10−3 (6.0 × 10−4) kg N2O m−2 yr−1. Estimates for natural waterbodies are annual average release rates between 74 (87) and 139 (163.23) Tg CO2eq while artificial waterbodies reach between 32 (2) and 21 (21) Tg CO2eq according to INEGI and HydroLAKES datasets, respectively. Considerable uncertainty was determined in the calculated mean emission factor, mostly for anthropogenic emissions. Waterbody area and chlorophyll a concentration were used as proxies to model CO2 and CH4 fluxes through regression analysis. According to SPW and IPCC models, computed mean annual CH4 emission factors were close to our estimates and exhibited a strong influence from eutrophication. In a likely scenario of increased eutrophication in Mexico, an increase in total net emissions from inland waters could be expected. This research was partially funded by the Universidad Nacional Autónoma de México, UNAM [National Autonomous University of Mexico], and the Dirección General de Asuntos del Personal Académico [Directorate General for Academic Personnel Affairs] PAPIIT-IN216818 “Flujos de carbono, nutrientes y sedimentos en un sistema lótico tropical” [Carbon, nutrient and sediment fluxes in a tropical lotic system], PAPIIT-IV200319 “Área Experimental de Lagos Tropicales” [Tropical Lakes Experimental Area], PAPIIT- IN219220 “Los lagos como centinelas de cambio climático, and PPAIIT- IV200122 “AELT - Efectos del cambio global y climatico sobre la limnologia y biodiversidad acuatica” [AELT - Effects of global and climate change on the limnology and aquatic biodiversity]. Acoplamiento clima-lago-agua subterránea en cuencas endorreicas semiáridas” [Lakes as sentinels of climate change. Climate-lake-groundwater coupling in semi-arid endorheic basins], and Programa de Investigación en Cambio Climático [Climate Change Research Program] PINCC-2020 and 2021 “Cuerpos acuáticos epicontinentales: papel de la dinámica del carbono y emisiones de gases de efecto invernadero en México” [Epicontinental aquatic bodies: role of carbon dynamics and greenhouse gas emissions in Mexico]. Peer reviewed