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International audienceThe global energy consumption was 540 EJ in 2010, representing an increase of about 80 % from 1980. Energy demand is predicted to grow more than 50 % by 2025. Fossil fuels will supply about 75 % of the future energy demand in 2030–2050 if there are no significant technological innovations or carbon emission constraints. This will induce in a substantial increase of CO2 atmospheric concentration and, in turn, adverse climatic impacts. A solution to this issue is to replace fossil fuels by renewable fuels such as biomass. For instance cultivated woody biomass shows many advantages such as allowing multiple harvests without having to re-plant. Poplar, eucalyptus, salix, paulownia and black locust are common examples of woody biomass. Here we review the current situation and future tendency of renewable energy focusing on solid biomass in Europe and Spain. We also discuss the potential production for short-rotation plantations in the bioenergy sector and existing constraints for the implantation in Spain in a sustainable context. Countries with low biomass resources and high targets for renewable electricity may have to depend on imported solid biomass, whereas countries with wide solid biomass resources benefit from international markets. The expansion of short-rotation plantations is much lower than expected in some countries such as Spain

In the Mediterranean region the intensities and amounts of soil loss and runoff on sloping land are governed by rainfall pattern and vegetation cover. Over a two-year period (1998)(1999), six wild species of aromatic and mellipherous plants (Thymus serpylloides subsp. Gadorensis, Thymus baeticus Boiss, Salvia lavandulifolia Vahl., Santolina rosmarinifolia L., Lavandula stoechas L. and Genista umbellata Poiret) were selected for erosion plots to determine their effectiveness in reducing water erosion on hillslopes of the Sierra Nevada Mountain (SE Spain). The erosion plots (including a bare-soil plot as control), located at 1,345 m in altitude, were 2 m 2 (2 m × 1 m) in area and had 13% incline. The lowest runoff and soil erosion rates, ranging from 9 to 26 mm yr −1 and from 0.01 to 0.31 Mg ha −1 yr −1 , respectively, over the entire study period, were measured under the Thymus serpylloides. Lavandula stoechas L. registered the highest rates among the plant covers tested, runoff ranging from 77 to 127 mm yr −1 and erosion from 1.67 to 3.50 Mg ha −1 yr −1 . In the bare-soil plot, runoff ranged from 154 to 210 mm yr −1 and erosion from 4.45 to 7.82 Mg ha −1 yr −1 . According to the results, the lowest-growing plant covers (Thymus serpylloides and Salvia lavandulifolia Vahl.) discouraged the soil erosion and runoff more effectively than did the taller and open medium-sized shrubs (Santolina rosmarinifolia L., Genista umbellata Poiret , Thymus baeticus Boiss and Lavandula stoechas L.). Monitoring allowed more direct linkage to be made between plant covers and the prevention of erosion, with implications for sustainable mountain agriculture and environmental protection.

Olive is a key crop in the Mediterranean basin, socially, economically, and environmentally, being a major source of rural employment. Organic products such as olive oil have attracted many types of consumers in recent years. In this context, the Mediterranean basin represents 5 Mha of the 10 Mha of olive farming worldwide, with Spain being the leading producer. Also, during the recent decades, olive farmers met the challenges of sustainability by implementing principles of agroecological production. Therefore, the focal point is no longer exclusively on yields but also on the quality, health, and environmental aspects of products and systems. In this work, we review and analyse the global situation of organic farming, focusing on the development, current status, perspectives, and opportunities of organic olive farming in Andalusia (S Spain). In addition, we assess the environmental benefits and consequences of the shift from conventional to organic management of olive orchards, focusing on the improvement of soil quality and biodiversity. Also, the general factors affecting the decision making for acquiring organic olive oil are discussed. Our main findings show the following: (1) It is necessary to encourage educational and research programmes to promote the demand for these products, positively affecting consumer health, protecting the environment, and improving rural economies. (2) The future of organic agriculture will depend on its economic viability and on the determination shown by governments to protect these practices. (3) Further support for funding research is needed to continue studying the effect of olive cultivation on soil biological quality, changes in soil properties, and biodiversity. More importantly, these beneficial extra outputs produced for society must be interiorised in economic value to compensate organic oil producers. (4) Finally, a clear understanding of attitudes and preferences, as well as the motivations of consumer when making the choice for organic olive products, is essential in responding to this specific demand. However, as stated above, major institutional and educational actions are also needed in order to boost sustainable organic olive farming and thus the preference for organic olive oil.

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