Distribució espacial del valor mitjà de la durada del cicle vegetatiu de la vinya (dies) a la D.O... more Distribució espacial del valor mitjà de la durada del cicle vegetatiu de la vinya (dies) a la D.O. Baix Empordà (Baix Empordà) per l'escenari de canvi climàtic moderat RCP 4.5 projectat per a les dècades dels anys 2030, 2050, 2070 i 2090. A dalt a l'esquerra es mostra l'escenari control on es representa el valor mitjà del període 1972-2005.
<p>The presentation will summarize the main findings of the chapter &am... more <p>The presentation will summarize the main findings of the chapter “Water”[1] of the report “Climate and Environmental Change in the Mediterranean Basin – Current Situation and Risks for the Future”. This report was published in November 2020 and prepared by 190 scientists from 25 countries, who belong to the scientific network “Mediterranean Experts on Climate and Environmental Change”.</p><p>Water resources in the Mediterranean are scarce, unevenly distributed and often mismatching human and environmental needs. Approx. 180 million people in the southern and eastern Mediterranean countries suffer from water scarcity (<1000 m<sup>3</sup> capita<sup>-1</sup> yr<sup>-1</sup>). The main water use is for agriculture, and more specifically on the southern and eastern rim. Water demand for both tourism and agriculture peak in summer, potentially enhancing conflicts in the future. Municipal water use is particularly constrained in the south and will likely be exacerbated in the future by demographic and migration phenomena. Northern countries face additional risks in flood prone areas where urban settlements are rapidly increasing.</p><p>Climate change, in combination with demographic and socio-economic developments, has mainly negative consequences for the water cycle in the Mediterranean Basin, including reduced runoff and groundwater recharge, increased crop water requirements, increased conflicts among users, and increased risk of overexploitation and degradation. These impacts will be particularly severe for global warming higher than 2°C.</p><p>Adequate water supply and demand management offers some options to cope with risks. Technical solutions are available for improving water use efficiency and productivity, and increasing reuse. Seawater desalination is increasingly used as adaptation measure to reduce (potable) water scarcity in dry Mediterranean countries, despite known drawbacks in terms of environmental impacts and energy requirements. Promising solar technologies are under development, potentially reducing emissions and costs. Reuse of wastewater is a solution for agriculture and industrial activities but also recharge of aquifers. Inter-basin transfers may lead to controversies and conflicts. Construction of dams contributes to the reduction of water and energy scarcities, but with trade-offs in terms of social and environmental impacts.</p><p>Overall, water demand management, which increases water use efficiency and reduces water losses, is crucial for water governance for a sustainable development. Maintaining Mediterranean diet or coming back to it on the basis of locally produced foods and reducing food wastes may save water but also carbon emissions while having nutritional and health benefits.</p><div><br><div> <p>[1] <strong>Fader M.</strong>, Giupponi C., Burak S., Dakhlaoui H., Koutroulis A., Lange M.A., Llasat M.C., Pulido-Velazquez D., Sanz-Cobeña A. (2020): Water. In: Climate and Environmental Change in the Mediterranean Basin – Current Situation and Risks for the Future. First Mediterranean Assessment Report [Cramer W, Guiot J, Marini K (eds.)] Union for the Mediterranean, Plan Bleu, UNEP/MAP, Marseille, France, 57pp, in press. Download</p> </div> </div>
Mediterranean environments are often characterized by a double stress: summer drought and winter ... more Mediterranean environments are often characterized by a double stress: summer drought and winter cold (Mitrakos 1980; Miller 1981; Terradas and Save 1992). Summer drought results from the coincidence of low summer precipitation with high temperature, high irradiance, and high water vapour pressure deficit (Di Castri and Mooney 1973); it has been traditionally recognized as the main climate constraint characterizing Mediterranean-type ecosystems. However, some degree of stress can be also due to winter cold, which may be determinant in montane and/or continental sites. This is reflected in the seasonal patterns of plant activity. Photosynthetic activity is typically relatively high in spring, decreases strongly in summer due to drought (Oechel et al. 1981, Tenhunen et al. 1990), increases again after the first autumn rains, and decreases or ceases during the winter months. Plant growth and leaf transpiration may follow similar patterns.
Quercus ilex evergreen-oak forests are often viewed as climax communities in large areas of the I... more Quercus ilex evergreen-oak forests are often viewed as climax communities in large areas of the Iberian Peninsula influenced by a mediterranean type climate (see also discussion by Naveh in this volume). Nevertheless, there are genetic and floristic differences in Q. ilex populations and forests found throughout this region. In parts of northeast Spain under humid meso-mediterranean conditions, evergreen-oak belongs to the phytosociological association Quercetum mediterraneo-montanum (Bolos 1983) which is dominated by Q. ilex ssp. ilex. The water use by plants and hydrological balance in these ecosystems have been little studied, despite the importance of these forests for water yield, soil protection, and maintenance of environmental quality. We report here the results of studies at two experimental forest plots located in the Prades (l’Avic) and Montseny (La Castanya) mountain ranges. Data have been gathered to describe the water budget for a watershed on watertight rock. Other measurements have been focused on understanding the ecophysiology of Q. ilex and movement of water vertically through the forest canopy.
Plants of Asplenium nidus-avis Hort. were submitted to a cycle of drying/rewatering under control... more Plants of Asplenium nidus-avis Hort. were submitted to a cycle of drying/rewatering under controlled conditions. Xylem water potential of the fronds (ψpxylem), their stomatal conductance (g), and their net photosynthetic rate (Pn) along the matric potential of the substrate (ψm) were measured during this cycle. The relationship be tween ψpxylem and g was an exponential curve. This relationship consisted of 2 phases with a threshold of ψPxylem near –0.77 MPa (1 bar = 0.1 MPa). Above this value, there were small changes in g, but below –1.01 MPa, g decreased rapidly. Pn declined below ψpxylem –1.01 MPa. Pn and g tended to correlate at low values of g. Initial values of ψpxylem, g, and Pn were reattained 48 hr after watering.
Distribució espacial del valor mitjà de la durada del cicle vegetatiu de la vinya (dies) a la D.O... more Distribució espacial del valor mitjà de la durada del cicle vegetatiu de la vinya (dies) a la D.O. Baix Empordà (Baix Empordà) per l'escenari de canvi climàtic moderat RCP 4.5 projectat per a les dècades dels anys 2030, 2050, 2070 i 2090. A dalt a l'esquerra es mostra l'escenari control on es representa el valor mitjà del període 1972-2005.
<p>The presentation will summarize the main findings of the chapter &am... more <p>The presentation will summarize the main findings of the chapter “Water”[1] of the report “Climate and Environmental Change in the Mediterranean Basin – Current Situation and Risks for the Future”. This report was published in November 2020 and prepared by 190 scientists from 25 countries, who belong to the scientific network “Mediterranean Experts on Climate and Environmental Change”.</p><p>Water resources in the Mediterranean are scarce, unevenly distributed and often mismatching human and environmental needs. Approx. 180 million people in the southern and eastern Mediterranean countries suffer from water scarcity (<1000 m<sup>3</sup> capita<sup>-1</sup> yr<sup>-1</sup>). The main water use is for agriculture, and more specifically on the southern and eastern rim. Water demand for both tourism and agriculture peak in summer, potentially enhancing conflicts in the future. Municipal water use is particularly constrained in the south and will likely be exacerbated in the future by demographic and migration phenomena. Northern countries face additional risks in flood prone areas where urban settlements are rapidly increasing.</p><p>Climate change, in combination with demographic and socio-economic developments, has mainly negative consequences for the water cycle in the Mediterranean Basin, including reduced runoff and groundwater recharge, increased crop water requirements, increased conflicts among users, and increased risk of overexploitation and degradation. These impacts will be particularly severe for global warming higher than 2°C.</p><p>Adequate water supply and demand management offers some options to cope with risks. Technical solutions are available for improving water use efficiency and productivity, and increasing reuse. Seawater desalination is increasingly used as adaptation measure to reduce (potable) water scarcity in dry Mediterranean countries, despite known drawbacks in terms of environmental impacts and energy requirements. Promising solar technologies are under development, potentially reducing emissions and costs. Reuse of wastewater is a solution for agriculture and industrial activities but also recharge of aquifers. Inter-basin transfers may lead to controversies and conflicts. Construction of dams contributes to the reduction of water and energy scarcities, but with trade-offs in terms of social and environmental impacts.</p><p>Overall, water demand management, which increases water use efficiency and reduces water losses, is crucial for water governance for a sustainable development. Maintaining Mediterranean diet or coming back to it on the basis of locally produced foods and reducing food wastes may save water but also carbon emissions while having nutritional and health benefits.</p><div><br><div> <p>[1] <strong>Fader M.</strong>, Giupponi C., Burak S., Dakhlaoui H., Koutroulis A., Lange M.A., Llasat M.C., Pulido-Velazquez D., Sanz-Cobeña A. (2020): Water. In: Climate and Environmental Change in the Mediterranean Basin – Current Situation and Risks for the Future. First Mediterranean Assessment Report [Cramer W, Guiot J, Marini K (eds.)] Union for the Mediterranean, Plan Bleu, UNEP/MAP, Marseille, France, 57pp, in press. Download</p> </div> </div>
Mediterranean environments are often characterized by a double stress: summer drought and winter ... more Mediterranean environments are often characterized by a double stress: summer drought and winter cold (Mitrakos 1980; Miller 1981; Terradas and Save 1992). Summer drought results from the coincidence of low summer precipitation with high temperature, high irradiance, and high water vapour pressure deficit (Di Castri and Mooney 1973); it has been traditionally recognized as the main climate constraint characterizing Mediterranean-type ecosystems. However, some degree of stress can be also due to winter cold, which may be determinant in montane and/or continental sites. This is reflected in the seasonal patterns of plant activity. Photosynthetic activity is typically relatively high in spring, decreases strongly in summer due to drought (Oechel et al. 1981, Tenhunen et al. 1990), increases again after the first autumn rains, and decreases or ceases during the winter months. Plant growth and leaf transpiration may follow similar patterns.
Quercus ilex evergreen-oak forests are often viewed as climax communities in large areas of the I... more Quercus ilex evergreen-oak forests are often viewed as climax communities in large areas of the Iberian Peninsula influenced by a mediterranean type climate (see also discussion by Naveh in this volume). Nevertheless, there are genetic and floristic differences in Q. ilex populations and forests found throughout this region. In parts of northeast Spain under humid meso-mediterranean conditions, evergreen-oak belongs to the phytosociological association Quercetum mediterraneo-montanum (Bolos 1983) which is dominated by Q. ilex ssp. ilex. The water use by plants and hydrological balance in these ecosystems have been little studied, despite the importance of these forests for water yield, soil protection, and maintenance of environmental quality. We report here the results of studies at two experimental forest plots located in the Prades (l’Avic) and Montseny (La Castanya) mountain ranges. Data have been gathered to describe the water budget for a watershed on watertight rock. Other measurements have been focused on understanding the ecophysiology of Q. ilex and movement of water vertically through the forest canopy.
Plants of Asplenium nidus-avis Hort. were submitted to a cycle of drying/rewatering under control... more Plants of Asplenium nidus-avis Hort. were submitted to a cycle of drying/rewatering under controlled conditions. Xylem water potential of the fronds (ψpxylem), their stomatal conductance (g), and their net photosynthetic rate (Pn) along the matric potential of the substrate (ψm) were measured during this cycle. The relationship be tween ψpxylem and g was an exponential curve. This relationship consisted of 2 phases with a threshold of ψPxylem near –0.77 MPa (1 bar = 0.1 MPa). Above this value, there were small changes in g, but below –1.01 MPa, g decreased rapidly. Pn declined below ψpxylem –1.01 MPa. Pn and g tended to correlate at low values of g. Initial values of ψpxylem, g, and Pn were reattained 48 hr after watering.
Uploads
Papers by Robert Save