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Global climate change leads to increasing frequency of droughts, threatening the productivity and quality of forage plants. Therefore, this glasshouse experiment was conducted to investigate the effects of reoccurring droughts on productivity and nutritive value of alfalfa and hybrid fescue plants. Starting from 63 days after sowing, seedlings of plants were exposed to double drought‐recovery treatments, each separate period lasting for 1 week. At the end of each treatment, growth of above‐ and below‐ground dry weight, lipid peroxidation, total antioxidative capacity, content of polyphenols, soluble and insoluble carbohydrates and proteins, as well as elemental composition of shoots were investigated. The findings confirmed our hypothesis, as growth of both plant species were mostly insignificantly affected by subsequent drought events. Whereas effect on leave redox homeostasis and plant nutritive value was much stronger, highly depending on both plant species and the order of stress event. We found significant drought‐induced increase in the content of water‐soluble carbohydrates (WSCs), starch, soluble and insoluble proteins, and polyphenols. Water shortage tended to decrease and increase the content of most macro‐ and microelements in alfalfa and fescue, respectively. These effects were reversed by re‐watering with several exceptions, such as constant reduction of Ca content in alfalfa. To conclude, alfalfa was found to be more sensitive than fescue to the first drought, but able to recover after both stress events. The second drought‐initiated prolonged accumulation of WSC implies a shift in plants metabolism towards increased resistance and herewith nutritive value with respect to soluble sugars. [ABSTRACT FROM AUTHOR]

Different species have different sensitivity to heat waves; therefore, interspecific competition may affect the crop response to heat waves. We investigated the effects of heat waves on spring barley (Hordeum vulgare L.) grown with and without wild mustard (Sinapis arvensis L.) as well as the recovery of barleys from stress. The plants were exposed to a 7‐day 35/28ºC (day/night) heat wave at ambient CO2 (400 μmol/mol) and elevated CO2 (800 μmol/mol). All seedlings were rehydrated and returned to control conditions (21/14ºC, CO2 400 μmol/mol) after the cease of heat wave and grown for a 7‐day period of recovery. Heat wave had more pronounced negative effect on the barley's aboveground biomass under competition with mustard, whereas the response of root biomass was not influenced by the presence of weeds. The heat wave induced reductions in barley's photosynthetic rate, stomatal conductance and water use efficiency under interspecific competition were higher compared to monocultured conditions. Interspecific competition impaired and delayed the recovery of barley's biomass production and leaf gas exchange parameters after heat wave. Elevated CO2 slightly mitigated negative heat wave impact on the growth and leaf gas exchange parameters but had no effect during the recovery period. [ABSTRACT FROM AUTHOR]

Abstract: This paper analyses the compatibility of growth and sustainability in the European Union (EU) including a new EU member states from the former Soviet bloc (EU10). The extension of EU borders, financial and technological support stimulated rapid convergence and decreased the socio-economic differences between the old (EU15) and newly accepted EU member states. The transition from a command to a market economy resulted in the remarkable increase in resource efficiency and other positive aspects of sustainability. Along with 1.5 times increased GDP, final energy consumption decreased by 20%, greenhouse gases emissions by 25% and the emissions of acidifying compounds were halved during the period from the collapse of former Soviet bloc to the recent economic crisis. However, the per capita production and consumption in EU10 is still approximately half that of EU15, and further catch-up growth should be expected ensuring that economic and social cohesion is not achieved at the expense of increased environmental impact. Decelerated economic growth is a feature characteristic of mature economies and the GDP growth rate in EU15 states decreased almost 2.5 times during the last 50 year. Similar trends are characteristic of other developed countries, and market economies have adapted to this trend. Even with a decelerated growth rate, the ecological footprint in developed countries currently exceeds three and more times the allowable limits and almost two-thirds of the ecological footprint relates to traditional energy. De-fossilisation by a greater increase in energy efficiency, use of renewable energy, and more intense material recovery is the most promising option for reducing the ecological footprint of these countries. Deceleration of the economic growth rate supplemented by the aforementioned options is a hard but realistic track leading to the reduction of ecological footprint in developed countries to allowable limits without radical de-growth in consumption and production that can result in unpredictable and unacceptable consequences. [Copyright &y& Elsevier]