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A general obstacle to the development of perennial grasses is the relatively high cost of propagation and planting. The objective of the present study was to investigate new propagation and planting methods of giant reed (Arundo donax L.), miscanthus (Miscanthus x giganteus Greef et Deuter) and switchgrass (Panicum virgatum L.). Field and open-air pot trials were carried out in four different locations across Europe: hydro-seeding of switchgrass was tested in field trials at the experimental farm of the University of Bologna, Italy; stem propagation and bud activation methods of miscanthus were evaluated in field experiments in Péteri, Hungary; giant reed rhizome and stem propagations were compared in a field trial in Aliartos, Greece; finally, an open-air pot trial was carried out in Catania, Italy, using single-node stem cuttings of giant reed. Hydro-seeding emerged as a feasible and promising technique for switchgrass to ensure prompt seed emergence and weed control during plant establishment. Direct stem plantings of miscanthus were successful, and activated stem-buds were able to sprout in field conditions; however, timely stem transplant was determinant for shoot density and biomass yield. In giant reed, rhizome propagation showed a higher stem density and biomass yield than stem propagation; however, the yield gap was not significant from the second year onwards. Single-node rooting was mainly driven by air temperature. Nodes from basal stems showed higher rooting rates than median and apical ones. Growth regulator pretreatments enhanced rooting rate only at transplanting times under suboptimal air temperatures. In general, these experiments provided insights into propagation strategies aimed at enhancing the establishment phase of perennial grasses.

Abstract A series of laboratory experiments were performed in continuously stirred tank reactors at mesophilic conditions, fed semi-continuously with various mixtures of diluted poultry manure and whey. Co-digestion of whey with manure was proved to be possible without any need of chemical addition up to 50% participation of whey (by volume) to the daily feed mixture. Up to this point, specific biogas production (L/kg VSin) remained roughly unchanged at the various whey fractions added in the feed mixture, mainly due to the lower chemical oxygen demand (COD) of whey compared to that of manure. At whey fractions above 50%, the reactor turned to be unstable, as shown by the considerable decrease in pH and biogas production. The experiments were scaled up to a continuously stirred pilot tank reactor, which had previously been acclimated to poultry manure digestion. Whey was gradually introduced in the feed, at increasing rates, replacing equivalent volumes of manure, in such a way, that total COD of the feed remained constant. For an hydraulic retention time of 18 days at 35 °C and organic loading rate of 4.9 g COD/LR d, it was found that biogas production increased from 1.5 to 2.2 L/LR d (almost 40%). This could be mainly attributed to the higher biodegradability of carbohydrates (main constituent of whey) compared to lipids (main constituent of manure) and to the correction (increase) of C:N ratio.

Hourly water level measurements were used to investigate the flood characteristics of a semi-arid river in Greece, the Evrotas. Flood events are analysed with respect to flood magnitude and occurrence and the performance of Curve Number approach over a period of 2007–2011. A distributed model, Soil and Water Assessment Tool, is used to simulate the historic floods (1970–2010) from the available rainfall data, and the performance of the model assessed. A new flood classification method was suggested the Peaks-Duration Over Threshold method that defines three flood types: ‘usual’, ‘ecological’ and ‘hazardous’. We classify the basin according to the flood type for the most serious past simulated flood events. The proportion of hazardous floods in the main stream is estimated to be 5–7% with a lower figure in tributaries. Flood Status Frequency Graphs and radar plots are used to show the seasonality of simulated floods. In the Evrotas, the seasonality pattern of hazardous flood is in agreement with other studies in Greece and differs from other major European floods. The classification in terms of flood types in combination with flood type seasonality is identified as an important tool in flood management and restoration.

AbstractGiven the accelerating rate of biodiversity loss, the need to prioritize marine areas for protection represents a major conservation challenge. The three‐dimensionality of marine life and ecosystems is an inherent element of complexity for setting spatial conservation plans. Yet, the confidence of any recommendation largely depends on shifting climate, which triggers a global redistribution of biodiversity, suggesting the inclusion of time as a fourth dimension. Here, we developed a depth‐specific prioritization analysis to inform the design of protected areas, further including metrics of climate‐driven changes in the ocean. Climate change was captured in this analysis by considering the projected future distribution of >2000 benthic and pelagic species inhabiting the Mediterranean Sea, combined with climatic stability and heterogeneity metrics of the seascape. We identified important areas based on both biological and climatic criteria, where conservation focus should be given in priority when designing a three‐dimensional, climate‐smart protected area network. We detected spatially concise, conservation priority areas, distributed around the basin, that protected marine areas almost equally across all depth zones. Our approach highlights the importance of deep sea zones as priority areas to meet conservation targets for future marine biodiversity, while suggesting that spatial prioritization schemes, that focus on a static two‐dimensional distribution of biodiversity data, might fail to englobe both the vertical properties of species distributions and the fine and larger‐scale impacts associated with climate change.

Integrating of lignocellulose-based and starch-rich biomass-based hydrogen production was investigated by mixing wheat straw hydrolysate with a wheat grain hydrolysate for improved fermentation. Enzymatic pretreatment and hydrolysis of wheat grains led to a hydrolysate with a sugar concentration of 93.4 g/L, while dilute-acid pretreatment and enzymatic hydrolysis of wheat straw led to a hydrolysate with sugar concentration 23.0 g/L. Wheat grain hydrolysate was not suitable for hydrogen production by the extreme thermophilic bacterium Caldicellulosiruptor saccharolyticus at glucose concentrations of 10 g/L or higher, and wheat straw hydrolysate showed good fermentability at total sugar concentrations of up to 10 g/L. The mixed hydrolysates showed good fermentability at the highest tested sugar concentration of 20 g/L, with a hydrogen production of 82-97% of that of the control with pure sugars. Mixing wheat grain hydrolysate with wheat straw hydrolysate would be beneficial for fermentative hydrogen production in a biorefinery.

Our Planet suffers from human activities. As scientists, we know more and more about our environment, about processes, rates of change, new threats, and risks. However, the challenges we face seem to grow quicker than the solutions we can create. To achieve sustainability, the key is to make solutions not only functional from an environmental point of view, but also socially acceptable and economically viable. In this context, the TERRAenVISION conference series gathers diverse groups of scientists to discuss sustainability. The first TERRAenVISION meeting in January 2018 was framed around 7 themes: (1) Climate Change: Mitigation and Adaptation, (2) Water Resources: Quality and Quantity, (3) Land Degradation and Restoration, (4) Nature-based Solutions, (5) Fire in the Earth System, Effects, and Prevention, (6) Ecosystem Services and Health, and (7) Science Interface with Policy and Public. Among the works presented in the conference, this Special Issue collates 22 papers that illustrate the best, problems and solutions the scientific community is currently working on to achieve sustainability. Similar to the concept of the SDGs, paper subjects often intertwine and bridge the conference themes. The papers are grouped in two main chapters dealing with Water and Land, with two additional cross cutting chapters of Scientific Tools and Science-Policy Interface. Drawing from the conclusions of these works as well as those of the TERRAenVISION 2018 conference, we make recommendations regarding raising awareness, connecting scientific fields, and supporting robust economic and policy transitions.