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River ecosystems are most often subject to multiple co-occurring anthropogenic stressors. Mediterranean streams are particularly affected by water scarcity and organic loads that commonly lead to a simultaneous reduction in flow and increasing depletion of dissolved oxygen. In the present study, the single and combined effects of water scarcity (flow velocity reduction) and dissolved oxygen depletion were used to evaluate alterations of drifting macroinvertebrates on a channel mesocosm system, by employing a multiple trait-based approach. Our main findings confirmed that the impact of the two combined stressors can be implicated in alterations of ecosystem functions as result of the changes in proportions of biological traits. Overall, our results showed that, individually, flow velocity reduction and a severe oxygen depletion promoted a shift in community traits. In more detail, biological traits describing the dispersal of organisms and their respiration showed the strongest responses. The respiration mode responded to low flow with drift increase of gill breathers and decrease of individuals with tegument, whereas dispersal was clearly affected by the combination of stressors. Resistance through eggs was higher with the single effect of flow reduction, while swimmers´ relative abundance increased in individuals that drift after exposure to the combination of stressors. Thus, while flow reduction alone is expected to specifically filter out the gill breathers and the egg producers, the combination of stressors will impact more drastically organism's dispersal and swimmers. Such changes in biological traits can result in variations in ecosystem functioning through, for example, local changes in biomass, secondary production, stream metabolism as well as resulting in biodiversity losses or alterations of its distribution patterns.

(Uploaded by Plazi for the Bat Literature Project) During the day, flying animals exploit the environmental energy landscape by seeking out thermal or orographic uplift, or extracting energy from wind gradients.1, 2, 3, 4, 5, 6 However, most of these energy sources are not thought to be available at night because of the lower thermal potential in the nocturnal atmosphere, as well as the difficulty of locating features that generate uplift. Despite this, several bat species have been observed hundreds to thousands of meters above the ground.7, 8, 9 Individuals make repeated, energetically costly high-altitude ascents,10, 11, 12, 13 and others fly at some of the fastest speeds observed for powered vertebrate flight.14 We hypothesized that bats use orographic uplift to reach high altitudes,9,15, 16, 17 and that both this uplift and bat high-altitude ascents would be highly predictable.18 By superimposing detailed three-dimensional GPS tracking of European free-tailed bats (Tadarida teniotis) on high-resolution regional wind data, we show that bats do indeed use the energy of orographic uplift to climb to over 1,600 m, and also that they reach maximum sustained self-powered airspeeds of 135 km h−1. We show that wind and topography can predict areas of the landscape able to support high-altitude ascents, and that bats use these locations to reach high altitudes while reducing airspeeds. Bats then integrate wind conditions to guide high-altitude ascents, deftly exploiting vertical wind energy in the nocturnal landscape.

Climate change and increasing socio-economic pressure is placing many ecosystems of high ecological and economic value at risk. This is particularly urgent in dryland ecosystems, such as the montado, a multifunctional savannah-like system heavily modeled by grazing. There is still an ongoing debate about the trade-offs between livestock grazing and the potential for ecosystem regeneration. While it is consensual that overgrazing hinders the development of the shrubs and trees in this system, the effects of undergrazing or grazing exclusion are unclear. This study provides the unique opportunity to study the impact of grazing on compositional and structural biodiversity by examining the ecological chronosequence in a long-term ecological research site, located in Portugal, where grazing exclusion was controlled for over 15years. As the threat of intensification persists, even in areas where climate shifts are evident, there is a critical need to understand if and how the montado might recover by removing grazing pressure. We evaluate succession on structural and compositional diversity after grazing pressure is removed from the landscape at 5, 10, and 15years post-cattle exclusion and contrast it with currently grazed plots. A LiDAR-derived structural diversity index (LHDI), a surrogate of ecosystem structure and function first developed for the pine-grassland woodland systems, is used to quantify the impact of grazing exclusion on structure and natural regeneration. The distribution of the vegetation, particularly those of the herbaceous and shrub strata (>10≤150cm), presents statistically significant changes. The LHDI closely mimics the compositional biodiversity of the shrubs, with an increase in diversity with increased years without grazing. Under present climate conditions, both shrub regeneration and the establishment of tree saplings were strongly promoted by grazing exclusion, which has important management implications for the long-term sustainability of montado systems.

An increasing global awareness that the supply and security of petroleum-based materials is diminishing, coupled with environmental concerns related to climate change, water availability, and soil degradation, has increased demand for more renewable, diversified, and sustainable agricultural production systems. The objective of this work was to determine if a biogenic approach, focused on producing perennial grasses on marginal Mediterranean land as feedstock for bioenergy or bio-based products, could reduce greenhouse gas (GHG) emissions without depleting soil nutrients, water supplies, or negatively impacting biological and landscape diversity. This study, funded by European Union (EU), was conducted under project optimization of perennial grasses for biomass production (OPTIMA) using environmental impact assessment (EIA) protocols to quantify local environmental impacts of producing perennial grasses, in the Mediterranean region. Different end uses were investigated and biogenic products were compared with conventional ones. The EIA assessment indicated that the biogenic system had low erodibility potential, reduced disturbance of soil properties, and minimal hydrological impacts. Less tillage and high biomass production supported biological and landscape diversity, but site-specific factors should be used to appropriately match the specific crop and location. We conclude that producing perennial grasses on marginal Mediterranean land is feasible and if appropriately managed will have relatively few environmental side effects.

Agricultural systems in the Mediterranean region are increasingly getting under pressure due to both global warming and the aggravating competition for agricultural land. Perennial grasses have the potential to tackle both challenges: they are drought-resistant crops and considered not to compete for high-productivity agricultural land because they can be grown on marginal land. This paper presents the outcome of a screening life cycle assessment (LCA) conducted as part of an integrated sustainability assessment within the EU-funded project ‘Optimization of Perennial Grasses for Biomass Production’ (OPTIMA). The project aims at optimised production of Miscanthus (Miscanthus × giganteus), giant reed (Arundo donax L.), switchgrass (Panicum virgatum L.) and cardoon (Cynara cardunculus L.) on marginal land in the Mediterranean region. Different cultivation and use options were investigated by comparing the entire life cycles of bioenergy and bio-based products to equivalent conventional products. The LCA results show that the cultivation of perennial grasses on marginal land and their use for stationary heat and power generation can achieve substantial greenhouse gas emission and non-renewable energy savings, with Miscanthus allowing for savings ranging up to 13 t CO2 eq./(ha · year) and 230 GJ/(ha · year), respectively. Negative environmental impacts are less pronounced. Significant parameters include irrigation needs and moisture content at harvest, which determines energy demand for technical drying. We conclude that the cultivation of perennial grasses on marginal land in the Mediterranean region provides potentials for climate change mitigation together with comparatively low other environmental impacts, if several boundary conditions and recommendations are met.

Abstract The use of biofuels can result on a decrease of greenhouse gas (GHG) emissions when compared to fossil fuels. However, the expansion of biofuels crops has been either based on direct or indirect displacement of natural ecosystems or on the use of degraded or marginal lands. The former results in direct habitat loss, whereas the later results in usual agricultural impacts (e.g., soil and biotic contamination and water eutrophication). However, in some circumstances biofuels crops can result on an increase in biodiversity compared to other agricultural crops. Agricultural zoning can mitigate the impacts of land use change (LUC), either direct (dLUC) or indirect (iLUC), whereas the use of wildlife-friendly techniques can mitigate the impacts of agriculture intensification. However, in both cases long-term biodiversity monitoring programs should be established in order to help the decision making process concerning the conflict between the expansion of biofuels crops and the conservation of biodiversity.

AbstractThe production of energy crops must be studied and evaluated in terms of environmental impact, in order to integrate them into a sustainable agricultural development. As bioenergy carriers they offer ecological advantages over fossil fuels by contributing to the reduction of greenhouse gases and acidifying emissions. However, there could be ecological shortcomings related to the intensity of agricultural production. There is a risk of polluting water and air, losing soil quality, enhancing erosion, and reducing biodiversity. In the scope of the project Future Crops for Food, Feed, Fiber and Fuel (4F Crops), supported by the European Union, an environmental impact assessment study was developed and applied to the production of potential energy crops in Europe. The following variables were selected as categories: use of water and mineral resources, soil quality and erosion, emission of minerals and pesticides to soil and water, waste generation and utilization, landscape, and biodiversity. In addition, a normalization and weighting procedure was applied, which attempts to aggregate environmental impacts. Results suggest that growing energy crops does not inflict higher impact on the environment compared to potato and wheat farming (regarding the studied categories). Although the different indicators did not yield a common pattern, overall results suggest that woody and lignocellulosic crops have an advantage over annual crop systems, namely regarding erodibility and biodiversity. Some crop management options, such as pesticides and fertilizers inputs, can influence the outcomes. However, site‐specific factors should be accurately assessed to evaluate the adequacy between crop and location. Environmental hotspots in the systems are detected and options for improvement are presented. © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd

The aim of this study was to characterize the chemical composition of different granulometric fractions obtained by milling of the bark of two softwood [Norway spruce, Picea abies (L.) Karst., and Scots pine, Pinus sylvestris L.] and two hardwood species (birch, Betula pendula Roth, and eucalypt, Eucalyptus globulus Labill.), and to discriminate between them on the basis of their chemical composition content via pattern recognition techniques [principal component analysis (PCA), cluster analysis (CA), and discriminant analysis (DA)]. Bark chemical composition differed between species, and chemical variables could be used to differentiate between them. Size reduction yields granulometric fractions that are not chemically homogeneous and that can also be discriminated. Therefore, potential applications of bark in valorization programs have to carefully consider the species-specific composition and their size reduction patterns. PCA and CA were adequate tools to characterize the different bark fractions within each species. DA allowed identifying the bark samples according to species and independently from particle size. Pattern recognition statistical methods were shown to be useful tools to analyse bark fractions and chemically discriminate species and fractions.

Abstract Realizing the potential of renewable energies in existing and new urban areas can reduce the fossil energy consumption of cities and the corresponding greenhouse emissions. In this paper, four different urban forms in the city of Constantine, a cold semi-arid city in Algeria, are analysed. Using the Citysim model, calibrated against local electricity and gas demand, and weather data taken from Meteonorm7.0, for both present and future climates, the study shows a significant difference between the energy demands of the urban forms due to their typo-morphological indicators. It is also shown that a small area of photovoltaics on rooftops can supply building demand, highlighting the favorable solar potential for the location. Future climate projections, for 2050, within the lifetime of many buildings, are expected to lead to higher energy demand, particularly in the summer. The increase in photovoltaic capacity to address that higher demand will open the opportunity to replace a significant fraction of gas usage with solar-powered heat pumps in the heating season.