Hydroponic systems: exploring the balance between co-cultivation of Chlorella vulgaris and Swiss chard (Beta vulgaris L. subsp. cicla)

Journal of Applied Phycology - Co-cultivation of plants and microalgae represents an optimized production method which is less resource intense and it is ecologically correct and clean....     

LCA application to integrated waste management planning in Gipuzkoa (Spain)

Goal, Scope and Background  Gipuzkoa is a department of the Vasque Country (Spain) with a population of about 700,000 people. By the year 2000 approximately 85% of municipal solid waste in this area was managed by landfilling, and only 15% was recycled. Due to environmental law restrictions and landfill capacity being on its limit, a planning process was initiated by the authorities. LCA was used, from an environmental point of view, to assess 7 possible scenarios arising from the draft Plan for the 2016 time horizon. Main Features  In each scenario, 9 waste flows are analysed: rest waste, paper and cardboard, glass containers, light packaging, organic-green waste, as well as industrial/commercial wood, metals and plastics, and wastewater sludge. Waste treatments range from recycling to energy recovery and landfilling. Results  Recycling of the waste flows separated at the source (paper and cardboard, glass, light packaging, organic-green waste, wood packaging, metals and plastics) results in net environmental benefits caused by the substitution of primary materials, except in water consumption. These benefits are common to the 7 different scenarios analysed. However, some inefficiencies are detected, mainly the energy consumption in collection and transport of low density materials, and water consumption in plastic recycling. The remaining flows, mixed waste and wastewater sludge, are the ones causing the major environmental impacts, by means of incineration, landfilling of partially stabilised organic material, as well as thermal drying of sludge. With the characterisation results, none of the seven scenarios can be clearly identified as the most preferable, although, due to the high recycling rates expected by the Plan, net environmental benefits are achieved in 9 out of 10 impact categories in all scenarios when integrated waste management is assessed (the sum of the 9 flows of waste). Finally, there are no relevant differences between scenarios concerning the number of treatment plants considered. Nevertheless, only the effects on transportation impacts were assessed in the LCA, since the plant construction stage was excluded from the system boundaries. Conclusions  The results of the study show the environmental importance of material recycling in waste management, although the recycling schemes assessed can be improved in some aspects. It is also important to highlight the environmental impact of incineration and landfilling of waste, as well as thermal drying of sludge using fossil fuels. One of the main findings of applying LCA to integrated waste management in Gipuzkoa is the fact that the benefits of high recycling rates can compensate for the impacts of mixed waste and wastewater sludge. Recommendations and Outlook  Although none of the scenarios can be clearly identified as the one having the best environmental performance, the authorities in Gipuzkoa now have objective information about the future scenarios, and a multidisciplinary panel could be formed in order to weight the impacts if necessary. In our opinion, LCA was successfully applied in Gipuzkoa as an environmental tool for decision making.     

Invasive round goby Neogobius melanostomus has sex‐dependent locomotor activity and is under‐represented in catches from passive fishing gear compared with seine catches

The higher proportion of males of the invasive round goby Neogobius melanostomus in samples from two activity selective passive fishing gears compared with one activity non‐selective fishing gear in three Dutch lakes is related to higher male locomotory activity and is a sex‐dependent trait. This difference in activity reflects the different ecology of male and female N. melanostomus.     

Ontogenetic plasticity of anatomical and ecophysiological traits and their correlations in Iris pumila plants grown in contrasting light conditions

To better understand what directs and limits the evolution of phenotype, constraints in the realization of the optimal phenotype need to be addressed. That includes estimations of variability of adaptively important traits as well as their correlation structures, but also evaluation of how they are affected by relevant environmental conditions and development phases. The aims of this study were to analyze phenotypic plasticity, genetic variability and correlation structures of important Iris pumila leaf traits in different light environments and ontogenetic phases, and estimate its evolutionary potential. Stomatal density, specific leaf area, total chlorophyll concentration and chlorophyll a/b ratio were analyzed on I. pumila full‐sib families in the seedling phase and on the same plants after 3 years of growth in contrasting light conditions typical for ontogenetic stage in question. There was a significant phenotypic plasticity in both ontogenetic stages, but significant genetic variability was detected only for chlorophyll concentrations. Correlations of the same trait between different stages were weak due to changes in environmental conditions and difference in ontogenetic reaction norms of different genotypes. Ontogenetic variability of correlation structures was detected, where correlations and integration were higher in seedlings compared with adult plants 3 years later. Correlations were affected by environmental conditions, with integration being higher in the lower light conditions, but correlations between phases being stronger in the higher light treatment. These findings demonstrated that the analyzed traits can be selected and can mostly evolve independently in different environments and ontogenetic stages, with low genetic variability as a potentially main constraint.     

Clonal structure and reduced diversity of the invasive alien plant Erigeron annuus in Lithuania

The alien species Erigeron annuus (L.) Pers. is in an intensive spreading phase in Lithuania. Random amplified polymorphic DNA (RAPDs) and inter-simple sequence repeats (ISSRs) assays were used to study the genetic structure of old and new invasive populations and to determine the most spread genotypes of this species in Lithuania. Pairwise genetic distances between populations established using RAPD and ISSR markers significantly correlated (r=0.91, P<0.05). Our study indicates that there are two genetically different types of E. annuus populations. The first type is represented by a widely spread main clone and related monomorphic populations. The second type is represented by polymorphic populations, some of them present at sites where E. annuus has not been previously observed. Main clone predominates in nine populations and is from the region where this species was first described in natural ecosystems of Lithuania. UPGMA cluster analysis revealed genetic relationships between the main clone and accessions from old cemeteries where E. annuus has been grown as an ornamental plant. We found high genetic differentiation among populations (G _ST=0.58 for RAPDs, G _ST=0.64 for ISSRs). Taken together, our results will contribute to the monitoring of E. annuus spread in Lithuania.