18 research outputs found

    Long-run impacts assessment of planned motorways and expressways in the Czech Republic

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    In a large number of countries (including the Czech Republic), implementation of large projects of transport infrastructure is justified by a general reference to its broad economic benefits, which are, however, seldom further specified. One of important reasons for such an approach is the non-existence of an empirically verified model for complex assessment of the degree of necessity of the development of these projects. Therefore, the main objective of the paper is to present an original method for comparative assessment of motorway and expressway constructions. The method has been applied to eight cases of the most significant projects planned in the Czech Republic verifying that its use can provide the necessary information on their potential benefits (in spite of some simplifications). The methodology for the generalized assessment attempts to connect technical, economic, political, spatial and environmental aspects and includes five basic criteria: relevance (traffic intensity as the underlying factor determining the technical need for a project), usefulness (time saved in personal transport and haulage, due to the insecurity concerning future transport flows interpreted by relative values derived from design speeds), integration (strategic significance of the projects regarding the connection of the most significant residential areas and the connection with neighbouring countries), stimulation (economic impacts assessed based on a potential improvement of the factor of road and railway quality as an integral part of the regional quality of business environment), and sustainability (environmental impacts of the construction on more significant residential centres and selected protected areas, with emphasis on pollution and noise). The complex assessment of selected projects of motorways (D) and express ways (R) has been performed based on an aggregation of rankings of the projects within the defined criteria. The projects were then divided into three groups: projects where need for construction has been proven, has been found disputable or has not been proven. The first group contains R 55), D 3 and R 35. However, this does not mean that there are no drawbacks – e.g. R 35 has the lowest ranking within the sustainability criterion. The second group contains D 11 and R 49. The assessment of their construction has been negatively affected by their ranking within the usefulness and stimulation criteria (D 11), and relevance and integration criteria (R 49). The position of the projects in the third group, R 6, R 7 and R 43 follows from their bad ranking within most of the established criteria (R 6 and R 7 – three criteria; R 43 – all criteria except usefulness)

    DISPERSE, a trait database to assess the dispersal potential of European aquatic macroinvertebrates

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    Dispersal is an essential process in population and community dynamics, but is difficult to measure in the field. In freshwater ecosystems, information on biological traits related to organisms’ morphology, life history and behaviour provides useful dispersal proxies, but information remains scattered or unpublished for many taxa. We compiled information on multiple dispersal-related biological traits of European aquatic macroinvertebrates in a unique resource, the DISPERSE database. DISPERSE includes nine dispersal-related traits subdivided into 39 trait categories for 480 taxa, including Annelida, Mollusca, Platyhelminthes, and Arthropoda such as Crustacea and Insecta, generally at the genus level. Information within DISPERSE can be used to address fundamental research questions in metapopulation ecology, metacommunity ecology, macroecology and evolutionary ecology. Information on dispersal proxies can be applied to improve predictions of ecological responses to global change, and to inform improvements to biomonitoring, conservation and management strategies. The diverse sources used in DISPERSE complement existing trait databases by providing new information on dispersal traits, most of which would not otherwise be accessible to the scientific community. Measurement(s): dispersal • movement quality • morphological feature • behavioral quality Technology Type(s): digital curation Factor Type(s): taxon Sample Characteristic - Organism: Arthropoda • Mollusca • Annelida Sample Characteristic - Environment: aquatic biome • freshwater biome Sample Characteristic - Location: Europe Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.1314833

    Simulating rewetting events in intermittent rivers and ephemeral streams: a global analysis of leached nutrients and organic matter

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    Climate change and human pressures are changing the global distribution and extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56‐98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached organic matter. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events

    Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter

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    Climate change and human pressures are changing the global distribution and the ex‐ tent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (precon‐ ditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experi‐ mentally simulated, under standard laboratory conditions, rewetting of leaves, river‐ bed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative character‐ istics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dis‐ solved substances during rewetting events (56%–98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contrib‐ uted most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental vari‐ ables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached sub‐ stances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying event

    The recovery of European freshwater biodiversity has come to a halt

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    Owing to a long history of anthropogenic pressures, freshwater ecosystems are among the most vulnerable to biodiversity loss1. Mitigation measures, including wastewater treatment and hydromorphological restoration, have aimed to improve environmental quality and foster the recovery of freshwater biodiversity2. Here, using 1,816 time series of freshwater invertebrate communities collected across 22 European countries between 1968 and 2020, we quantified temporal trends in taxonomic and functional diversity and their responses to environmental pressures and gradients. We observed overall increases in taxon richness (0.73% per year), functional richness (2.4% per year) and abundance (1.17% per year). However, these increases primarily occurred before the 2010s, and have since plateaued. Freshwater communities downstream of dams, urban areas and cropland were less likely to experience recovery. Communities at sites with faster rates of warming had fewer gains in taxon richness, functional richness and abundance. Although biodiversity gains in the 1990s and 2000s probably reflect the effectiveness of water-quality improvements and restoration projects, the decelerating trajectory in the 2010s suggests that the current measures offer diminishing returns. Given new and persistent pressures on freshwater ecosystems, including emerging pollutants, climate change and the spread of invasive species, we call for additional mitigation to revive the recovery of freshwater biodiversity.N. Kaffenberger helped with initial data compilation. Funding for authors and data collection and processing was provided by the EU Horizon 2020 project eLTER PLUS (grant agreement no. 871128); the German Federal Ministry of Education and Research (BMBF; 033W034A); the German Research Foundation (DFG FZT 118, 202548816); Czech Republic project no. P505-20-17305S; the Leibniz Competition (J45/2018, P74/2018); the Spanish Ministerio de Economía, Industria y Competitividad—Agencia Estatal de Investigación and the European Regional Development Fund (MECODISPER project CTM 2017-89295-P); Ramón y Cajal contracts and the project funded by the Spanish Ministry of Science and Innovation (RYC2019-027446-I, RYC2020-029829-I, PID2020-115830GB-100); the Danish Environment Agency; the Norwegian Environment Agency; SOMINCOR—Lundin mining & FCT—Fundação para a Ciência e Tecnologia, Portugal; the Swedish University of Agricultural Sciences; the Swiss National Science Foundation (grant PP00P3_179089); the EU LIFE programme (DIVAQUA project, LIFE18 NAT/ES/000121); the UK Natural Environment Research Council (GLiTRS project NE/V006886/1 and NE/R016429/1 as part of the UK-SCAPE programme); the Autonomous Province of Bolzano (Italy); and the Estonian Research Council (grant no. PRG1266), Estonian National Program ‘Humanitarian and natural science collections’. The Environment Agency of England, the Scottish Environmental Protection Agency and Natural Resources Wales provided publicly available data. We acknowledge the members of the Flanders Environment Agency for providing data. This article is a contribution of the Alliance for Freshwater Life (www.allianceforfreshwaterlife.org).Peer reviewe

    Ecological values of intermittent rivers for terrestrial vertebrate fauna

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    Rivers are generally considered critical habitats for biodiversity; however, this often ignores the fact that many rivers may run dry and support terrestrial as well as aquatic fauna. Here, we investigated the ecological value of intermittent rivers for terrestrial vertebrates by installing camera traps along rivers subject to varying dry periods in two contrasting European climatic zones. We then analysed i) species presence and behaviours (as a proxy of ecological functions) on perennial and intermittent streams; ii) environmental (hydrological and geomorphological) and anthropogenic factors affecting the frequency of occurrence and number of species recorded; and iii) the importance of hydrological factors as regards ecological functioning. In both study areas, we recorded a higher number of species and individuals along intermittent streams than perennial streams, with highest values in intermittent reaches exhibiting shorter dry periods. Both abundance and species richness were strongly affected by hydrological factors in both study areas, including not only the occurrence but also the duration of the dry period. Dry channels played a key role as migration corridors and as a source of food, being used more frequently than riparian habitats when the river ran dry. Our findings indicate that terrestrial vertebrate fauna benefit from dry phases in rivers. Intermittent rivers, supporting a high abundance and diversity of fauna, should be considered as target ecosystems for wildlife conservation. Not doing so will jeopardise urgently needed conservation strategies in the face of accelerating global climate change

    Ecological values of intermittent rivers for terrestrial vertebrate fauna

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    ©. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the accepted version of a Published Work that appeared in final form in [Science of the Total Environment]. To access the final edited and published work see [https://doi.org/10.1016/j.scitotenv.2021.151308]Rivers are generally considered critical habitats for biodiversity; however, this often ignores the fact that many rivers may run dry and support terrestrial as well as aquatic fauna. Here, we investigated the ecological value of intermittent rivers for terrestrial vertebrates by installing camera traps along rivers subject to varying dry periods in two contrasting European climatic zones. We then analysed i) species presence and behaviours (as a proxy of ecological functions) on perennial and intermittent streams; ii) environmental (hydrological and geomorphological) and anthropogenic factors affecting the frequency of occurrence and number of species recorded; and iii) the importance of hydrological factors as regards ecological functioning. In both study areas,we recorded a higher number of species and individuals along intermittent streams than perennial streams, with highest values in intermittent reaches exhibiting shorter dry periods. Both abundance and species richnesswere strongly affected by hydrological factors in both study areas, including not only the occurrence but also the duration of the dry period. Dry channels played a key role as migration corridors and as a source of food, being used more frequently than riparian habitatswhen the river ran dry. Our findings indicate that terrestrial vertebrate fauna benefit fromdry phases in rivers. Intermittent rivers, supporting a high abundance and diversity of fauna, should be considered as target ecosystems for wildlife conservation. Not doing so will jeopardise urgently needed conservation strategies in the face of accelerating global climate change

    European co-operation in wood research From native wood to engineered materials : Part 2: densification modification in product development

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    Wood  is  a  renewable,  biological  material  used  in  numerous  applications  and  it  is  growing  in  importance  due  to  sustainable  development  efforts.  Wood  also  suffers  from  a  number  of  disadvantages,  were low hardness and abrasive resistance are characteristic for low-density species.  This paper presents state of the art on different wood densification processes as one emerging process technology for increased use  of  low-density  species.  The  presentation  is  based  on  work  by  different  European  research  groups  in  wood  science,  collaborating  in  the  field  mainly  through  different  COST  Actions.  The  main  principles  for  processes are discussed, such as bulk and surface densification, as well as methods for reducing the shape memory  effect  of  densified  wood.  The  main  challenges  for  the  future  are  in  the  field  of  finding  fast  and  environmental  friendly  method  for  elimination  of  the  set-recovery  and  scaling  up  to  profitable  industrial  applications.  To  provide  a  better  understanding  with  this  regard,  some  relevant  applications  of  densified  wood are presented.2018-01-23 (rokbeg);Konferensartikel i tidskrift</p
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