Development of comprehensive river typology based on macrophytes in the mountain-lowland gradient of different Central European ecoregions

The aim of the study was to identify the vegetation pattern in the different types of watercourses basing on survey in reference conditions in a wide geographical gradient, including mountain, upland and lowland rivers. We tested relationship between composition of macrophytes to environmental variables including: altitude, slope, catchment area, geology of valley, land use, hydromorphological sfeatures, water physical and chemical measurements. Analysis based on 109 pristine river sites located throughout major types of rivers in Central Europe. Qualitative and quantitative plant surveys were carried out between 2005 and 2013. Based on TWINSPAN classification and DCA analysis, six macrophyte types were distinguished. The lowland sites were divided into the following three types: humic rivers and two types of siliceous rivers depending on the catchment area, including medium-large and small rivers. The mountain and upland rivers were divided into three geological types: siliceous, calcareous and gravel. We found that the variation of macrophyte communities was determined by several habitat factors (mainly altitude, flow type, riverbed granulometry, conductivity and alkalinity), whereas the spatial factor was rather limited; further, the plant diversity was not reflected accurately by the European ecoregion approach

The value of the terricolous lichen Cetrariella delisei in the biomonitoring of heavy-metal levels in Svalbard

The aim of this study was to identify a suitable lichen species for the long−term monitoring of heavy−metal atmospheric pollution in Svalbard. Cladonia and Cetraria s.l. species that have been widely used until now for assessing heavy−metal deposition in the Arctic are in decline over extensive areas of Svalbard, mainly due to climate change and over−grazing by reindeer. Cetrariella delisei, rarely used for biomonitoring, is still common and widespread in this area. Levels of Cr, Ni, Fe, Cu, Pb, Zn, Cd and Mn were measured in three lichen species: Cetrariella delisei, Cladonia uncialis, Flavocetraria nivalis and in a moss Racomitrium lanuginosum from Sørkapp Land, South Spitsbergen. The results imply that Cetrariella delisei can be safely compared to Cladonia uncialis for identifying the levels of heavy metals, but direct comparison between Cetrariella delisei and other species studied is more difficult owing to differences in levels of heavy metals even in samples from the same site

Urban hedges: a review of plant species and cultivars for ecosystem service delivery in north-west Europe

Urban hedges provide a number of important ecosystem services (ESs) including microclimate alteration, flood and pollution mitigation, and biodiversity provision, along with some disservices (DSs, e.g. invasiveness, allergenicity). However, hedge plant species differ in their capacity to promote different services, so it is important that the decision to plant hedges is evidence-based. The objectives of this study were thus to (i) to review the role of urban hedges within NW Europe; (ii) review the available literature detailing the ESs and DSs provided by different plant species and cultivars when used as hedge plants; (iii) identify where there is a lack of evidence for certain species or ESs/DSs; and (iv) develop a starting point for a discussion about appropriate species/cultivar selection to deliver multiple ESs, and avoid DSs. Many studies consider biodiversity and air quality ESs. There are significant gaps in the literature relating to rainfall mitigation/flood protection, but also CO2 sequestration, allergenicity and human psychological well-being impact of different species. Additionally, for noise and pollution mitigation studies, a range of methodologies and units are used, making comparisons between hedge species difficult/impossible. A number of common hedge species demonstrated high levels of ESs delivery, including Fagus sylvatica, Crataegus monogyna, Ilex aquifolium and Rosa rugosa. No species surveyed had an entirely negative association with ESs, and most provide at least some benefits in supporting ESs provision (e.g. Viburnum tinus, Laurus nobilis). We created a matrix, in a table form, linking plant species, key plant traits and ESs/DSs, which should make it easier for professionals to choose species best suited to provide multiple benefits, whilst minimising the drawbacks. Our review suggests that the relative contribution of urban hedges to ESs delivery may be under-valued currently, and calls for more research

Wetlands for wastewater treatment and subsequent recycling of treated effluent : a review

Due to water scarcity challenges around the world, it is essential to think about non-conventional water resources to address the increased demand in clean freshwater. Environmental and public health problems may result from insufficient provision of sanitation and wastewater disposal facilities. Because of this, wastewater treatment and recycling methods will be vital to provide sufficient freshwater in the coming decades, since water resources are limited and more than 70% of water are consumed for irrigation purposes. Therefore, the application of treated wastewater for agricultural irrigation has much potential, especially when incorporating the reuse of nutrients like nitrogen and phosphorous, which are essential for plant production. Among the current treatment technologies applied in urban wastewater reuse for irrigation, wetlands were concluded to be the one of the most suitable ones in terms of pollutant removal and have advantages due to both low maintenance costs and required energy. Wetland behavior and efficiency concerning wastewater treatment is mainly linked to macrophyte composition, substrate, hydrology, surface loading rate, influent feeding mode, microorganism availability, and temperature. Constructed wetlands are very effective in removing organics and suspended solids, whereas the removal of nitrogen is relatively low, but could be improved by using a combination of various types of constructed wetlands meeting the irrigation reuse standards. The removal of phosphorus is usually low, unless special media with high sorption capacity are used. Pathogen removal from wetland effluent to meet irrigation reuse standards is a challenge unless supplementary lagoons or hybrid wetland systems are used