Lead in grass in the Scottish uplands: deposition or uptake?

If it is assumed that the Pb collected in grass samples is derived mainly from atmospheric deposition then grass samples can be used as a convenient and easily analysed monitor for Pb deposition, in particular to establish the isotopic composition of current deposition in remote locations. As some studies have demonstrated a strong correlation between soil and grass Pb concentrations, it was considered important to establish the proportion of soil Pb in the grasses used to monitor atmospheric deposition at upland locations in Scotland. Consideration of earlier studies provided evidence that very little, if any, Pb in grass was derived from soil. Lead isotope analysis, by thermal ionisation mass spectrometry, of grasses grown on soils spiked with enriched (207)Pb in the field situation allowed the relative contribution of atmospheric deposition and soil to the grass Pb to be calculated. In most cases, >80% of Pb in grass was derived from atmospheric deposition and in recent years this value was >90%. Recalculation of the (206)Pb/(207)Pb ratio in grass samples showed that there was very little error in the results, published previously, which were based on the assumption that all the Pb collected with grass was derived from the atmosphere. The trends established by measuring the (206)Pb/(207)Pb ratio in grasses were confirmed and remain valid.     

Ecosystem services in environmental assessment — Help or hindrance?

This paper presents a critical analysis of the potential role of ecosystem services within environmental assessment, including both strategic environmental assessment (SEA) and environmental impact assessment (EIA). It identifies some of the common problems with current environmental assessment practice and then explores whether integrating ecosystem services may be able to help address some of these problems. Case studies are included to illustrate different approaches to using ecosystem services within environmental assessment and to highlight how context (e.g. sector, scale, environmental situation) will influence the most appropriate way of integrating ecosystem services into environmental assessment practice. The analysis also reflects on how ecosystem services' potential role may, or may not, differ from previous integrated approaches to environmental assessment and what lessons can be learnt from their development.Two main approaches are recognised from the literature and the case studies to integrating ecosystem services within environmental assessment: firstly a comprehensive approach, where the assessment framework is entirely guided by ecosystem services; and secondly a philosophical approach that applies more of a light-touch ecosystems-thinking mind-set, helping to frame the assessment methodology rather than fundamentally defining it. Inevitably, there are variations between these two extremes, and benefits and criticisms of both.The authors conclude that ecosystem services provides a potentially valuable framing for environmental assessment, but that it requires a pragmatic, context specific consideration of how ecosystem services can be used to help address some of the common problems with current environmental assessment practice. There is also a need to recognise that at times it may just not be appropriate if it does not provide added value.     

Community Participation in Natural Resources Management: Reality or Rhetoric?

In the developing world, the term ‘participation’ has in recent years become a household word in the same way that ‘democracy’ or ‘gender’ have. Development agencies are demanding increased participation in their programmes. The use of the word or its application has become a centre of debate. Due to the difficulties involved in measuring ‘participation’ or indeed determining levels at which participation should take place, who participates and when, many ‘doubting Thomases’ have questioned its effectiveness. It has, however been acknowledged in many areas that popular participation changes policies and enhances management and governance. In complex issues of natural resources management, participatory techniques have helped communities develop collective responsibilities towards management of their resources and projects. This paper discusses the complexities of community participation in natural resources management, ranging from interrelations among stakeholders to resource ownership based on the experiences in the Kasanka Game Management Area (KGMA). Lessons learnt from the Kasanka Game Management Area (GMA) communities, Serenje district, Zambia     

Sorption of nano-C60 clusters in soil: hydrophilic or hydrophobic interactions?

We studied the sorption behaviour of fullerene nano-C(60) particles (nC(60)) in soil from binary solvent mixtures of ethanol-water in order to critically evaluate the previous reports in the literature that the partitioning mechanism explains the soil sorption of fullerene C(60) as hydrophobic molecules. The sorption of nC(60) particles was studied in a range of solvent mixtures by changing volume fractions of ethanol from 20 to 100 percent. Sorption and particle characteristics were found to be very different in ethanol : water mixtures above and below 60% ethanol. In the range of 20-60% ethanol, sorption increased from 1.2 to 14.6 L kg(-1) accompanied by a change in zeta (ζ) potential from -32.4 to -7.2 mV. This observation can be attributed to hydrophilic interactions that negatively charged nC(60) particles undergo with soil colloids and water molecules. From 60% to 100% ethanol volume fractions, hydrophobic interactions of weakly charged nanoparticles may control the overall extent of soil sorption. The findings of this study indicate the importance of hydrophilic forces in controlling the sorption behaviour of nC(60) particles which are stabilized in water dominated solvent mixtures. The validity of the partitioning mechanism and K(OC) modelling approach in describing and estimating the sorption of nC(60) particles in soil (previously suggested in the literature) are, therefore, questioned.     

Pollute less or tax more? Asymmetries in the EU environmental taxes – Ecological balance nexus

This paper examines the impact of environmentally related taxes on environmental performance in the EU-15 countries during the period of 1995–2016 by utilizing an innovative non-linear model, which is the panel smooth transition regression (PSTR) model. Although the effectiveness of environmental taxes has been discussed before, the potential effects of these taxes on ecological balance sheets as a measure to reflect human pressures on the environment/ecosystem have not been fully investigated. This paper, therefore, deals with total ecological balance and its main components, which are based on the major types of ecologically productive areas such as cropland, grazing land, forest area, and fishing grounds. The results indicate that revenues from environmentally-related taxes as a share of GDP significantly lower the ecological deficits after exceeding a certain threshold level, but not cropland balance accounts. Thus, well-designed environmental taxes on the optimal level have the potential to reduce environmental problems/ ecological imbalance, if not implemented in conjunction with policies such as tax exemptions, refunds or tax allowances that limit their impact.     

Does road salting induce or ameliorate DOC mobilisation from roadside soils to surface waters in the long term?

Soils down slope of roads have been affected over decades by road salting in the UK uplands. Salt additions to fresh soil facilitate dispersal of organic matter so there is a potential risk of release of DON and DOC to nearby rivers where these run parallel to roads. Over time, however, salting enhances soil pH of naturally acid soils, and thus organic matter degradation through to CO2, thereby, lowering soil organic matter content. In addition any relatively labile organic matter may have already been dispersed. Thus, it is hypothesised that enhanced DOC mobilisation should only be a potential problem if soils not previously exposed to salt become heavily exposed in the future. This paper combines data from field observations and laboratory simulations to elucidate mechanisms controlling organic matter mobilisation processes to determine what controls spatial and temporal trends in DOC concentrations in soil solutions down slope of roads. Organic matter solubilisation is dependent on the degree of road salt exposure soils have had. The laboratory experiment provided evidence that there are two competing effects upon which solubilisation is dependent (a) pH suppression and (b) sodium dispersion. Other organic matter solubility models, if correct, link quite well with the authors "when it's gone, it's gone" hypothesis.     

Are Nitrogen-Fertilized Forest Soils Sinks or Sources of Carbon?

We developed a simple conceptual model that tracks nitrogen and carbon jointly through an N fertilized forest ecosystem. The stimulation of growth increases the litterfall and imports substrate for soil microorganisms. Microbial biomass forms according to the supply of C and N. The formation of microbial biomass is accompanied by respiratory C losses. The quantity of CO₂ efflux depends on the C use efficiency of microbes. When excess N is available, the microbial activity is accelerated and the demand for substrate is high. Litterfall supplies an insufficient amount of C to the soil. In such a case, labile soil C is mineralized and the net effect of N fertilization is a loss of soil C. A strong N fertilization effect on the aboveground biomass can offset the soil C loss. In the case of a low N dosage or high N losses due to leaching or emission of nitrogen oxides, the soil C loss is small. The conceptual model was applied to a case study. The field data, collected over a time span of several decades, could not support sound conclusions on the temporal trend of soil C because the spatial and temporal variability of the chemical data was high. The conceptual model allowed to give an evaluation of the fertilization effect on soil C based on reproducible principles.     

Radon, helium and uranium survey in some thermal springs located in NW Himalayas, India: mobilization by tectonic features or by geochemical barriers?

Radon, helium and uranium measurements have been carried out in hot water springs in the Parbati and Beas valleys of Himachal Himalaya. Most of these hot springs are known as famous pilgrimage centers. The activity of dissolved radon in the liquid phase is found to vary widely, by an order of magnitude, between 10 and 750 Bq L(-1), whereas, the dissolved helium content in these thermal springs varies between 10 and 100 ppm. The uranium contents are low and vary from <0.01 to 5 microg L(-1). The measured values of radon, helium and uranium are possibly controlled by structural geology, namely the presence of pervious fault systems, and by the lithology of the leached host rocks. Redox-potential geochemical barriers cause the mobilization of uranile ions in solution (UO2+); the most plausible hypothesis is when the conditions are oxidising, confirming the importance of physico-chemical conditions up to the supergenic environment, to control the fluid geochemistry of the U-He-222Rn system. Some evidence is available from both geothermometric considerations and geochemical data which will be reported elsewhere, whereas the present study is focused on U decay series-noble gas geochemistry. The first analysis of collected 3He/4He data is consistent with a crustal signature at the studied thermal springs.     

Simulation and Trend Analysis of the Water Quality Monitoring Daily Data in Nestos River Delta. Contribution to the Sustainable Management and Results for the Years 2000–2002

The transboundary River Nestos in the Balkan Peninsula is a surface water resource shared by Hellas and Bulgaria. The Public Power Corporation of Hellas (DEH) proceeded to the dams' construction of Thesaurus in 1997 and Platanovrissi in 2000, to satisfy the increased needs for power production and irrigation in the Regions of Eastern Macedonia and Thrace in the Hellenic Territory. DEH following the Ministerial Agreement of the Hellenic Parliament ‘`KYA 18492/19—09—1996’' funded a series of Research Projects concerned on the monitoring of the water quantity and quality data of Nestos from the Hellenic-Bulgarian borders to its estuaries in the Thracian sea. ‘`PERSEAS’' Research Group from Aristotle University of Thessaloniki, carried out the research, design, construction, installation, operation and maintenance of the ‘`R.E.MO.S.’' (Remote Environmental MOnitoring System) networks. Three REMOS networks have been installed in the areas of (a) the River Nestos deltaic channel, (b) Thesaurus dam-lake in the intramountainous valley and (c) Potamoi (Despat) and Pagoneri (Nestos) villages close to the borders between Hellas and Bulgaria. They record water level (H), water and air temperature (T), water conductivity (ECw), Redox potential (RP) and dissolved oxygen (DO) on a 24h basis, since the beginning of the year 2000. The research carried out in this paper, is focused on the REMOS station in the final course of Nestos in the deltaic area. The continuous monitoring and the data analysis yield useful results for the quality and quantity of the hydrologic regime of Nestos after the dams' construction, as well as for the trends detected of the quality parameters (ECw, RP and DO) and the water level, using the nonparametric Spearman's criterion. The best fitted model of time trend, for each variable, was chosen. The statistical sample of each one of the quality variables consisted of about 1000 values based on daily measures on a three years monitoring program (1/1/2000—31/12/2002). Further research and analysis for the other network stations of REMOS should provide useful results for the sustainable management of the transboundary River Nestos.     

Establishing ecological networks for habitat conservation in the case of ?e?me�CUrla Peninsula, Turkey

The study involves the Çe?me?CUrla Peninsula, where habitat fragmentation and loss, which threaten biological diversity, have become an urgent matter of concern in recent decades. The study area has been subjected to anthropogenic pressures and alterations due to ongoing and impending land uses. Therefore, ecological networks, as an appropriate way to deal with habitat fragmentation and loss and to improve ecological quality, were identified in the study area as one of the early attempts in the country to maintain its rich biodiversity. In this sense, core areas and ecological linkages as primary components of ecological networks were established on the basis of sustaining natural habitats. A GIS-based model was created to identify core areas and to facilitate the ecological connectivity. The modeling process for core areas and corridors combined 14 and 21 different variables, respectively. The variables were used as environmental inputs in the model, and all analyses were materialized in ArcGIS 9.2 using grid functions of image analysis and spatial analyst modules. As a result, six core areas and 36 corridor alternatives were materialized. Furthermore, some recommendations for the implementation and management of the proposed ecological networks were revealed and discussed.     

Do Risk Preferences Really Matter? The Case of Pesticide Use in Agriculture

Environmental Modeling & Assessment - Even if there exists an extensive literature on the modeling of farmers’ behavior under risk, actual measurements of the quantitative impact of risk...     

Is Clean Development Always Possible? The Role of Environmental Policy in Developing Countries in the Presence of Aggregate Demand Spillovers

Environmental Modeling & Assessment - This paper investigates whether economic development is impeded by binding national emission standards to control climate change. We develop a simple model...     

Is gender inequality an essential driver in explaining environmental degradation? Some empirical answers from the CO2 emissions in European Union countries

The effect of gender inequality on environmental degradation was examined for panel data of fourteen countries from the European Union (EU) from 1991 to 2016. The Quantile via Moments (QvM) and Fixed effects models were used to perform the empirical investigation. The results from the QvM and the Fixed effects models support that the gender gap pay and energy consumption increase the CO₂ emissions in the EU. However, the economic growth, globalisation and urbanisation deepening do not increase the environmental problem. This empirical investigation will contribute to the literature, policymakers, and governments. It will help develop more initiatives to reduces gender inequality at the same time it mitigates the environmental degradation in the EU countries. Finally, the empirical finds of this investigation will open a new topic of investigation in the literature about the relationship between environmental degradation and gender inequality.     

How best to quantify soil seed banks in arid rangelands of the Nama Karoo?

Sampling design and three sample treatments prior the application of the seedling emergence method were tested in order to find the best method for seed bank quantification in arid Nama Karoo rangelands. I analyzed species composition and seed densities by contrasting undercanopy and open-matrix samples from two soil depths and by comparing the effects of cold-, heat-, and no stratification on germination rates of species in a greenhouse setting. The soil seed bank showed minimal similarity to the standing vegetation, with only 20 plant species germinated. Spatial distribution of seeds was highly heterogeneous. Nearly 90% of germinated seeds were located in 0- to 4-cm compared to >4- to 8-cm soil depth. Undercanopy seed banks contained significantly more species and seeds than open-matrix seed banks. Neither the number nor the diversity of seeds germinated differed significantly among the three treatments. Cold stratification tended to detect more species and seeds only at >4- to 8-cm soil depth. The results highlight the importance of spatial heterogeneity in the accurate evaluation of soil seed banks in the arid Nama Karoo and the importance of considering seasonal variability in the availability of readily germinable seeds. Data also suggest that sample pretreatment in germination trials may give little return for cost and effort, which emphasizes that it is more important to choose the sampling design most likely to give a representative number of seed bank species. Further studies are needed to analyze seed bank dynamics and species-specific germination requirements to promote recruitment of plant taxa underrepresented in the seed bank.     

Can fish gill anomalies be used to assess water quality in freshwater Neotropical systems?

Gill anomalies in two fish species (Geophagus brasiliensis and Astyanax bimaculatus) were compared among three freshwater systems with different water quality: one eutrophic river, one eutrophic reservoir, and one oligotrophic reservoir. The raised hypotheses are that reservoirs with low water quality (eutrophic) have fish with more gills anomalies compared with reservoirs with high water quality (oligotrophic), and that the more stable environmental conditions of eutrophic rivers have fish with better healthy conditions than eutrophic reservoirs that have lesser stable environmental conditions. Gills of 36 adult individuals of G. brasiliensis and 23 of A. bimaculatus collected during the winter 2008 and winter 2009 were examined, and the proportions of occurrence of nine histological alterations were compared for the two species among the three systems using a binomial t test for independent samples. Histological changes in fish gills that are reversible and unspecific, such as epithelial lifting, interstitial edema, leukocyte infiltration, hyperplasia of the epithelial cells, lamellar fusion, and vasodilatation were common in both fish species in the three systems. However, lamellar aneurism, which is a more serious and often irreversible anomaly, and lamellar blood congestion occurred only in fish from the two reservoirs. Alternatively, necrosis occurred more in fish from the river. Fish gill anomalies in both species did not differ between the two reservoirs, despite having different water quality. We rejected the hypothesis that reservoirs with lower water quality have fish with more gill injuries compared with high water quality reservoirs. Moreover, the eutrophic river seems to affect differently the healthy condition of fish species, compared with the eutrophic reservoir.     

Recent temporal trend monitoring of mercury in Arctic biota--how powerful are the existing data sets?

The goal of this paper is to describe and discuss statistical power with respect to mercury in Arctic biota, using data gathered during the past two or three decades, mostly under the auspices of AMAP Phases I and II. It will describe the current levels of power of existing data sets to detect temporal trends of Hg concentrations. If the desired power is fixed to an appropriate magnitude, the minimum size of a detectable trend within a specified time period or the number of years that is required to detect a certain trend could be estimated provided that the random between-year variation for the current time-series is known. These various measures of performance of the AMAP mercury time-series, derived from the power analysis, are discussed in some detail. The number of years required to detect a certain trend at a particular power at a specific Type I error rate (alpha) is compared with the actual number of years available when the AMAP Phase II assessment was carried out. In general the investigated time-series were too short to possess an acceptable statistical power. The effect of varying the Type-I error rate, the slope of a trend and the desired power is investigated to rank the importance of the various components regulating the statistical power. The consequence of sampling less frequently than once a year is considerable loss of power.     

Does seston size structure reflect fish-mediated effects on water quality in a degraded semiarid wetland?

This study evaluates whether the size structure of seston (the sum of living and nonliving particles in the water column) reflects the effects of fish on wetland water quality. Using enclosures, we measured water quality and zooplankton community structure in the presence and absence of two fish species with distinct foraging strategies [benthivorous carp (Cyprinus carpio) and planktivorous mosquitofish (Gambusia holbrooki)]. Seston collected from the enclosures was counted and sized automatically with a Coulter counter, and the size structure in the range of 1–60 μm was modelled using the underlying Pareto distribution of particles. Only Cyprinus contributed to a loss of water quality (increased nutrient levels, algal and non-algal turbidity, hypoxia), while both fish species changed zooplankton community composition compared to fishless controls. However, these changes were not reflected in parameters [goodness of fit (r ²) and parameter c (slopes)] of Pareto models. Multivariate statistics suggest that seston size structure responded more to environmental gradients related to water depth but the relationships were also weak. Our overall result contrasts with the regulation of size spectra constructed from living organisms. Although seston integrates many structural and functional features of the water column, the lack of strong relationships between Pareto model parameters and water quality suggests that a size-based approach to characterise seston structure has a limited potential for assessing biota-mediated effects in wetlands in a straightforward manner.     

Metal levels in sediments from the Minho estuary salt marsh: a metal clean area?

Total-recoverable metals (Al, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in sediments from Minho estuary salt marsh were determined to evaluate possible increase in anthropogenic contamination by metals and to evaluate the possibility of this area to be considered a pristine area in terms of metals, which can be used as a reference site for other metal-contaminated national and international estuaries/salt marshes. This study revealed that the spatial distribution of metals in the salt marsh sediments was not homogeneous and that two sampling sites (sites 5 and 7) had indications of anthropogenic contamination. However, metal levels in these salt marsh sediments were lower than those observed in the wetlands of the main Portuguese estuaries. Comparison with Portuguese and international reference values used in the evaluation of the ecological quality of sediments, indicated that the sediments can be classified as “clean sediment” and that metal levels were lower or similar (only for Cu and Ni) to the values of ERL, which are the values that define the concentrations ranges that are rarely associated to adverse biologic effects in organisms. In addition, metal levels in the sediments were in chemical forms that were not easily available to organisms, indicating that these sediments probably will not have negative influences in the organisms living in the salt marsh, although no life-form ecological safety tests have been carried out. Therefore, the Minho estuary salt marsh area can probably be considered a pristine area in terms of metals and can be used as a reference for other metal-contaminated estuaries/salt marshes.