Visitor perceptions of rural landscapes: a case study in the Peak District National Park, England

Maintaining national parks is an integral policy tool to conserve rare habitats. However, because national parks are funded by taxpayers, they must also serve the needs of the general public. Increasingly, and thanks to today's diverse society, there is evidence that this creates challenges for park managers who are pulled in two opposing directions: to conserve nature on the one hand and to meet different visitor expectations on the other. This tension was explored in the Peak District National Park, a rural landscape dominated by heather moorland and sheep farming in Northern England where research was conducted to determine how social class and ethnicity shaped perceptions of the park. Results uncovered that social class played a very strong role in shaping perceptions of this region with 'middle class' respondents reacting far more favourably to the park than people from more working class backgrounds. We observed ethnicity playing a similar role, though our results are less significantly different.     

Influence of hydroxypropyl-β-cyclodextrin on the biodegradation of C-phenanthrene and C-hexadecane in soil

Soil was spiked with [9-¹⁴C]phenanthrene and [1-¹⁴C]hexadecane at 50 mg kg⁻¹ and aged for 1, 25, 50, 100 and 250 d. At each time point, the microcosms were amended with aqueous solutions of cyclodextrin (HP-β-CD) at a range of concentrations (0-40 mM). Mineralisation assays and aqueous HP-β-CD extractions were performed to assess the effect of the amendments on microbial degradation. The results showed that amendments had no significant impact on the microbial degradation of either of the ¹⁴C-contaminants. Further, HP-β-CD extractions were correlated with the mineralisation of the target chemicals in each of the soil conditions. It was found that the HP-β-CD extraction was able to predict mineralisation in soils which had not been amended with cyclodextrin; however, in the soils containing the HP-β-CD, there was no predictive relationship. Under the conditions of this study, the introduction of HP-β-CD into soils did not enhance the biodegradation of the organic contaminants.     

Linking chemical extraction to microbial degradation of 14C-hexadecane in soil

Chemical extractions have been shown to measure the biodegradable fraction of aromatic contaminants in soil; however, there is little research on the chemical prediction of aliphatic hydrocarbon degradation. The aim of this study was to investigate the potential for cyclodextrin extractions to predict hexadecane biodegradation in soil. Soils were amended with 10 or 100 mg kg⁻¹ of a model alkane n-hexadecane and 100 Bq g⁻¹¹⁴C-n-hexadecane. Correlations between the extents of mineralisation and extractions of the ¹⁴C-contaminant were determined. Solvent shake extractions and aqueous CaCl₂ extractions were poor predictors of hexadecane bioaccessibility. However, the novel HP-α-CD shake extraction showed close correlation (r² = 0.90, n = 36, p < 0.05) to the mineralisation data. This novel extraction technique has the potential to be used to assess the biodegradable aliphatic hydrocarbon fraction in contaminated soils.     

Phytotoxicity and phytoremediation of 2,6-dinitrotoluene using a model plant, Arabidopsis thaliana

Biochemical and genetic studies of xenobiotic metabolism in the model plant Arabidopsis have significant potential in providing information for phytoremediation. This paper presents the toxicity of 2,6-dinitrotoluene (2,6-DNT) to Arabidopsis under axenic conditions, the fate and transformation of 2,6-DNT after uptake by the plant, and the effect of a putative glutathione S-transferase (GST), which is highly induced by 2,4,6-trinitrotoluene (TNT) in the previous study, on the detoxification of 2,6-DNT. 2,6-DNT had toxic effects on the growth of Arabidopsis based on whole seedling as well as root growth assays. Using [U- 14C]2,6-DNT, the recovery was over 87% and less than 2% accounted for the mineralization of 2,6-DNT in axenic liquid cultures during the 14d of exposure. About half (48.3%) of the intracellular radioactivity was located in the root tissues in non-sterile hydroponic cultures. 2-Amino-6-nitrotoluene (2A6NT) and two unknown metabolites were produced as transformation products of 2,6-DNT in the liquid media. The metabolites were further characterized by proton NMR spectra and the UV-chromatograms when the plant was fed with either 2,6-DNT or 2A6NT. In addition, polar unknown metabolites were detected at short retention times from radiochromatograms of plant tissue extracts. The GST gene of the wild-type of Arabidopsis in response to 2,6-DNT was induced by 4.7-fold. However, the uptake rates and the tolerance at different concentrations of 2,6-DNT and TNT were not significantly different between the wild-type and the gst mutant indicating that induction of the GST gene is not related to the detoxification of 2,6-DNT.     

Transport and transformation of sulfur compounds over East Asia during the TRACE-P and ACE-Asia campaigns

On the basis of the recently estimated emission inventory for East Asia with a resolution of 1×1°, the transport and chemical transformation of sulfur compounds over East Asia during the period of 22 February through 4 May 2001 was investigated by using the Models-3 Community Multi-scale Air Quality (CMAQ) modeling system with meteorological fields calculated by the regional atmospheric modeling system (RAMS). For evaluating the model performance simulated concentrations of sulfur dioxide (SO₂) and aerosol sulfate (SO₄²⁻) were compared with the observations on the ground level at four remote sites in Japan and on board aircraft and vessel during the transport and chemical evolution over the Pacific and Asian Pacific regional aerosol characterization experiment field campaigns, and it was found that the model reproduces many of the important features in the observations, including horizontal and vertical gradients. The SO₂ and SO₄²⁻ concentrations show pronounced variations in time and space, with SO₂ and SO₄²⁻ behaving differently due to the interplay of chemical conversion, removal and transport processes. Analysis of model results shows that emission was the dominant term in regulating the SO₂ spatial distribution, while conversion of SO₂ to SO₄²⁻ in the gas phase and the aqueous phase and wet removal were the primary factors that controlled SO₄²⁻ amounts. The gas phase and the aqueous phase have the same importance in oxidizing SO₂, and about 42% sulfur compounds (25% in SO₂) emitted in the model domain was transported out, while about 57% (35% by wet removal processes) was deposited in the domain during the study period.     

Design principles and common pool resource management: an institutional approach to evaluating community management in semi-arid Tanzania

This paper analyses the role of institutions in the management of common pool resources (CPRs) in semi-arid Tanzania. Common property regimes have often been considered inadequate for the management of CPRs because of the problems of excludability, but they are becoming more widely supported as the way forward to overcome the problems of resource use and degradation in developing countries. A series of design principles for long enduring common property institutions have been proposed by Ostrom, but there is concern that they are not applicable to a wide range of real life situations or that they may be specific to certain types of CPR. Here, we compare these principles to the situation prevailing in 12 villages in six districts in semi-arid Tanzania. Data on management institutions were collected through semi-structured interviews and meetings at district and village level. The combined information was used to make a qualitative assessment of the strength with which each design principle appeared to operate in the management of forest, pasture and water resources. Boundaries, conflict and negotiation in CPR management are of key importance in semi-arid regions. However, the need for flexibility in order to deal with ecological uncertainty means that many management institutions would be considered weak or absent according to the design principle approach. This supports the view that the design principles should not be used as a 'blueprint to be imposed on resource management regimes' rather that they provide a framework for investigating common property regimes with the proviso that, certainly for semi-arid regions, they may highlight where management cannot be explained by institutional theory alone.     

Role of plant activity and contaminant speciation in aquatic plant assimilation of 2,4,5-trichlorophenol

Aquatic plants uptake, transform and sequester organic contaminants and are used as a bioremediation strategy for the removal of pollutants from wastewaters. A better understanding of factors affecting rate of uptake of contaminants by aquatic plants is needed to improve engineered systems for removal of pollutants from wastewaters. This work focused on delineating sorption to plant surfaces and understanding effects of plant metabolic activity, inhibition, and media pH on the uptake of the ionizable contaminant 2,4,5-trichlorophenol (TCP) by aquatic plant Lemna minor. During L. minor exposure to TCP (0.5-13.9 mg l(-1)), a range of plant metabolic activities was measured using oxygen production rate (0-18.4 micromol h(-1)). A positive correlation was shown between contaminant uptake rate and plant activity. Contaminant uptake was examined at a range of media pH values (6-9) and uptake rates were linearly correlated to fraction of contaminant in protonated form. These results demonstrated a link between plant activity and uptake of contaminant by plants and stress the importance of incorporating plant metabolic activity and contaminant speciation in development of natural and engineered phytoremediation systems. This research also indicates that aquatic plants can actively accumulate trace-organic contaminants and may ultimately serve as a sink for these materials in the natural environment.     

A microcosm test of adaptation and species specific responses to polluted sediments applicable to indigenous chironomids (Diptera)

Chironomids may adapt to pollution stress but data are confined to species that can be reared in the laboratory. A microcosm approach was used to test for adaptation and species differences in heavy metal tolerance. In one experiment, microcosms containing different levels of contaminants were placed in polluted and reference locations. The response of Chironomus februarius to metal contaminants suggested local adaptation: relatively more flies emerged from clean sediment at the reference site and the reverse pattern occurred at the polluted site. However, maternal effects were not specifically ruled out. In another species, Kiefferulus intertinctus, there was no evidence for adaptation. In a second experiment, microcosms with different contaminant levels were placed at two polluted and two unpolluted sites. Species responded differently to contaminants, but there was no evidence for adaptation in the species where this could be tested. Adaptation to heavy metals may be uncommon and species specific, but more sensitive species need to be tested across a range of pollution levels. Factors influencing the likelihood of adaptation are briefly discussed.