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PubMed2003

Seasonality and water quality trends in a maturing recreated reed bed.

The socio-economic and ecological value of wetland ecosystems is widely acknowledged. As a result, considerable efforts are now being made to rehabilitate and in some cases recreate wetlands throughout Europe. An option for the restoration of worked-out peat pits is to establish reed beds. Ham Wall, located in Somerset in the UK, comprises reed bed and a mosaic of other wetland habitats that has been constructed as a wildlife area. Since 1996, water chemistry has been monitored for a 16.5 ha wetland compartment planted with reeds in July 1995. Water is pumped into the reed bed from Ham Wall Rhyne, a drainage ditch supplied with nutrient-rich runoff from the surrounding agricultural land. The principal objectives of the research described in this paper were to investigate differences in the chemistry of water from different locations in the vicinity of the wetland and to evaluate seasonal changes and trends in water quality as the reeds matured. The results obtained provide insight into the biogeochemical functioning of the wetland system.

Conservation of Natural Resources↗
PubMed2005

Community-level analysis: key genes of aerobic methane oxidation.

Aerobic methane-oxidizing bacteria (methanotrophs) are a diverse group of bacteria that are currently represented by 13 recognized genera. They play a major role in the global methane cycle and are widespread in nature with representatives found in soils, freshwater, seawater, freshwater and marine sediments, peat bogs and at extremes of temperature, salinity, and pH. There has been an interest in methanotrophs for their potential in bioremediation processes. Methanotroph diversity and ecology are often studied using the "functional" genes pmoA, mmoX, and mxaF, encoding subunits of the particulate methane monooxygenase, soluble methane monooxygenase, and the methanol dehydrogenase, respectively. This chapter describes methods used to detect and analyze these functional genes.

Alcohol Oxidoreductases↗
PubMed2001

Treatment of wastewater by natural systems.

Experimental results from a pilot-scale constructed wetland (CW) treatment plant have been described. The study was conducted at two different systems: continuous and batch. In the continuous system, the treatment yields were monitored in different loading conditions in 1-year period. The pilot plant consists of two serially connected tanks settled up with fillers; Cyperus was used as treatment media and wastewater between the two tanks was recycled periodically. Chemical oxygen demand (COD) and suspended solid (SS) removal efficiencies were obtained as 90% and 95%, respectively. The effluent COD concentration at an average loading of 122 g COD/m2 day was satisfactory for the Turkish Water Pollution Control Regulation. This means that a 0.8 m2 of garden area per person is required. Other removal values for the same conditions were as follows: total Kjeldahl nitrogen (TKN) was 77%, total nitrogen (TN) was 61%, and PO4(3-) -P was 39%. The batch experimental systems consist of 12 pairs of serially connected tanks, with each pair having a surface area of 1 m2. Each set was filled with sewage once a day, and the wastewater between the paired tanks was recycled periodically by the pump. Each pair of tanks was filled with materials such as gravel, peat, and perlite. Seven of them were vegetated with Phragmites, Cyperus, Rush, Iris, Lolium, Canna, and Paspalum, while the other five were not seeded. The best performances were obtained by Iris for COD (% 94), by Canna for ammonia nitrogen (% 98), and by Iris for total nitrogen (% 90) and phosphorus (% 55) removal.

Humans↗
PubMed2003

Study of aluminium concentration and speciation of surface water in four catchments in the Limousin region (France).

This study highlights the contamination of the upstream catchment of several rivers (Vienne, Gartempe, Vézère) in the Limousin (France) by aluminium in the absence of atmospheric pollution. The presence of acid soils on a granitic platform is a natural factor which contributes to the presence of protons and aluminium in water. In the Limousin, it seems that the presence of aluminium in surface water is due to a combination of natural factors: poor acid soils, numerous wet moors and peat bogs. It is currently difficult to evaluate the real impact of intensive cultivation of coniferous trees on the aluminium concentrations found in water in this area. In water, the concentration in total aluminium increases with a decrease in pH and an increase in organic matter. Despite, high concentrations of total aluminium at low pH (close to or lower than 6), the monomeric toxic forms of aluminium, computed with a speciation software, are always inferior to the toxic values for fish. Under such conditions, the concentration in aluminium recorded in some upstream catchments of the Limousin rivers may not cause damage to aquatic life.

Aluminum Compounds↗
PubMed2003

Influence of suspended solids on acute toxicity of carbofuran to Daphnia magna: II. An evaluation of potential interactive mechanisms.

It has been demonstrated that simultaneous exposure of Daphnia magna to suspended solids and a carbamate pesticide potentiates the toxic response to the pesticide. The toxicodynamics between these stressors were investigated to determine possible mechanisms of interaction. Three experimental series were conducted with D. magna to determine: the effect of food availability on carbofuran toxicity; the effect of food availability on jointly administered carbofuran and suspended solids; and changes in the magnitude of effects which can occur with suspended solids of different composition. These experiments demonstrated that both carbofuran toxicity and the joint toxicity of carbofuran and suspended solids to D. magna can be modulated by food availability. While it is clear that food dilution could contribute to energy stress, it appears likely that additional interactive processes also contribute to the observed synergism between carbofuran and suspended solids. Additionally, decomposed peat was shown to be less of a stressor to these pelagic invertebrates than inorganic subsoil.

Animals↗
PubMed2001

Irish soil and land-use classifications as predictors of numbers of badgers and badger setts.

This study investigated possible associations between soil types, land use and badger numbers in an area of the Irish Midlands where badger removal had been conducted during 1989-1994. For this purpose, the area was divided into approximately 2500 geo-referenced square grids of 0.5 degrees km per side. For the outcomes (setts per grid, badgers per grid and tuberculous badgers per grid), Poisson models of land use, of soil type, and a combination of these two were developed. Influential grids were removed and the models adjusted for over-dispersion in the badger outcomes. Mineral-based soils, dry and very-dry peat soils supported increased numbers of setts and badgers. High-quality pasture was the major land use (pastures often are found on mineral-based soils) and supported increased numbers of setts, badgers, and tuberculous badgers. "Natural" areas also supported more setts and broad-leaf forested areas were associated with increased tuberculous badger numbers. Discontinuous urban areas tended to decrease sett numbers per grid. Hedgerow length was not an important predictor given the information on soil type and land use. Spatial correlations existed for badger setts in 1 degrees km grids, for badger numbers in 1.5 degrees km grids, and for tuberculous badgers in 2 degrees km grids. The latter two grids have approximately the same area as the territory size used by a social group of badgers. There were no spatial correlations at the smallest (0.5 km) grid size.

Agriculture↗
PubMed1999

Molecular monitoring of an uncultured group of the class Actinobacteria in two terrestrial environments.

Previous investigations of 16S rRNA clone libraries from a wide spectrum of mainly terrestrial origin have shown the worldwide distribution of several as yet uncultivated phylogenetically deeply rooting groups of Actinobacteria. From the percentage of the occurrence of these clones it was concluded that these organisms constitute a significant part of the bacterial microflora in these habitats. Two of the clone groups, previously designated group II and group III, were shown to be phylogenetically moderately related among each other. In order to more exactly determine the abundance of a representative of group II, clone DA079, the fraction of the organism's rRNA in total extracted rRNA was determined in several neighboring samples from Drentse A grassland soil (The Netherlands). The fraction ranged from 2.6 to 9.1%, averaging 5.5%. Based upon comparison of total rRNA and strain DA079-specific rRNA it was concluded that on the average 2 x 10(6) cells/g of this organism are present in the investigated soil. Attempts to isolate members of one of the 16S rDNA clone groups of Actinobacteria were made with samples from a German peat bog, in which the organisms had been detected previously. Molecular detection of group III organisms by a nested PCR approach was possible in different cultivation media. Despite the wide spectrum of growth media employed the isolation of group III strains failed.

Actinobacteria↗
PubMed2001

Important factors governing exposure of the population and countermeasure application in rural settlements of the Russian Federation in the long-term after the Chernobyl accident.

Rural settlements located in areas of the Russian Federation contaminated after the Chernobyl accident and exceeding an annual dose of 1 mSv a-1 have been classified according to 137Cs contamination density, internal dose and the neighbourhood of forests. It has been shown that, with the exception of the most contaminated areas, the internal doses decreased in accordance with a decline in 137Cs availability for plant root uptake. An inverse tendency was observed in areas with 137Cs contamination above 555 kBq m-2 which can be explained by a reduction or even termination of countermeasure application and by an increasing consumption of forest products in areas where restrictive countermeasures are still implemented. Twenty-seven settlements have been studied to estimate the effectiveness of countermeasures applied previously and to identify the most important factors governing the radiation exposure to the population and its change with time. It has been shown that the effectiveness of countermeasures which resulted in a decrease of up to 40% of doses has a tendency to decline in the long term. The need for continuation of remediation in rural settlements was evaluated both for selected settlements and extrapolated to the whole contaminated area and it has been shown that the application of countermeasures will be of importance at least up to the year 2045. Rather high effectiveness in terms of internal dose reduction (factor of 2-2.5) of radical improvement (disking, ploughing and reseeding) and administration of Cs binders to animals (Ferrocyn) was demonstrated for the selected settlements. It could be demonstrated that for forest-remote settlements there is a linear dependence between internal dose normalised to the density of contamination and the proportion of peat soils around settlements. For near-forest settlements, this dependence was less pronounced which can be explained by the high contribution of forest food products to the internal dose. Milk is still the major dose-forming product in rural Russian settlements (its contribution to internal dose in forest-remote settlements is above 70%); however, in near-forest settlements, the contribution of mushrooms to the internal dose is comparable to the contribution from milk.

Agriculture↗
PubMed2002

The influence of the sorptive properties of organic soils on the migration rate of 137Cs.

Using a compartment model, the migration rates of 137Cs were calculated for two types of organic soils: a low peat-muck soil and a black earth. The migration rates of 137Cs in the tested soils turned out to be significantly higher than in mineral types examined earlier and ranged from 0.6 to 12.3 cm/year. The partition coefficients (Kd) were also determined for samples with varying organic matter content (OM) that were taken from different layers of the studied soils. The experimental results indicate that there is a clear relationship between Kd values and OM. The investigation was widened by microcalorimetric measurements which confirmed that the adsorption of 137Cs on the organic soils is low.

Adsorption↗
PubMed2001

Cadmium accumulation in the freshwater isopod Asellus racovitzai: the relative importance of solute and particulate sources at trace concentrations.

A stable isotope tracer technique was used to evaluate the relative importance of particulates and water as respective sources of cadmium (Cd) uptake in the freshwater isopod Asellus racovitzai (Isopoda, Crustacea). 113Cd(NO3)2 was applied to the sediment at a nominal concentration of 20.0 ng g-1, and 114Cd(NO3)2 was added to the overlying water (nominal concentration of 4.4 ng g-1), in the same test systems. Asellids added were either free-ranging on the sediment surface, where they were exposed to both particulate and water sources of Cd, or were enclosed in dialysis 'tubes', 10 cm above the sediment surface, and were therefore exposed to Cd in water only. By analysis of both isotopes, uptake vectors could be determined simultaneously. After 7 days of exposure, average 114Cd concentrations in 'free' asellids were 15.6 +/- 2.0 micrograms/g, compared with 10.4 +/- 1.8 micrograms/g in 'tube'-held asellids (P < 0.05), i.e. at least 60% of accumulated 114Cd was from water. Furthermore, water-spiked 114Cd was accumulated in asellids to tissue concentrations that were more than four-times greater than sediment-spiked 113Cd. When the sediment organic content was increased (20% peat moss), total Cd concentrations in both overlying water and asellids were significantly lower (P < 0.01), compared with the mineral sediment treatments, and Cd accumulation in tube and free asellids was similar. This study shows that water is an important vector of Cd accumulation in A. racovitzai, and factors that lower Cd concentrations in solution (such as increased organic content of sediment), decrease Cd bioaccumulation.

Animals↗
PubMed2001

Response of mycorrhizal Norway spruce seedlings to various nitrogen loads and sources.

Norway spruce seedlings were grown under greenhouse conditions in Rootrainers with a vermiculite-peat moss mixture under various N-regimes for 6 months. Either ammonium or nitrate was applied in loads of 100 or 800 kg N ha(-1) year(-1) to seedlings which were either non-mycorrhizal or inoculated with the mycorrhizal fungi Hebeloma crustuliniforme or Laccaria bicolor. The use of increasing N loads enhanced shoot and total biomass, whereas root/shoot ratio, number of short roots and mycorrhization decreased. A significant enhancement of the concentration and content was obvious for the element N, whereas a significant decrease was obvious for P and Zn concentrations. The use of ammonium, as opposed to nitrate, significantly enhanced the biomass and the numbers of short roots, and reduced the root/shoot ratios, but did not influence the mycorrhization. It further significantly enhanced the N concentrations in roots and shoots. Fungal inoculation with H. crustuliniforme or L. bicolor compared to non-inoculated controls significantly enhanced shoot and total biomass, but reduced root/shoot ratios. The mycorrhization further significantly enhanced N and P concentrations and contents, but reduced Mn. Overall, the mycorrhization improved the P nutrition of the seedlings independently on the applied N loads or N sources. Dose response curves using ammonium nitrate as N source with a maximum load of 1600 kg N ha(-1) year(-1) applied on seedlings associated with H. crustuliniforme revealed that the maximum growth was reached at a load of 800 kg N ha(-1) year(-1) with a simultaneous decrease of the mycorrhization. In both shoots and roots, N concentrations increased constantly with increasing N loads, while P, Ca, and Zn concentrations decreased constantly.

Air Pollutants↗
PubMed2002

Seasonal phosphatase activity in three characteristic soils of the English uplands polluted by long-term atmospheric nitrogen deposition.

Phosphomonoesterase activities were determined monthly during a seasonal cycle in three characteristic soil types of the English uplands that have been subject to long-term atmospheric nitrogen deposition. Activities (micromol para-nitrophenol g(-1) soil dry wt. h(-1)) ranged between 83.9 and 307 in a blanket peat (total carbon 318 mg g(-1). pH 3.9), 45.2-86.4 in an acid organic grassland soil (total carbon 354 mg g(-1), pH 3.7) and 10.4-21.1 in a calcareous grassland soil (total carbon 140 mg g(-1) pH 7.3). These are amongst the highest reported soil phosphomonoesterase activities and confirm the strong biological phosphorus limitation in this environment.

England↗
PubMed1998

Sulphur isotopic investigation of a polluted raised bog and the uptake of pollutant sulphur by Sphagnum.

The sulphur content and sulphur isotopic composition of Sphagnum as well as anionic compositions and sulphur isotope ratios of rainwater inputs and bog waters have been measured at Thorne Moors, a raised bog in eastern England. Rainwater sulphate isotopic composition shows the sulphur input at this site to be dominated by anthropogenic pollution from fossil fuel burning. Strong depletion of sulphate (low SO4(2-)/Cl-) and enrichment in 34S in sulphate occurs at depth in the bog porewaters due to bacterial sulphate reduction. Some surface waters have low SO4(2-)/Cl-) and are 34S enriched due to removal of sulphate by downward diffusion into a sulphate-reducing zone. Other sites have high SO4(2-)/Cl-) which appears to result from oxidation of organically bound sulphur in the peat. Sulphur is present in Sphagnum at around 0.2% by weight and is depleted by 0 to -9 per thousand in the heavier 34S isotope compared to sulphate. Comparison with similar data from pristine coastal sites shows that sulphur incorporation into Sphagnum is enhanced in the polluted site (as Sphagnum sulphur concentrations are higher at lower total sulphur inputs) and that sulphur incorporation is accompanied by a smaller isotopic shift than in the pristine sites. The data support a model of preferential incorporation of partially reduced sulphur species (probably HSO3-) into Sphagnum. In pristine sites these are only available as oxidation products of sulphide formed by sulphate reduction and are 32S depleted. In polluted sites this source is augmented by sulphur(IV) species in atmospheric inputs and the resultant mixture is less depleted in 32S. Thus, in the polluted sites more HSO3- is available for uptake and the isotopic shift between Sphagnum and aqueous sulphur species is smaller.

Journal Article↗
PubMed2000

Retention of organic and inorganic chemicals by the drainage/supply piping material.

A critical issue facing the turfgrass industry is the environmental fate and transport of organic and inorganic chemicals used on golf courses. The fate and distribution of those chemicals are strongly influenced by sorptive interactions with soil and sediment. In this study, the drainage and water supply piping material (used for construction of a prototype encapsulated golf green) was utilized to determine its potential sorption of three organic chemicals [2,4-dichloro-phenoxyacetic acid] (2,4-D), naphthalene and toluene and nitrate. Crushed piping material (small-to-large particle sizes) was evaluated. Isotherms were constructed using a batch equilibration technique. The results showed that the drainage/supply piping material at small particle sizes (<2.5 mm) has higher sorptive ability compared to soil (1.7 for 2,4-D and 13.4 for naphthalene). The K(F) value was 44, 253 and 70 for 2,4-D, naphthalene and toluene, respectively. K(oc) values were much higher than those of peat and soil at lower equilibrium concentrations. However, sorption decreased dramatically with increasing particle size (approaching zero at particle size 10 mm), due to reduction of surface areas and sorption sites. Sorption of NO(3)-N by the piping material was negligible. We concluded that sorption by intact drainage/supply piping material would not affect the recycling efficiency of pesticides and nutrients in the constructed encapsulated green. Conversely, drainage/supply piping material particles smaller than 2.5 mm in diameter can effectively be utilized as a filtering material.

Journal Article↗
PubMed2000

Container-grown tree seedling responses to sodium chloride applications in different substrates.

Seedlings of Norway maple (Acer platanoides), silver birch (Betula pendula), Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) were grown in selected sodium chloride (NaCl) concentrations, soil types and under different watering regimes. Plants were raised from seeds, except for Scots pine plants which were obtained from a commercial source. Among the plant species tested, Scots pine was the most tolerant to soil salinity, while Norway spruce was the most susceptible. For both Norway maple and Norway spruce some half-sib families were more tolerant than others. No significant correlation was found between the tolerance of different half-sib families and the tolerance of mother trees observed in the field. The extent of leaf necrosis correlated significantly with the leaf concentrations of sodium (Na) and chloride (Cl). Among half-sib families within the species no such correlation was found. On the other hand, the least injured progeny of Norway maples had the highest concentrations of NaCl. The extent of salt-induced leaf necrosis varied with soil type, and a significant interaction between species and soil type was observed. Seedlings of Norway spruce grown in sand showed more severe necrosis and significantly higher concentrations of Na and Cl than seedlings grown in loam, silt loam, and peat. The severity of salt-induced leaf injury varied with the watering regime. Silver birch was the most affected species by drought and autumn watering treatments. Plants of silver birch subjected to drought showed increased leaf necrosis compared to the non-treated plants, and autumn watering treatment reduced the severity of leaf necrosis.

Journal Article↗
PubMed2003

Sampling Broad Habitat change to assess biodiversity conservation action in Northern Ireland.

A habitat monitoring programme, the Northern Ireland Countryside Survey, carried out by the University of Ulster for the Department of the Environment for Northern Ireland, is described. It was based on a random sample of quarter kilometer grid squares, stratified by multivariate land classification. Estimates of change in habitat area between 1987-1992 and 1998 are presented and used to assess policy-related priorities for biodiversity conservation action in widespread habitats in Northern Ireland (NI). The basis of the assessment is Broad Habitats, a classification developed as part of the United Kingdom (UK) Biodiversity Action Plan. Improved Grassland, Neutral Grassland and Bog Broad Habitats occupy the largest area of NI, which holds a large proportion of the UK Neutral Grassland and Fen Marsh and Swamp Broad Habitat resource. The greatest net area increases with time were in Improved Grassland (33%), Coniferous Woodland (12%) and Broadleaved, Mixed and Yew Woodland (9%). The greatest net area decreases were in Neutral Grassland (-32%), Arable and Horticulture (-25%), Fen, Marsh and Swamp (-19%), Bog (-8%) and Calcareous Grassland (-7%). These changes are a function of agriculture, public and private forestry, building construction and peat cutting for fuel. The Key biodiversity issue is seminatural Broad Habitat loss, in particular, Neutral Grassland and Fen, Marsh and Swamp, highlighting the lack of effective action for protecting biodiversity in the countryside as a whole. The extent to which current land use is shown to be driving change, indicates that biodiversity conservation action through implementing landscape-scale agri-environment measures could deliver major biodiversity gains. The reliable information on recent changes, provided by the Northern Ireland Countryside Survey, has been used to guide conservation planning. Future re-survey will allow the effectiveness of the conservation strategy as it applies to the countryside as a whole, to be determined. As decisions on land use increasingly have a strong European dimension, concerted action for protecting biodiversity in the countryside as a whole is needed. This would be promoted by a structured sampling approach, based on standard habitat mapping procedures.

Agriculture↗
PubMed2002

Treatment of creosote-contaminated groundwater in a peat/sand permeable barrier--a column study.

A column study was conducted to determine if a permeable barrier can be used to treat creosote-contaminated groundwater based on sorption and biodegradation, and to determine which processes remove the various creosote compounds. Creosote-contaminated water (sterile and non-sterile) was applied to sterile and non-sterile saturated columns with peat (20 vol.%) and sand (80 vol.%) for 2 months. Temperature was 9 degrees C, inlet oxygen concentration 9-10mg/l and average residence time was two days. The peat/sand barrier material removed 94-100% polycyclic aromatic hydrocarbons (PAHs), 93-98% nitrogen/sulfur/oxygen (NSO)-containing heterocyclic aromatic compounds, and 44-97% total phenols. The peat/sand material efficiently sorbed PAHs (>2 rings) and three-ring NSO-compounds, and also sorbed significant amounts of two-ring NSO-compounds and naphthalene. Naphthalene and NSO-compounds not sorbed were biological degraded. Phenol and cresols were efficiently removed by microbial degradation. The barrier material was somewhat less efficient removing dimethylphenols (DMPs) and trimethylphenols (TMPs), where DMPs were hardly sorbed and TMPs were hardly degraded. The results imply that a peat/sand barrier can treat creosote-contaminated groundwater. Modifications might be needed for enhanced removal of DMPs and TMPs, and oxygen supply might be necessary in aquifers with low oxygen content.

Adsorption↗
PubMed2002

Effect of humic substances on Cu(II) solubility in kaolin-sand soil.

The type and amount of organic matter present in industrially contaminated soils will influence the risk they pose. Previous studies have shown the importance of humic and fulvic acids (FAs) (important components of soil organic matter) in increasing the solubility of toxic metals but were not carried out using toxic metal levels and the pH range typical of industrially contaminated soils. This study investigated the influence of three humic substances (HSs: humates, fulvates and humins) on the solubility of copper(II) ions in kaolinitic soil spiked with Cu at levels representative of industrially contaminated soil. Humates, fulvates and humin were extracted from Irish moss peat, and controlled pH batch leaching tests were conducted on an artificial kaolin-sand soil that was spiked with each. Further leaching tests were conducted on soil spiked with each HS and copper nitrate. Dissolved organic contents were determined by titration and total and free aqueous copper concentrations in the leachate were measured using AAS and ion selective electrode (ISE) potentiometry respectively (dissolved complexed copper levels were determined by difference). It was found that humates and fulvates are partially sorbed by the soil, probably by chemisorption on positively charged gibbsite (Al-hydroxide) sites in the kaolinite. The addition of 340 mg/kg Cu(II) ions did not significantly affect the amount of humate or fulvate sorbed. Dissolved humates and fulvates form soluble complexes with copper over the pH range 3-11. However, in the presence of kaolinite, soluble copper humates and fulvates are unable to compete with the kaolinite for Cu ions at pH 6-7. Above pH 8, humate and fulvate complexes are the only forms of dissolved Cu. Humin is largely insoluble and has little effect on Cu mobility between pH 2 and 12. The implication of this study is that measurement of total soil organic content and water leaching tests should be a standard part of contaminated site investigation.

Adsorption↗