The agricultural impact of opencast coal mining in England and Wales

Opencast coal mining in England and Wales can cause a wide range of environmental problems which are increasingly public issues due to the planned expansion in output and the impact this may have on agriculture and landscape. Opencast mining is reviewed on a county by county basis to identify the variations in the disturbance caused. A detailed review of restoration techniques and the agricultural quality of the restored land is presented, and the role of Planning Authorities is discussed. Significant variations in the impact of opencast operations are identified, especially in relation to the potential for derelict land reclamation and the grade of agricultural land affected. The latter is generally lower grade 3 and below, although in certain areas operations are entering land of higher agricultural and scenic quality. The quality of restoration, while good, still has scope for improvements, such as reducing soil compaction and the subsequent management of the land by the farmer. The impact on agricultural productivity is difficult to assess, but it appears to be only slight in those cases where recent restoration techniques were used and when lower grade agricultural land is taken.     

Generating productive topsoil substitutes from hard rock overburden in the southern appalachians

Natural soils on steeply sloping landscapes in the Appalachian coal fields of Virginia. West Virginia. Kentucky, and Tennessee are often thin, rocky, acidic and infertile, making the topsoiling of surface mined sites impractical in many cases. Topsoil substitutes composed of blasted rock fragments are commonly used in this region. The proper selection and placement of designated topsoil substitutes is therefore critical to long term reclamation success. These mine soil surfaces are not in equilibrium and with the surface environment, and it is quite difficult to diferentiate among dissolution, adsorption, desorption and precipitation reactions as these surfaces weather with time. Severe compaction limits the productivity of many otherwise suitable topsoil substitutes. A minimum non-compacted thickness of 1 m is desirable to insure long run mine soil productivity for a variety of post-mining land uses. Significant changes in the physical, chemical, and mineralogical properties of mine soils occur within one year after placement. Mine soils high in silt content often form hard vesicular surface crusts, particularly when left unvegetated. The long term survival of plant communities on these mine soils is dependent upon mine soil organic matter accumulation and N and P cycling. Little is currently known about N and P dynamics in these mine soils, but P-fixation is a profound problem in high Fe^3- spoils. Revegetation practices that were designed to meet 2-year bond release requirements may not he sufficient to meet new 5-year release standards. Hard rock derived mine soils can often equal or exceed native topsoil in productivity and post mining land use potential.     

Resin embedments of quantitative meiofauna samples for ecological and structural studies — Description and application

In enumerating data for systematic and ecological studies on meiofauna, an unfortunate diversification exists in the methods used for observation, identification, preservation and curatorial treatment of various taxa. The application of transmission electron microscopy resin embedment techniques to whole, quantitative, extracted meiofauna samples is described here as a new method, which overcomes most of these problems. Slide-shaped resin blocks are produced by this method; they contain the mass-embedded meiofauna on one side and sand from the sample site on the other side; the latter can be used in studying sand-grain epigrowth of Protista, Fungi and Monera. Examples for the applicability of these slides to various meiobenthic studies are given for most taxa, but especially for Turbellaria, Annelida and Mystacocarida. Using this resin-slide technique, whole quantitative transects can be deposited as “ecotype material” in museums.     

Reducing the environmental impact of coal-washing practice in Australia

All Australian coal for export is washed — that is, the low-grade high-ash material is separated out and disposed of at the washery site. The coarse rejects are generally placed in embankments and the tailings are pumped into settling ponds. These methods of waste disposal can create environmental problems. In addition, they represent a significant energy loss, because about one-third of the waste material is combustible and is thus a potentially valuable source of energy. Laboratory studies at the CSIRO Division of Fossil Fuels at North Ryde, New South Wales, have shown that energy can be successfully recovered from washery wastes by the process of fluidized-bed combustion. A pilot fluidized-bed combustor, with a capacity of 2 tonnes/hour, is undergoing prolonged trial at the Clutha washery near Camden, New South Wales, in a joint project between the Joint Coal Board and CSIRO. The results from the pilot plant tests have provided the basis for a conceptual design and feasibility study for a full-scale tailings treatment plant. This study has indicated that fluidized-bed combustion:

1. offers an environmentally attractive and economically competitive alternative to the disposal of tailings in settling ponds, and
2. can be used to generate large quantities of energy from the wastes, reducing the energy lost in coal washing from around 16% to 6% of the coal mined.

     

Dimethyl disulfide and dimethyl trisulfide: so similar yet so different in evoking biological responses in saprophilous flies

Dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS) are used by saprophilous insects to locate breeding sites (decaying organic matter), and by brood-site deceptive flowers to attract such insects. However, little is known about the relative importance of these two compounds in eliciting electrophysiological and behavioral responses in the insects. Here, we compared the relative attractiveness of DMDS and DMTS to saprophilous flies in field choice experiments and tested whether potential differences in field responses can be explained by differences in electrophysiological antennal responses to these compounds. Field experiments revealed that the attractiveness of a mixture of these compounds is due to DMTS alone. This result was confirmed by electroantennographic recordings in which flies of four tested species of Calliphoridae (Lucilia sericata, L. caesar, Calliphora vicina, Protocalliphora azurea) and one Muscidae (Musca domestica) respond clearly to DMTS, but not to DMDS. In house flies, however, DMTS elicited electrophysiological responses only, not reflected in behavioral assays. Despite the fact that DMTS and DMDS exhibit similar chemical structures, both the electroantennographic and field responses from saprophilous flies to these two compounds strongly differed. Our study suggests that oligosulfide-responsive saprophilous flies rely on DMTS and not DMDS for finding appropriate breeding sites and that DMTS and not DMDS could act as a key mediator for pollinator attraction in brood-site deceptive plants.     

Molecular characterization of symbiotic algae (Symbiodinium spp.) in soritid foraminifera (Sorites orbiculus) and a scleractinian coral (Orbicella annularis) from St John,US Virgin Islands

The exchange of Symbiodinium symbionts among scleractinian and soritid hosts could facilitate acclimatization to changing conditions by establishing novel symbiotic unions better tuned to prevailing conditions. In this study, we compare the communities of Symbiodinium spp. in neighboring populations of Orbicella annularis and Sorites orbiculus from St. John, US Virgin Islands, using operational taxonomic unit (OTU) clustering of cloned internal transcribed spacer 2 (ITS-2) rDNA sequences. We tested for partitioning of Symbiodinium OTUs by host and depth within and between two sites to explore the potential for symbiont exchange between hosts and light-dependent microhabitat specialization. An apparent lack of overlap in Symbiodinium communities (13 OTUs representing 7 clades) hosted by O. annularis and S. orbiculus suggests that exchange among these hosts does not occur. A low number of novel clade G ITS-2 sequences were found in one O. annularis and one S. orbiculus. A phylogenetic analysis of these sequences revealed them to be sub-clade G2 Symbiodinium, which are most commonly hosted by excavating clionid sponges. A permutational MANOVA revealed within host differences in the partitioning of Symbiodinium OTUs by site but not depth. This finding highlights the potential roles of either dissimilar environmental conditions between sites, or at least partial separation between populations, in determining the types of Symbiodinium contained in different hosts on a spatial scale of a few kilometers.     

Environmental problems of coal production in the United Kingdom with particular reference to the Yorkshire coalfield

This paper reviews the environmental problems associated with the coal-mining industry on the Yorkshire coalfield. The main environmental problems are identified as being caused by:

1. The need to dispose of large quantities of colliery waste or ‘spoil’, in an environmentally acceptable manner.
2. Derelict and despoiled land, including the problems caused by the re-working of old tips for their coal content.
3. Opencast coal mining.
4. Subsidence.
5. Transportation of coal and coal waste.

These problems are reviewed in the context of the role of coal in meeting the United Kingdom's energy needs and the framework of environmental control within which the coal-mining industry has to operate. Particular stress is laid on the fact that the Yorkshire coalfield, as with the majority of coalfields, is an old one with a legacy of inherited dereliction. Whilst modernisation of the mining industry is proceeding there have not been parallel developments put in hand to cope with the changing nature of the environmental problems resulting from the modernisation of the industry. Particular stress is placed on the need to dispose of the greatly increased quantities of spoil now being produced.     

Primary vegetative growth on an old tailings dam,Zawar mines

Tailings containing toxic qualities of heavy metals are a potential source of pollution. Stabilisation by vegetative methods have been found the most effective. In an attempt to vegetate tailings dams it has been noted that while certain milky latex containing plants can be grown without any preconditioning of the soil, almost any plant can be grown after proper conditioning. However, the plants grown there cannot be consumed by humans or cattle due to their high metal content.     

Estimation of coral growth-rates from laboratory 45Ca-incorporation rates

Laboratory ⁴⁵Ca-incorporation rates in hermatypic coral skeletons have previously been used successfully as an index of physiological function. This laboratory method would become more meanigful if it also provided an absolute measure of coral growth rates. In two coral species, Porites compressa and Pocillopora damicornis, ⁴⁵Ca incorporation rates were obtained from short (0.5 h) laboratory incubations using apical (determined as fast growing) portions of freshly collected coral branches. ⁴⁵Ca exchange across the coenosarc was not significant and not corrected for, whereas diurnal fluctuation in ⁴⁵Ca in Pocillopora damicornis was significant and a necessary correction. A calculated surface area is used to express calcification rate. Typical growth rates calculated from the ⁴⁵Ca-incorporation rates were 20 and 6 mm/year for Porites compressa and Pocillopora damicornis, respectively. These rates are considerably higher than those previously obtained in the laboratory, and compare favorably with field growth rates — 24 and 14 mm/year, respectively.     

A light and electron microscope investigation of gametogenesis in Nicolea zostericola (Polychaeta: Terebellidae)

A light and electron microscope study was conducted on Nicolea zostericola (Oersted: Grube, 1860) to describe the processes of gametogenesis. N. zostericola is a monotelic species which spawns from 2 to 5 times over a period of 2 weeks at the end of its 1-year life span. The gonads consist of plates of cells bulging from beneath the peritoneum in the thoracic region of the body. Oogenesis has been divided into 3 phases: an ovarian phase in which gametogonia and primary oocytes are retained within the ovary, a follicular phase, in which oocytes are ovulated into the coelom surrounded by several layers of follicle cells and the vitellogenic phase, where individual oocytes rupture through the follicle cells and enter the coelomic fluid where cell growth and yolk synthesis occur. The combined ovarian and follicular phases have a duration of about 3 to 5 weeks and the vitellogenic phase about 5 to 6 months. Vitellogenesis is described on the ultrastructural level. Yolk synthesis involves the participation of the Golgi apparatus and endoplasmic reticulum of the oocyte in possible combination with nutrient absorption from the coelomic fluid. Spermatogenesis involves the rupturing of masses of spermatogonia into the coelom from the testis, surrounded by peritoneal cells. Smaller clusters of spermatocytes are later released into the coelomic fluid where mitotic and meiotic divisions eventually produce flattened plates of sperm. The mature spermatozoan possesses an elongate head, atypical for most polychaetes.     

Regional assessment of plant growth problems for colliery spoil reclamation

The data on plant growth conditions collected for 34 sites in the Barnsley and South Yorkshire Areas of the National Coal Board are analysed using methods of ordination and numerical classification in order to display the regional variations of plant growth characteristics. The potential value of such regional analyses and the manner in which such information could be used by reclamation agencies is discussed and a detailed example is presented for one site. The complete methodology and its limitations are reviewed and the implications for planning of reclamation projects discussed.     

Habitat selection in the tropical polychaeteSpirobranchus giganteus

Total body weight, tube length, abdomen weight and branchial crown weight of individualSpirobranchus giganteus (Pallas) living on four different coral species on the bank reef on the west coast of Barbados were investigated in 1986. Worms onDiploria strigosa were larger in all size parameters than those onMontastrea annularis, which were larger than those onMontastrea cavernosa, which were larger than those onPorites porites. The differences between worms onM. annularis andM. cavernosa were not significant. Variation in worm size on the different corals could result from variation in mortality and/or variation in growth. Whichever the case, larger worms may have higher lifetime reproductive success. Abdomen weight is an index of gamete production inS. giganteus, and increases with increasing body weight for worms on all corals. Moreover, larger worms do not have lower abdomen weight at a given body size than smaller worms. This may imply that faster growth does not reduce gamete production at body size. The coral species on which worms are largest are those most preferred by worm larvae in the laboratory and most heavily colonised by adult worms in the field. The results suggest adaptive habitat selection by planktonic larvae ofS. giganteus.     

Connectivity in solitary ascidians: Is a 24-h propagule duration sufficient to maintain large-scale genetic homogeneity?

Ascidians are considered to have lower dispersal potential than most other sessile marine invertebrates with planktonic propagules by virtue of a very brief propagule duration. The larvae of colonial forms remain in the water column for only a few minutes, whereas most solitary forms settle in less than 24 h. This difference in propagule duration has been used to explain why allozyme data from colonial ascidians on the Australian east coast were genetically distinct at different sampling sites, whereas a solitary species exhibited no genetic structure. Spatial homogeneity in solitary species is surprising because genetic structure of species with much higher dispersal potential can be characterised by isolation by geographic distance, suggesting that these disperse by means of a stepping-stone pattern of dispersal. I reassessed the dispersal potential of solitary ascidians using DNA sequence data from the mitochondrial cytochrome oxidase subunit 1 gene and the intron of the nuclear adenine nucleotide transporter gene of a common south-eastern Australian solitary ascidian, Pyura praeputialis, using samples that span the species’ distribution range. Congruent with earlier findings, there was no evidence for stepping-stone dispersal, but it must be conceded that these results could be strongly affected by frequent adult dispersal, particularly by means of anthropogenic vectors, as well as insufficient marker resolution.     

Density and composition of heterotrophic bacterial populations in North Sea sediments

The bacteria from 119 sediment samples collected off the Belgian and Dutch North Sea coast were enumerated on marine agar. Geographical and seasonal variations were observed. The colony formers were mainly obligate aerobes. Coliform organisms were relatively rare. An exhaustive analysis of a few samples revealed a great number of species belonging to different taxonomic groups. A survey of physiological and biochemical characteristics of 71 isolates is presented.     

Soil organic matter and salinity affect copper bioavailability in root zone and uptake by Vicia faba L. plants

Processes that control the mobility, transformation and toxicity of metals in soil are of special importance in the root-developing zone. For this reason, there is a considerable interest in understanding trace elements (TEs) behavior in soil, emphasising the processes by which plants take them up. Increased root-zone salinity can affect plant TEs uptake and accumulation in plant tissue. Furthermore, copper (Cu) complexation by soil organic matter (SOM) is an effective mechanism of Cu retention in soils, controlling thus its bioavailability. Therefore, a greenhouse pot experiment was conducted to study the effects of soil Cu contamination in a saline environment on faba bean (Vicia faba L.) element uptake. Treatment with NaCl salinity was applied (control, 50 mM NaCl and 100 mM NaCl) on faba bean plants grown in a control and in a soil spiked with Cu (250 and 500 mg kg^?1). Low and high SOM content trial variants were studied. Cu accumulation occurred in faba bean leaf, pod and seed. Cu contamination affected plant element concentrations in leaves (Na, Ca, Mg, Mn), pod (Zn, Mn) and seed (Mn, Mo, Zn). Root-zone salinity also affected faba bean element concentrations. Furthermore, Cu contamination—salinity and salinity—SOM interactions were significant for pod Cu concentration, suggesting that Cu phytoavailability could be affected by these interactions. Future research will be focused on the mechanisms of Cu translocation in plant and adaptation aspects of abiotic stress.     

Spatio-temporal log-Gaussian Cox processes for modelling wildfire occurrence: the case of Catalonia, 1994–2008

Wildfires have become one of the principal environmental problems in the Mediterranean basin. While fire plays an important role in most terrestrial plant ecosystems, the potential hazard that it represents for human lives and property has led to the application of fire exclusion policies that, in the long term, have caused severe damage, mainly due to the increase of fuel loadings in forested areas, in some forest systems. The lack of an easy solution to forest fire management highlights the importance of preventive tasks. The observed spatio-temporal pattern of wildfire occurrences may be idealized as a realization of some stochastic process. In particular, we may use a space–time point pattern approach for the analysis and inference process. We studied wildfires in Catalonia, a region in the north-east of the Iberian Peninsula, and we analyzed the spatio-temporal patterns produced by those wildfire incidences by considering the influence of covariates on trends in the intensity of wildfire locations. A total of 3,166 wildfires from 1994–2008 have been recorded. We specified spatio-temporal log-Gaussian Cox process models. Models were estimated using Bayesian inference for Gaussian Markov Random Field through the integrated nested Laplace approximation algorithm. The results of our analysis have provided statistical evidence that areas closer to humans have more human induced wildfires, areas farther have more naturally occurring wildfires. We believe the methods presented in this paper may contribute to the prevention and management of those wildfires which are not random in space or time.     

Growth and form in the reef-building coral Montastrea annularis

The in-situ growth rate of the reef coral Montastrea annularis on a reef at Jamaica, W. Indies was determined for a 1-year period using Alizarin Red-S staining techniques. Growth rate is correlated with water depth and growth form. The flattened growth form of M. annularis allows for continued rapid increase in colony surface area at low light intensities. The geomorphology of Jamaican reefs may in part be controlled by the population ecology of M. annularis.     

Lipids and fatty acid composition of particulate matter in the North Atlantic: importance of spatial heterogeneity,season and community structure

Lipid class profiles and total fatty acid composition of particulate matter were studied in the northeast Atlantic during the spring bloom and fall. Eddies of known physical and chemical properties were sampled at different depths. HPLC pigment data were used to characterize the phytoplankton communities. In spring, a dominance of prymnesiophytes was recorded at all depths, while in fall prochlorophytes dominated near the surface and prymnesiophytes only at deep chlorophyll maximum. Lipid classes included triglycerides, sterols, glycolipids and phospholipids. A differential relationship between phytoplankton abundance and lipid accumulation was observed: spring lipid concentrations were positively related to phytoplankton biomass, while fall particulate lipid did not show any relationship. The main feature was a northward increase in lipid concentrations unrelated to the mesoscale hydrological structures. Polar lipids dominated over neutral acyl-glycerols with phospholipids dominating over glycolipids in spring, while glycolipids dominated in fall. This resulted from different nutrient availability with a dominance of flagellates associated with mesotrophy in spring and of picophytoplankton associated with oligotrophy in fall. In terms of fatty acids, factorial correspondence analyses illustrate the influence of seasonally changing assemblages: (1) in spring, the main source of variability was the bloom with an opposition between bloom sites characterized by n-3 and n-6 PUFA, and more detrital deep samples characterized by saturated, monoenoic and branched acids; (2) fall fatty acid profiles were similar at all depths and very close to those observed for spring deep samples. Comparison of pigment and fatty acids using redundancy analysis suggested that pelagophytes were linked to saturated and branched acids. It also showed that prymnesiophytes and prochlorophytes were significantly associated with n-6 and n-3 PUFA. The spring period illustrated the complexity of these relationships with dinoflagellates and prymnesiophytes linked with n-3 PUFA, diatoms linked with palmitoleic and myristic acids, and pelagophytes linked with n-6 PUFA and higher-chain-length monoenes.     

The role of metabolic nitrogen in coral calcification

When pieces of the staghorn coral Acropora acuminata are incubated with ¹⁴C-urea, the label is incorporated into skeletal carbonate. Incorporation of this label differs from that of H¹⁴CO ₃ ^- , suggesting urea is not immediately hydrolysed to provide a further source of HCO ₃ ^- . The effects of certain organic substrates upon calcification suggest the ornithine cycle is involved. Citrulline, an ornithine cycle intermediate, is found in high concentrations in the tissues of hermatypic corals. Urea, allantoins, NH₃ and arginine are also present. These compounds are barely detectable in zooxanthellae or an ahermatypic coral. The allantoins may be present as calcium salts. It is suggested that allantoins are the medium by which Ca²⁺ and CO₂ are transported to sites of calcification. Hydrolysis of urea, formed by breakdown of allantoins, yields CO₂ and NH₃. The NH₃ may neutralise protons formed during precipitation of CaCO₃ and bring about their removal from sites of calcification. As well as providing urea, the ornithine cycle may also be involved in the removal of NH₃ from sites of calcification.