Streams in the Harz National Parks (Germany) — a hydrochemical and hydrobiological evaluation

Between 1995 and 2001, 16 measuring points at small and medium sized brooks in the Harz National Parks were sampled. The samples have been evaluated by means of hydrochemistry and macroinvertebrate biology. Although nearly all streams are largely uncontaminated by oxygen-consuming substances, they are settled only by a small number of macroinvertebrate species. There is a clear correlation between this number and pH. The reduction in species number with decrease of pH is mainly caused by the absence of most Ephemeroptera, some Coleoptera and Trichoptera. Comparing biological evaluation of acidity with physico-chemical measurements, a unacceptable underestimation was found. The reason could be that different sensitivities to acidification between regional populations seem to exist.

Despite of the low species number, there is a very specific macroinvertebrate fauna that emphasizes the conservation value of the Harz National Parks.     

Copper and sewage inputs from recreational vessels at popular anchor sites in a semi-enclosed Bay (Qld, Australia): estimates of potential annual loads

Environmental impacts of vessels are well documented; Cu pollution as result of Cu based antifouling paints and nutrient pollution (such as N) from marine sewage are two examples of such disturbances. Understanding environmental impacts as well as the use of coastal waterways by recreational vessels is of concern to regulatory authorities, waterway users and local residents. In this study more than 55 aerial surveys were conducted of selected popular anchorages in eastern Moreton Bay, Queensland, Australia. Numbers of recreational vessels at certain times during the year were used in multiple linear regression analyses to develop predictive models for recreational vessel numbers. Over one year approximately 10,000 locally registered recreational craft (>6m length overall) generated an estimated 59,000 vessel nights. With Cu leaching rates from the literature, and estimates of sewage inputs (assuming little or no use of pump-out facilities), load estimates associated with overnight use of 20 popular anchor sites were calculated as 141+/-46 kg of Cu and 1.17+/-0.38 t of nitrogen (N) annually. More importantly, the models showed vessel activity to be highly variable, and focused at peak holiday times, with 14% of vessel activity and associated pollutant loads entering the environment during Christmas and Easter. This study highlighted the inherent difficulties in managing a popular maritime amenity and Marine Parks such as the Moreton Bay Marine Protected Area, Queensland, Australia with its variety of stakeholders and types and intensities of uses.     

Copper and sewage inputs from recreational vessels at popular anchor sites in a semi-enclosed Bay (Qld,Australia): Estimates of potential annual loads

Environmental impacts of vessels are well documented; Cu pollution as result of Cu based antifouling paints and nutrient pollution (such as N) from marine sewage are two examples of such disturbances. Understanding environmental impacts as well as the use of coastal waterways by recreational vessels is of concern to regulatory authorities, waterway users and local residents. In this study more than 55 aerial surveys were conducted of selected popular anchorages in eastern Moreton Bay, Queensland, Australia. Numbers of recreational vessels at certain times during the year were used in multiple linear regression analyses to develop predictive models for recreational vessel numbers. Over one year approximately 10,000 locally registered recreational craft (>6 m length overall) generated an estimated 59,000 vessel nights. With Cu leaching rates from the literature, and estimates of sewage inputs (assuming little or no use of pump-out facilities), load estimates associated with overnight use of 20 popular anchor sites were calculated as 141 ± 46 kg of Cu and 1.17 ± 0.38 t of nitrogen (N) annually. More importantly, the models showed vessel activity to be highly variable, and focused at peak holiday times, with 14% of vessel activity and associated pollutant loads entering the environment during Christmas and Easter. This study highlighted the inherent difficulties in managing a popular maritime amenity and Marine Parks such as the Moreton Bay Marine Protected Area, Queensland, Australia with its variety of stakeholders and types and intensities of uses.     

Geomorphic and sediment volume responses of a coastal dune complex following invasive vegetation removal

This paper documents application of an established geostatistical methodology to detect significant changes in a foredune–transgressive dune complex where Parks Canada Agency (PCA) implemented a dynamic restoration program to remove invasive marram grasses (Ammophila spp.) and enhance dynamic dune habitat for an endangered species. Detailed topographic surveys of a 10 320 m² site in the Wickaninnish Dunes in Pacific Rim National Park, British Columbia, Canada for the first year post‐treatment are compared to a pre‐restoration LiDAR baseline survey. The method incorporates inherent spatial structure in measured elevation datasets at the sub‐landscape scale and models statistically significant change surfaces within distinct, linked geomorphic units (beach, foredune, transgressive dune complex). Seasonal and annual responses within the complex are discussed and interpreted. All geomorphic units experienced positive sediment budgets following restoration treatment. The beach experienced the highest differential volumetric change (+1656 m³) and net sediment influx (+834 m³, 0 · 19 m³ m^–2) mostly from supply to the supratidal beach and incipient dune. This sediment influx occurred independent of the restoration effort and was available as a buffer against wave erosion and as supply to the landward dunes. The foredune received +200 m³ (0 · 13 m³ m^‐2) and its seaward profile returned to a similar pre‐restoration form following erosion at the crest from vegetation removal and scarping by high water events. Sediment bypassing and minimal change was evident at the mid‐stoss slope with appreciable extension of depositional lobes in the lee. The transgressive dune complex experienced high accretion following restoration activity (+201 m³) and over the year (+284 m³, 0 · 07 m³ m^–2) mostly from depositional lobes from the foredune, precipitation ridge growth along the downwind boundary, and growth of existing lobes within the complex. Further integration of this methodology to detect significant geomorphic changes is recommended, particularly for applications where sampling densities are limited or logistically defined. Copyright © 2013 John Wiley & Sons, Ltd.     

Agricultural land use and hydrology affect variability of shallow groundwater nitrate concentration in South Florida

South Florida's Miami‐Dade agricultural area is located between two protected natural areas, the Biscayne and Everglades National Parks, subject to the costliest environmental restoration project in history. Agriculture, an important economic activity in the region, competes for land and water resources with the restoration efforts and Miami's urban sprawl. The objective of this study, understanding water quality interactions between agricultural land use and the shallow regional aquifer, is critical to the reduction of agriculture's potentially negative impacts. A study was conducted in a 4‐ha square field containing 0·9 ha of corn surrounded by fallow land. The crop rows were oriented NW–SE along the dominant groundwater flow in the area. A network of 18 monitoring wells was distributed across the field. Shallow groundwater nitrate–nitrogen concentration [N‐NO₃^?] was analyzed on samples collected from the wells biweekly for 3 years. Detailed hydrological (water table elevation [WTE] at each well, groundwater flow direction [GwFD], rainfall) and crop (irrigation, fertilization, calendar) data were also recorded in situ. Flow direction is locally affected by seasonal regional drainage through canal management exercised by the local water authority. The data set was analyzed by dynamic factor analysis (DFA), a specialized time series statistical technique only recently applied in hydrology. In a first step, the observed nitrate variation was successfully described by five common trends representing the unexplained variability. By including the measured hydrological series as explanatory variables the trends were reduced to only three. The analysis yields a quantification of the effects of hydrological factors over local groundwater nitrate concentration. Furthermore, a spatial structure across the field, matching land use, was found in the five remaining common trends whereby the groundwater [N‐NO₃^?] in wells within the corn rows could be generally separated from those in fallow land NW and SE of the crop strip. Fertilization, masked by soil/water/plant‐delayed processes, had no discernible effect on groundwater nitrate levels. Copyright © 2006 John Wiley & Sons, Ltd.     

内蒙古乌兰泡湿地环带状植被区土壤有机质及全氮空间分异规律

本文以乌兰泡湿地为研究对象,对该区环带状植被区湿地土壤有机质有全氮的空间分布规律进行了初步研究,结果表明不同植被区养发含量分异趋势一致,但水平分异显著,沿土壤水分梯度变化而变化,表现为蓼区＞香蒲区＞芦苇区,反映出距泡心越远含量越低的规律;各植被区土壤碳氮比都相对较低（在5－12之间）,表层土壤碳氮经值也沿土吉水分梯度变化,表现为芦苇区＞香莆区＞蓼区;泡沼湿地土壤与草原土壤的碳氮比对水分条件及有机质和全氮的含量的响应差异显著;水分和植被是影响其水平分异的关键因子,而湿地土壤pH值并不是影响土壤有机质及全氮分异的主要因子。     

The Icelandic ‘rofabard’ soil erosion features

Soil erosion and desertification are severe problems in Iceland. Erosion processes are numerous, and more than one can occur at each site, resulting in many erosional forms. Erosion forms and an erosion severity scale are the basis for a recent national survey of erosion in Iceland. One of the most distinctive erosion forms in Iceland is an erosion escarpment, termed ‘rofabard’ in Icelandic. Rofabards are formed in thick but non‐cohesive Andosols that overlie more cohesive materials such as glacial till or lava. The relatively loose Andosols beneath the root mat are undermined, creating escarpments, or rofabards. The rofabards retreat as a unit, with a fully vegetated and rich ecosystem on top but leaving barren desert in their place. Rofabards are common within a 20 000 km² area. The Agricultural Research Institute and Soil Conservation Service erosion database suggests that erosion associated with rofabards has denuded 15 000 –30 000 km² of land that was previously fully vegetated and had fertile Andosols, but is now mostly desert. Erosion rates associated with rofabards are reported as the loss of vegetated land with Andosol mantle, measured as hectares per square kilometre per year. This measure of erosion has more meaning for Icelandic landscapes than the traditional tonnes per hectare per year. Estimated losses of Andosol cover in rofabard areas for the whole country are currently about 230 ha a⁻¹. This rate is about 10 times lower than the rate needed to cause estimated losses of Andosol mantle in rofabard areas since settlement, 1125 years ago. During peak years of soil erosion, losses were probably several thousand hectares per year, but the erosion rates slowed down as extensive Andosol areas have become barren deserts. Copyright © 2000 John Wiley & Sons, Ltd.     

Adaptability of rainfall simulators as a research tool on urban sealed surfaces – a review

Rainfall simulators can be a useful research tool for some purposes but are quite unsuitable for others. They have been useful in soil erosion and infiltration studies for over eight decades, but the possibility of using a rainfall simulator in urban nonpoint source pollution involving urban non-erodible surfaces has not been fully explored. In this review, the versatility of different rainfall simulators of varying sizes, configurations and styles used in the past two decades are appraised for possible adaptation to urban sealed surfaces. Recommended criteria for detailed rainfall simulator reporting are also outlined.

EDITOR M.C. Acreman

ASSOCIATE EDITOR not assigned     

Total mercury,methyl mercury and sulphide in river carron sediments

Total mercury, methyl mercury and sulphide contents of River Carron sediments (Lothian, Scotland) have been determined. Total mercury concentrations are comparable to other mercury polluted estuaries in the UK, but the methyl mercury values for low-sulphide Carron sediments are generally higher. It has been found that methyl mercury levels are initially in direct proportion to the sulphide concentrations of the sediments but beyond sulphide concentrations of 1.8 mg g^?1 the methyl mercury levels decline sharply.     

Quantifying the temporal dynamics of wood in large rivers: field trials of wood surveying,dating, tracking,and monitoring techniques

Wood plays an important role in stream ecology and geomorphology. Previous studies of wood in rivers have quantified spatial distributions but temporal dynamics remain poorly documented. The lack of such data is related to limitations of existing methods, especially when applied to large rivers. Five techniques are field‐tested to assess their utility for quantifying the temporal dynamics in rivers: repeated high‐resolution aerial surveys, the measurement of wood physical characteristics as proxies for ¹⁴C dating, passive and active radio frequency identification (RFID) tags, radio transmitters, and video. The spatial distribution of wood is surveyed using aerial imagery with a resolution finer than 0·10 m. The estimation of temporal trends by repeated aerial‐based surveys needs to consider vegetation growth and hiding. Wood residence times can be calculated using ¹⁴C analysis, but the assessment of wood physical characteristics including decay status and wood density offers a cheaper, if less accurate, alternative. Wood resistance to penetration is tested but results are not significant. Radio transmitters are reliable for multi‐year (～5 year) surveys and can be detected at 800 m. Passive RFID tags are limited by a read range of 0·30 m but are reliable for longer term (>5 year) studies. Active RFID tags combine a moderate read range (10–300 m) and low cost with in‐flood detection but require more testing. Video monitoring of wood passing on the surface of a river is successfully implemented. For a single flood on the Ain River (France), wood transport rates are an order of magnitude higher on the rising limb of the hydrograph than on the falling limb. Overall, the techniques improve the ability to gather the data needed to understand wood transfer processes and calibrate budgets of wood in rivers. Copyright © 2009 John Wiley & Sons, Ltd.     

Probability of radial anisotropy in the deep mantle

It is well established that the Earth's uppermost mantle is anisotropic, but observations of anisotropy in the deeper mantle have been more ambiguous. Radial anisotropy, the discrepancy between Love and Rayleigh waves, was included in the top 220 km of PREM, but there is no consensus whether anisotropy is present below that depth. Fundamental mode surface waves, for commonly used periods up to 200 s, are sensitive to structure in the first few hundred kilometers and therefore do not provide information on anisotropy below. Higher mode surface waves, however, have sensitivities that extend to and below the transition zone and should thus give insight about anisotropy at greater depths, but they are very difficult to measure. We previously developed a new technique to measure higher mode surface wave phase velocities with consistent uncertainties. These data are used here to construct probability density functions of a radially anisotropic Earth model down to approximately 1500 km. In the uppermost mantle, we obtain a high probability of faster horizontally polarized shear wave speed, likely to be related to plate motion. In the asthenosphere and transition zone, however, we find a high probability of faster vertically polarized shear wave speed. To a depth of 1500 km in the lower mantle, we see no significant shear wave anisotropy. This is consistent with results from laboratory measurements which show that lower mantle minerals are anisotropic but LPO is unlikely to develop in the pressure–temperature conditions present in the mid-mantle.     

Geochemistry and chronology of large-superlarge nonmetal deposits in eastern Zhejiang Province: A case study

From geology and geochemistry studies on four typical large-superlarge nonmetal deposits in eastern Zhejiang Province, it is concluded that nonmetal mineralization is an in situ reduction process in which SiO₂ and Fe₂O₃ are lost, and Al₂O₃ and K₂O are enriched. Moreover, incompatible elements are depleted in zeolite but enriched in alunite. Rb-Sr isotopic age of zeolite and K-Ar isotopic age or micro-area⁴⁰Ar-³⁹Ar isochron age of alunite are coincident with their geological data. respectively. Comparison studies of various chronology methods indicate that K-Ar and Rb-Sr methods are effective for zeolite and alunite, but should be carefully used for pyrophyllite, dekite and illite. From isotopic ages of ore and wall rocks of zeolite and alunite, it could be deduced that the age difference of metallogenism and volcanism is about 10–20 Ma.     

Petrology and genetic significance of an ultramafic xenolith suite from Tahiti

A suite of ultramafic xenoliths 2–10 cm in size occurs in basanite near Papeete, Tahiti, and consists of spinel lherzolites with minor dunites and wehrlites. Petrographic examination of xenoliths reveals that they are typically coarse grained with well-developed annealed textures. Microprobe analyses of constituent minerals in 11 xenoliths indicate that bulk compositions of xenoliths are magnesian but with significant variability from xenolith to xenolith especially in Fe/Mg and Cr/Al ratios and in absolute amounts of Al₂O₃ and Cr₂O₃. Within any single xenolith, however, coexisting minerals are homogeneous and appear to be compositionally equilibrated. Geothermometry of coexisting orthopyroxene and augite indicates temperatures of equilibration of about 1100°C but there is considerable uncertainty in this estimate due to significant non-quadrilateral pyroxene substitutions. There is no accurate way to determine pressures, but the ubiquity of Cr-poor spinel and absence of garnet imply pressures less than about 15–20 kbar.The margins of most xenoliths show significant alteration through reaction with enclosing alkaline magma. Principal reaction features include zoning of spinels and olivines toward compositions in equilibrium with the magma, and reaction-melting of orthopyroxene to a symplectite of olivine plus silica-rich glass. Glass composition profiles across the symplectites indicate that alkalis, titanium and aluminum diffused into the symplectite from the magma and that silica diffused into the magma. All glass analyses show very low iron, magnesium and calcium.Xenolith mineral assemblages and chemistry indicate their origin in the upper mantle at relatively shallow depths. They are therefore not related genetically to the enclosing basanite magma which came from deeper in the mantle, but rather are accidental fragments of country rock picked up by magma on its way to the surface. The details of the reaction features strongly imply that the magma had partially crystallized by the time it reacted with xenoliths, possibly while still in the mantle.     

Long term variations in the mesospheric mean flow observed at Grahamstown (South Africa) and Adelaide (Australia)

The seasonal and interannual behaviour of monthly mean winds at a height of 90 km recorded at Grahamstown (33.3°S, 26.5°E) and Adelaide (34.5°S, 138.5°E) between 1987 and 1994 are compared. The zonal wind is found to be consistently stronger at Grahamstown and is always eastward, whereas at Adelaide it sometimes reverses. Maxima tend to occur near the solstices, the primary maximum during summer at Grahamstown, in agreement with satellite results, and during winter at Adelaide. The meridional wind also tends to be stronger at Grahamstown, but at both stations is predominantly northward with a maximum in summer and generally not as strong as the zonal component. This seasonal behaviour is reasonably well understood in terms of the interaction of the mean flow with gravity waves propagating up from below, with coriolis forces also playing an important role in the case of the meridional wind. Satellite observations do not generally support the idea that longitudinal differences between the stations could be attributed to the presence of a tropospheric/stratospheric stationary wave. It is suggested that these differences are more probably associated with local effects. Interannual zonal wind patterns at the two sites are similar over the summer months but are less well correlated during the rest of the year. The underlying causes of this variability are not well understood but are most probably global in nature, at least during the summer.     

用简单模式法对高纬电离层电场的进一步研究

本文采用的是有二区场向电流但无电导率时角变化的简单模式。文章通过模式计算,系统讨论了在恒稳条件下二区场向电流强度及位相和Hall与Pederson电导率在极光带升高等因素对高纬电场分布的影响。模式说明,二区场向电流的存在使二区电流圈以内电场加强,其外电场大大削弱。这种加强与削弱作用与二区电流的强度与位相均有关。Hall电导率在极光区升高会加强上述作用,Pederson电导率的升高则对其有所削弱。一般说来,极盖区外电场分布的位相与极盖区边界的驱动势不同,一、二区场向电流的位相与驱动势也有差异。这些现象都是场向电流与电导率共同影响的结果。以下结果初步解释了近年来的某些观测现象。最后,本文对简单模式法的应用及今后的某些方向作了探讨。     

Production de26Al dans Fe et Si par protons de 0.6 et 24 GeV

A total of 139 breccia and crystalline rock fragments in the size range 2–4 mm from four Apollo 15 soil samples have been examined. Two of the sample stations are on the mare surface (4 and 9A) and two are on the Apennine Front (2 and 6). Approximately 90% of the fragments from the Apennine Front are brown-glass “soil” breccias, but those from the mare surface are 60%–70% basalt. Several textural varieties of mare basalt have been recognized, but within experimental error there is no difference in their⁴⁰Ar-³⁹Ar ages. The major non-mare (Pre-Imbrian) crystalline rock types in the Apennine Front regolith are KREEP basalt, anorthositic rocks, recrystallized norite (including anorthositic norite) and recrystallized polymict breccias; however, such crystalline rocks are rare in the samples examined. Apparently, the near surface Imbrium ejecta below the regolith has not been thermally recrystallized, and probably there are no outcrops of crystalline rocks upslope from the sample stations.     

Transient creep and semibrittle behavior of crystalline rocks

We review transient creep and semibrittle behavior of crystalline solids. The results are expected to be pertinent to crystalline rocks undergoing deformation in the depth range 5 to 20 km, corresponding to depths of focus of many major earthquakes. Transient creep data for crystalline rocks at elevated temperatures are analyzed but are poorly understood because of lack of information on the deformation processes which, at low to moderate pressure, are likely to be semibrittle in nature. Activation energies for transient creep at high effective confining pressure are much higher than those found for atmospheric pressure tests in which thermally-activated microfracturing probably dominates the creep rate. Empirical transient creep equations are extrapolated at 200° to 600°C, stresses from 0.1 to 1.0 kbar, to times ranging from 3.17×10² to 3.17×10⁸ years. At the higher temperatures, appreciable transient creep strains may take place but the physical significance of the results is in question because the flow mechanisms have not been determined. The purpose of this paper is to stimulate careful research on this important topic.     

On recording sea surface elevation with accelerometer buoys: lessons from ITOP (2010)

Measurements of significant wave height are made routinely throughout the world’s oceans, but a record of the sea surface elevation (η) is rarely kept. This is mostly due to memory limitations on data, but also, it is thought that buoy measurements of sea surface elevation are not as accurate as wave gauges mounted on stationary platforms. Accurate records of η which contain rogue waves (defined here as an individual wave at least twice the significant wave height) are of great interest to scientists and engineers. Using field data, procedures for tilt correcting and double integrating accelerometer data to produce a consistent record of η are given in this study. The data in this study are from experimental buoys deployed in the recent Impact of Typhoons on the Ocean in the Pacific (ITOP) field experiment which occurred in 2010. The statistics from the ITOP buoys is under that predicted by Rayleigh theory, but matches the distributions of Boccotti and others (Tayfun and Fedele) (Ocean Eng 34:1631-1649, 2007). Rogue waves were recorded throughout the experiment under various sea state conditions. Recommendations, as a result of lessons learned during ITOP, are made for the routine recording of η which may not add significantly to the existing data burden. The hope is that we might one day collect a worldwide database of rogue waves from the existing buoy network, which would progress our understanding of the rogue wave phenomenon and make work at sea safer.     

Seismicity and seismic intensities in Jamaica,West Indies: A problem in risk assessment

A review of the history of earthquake observations in Jamaica is presented; there have been several high-intensity earthquakes in the last 300 years. The observed seismicity of the Jamaica region is discussed in the context of what is known of regional tectonics, and possible source regions of earthquakes are identified but a comparison between instrumentally determined seismicity and macroseismicity shows that the instrumental data are of insufficient quantity or quality to permit direct assessment of earthquake risk by conventional techniques. An alternative approach has been adopted; consideration of the macroseismic record suggests that the peak acceleration in rock with 90 per cent probability of not being exceeded in any 50-year period is of order 0.3 g but that there are very significant local variations caused by near-surface geology. Especially this applies to the capital, Kingston, and envelope response spectra are derived for shallow, intermediate and deep thickness of sediments under the city to demonstate the possibility that localized amplification may occur. A current apparent decline in the seismicity of the Jamaica region is noted but it is shown that the decline in the number of earthquakes of engineering interest is not yet statistically significant.     

Defensive reactions of freshwater ecosystems against external influences

Eutrophication and toxic loading of freshwater occurred even in early geological epochs as a result of natural factors (e.g., large animals, volcanism), and nutrients and xenobiotics are more quickly integrated in material cycling in aquatic than in terrestrial systems. Therefore, aquatic ecosystems show many defensive mechanisms against organic and toxic loading. Many other defensive reactions can be described in addition to the well-known example of microbial self-purification.Freshwater ecosystems possess compartments which cooperate towards the function and protection of the whole system but, in opposition to these “euoecisms”, there are also “dysoecisms”. The defensive reactions of an ecosystem are founded largely on species-egoistic adaptations that have an (accidental) system-altruistic effect. The whole ecosystem reacts only seldom, and it is not clear whether there are selection processes which favour water bodies with a slow eutrophication and therefore slow silting-up, because the freshwaters are important for the global water balance.It is possible to compare organismic with ecosystemic defensive reactions but the origin of both reactions is very different.