Copepod distribution as an indicator of epikarst system connectivity

The distribution of 27 copepod species was determined in 35 drips in four Slovenian caves (Dimnice, Postojna Planina Cave System, Škocjanske Jame, Županova Jama), and of ten species from 13 drips in one US cave (Organ Cave, West Virginia). The dripping water comes from epikarst, the skin of karst. A significant fraction of the copepod species found (nine species in Slovenia and three in West Virginia) occurred over a maximum linear extent of 100 m. These and other localized distributions probably resulted from colonization of epikarst by an ancestral surface population in a single location, with subsequent lateral spread in the direction of epikarst flow. This suggests that the distribution of copepods could potentially be used to trace major flow paths in epikarst without the need for the injection of dyes or other tracers.

---

Résumé La distribution de 27 espèces de copépodes a été déterminée dans 35 zones de percolation de quatre grottes slovènes (Dimnice, système de grottes Postojna Planina, Škocjanske Jame, Županova Jama) et grace à dix espèces de 13 zones de percolation d’une grotte des Etats-Unis (Grotte Organ, Ouest de la Virginie). L’eau de percolation provient de l’épikarst, la partie supérieure du karst. Une fraction importante des espèces de copépodes trouvées (9 espèces en Slovénie et 3 dans l’Ouest de la Virginie) s’étendait sur une longueur maximum de 100 m. Ces dernières ainsi que d’autres distributions localisées étaient probablement issues de la colonisation par une population ancienne de surface, de zones localisées de l’épikarst, puis par une dispersion latérale dans la direction de l’écoulement dans l’épikarst. Ceci suggère que la distribution des copépodes pourrait potentiellement être utilisée pour identifier les principales trajectoires d’écoulement dans l’épikarst, sans utiliser l’injection de colorants ou d’autres traceurs.

---

Resumen Se determina la distribución de 27 especies de copépodo en 35 gotas de cuatro cavernas de Eslovenia (Dimnice, Sistema de Caverna Planina Postojna, Jame Škocjanske, y Jama Županova), y de diez especies en 13 gotas de una caverna de Estados Unidos (Caverna órgano, Virginia Occidental). El agua que gotea se deriva del epikarst, la piel del karst. Una fracción significativa de las especies de copépodos encontradas (9 especies en Eslovenia y 3 en Virginia Occidental) se presentaron en una extensión linear máxima de 100 m. Estas y otras distribuciones localizadas resultaron probablemente de colonización del epikarst por poblaciones superficiales ancestrales en una sola localización, con una expansión lateral subsiguiente en la dirección de flujo epikárstico. Esto sugiere que la distribución de copépodos podría tener un uso potencial para trazar rutas de flujo principales en epikarst sin tener la necesidad de inyectar colorantes u otros trazadores.

     

Hydrological analysis of Skradinski Buk tufa waterfall (Krka River,Dinaric karst,Croatia)

The paper analyses complex hydrological behaviour of Skradinski Buk, the tufa waterfall, formed on the downstream part of the Krka River located in the coastal part of the Croatian Dinaric karst. This waterfall is the central point of the Krka National Park (KNP) proclaimed in 1985. Skradinski Buk is the seventh, final and the largest tufa barrier on the Krka River. Morphology of Skradinski Buk is composed of 17 unevenly distributed steps and dozens of small depressions. Natural waterfall morphology strongly influenced the complex waterfall hydrological regime. Additionally, hydrological regime is disturbed by the operation of the hydroelectric power plant (HEPP) Jaruga. This paper analyses characteristic (minimum, mean, maximum) annual water levels and discharges monitored at two hydrological stations (Skradinski Buk Gornji-SBG and Nacionalni Park-NP). SBG controls the inflow of water into the waterfall, while the NP is established in order to control the use of water from the HEPP Jaruga operation. It is concluded that the HEPP Jaruga does not comply with the agreement signed between the KNP and the HEPP Jaruga. The goal of the paper is to give detailed hydrological analysis of the Skradinski Buk, which should play the crucial role in the protection of this wonderful and very vulnerable phenomenon.     

Suitability of linden and elder in the assessment of environmental pollution of Brestovac spa and Bor lake (Serbia)

The suitability of linden and elder as biomonitors was evaluated in the tourist zone of the Bor region well known for pyrometallurgical copper production. The concentrations of As, Cu, Pb and Zn in the soil, washed and unwashed leaves and roots of linden and elder were determined. The absorption of As, Cu, Pb and Zn from soil to roots and leaves, as well as the translocation of the studied elements from roots to leaves, was analysed. It was observed that the soil in the tourist zone of Bor (Bor lake and Brestovac spa) was greatly polluted with Cu and As. Linden and elder leaves can be used as a low-cost material for detection of As, Cu, Pb and Zn in the atmospheric deposition, which was concluded due to the amounts of these elements removed after a washing treatment. Thus, canopies of linden and elder might have an important role in the removal of the polluting substances from the air. The elder leaves were more suitable to be used for indication of environmental pollution with As, Cu and Pb than the linden leaves. The area of the Bor lake sampling site had higher air pollution with As and Pb than Brestovac spa, since greater amounts of As and Pb were washed off the linden and elder leaves from the Bor lake sampling site. The linden and elder used different adaptation strategies in conditions of the increased soil and air pollution. These strategies were based on different efficiencies of element absorption from the soil and on limited or efficient translocation of the studied elements from roots to leaves, and therefore, they have an important role in the biogeochemical cycling of the examined elements in the environment.     

Influence of changed vegetations fields on regional climate simulations in the Barents Sea Region

In the context of the EU-Project BALANCE () the regional climate model REMO was used for extensive calculations of the Barents Sea climate to investigate the vulnerability of this region to climate change. The regional climate model REMO simulated the climate change of the Barents Sea Region between 1961 and 2100 (Control and Climate Change run, CCC-Run). REMO on ~50 km horizontal resolution was driven by the transient ECHAM4/OPYC3 IPCC SRES B2 scenario. The output of the CCC-Run was applied to drive the dynamic vegetation model LPJ-GUESS. The results of the vegetation model were used to repeat the CCC-Run with dynamic vegetation fields. The feedback effect of the modified vegetation on the climate change signal is investigated and discussed with focus on precipitation, temperature and snow cover. The effect of the offline coupled vegetation feedback run is much lower than the greenhouse gas effect.     

Oligoprenyl-curcumanes and other new aromatic isoprenoids from the 1.64 billion year old Barney Creek Formation

Carbonaceous dolomites and shales of the 1.64 billion years (Ga) old Barney Creek Formation (BCF), McArthur Basin, northern Australia contain the oldest, clearly indigenous biomarkers. We describe three new series of regularly branched aryl isoprenoids with base ions at m/z 119, 161 and 175. The m/z 119 compounds were identified as a complete series of C₁₅–C₄₀ oligoprenyl-perhydro-ar-curcumenes (oligoprenyl-curcumanes). Their likely biogenic precursors are oligoprenyl-β-curcumenes that occur in a wide range of bacterial phyla.     

Spatio-temporal distribution of floating objects in the German Bight (North Sea)

Floating objects facilitate the dispersal of marine and terrestrial species but also represent a major environmental hazard in the case of anthropogenic plastic litter. They can be found throughout the world's oceans but information on their abundance and the spatio-temporal dynamics is scarce for many regions of the world. This information, however, is essential to evaluate the ecological role of floating objects. Herein, we report the results from a ship-based visual survey on the abundance and composition of flotsam in the German Bight (North Sea) during the years 2006 to 2008. The aim of this study was to identify potential sources of floating objects and to relate spatio-temporal density variations to environmental conditions. Three major flotsam categories were identified: buoyant seaweed (mainly fucoid brown algae), natural wood and anthropogenic debris. Densities of these floating objects in the German Bight were similar to those reported from other coastal regions of the world. Temporal variations in flotsam densities are probably the result of seasonal growth cycles of seaweeds and fluctuating river runoff (wood). Higher abundances were often found in areas where coastal fronts and eddies develop during calm weather conditions. Accordingly, flotsam densities were often higher in the inner German Bight than in areas farther offshore. Import of floating objects and retention times in the German Bight are influenced by wind force and direction. Our results indicate that a substantial amount of floating objects is of coastal origin or introduced into the German Bight from western source areas such as the British Channel. Rapid transport of floating objects through the German Bight is driven by strong westerly winds and likely facilitates dispersal of associated organisms and gene flow among distant populations.     

An application of least-squares inverse analysis in kinetic interpretations of hydrous pyrolysis experiments

A least-squares inverse method is applied to the estimation of optimum kinetic parameters with statistical error bounds from concentration data obtained in isothermal hydrous pyrolysis experiments. The inverse method requires the specification of a data-parameter relationship (e.g., classical kinetic theory), the prior covariance matrices of data and parameter errors, as well as the prior central estimates of data and parameters. The reaction scheme considered is the common case of kerogen breakdown by Gaussian-weighted independent parallel first-order reactions and bitumen cracking by a single first-order reaction. The nonlinearity of the problem is reduced by a logarithmic transformation, which suggests a parameterization in terms of logarithmic concentrations, activation energies, and logarithmic Arrhenius factors. The linearized variance analysis is valid for the case studied, and the posterior covariance matrix reveals which parameters are constrained by the data. We find that the statistical errors in the average activation energy and the associated Arrhenius factor are strongly correlated. Hence, the parameters which determine the temperature dependence of the reaction rate have not been resolved independently. Furthermore, the kinetic results are very sensitive to the presence of a distribution of activation energies in kerogen breakdown. This distribution is not constrained by the data. As a consequence, neglecting the consideration of distributions of activation energies results in activation parameter values which are much too low. This is the major reason for the commonly encountered discrepancy between kinetic parameter values obtained from hydrous pyrolysis and micropyrolysis experiments, respectively.     

Global analysis of land-use changes in karst areas and the implications for water resources

Karst areas contain valuable groundwater resources and high biodiversity, but are particularly vulnerable to climate change and human impacts. Land-use change is the cause and consequence of global environmental change. The releases of the Climate Change Initiative-Land Cover (CCI-LC) and World Karst Aquifer Map (WOKAM) datasets have made it possible to explore global land-use changes in karst areas. This paper firstly analyses the global karst land-use distribution in 2020, as well as the land-use transition characteristics between 1992 and 2020. Then, two indicators, proportion of land-use change and dominant type of land-use change, are proposed to identify the spatial characteristics of land-use change in global karst areas. Finally, three examples of land-use change in karst areas are analyzed in detail. Land-use types and proportions of the global karst areas from large to small are as follows: forest (31.78%), bare area (27.58%), cropland (19.02%), grassland (10.87%), shrubland (7.21%), wetland (1.67%), ice and snow (1.16%) and urban (0.71%). The total area of global karst land-use change is 1.30 million km², about 4.85% of global karst surface. The land-use change trend of global karst is dominated by afforestation, supplemented by scattered urbanization and agricultural reclamation. The tropical climate has a higher intensity of land-use change. Regions of agricultural reclamation are highly consistent with the population density. These results reflect the impact of human activities and climate change on land-use changes in global karst areas, and serve as a basis for further research and planning of land resource management.

     

Perceived concerns and possible management strategies for governing ‘wind farm–mariculture integration’

In offshore waters of the German North Sea multiple stakeholder activity is increasing in both type and intensity. Newcomers such as wind farms make for additional claims and exclude, due to current legal constraints, other sectors, such as traditional fisheries. In this context, integrating marine aquaculture with designated wind farm areas might provide chances to combine two industries in the frame of a multiple-use concept. This paper takes up concerns and possible management framework requirements as expressed through interviews with the wind farm industry and the mussel harvesting sector when inquiring about such a multiple-use setting. The article closes with a discussion on two co-management strategies that might be appropriate for governing potential interacting wind farm–mariculture activities.     

Early Archean spherule layers from the Barberton Greenstone Belt,South Africa: Mineralogy and geochemistry of the spherule beds in the CT3 drill core

Little is known about the Hadean and the Archean impact record on Earth. In the CT3 drill core from the Fig Tree Group of the northern Barberton Greenstone Belt, 17 spherule layer intersections occur, which, provide an outstanding new opportunity to gain insights into meteorite bombardment of the early Earth. CT3 spherules, as primary features, mostly exhibit textural patterns similar to those of the other Barberton spherule layers, but locally mineralogical and chemical compositional differences are observed, likely as a result of various degrees of alteration. The observed mineralogy of the spherule layers is of secondary origin and comprises K‐feldspar, phyllosilicates, carbonates, sulfides, and oxides, with the exception of secondary Ni‐Cr spinel that is of primary origin. Our petrographic investigations suggest alteration by K‐metasomatism, sericitization, silicification, and carbonatization. Siderophile element contents of bulk samples show significant enrichments in Ni (up to 2 wt%) and Ir (up to ~3 ppm), similar to previously studied Archean spherule layers. These values are indicative of the presence of a meteoritic component. On the other hand, lithophile and chalcophile element abundances indicate hydrothermal overprint on the CT3 samples; this may also have influenced the redistribution of the meteoritic component(s). Last, we group the CT3 spherule layers, which occur in three intervals (A, B, and C), according to their petrographic and geochemical features, which indicate evidence for at least three distinct impact events before tectonic overprint that affected the original deposits.