Is Artificial Light at Night Dangerous for the Balkan Strict Protected Areas at Present?

Water, Air, & Soil Pollution - In this study, a new composite membrane has been prepared by means of blending with maifanite (MFS), activated alumina (AA), and poly(vinylidene fluoride) (PVDF)...     

Thoughts on Integrated Monitoring of Ecological Environment at Provincial Level

The Law of Soil and Water Conservation entitles the administrations of water resources at various level to monitor ecological environment and to proclaim status of soil erosion periodically. Monitoring units of soil and water conservation approved by local governments are obliged to undertake this work. How to develop a monitoring program needs an overall and long-term concept. Particularity and objectives of ecological environment monitoring was discussed. Monitoring at provincial level may be divided into two levels,province-wide and at project level. Those indicators meaningful,sensitive to any disturbances,and simple to measure may be selected to test status of ecosystem stability and health. It makes sense to have an integrated sampling design, to set up permanent observation plots and to collect data, so that to have a relative timely,accurate understanding of ecosystems in the province. A program regarding sampling design, field methods, data analysis, documentation and implementation was detailed.     

Fractions in Drainage Waters from the BroadbalkContinuous Wheat Experiment at Rothamsted

Total P (TP), total particulate P (PP), total dissolved P (TDP), molybdate reactive P (MRP) and dissolved organicP (DOP) were determined in waters from pipe-drains (at 65-cm depth) from the Broadbalk Experiment at RothamstedResearch, UK. Average TP and PP exceeded 1 mg L-1 in about half of the 12 plots receiving superphosphate for the5 measurements taken between December 2000 and April 2001. Ranging between 33.8% and 87.3% of TP, PP was thelargest P fraction in drainage waters, with DOP, ranging from 0.5% to 26.2% of TP, being the smallest fraction. Meanproportions of PP, MRP and DOP in TP in drainage waters were 63.4%, 32.5% and 4.1%, respectively. These findingssupport previous findings that P losses from soil to drainage waters were much larger than previously thought, and couldtherefore make a significant contribution to eutrophication.     

Glucose slows down the heat-induced aggregation of β-lactoglobulin at neutral pH

The behavior of β-lactoglobulin (β-Lg) during heat treatments depends on the environmental conditions. The influence of the presence or absence of a reducing sugar, namely, glucose, on the modification of the protein during heating has been studied using fluorescence, polyacrylamide gel electrophoresis (PAGE), size-exclusion chromatography (SEC), and transmission electron microscopy. Glycated products were formed during heating 24 h at 90 °C and pH 7. The fluorescence results revealed an accumulation of the advanced Maillard products and the formation of aggregates during heating. PAGE and SEC data suggested that the products in the control samples were essentially composed of covalently linked fibrillar aggregates and that their formation was faster than that for glycated samples. We showed that glucose affected the growing step of covalent aggregates but not the initial denaturation/aggregation step of native protein. Glucose-modified proteins formed a mixture of short fibrils and polydisperse aggregates. Our results revealed that β-Lg forms fibrils at neutral pH after heating and that glucose slows the formation of these fibrils.     

Bacterial movement at high matric potentials—II. In fungal colonies

Bacillus subtilis spread readily along water films beside hyphae of killed colonies of Pythium ultimum on membrane filters at a matric potential of —50 cm of water, but movement was restricted at — 150 cm potential. Similar rates of spread occurred when the bacteria were inoculated at a point on the surface of a layer of artificial soil, placed over the killed fungal colony and equilibrated at either of the two matric potentials. This suggests that dead fungal mycelia do not aid bacterial spread to any extent at a matric potential of —150 cm of water.When live colonies of P. ultimum were grown in the artificial soil held at the two matric potentials, the rate of bacterial movement was comparable to that in killed colonies at ?50 cm potential, but was erratic at the lower potential. The accumulation of inhibitory fungal metabolites in the thin water films beside the actively-respiring hyphae probably restricted bacterial spread at some points in the soil. It appears that dead fungal mycelia may aid in the local spread of bacteria at matric potentials higher than —150 cm of water, but live mycelia may not. The ability of bacteria to spread along dead fungal hyphae was explained by a consideration of the thickness of water films imposed by the prevailing matric potential.     

Spatial variation of nitrate–N and related soil properties at the plot-scale

Neglecting the spatial variation in soil nutrient status may result in unused yield potential and in environmental damage. Site-specific management has been suggested to reduce inappropriate fertilization that can adversely affect soil, ground and surface water. Decision criteria for determining variable-rate nitrogen fertilization are, however, lacking. This paper analyses the spatial variation of nitrate nitrogen (NO₃–N) and soil properties related to the N cycle at the plot-scale. Three 50×50 m plots were sampled in nested sampling designs of varying complexities. Classical statistics revealed a characteristic ranking in the variability of soil properties. Geostatistical analysis of the NO₃–N data from two plots showed that the small-scale variation found in one small subgrid was not typical for the small-scale variation in the entire plot, indicating bias in the sampling design. A trend component was found in the NO₃–N data and, consequently, the minimal requirement for the regionalized variable theory was not fulfilled. Problems due to design were overcome with a more complex nested sampling at the third plot. However, the spherical model fitted to the NO₃–N data of the first year explained only 21% of the total variance, whereas a pure nugget effect was observed in the second year. The water content data also showed a low structural variance, which was different in the two years. In contrast, two thirds of the variance of total carbon (C_t) and total nitrogen (N_t) could be explained by the fitted models. Seasonal variations, such as varying duration of snow cover, and extrinsic management effects, such as growing of a cover crop, may have contributed to the observed differences in variability between the years. Due to the low proportion of structural variance and the observation that spatial distribution was not stable with time, geostatistical analysis of NO₃–N and water contents data added only little information to classical statistical analysis. However, geostatistical analysis of total C and N contents provided a useful means to calculate spatial distribution patterns of these properties.     

Biostimulants’ influence on tomato fruit characteristics at conventional and low-input NPK regime

ABSTRACT

Plant biostimulants are commercial products based on different chemical substances used to enhance plant growth and productivity. The effects of biostimulants, Megafol and Viva, with different dominant compositions (amino acids and humic acids) on two tomato cultivars (cv. Gravitet F1 and cv. Minaret F1) exposed to conventional and low-input macronutrient nutrition were investigated. Application of both biostimulants positively affected yield at conventional nutrition. In low-input nutrition variant, biostimulant application prevented yield loss only in cv. Minaret F1. Inter-cultivar differences were noticed in fruit characteristics (total phenol content, total flavonoids content and total antioxidative capacity) where application of biostimulants leads to opposite results in the examined cultivars. We considered the possibility of biostimulant usage as an effective nutritional addition for overcoming the problem of excessive fertilisation.     

Greenhouse gas diffusive fluxes at the sediment–water interface of sewage-draining rivers

Purpose

The purposes of this study were to analyse the spatiotemporal variations in greenhouse gas diffusive fluxes at the sediment–water interface of sewage-draining rivers and natural rivers, and investigate the factors responsible for the changes in greenhouse gas diffusive fluxes.

Materials and methods

Greenhouse gas diffusive fluxes at the sediment–water interface of rivers in Tianjin city (Haihe watershed) were investigated during July and October 2014, and January and April 2015 by laboratory incubation experiments. The influence of environmental variables on greenhouse gas diffusive fluxes was evaluated by Spearman’s correlation analysis and a multiple stepwise regression analysis.

Results and discussion

Sewage-draining rivers were more seriously polluted by human sewage discharge than natural rivers. The greenhouse gas diffusive fluxes at the sediment–water interface exhibited obvious spatiotemporal variations. The mean absolute value of the CO₂ diffusive fluxes was seasonally variable with spring>winter>fall>summer, while the mean absolute values of the CH₄ and N₂O diffusive fluxes were both higher in summer and winter, and lower in fall and spring. The annual mean values of the CO₂, CH₄ and N₂O diffusive fluxes at the sewage-draining river sediment–water interface were ??123.26?±?233.78 μmol m^?2 h^?1, 1.88?±?6.89 μmol m^?2 h^?1 and 1505.03?±?2388.46 nmol m^?2 h^?1, respectively, which were 1.22, 4.37 and 134.50 times those at the natural river sediment–water interface, respectively. The spatial variation of the N₂O diffusive fluxes in the sewage-draining rivers and the natural rivers was the most significant. As a general rule, the more serious the river pollution was, the greater the diffusive fluxes of the greenhouse gases were. On average for the whole year, the river sediment was the sink of CO₂ and the source of CH₄ and N₂O. There were positive correlations among the CO₂, CH₄ and N₂O diffusive fluxes. The main influencing factor for CO₂ and N₂O diffusive fluxes was the water temperature of the overlying water; however, the key factors for CH₄ diffusive fluxes were the Eh of the sediment and the NH₄⁺-N of the overlying water.

Conclusions

River sediment can be either a sink or a source of greenhouse gases, which varies in different levels of pollution and different seasons. Human sewage discharge has greatly affected the carbon and nitrogen cycling of urban rivers.

     

Should all degraded landscapes be restored? a look at the appalachian copper basin

Rehabilitation of degraded landscapes is generally regarded as the most appropriate objective. Occasionally, however, other aspects of the situation need to be considered and may lead to a different decision. This paper presents the case of the Appalachian Copper Basin, located mainly in south-eastern Tennessee, USA, which was degraded years ago as a result of copper mining and smelting. A brief history of the site is given, along with a review of some rehabilitative efforts. Discussion then turns to the way visitors and residents perceive this landscape, the impact these two viewpoints have had over the years, and how they have (or have not) changed. Landscape values are also examined, the interpretation of which largely determines a person's opinion toward rehabilitation. The point is made that some degraded landscapes can have value as degraded landscapes, in this instance now primarily historical and cultural. The current situation in the Copper Basin is summarized and an alternative course of action suggested. It is concluded that rehabilitation is not always the only, or even the most important, goal and that degraded landscapes of long standing sometimes require special consideration.     

Growth and rhizosphere P pools of legume–wheat rotations at low P supply

Legume pre-crops may increase P uptake of the following wheat, but the mechanisms behind this effect are unclear. A rotation study was carried out to assess the concentrations of rhizosphere P pools of three grain legumes and wheat (phase 1) and their effects on P uptake and P pools in the rhizosphere of the following wheat (phase 2). Faba bean, chickpea, white lupin and wheat were grown for 10 weeks in a loamy sand soil with low P availability. The following wheat was grown in the pre-crop soil with and without addition of pre-crop residues. Among the pre-crops, white lupin had the strongest effect on the P pools; it depleted the labile P pools, resin P and NaHCO₃-Pi and also the less labile P pools, NaOH-Pi and residual P; whereas the concentration of NaHCO₃-Po was higher than that in the rhizosphere of the other pre-crops. White lupin had a smaller biomass compared to faba bean which depleted the P pools to a lesser extent. Phosphorus uptake of the following wheat was greatest in white lupin pre-crop soil. Chickpea increased P uptake of the following wheat when residues were added. In the presence of residues, wheat after legumes depleted labile P pools to a greater extent than wheat after wheat, but this coincided with greater P uptake only in wheat after chickpea and white lupin, which may be explained by the small root biomass of wheat after faba bean. The results show that the greater P uptake of the following wheat induced by pre-crops may be due to two mechanisms: P mobilisation (white lupin) or P addition with legume residues (chickpea). This study further showed that P uptake by a crop is only partly a function of the depletion of P in the rhizosphere; another important factor is the ability to exploit a large soil volume.     

Bacterial movement at high matric potentials—I. In artificial and natural soils

The rate of active movement of five isolates from three genera of soil bacteria in an artificial and a natural soil at high matric potentials was studied. In nutrient-amended soils the order of motility at matric potentials of —50cm and —150cm of water was: Pseudomonus fluorescens > Bacillis subtilis (two isolates) >Azotobacter vinelandii >Azotobacter chroococcum. The rate of movement of all organisms was markedly greater at the same potential in the artificial soil than in the natural soil. The faster rate in the artificial soil was attributed to the lack of a component with a high surface charge density, onto which bacteria became adsorbed. Though the influence of soil physical factors on microbial activities may be more easily studied in artificial soil systems, the lack of such a component may limit its usefulness in interpreting activities involving adsorption phenomena. Thus, while A. vinelandii moved 26mm in 48 h in the artificial soil at —50cm matric potential, there was negligible movement (5 mm in 48 h) at the same potential in the natural soil. The results indicate that, in contrast to P. fluorescens, Bacillus subtilis and Azatobacter spp. are unlikely to move appreciably through natural soil at matric potentials of less than —150cm of water.     

Biodiversity development of terrestrial testate amoebae: is there any succession at all?

Heterotrophic protists (e.g. testate amoebae) play an important part in primary succession because these unicellular organisms occur immediately at newly exposed land surfaces in high abundances and biomasses, facilitating the establishment of plants and animals. We investigated testate amoebae from soils of different age and successional stage, which revealed remarkably high abundances and biomasses even at very dry sites. Emphasis was set on two inland dune microchronosequences of different plant successional stages (bare sand, Corynephorus canescens and Polytrichum piliferum as early stages; Festuca ovina and Pinus sylvestris as late stages). The number of testate amoebae species increased clearly with the successional stage of the vegetation cover, but no consistent replacement or extinction of taxa was observed. The newcomers obviously did not reduce the density of the residents, although the community pattern (abundances, biomasses, dominances) was significantly altered. Organism-free substrate of different quality exposed to the air or adjacent soil was colonised quickly and in high abundance by testate amoebae, but no temporal replacement of species occurred. Cluster analysis of species inventory and abundances of numerous types of soil of different age highlight a classification of amoebal communities towards regional influences rather than local successional stages of vegetation. These data corroborate the fact that belowground communities operate differently from plant communitites in that they are characterised by additive invasion and not by interspecific competition. This is typical for a neutral community model.     

Paleoenvironmental interpretation of multiple soil–loess sequence at Milford Reservoir,northeastern Kansas

A loess/soil section near the Republican River in northeastern Kansas includes three superposed soils/paleosols in at least three superposed loess units, including Peoria Loess (PL), the Gilman Canyon Formation (GCF), and Loveland Loess (LL), The GCF coincides with a composite soil with a 1.3 m thick, buried organic-rich (A) horizon that yields AMS radiocarbon ages from 30.3 to 22.4 ka (or 35.7 to 26.9 ka when calibrated) that overlies a 1.6 m oxidized B horizon complex. The B subhorizons stratigraphically and morphologically resemble the “reddish pedocomplex” described elsewhere in Kansas and Illinois that dates between about 69 and 35 ka. The upper LL yields a TL age of about 136 and 130 + 30 ka. Thus, PL, the GCF, and LL were probably deposited mainly during the late Wisconsinan, middle Wisconsinan, and Illinoian (∼ Oxygen Isotope Stages (OIS) 2, 3, and 6, or about 12 to 24, 24 to 60, and 130 to 188 ka, respectively). Soils 1, 2, and 3, then formed mainly during OIS stages 1, 3, and 5, respectively, or about 12 to 12, 60 to 60, and 73 to 130 ka.     

Contact angles at the water–air interface of hydrocarbon-contaminated soils and clay minerals

Contact angles at the water–air interface have been measured for triturated preparations of clays and soils in order to assess changes in their hydrophobic properties under the effect of oil hydrocarbons. Tasks have been to determine the dynamics of contact angle under soil wetting conditions and to reveal the effect of chemical removal of organic matter from soils on the hydrophilicity of preparations. The potentialities of static and dynamic drop tests for assessing the hydrophilic–hydrophobic properties of soils have been estimated. Clays (kaolinite, gumbrine, and argillite) have been investigated, as well as plow horizons of soils from the Republic of Tatarstan: heavy loamy leached chernozem, medium loamy dark gray forest soil, and light loamy soddy-calcareous soil. The soils have been contaminated with raw oil and kerosene at rates of 0.1–3 wt %. In the uncontaminated and contaminated chernozem, capillary water capacity has been maintained for 250 days. The contact angles have been found to depend on the degree of dispersion of powdered preparation, the main type of clay minerals in the soil, the presence and amount of oxidation-resistant soil organic matter, and the soil–water contact time. Characteristic parameters of mathematical models for drop behavior on triturated preparations have been calculated. Contamination with hydrocarbons has resulted in a reliable increase in the contact angles of soil preparations. The hydrophobization of soil surface in chernozem is more active than in soils poorer in organic matter. The complete restoration of the hydrophilic properties of soils after hydrocarbon contamination is due to the oxidation of easily oxidizable organic matter at the low content of humus, or to wetting during several months in the absence of the mazut fraction.