Short-term effects of clearfelling on soil CO2, CH4, and N2O fluxes in a Sitka spruce plantation

We examined the effects of forest clearfelling on the fluxes of soil CO₂, CH₄, and N₂O in a Sitka spruce (Picea sitchensis (Bong.) Carr.) plantation on an organic-rich peaty gley soil, in Northern England. Soil CO₂, CH₄, N₂O as well as environmental factors such as soil temperature, soil water content, and depth to the water table were recorded in two mature stands for one growing season, at the end of which one of the two stands was felled and one was left as control. Monitoring of the same parameters continued thereafter for a second growing season. For the first 10 months after clearfelling, there was a significant decrease in soil CO₂ efflux, with an average efflux rate of 4.0 g m⁻² d⁻¹ in the mature stand (40-year) and 2.7 g m⁻² d⁻¹ in clearfelled site (CF). Clearfelling turned the soil from a sink (−0.37 mg m⁻² d⁻¹) for CH₄ to a net source (2.01 mg m⁻² d⁻¹). For the same period, soil N₂O fluxes averaged 0.57 mg m⁻² d⁻¹ in the CF and 0.23 mg m⁻² d⁻¹ in the 40-year stand. Clearfelling affected environmental factors and lead to higher daily soil temperatures during the summer period, while it caused an increase in the soil water content and a rise in the water table depth. Despite clearfelling, CO₂ remained the dominant greenhouse gas in terms of its greenhouse warming potential.     

Malolactic fermentation in wine with Lactobacillus casei cells immobilized on Delignified cellulosic material

In this work Lactobacillus casei ATCC 393 cells immobilized on delignified cellulosic material (DCM) were used for malolactic fermentation (MLF) of wine. Wine was produced using yeast cells immobilized on DCM at 20 degrees C, and after alcoholic fermentation, MLF at 27 degrees C followed using immobilized L. casei ATCC 393 cells. A total of 11 repeated alcoholic and subsequent MLF batches were performed within a period of 1 month. As the repeated MLF batches proceeded, the MLF activity of the immobilized biocatalyst was reduced. Malic acid degradation was reduced from 80 to 2%, pH was reduced by 0.5-0.1 unit, acetic acid concentrations were slightly reduced or remained stable (0.002 g/L), the higher alcohols 1-propanol, isobutyl alcohol, and amyl alcohol were decreased by 84, 23, and 11%, respectively, and ethyl acetate concentration was increased by approximately 56%. Wine samples were analyzed by GC-MS before and after MLF, revealing some qualitative differences.     

Prioritizing marine invasive alien species in the European Union through horizon scanning

1. The disproportionately low presence of marine species in the list of invasive alien species (IAS) of Union concern of the European Union (EU) Regulation 1143/2014 does not fully acknowledge the threat they pose to the EU marine environment.
2. In this study, the first EU‐scale Horizon Scanning (HS) focusing on marine alien species was performed, aiming to deliver a ranked list of species that should be of high priority for risk assessment (Article 5 of the EU IAS Regulation).
3. Species absent from or with a limited distribution in EU marine waters were targeted. In total, 363 alien species were initially screened for HS by a panel of experts, including a broad range of taxonomic groups. Species were scored for their likelihood of arrival, establishment, spread, and impact in EU waters.
4. A consensus workshop ranked 267 species, including a subset of 26 prioritized species. These species are considered to be mainly introduced by shipping (fouling and ballast water), via the Suez Canal, and aquaculture activities. The 26 priority species were also scrutinized in terms of feasibility of their management; 18 of them were suggested for performing risk assessments on the basis of the EU IAS Regulation.
5. Since biological invasions are dynamic and connected with accelerated globalization and diversified human activities, we recommend HS to be repeated periodically to review the species already listed and assess new ones.

     

Thermoperiodic effects on larval growth parameters of the Sesamia nonagrioides (Lepidoptera: Noctuidae)

The effect of five constant (10, 15, 20, 25 and 30°C) and the corresponding cycling (25:10, 27.5:12.5, 30:15, 32.5:17.5 and 35:20°C) temperatures at a photoperiod of 16:8 (L:D) h on the development and biometry (HCW, weight) of larva of Sesamia nonagrioides (Lef) Lepidoptera–Noctuidae were investigated. Larvae under both temperature treatments seemed to complete six instars. Final mean head capsule widths did not differ significantly between constant and cycling temperatures. Larval weights increased considerably through larval period under all temperature regimes. However, alternating temperatures were not shown to stimulate larval weight or head capsule widths compared with those of constant temperatures, although tended to result in shorter larval developmental periods. Results are discussed regarding development and seasonal biology of the species.     

Pharmacokinetics and tissue distribution of oxytetracycline in sea bass, Dicentrarchus labrax, at two water temperatures

A pharmacokinetic study of oxytetracycline (OTC) following an intravascular administration (40 mg/kg) was carried out in sea bass, Dicentrarchus labrax (110 g), at 13.5 and 22 °C water temperature. Blood, muscle and liver samples were taken at 1, 2, 4, 8, 16, 32, 64 and 128 h post-injection. The plasma data were conformed to a two-compartment model. The kinetic profile of the drug was found to be temperature dependent. The absorption half-life (t_1/2) of OTC was 0.98 and 0.192 h at 13.5 and 22 °C, respectively, whereas the elimination half-time (t_1/2β) of the drug was 69 h at 13.5 °C and 9.65 h at 22 °C. The apparent volume of distribution of the drug at steady state [V_d(ss)] was 5.62 l/kg at 13.5 °C and 2.59 l/kg at 22 °C. The mean residence time (MRT) of OTC was found to be 37.7 h at 22 °C and 71 h at 13.5 °C. The total clearance of the drug (CL_T) was calculated to be 73.5 and 68.7 ml/kg/h at 13.5 and 22 °C, respectively.

Liver levels indicated higher OTC values than respective muscle levels at all time points and for both temperatures. The elimination of OTC from tissues tested was faster at the high temperature, whereas the drug was eliminated faster from liver compared to muscle when comparisons are made at the same temperature.     

Season-Dependent Fruit Loading: Effect on Nutrient Homeostasis of Tomato Plants

ABSTRACT

Greenhouse tomato plants were grown hydroponically during the period of lower temperatures of winter (LT) versus the period of higher temperatures of summer (HT). In these plants, the effect of season on fruit load was dramatic. In order to study the alterations season introduces to the developmental allocation of nutrients within the various organs, concentrations of total nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were determined during each season at weekly intervals in the dry mass of leaves and roots and in the extract of upper, middle, and lower parts of the stem. The level of N/P ratio was always higher in the leaves than in the roots, and these differences were more intense during HT. The short-term changes of ratio in the leaves during HT and LT were positively related with the changes in temperature (r = 0.59 and 0.51 for HT and LT, respectively). In contrast, such correlations in the root were negative (r = ?0.54 and r = ?0.33 for HT and LT, respectively). The increase of temperature increased P uptake but not its translocation to upper plant parts. HT affected the translocation of N, K, Mg, and Ca more and their uptake less. Fruit load differentially affected the concentration of nutrients. In contrast to total N and K, Ca concentration in plant parts presented a positive relation with the increase of fruit load. Calcium and total N concentration (as opposed to P and micronutrient concentrations) were always higher in the leaves than in the roots. Under HT conditions, P was accumulated in roots in combination with high concentrations of Fe, Zn, and Mn. On the other hand, K and N were accumulated in the roots during the period of low temperature in winter. Calcium and K compared with other nutrients presented a pronounced tendency to be transported toward the top of the stem during HT, and their extractable concentration in the upper part of stem presented a significant increase during summer. Extractable K concentration was two to nine times higher than that of the other macronutrients. Our data suggest that the extractable concentration of nutrients of the stem is a good index for the diagnosis of the mineral nutritional status of the plant.     

An overview of the epidemiology and epizootology of brucellosis in selected countries of Central and Southeast Europe

The objective of this paper is to give an overview of the epidemiologic and epizootic status of brucellosis in selected countries of Central and Southeast Europe (Balkan region). Based on dimension of the disease problem, there is a need to establish collaboration in the eradication and prevention of brucellosis between all countries in the region. Although there were no readily accessible data concerning epidemiology and epizootology of brucellosis in these countries, the limited official and published data were analyzed.

The incidence of brucellosis caused by Brucella melitensis in sheep, goats and humans is a very significant problem in Macedonia and Greece. In Greece, cattle are also affected either by B. melitensis or B. abortus. The disease is an endemic problem in some regions of Yugoslavia and includes B. suis biovar 2 in pigs and in Croatia, B. melitensis in sheep, goats and human is found occasionally. No problem appears to exist with brucellosis in Bulgaria.

Financial well-supported brucellosis control programs of the European Union that will include all countries, regardless of the magnitude of brucellosis incidence, are needed for eradication and control of brucellosis.     

An assessment of the effect of Sitka Spruce (Picea sitchensis Bong. Carr) plantation forest cover on carbon turnover and storage in a peaty gley soil

We investigated carbon (C) incorporation and sources of C in the surface CO₂ flux at two sites in northern England on peaty (stagnohumic) gley soil, one afforested by Picea sitchensis, the other under continuous Molinia grassland cover. Radiocarbon (¹⁴C) derived from atmospheric nuclear weapons testing was used to trace the incorporation of C into the soil and sources of C in the soil CO₂ flux from the soil surface and deeper layers. Larger values of ¹⁴CO₂ in surface flux were found at the afforested site (109–110 per cent modern (pM) compared with 107–108 pM at the grassland site). Surface litter fractions (O_i horizon) from the afforested site showed larger ¹⁴C signatures than the equivalent fractions in the grassland (113–115 pM in the forest compared with 106–109 pM in the grassland). Fine root fractions (<2 mm, O_e horizon) had similar signatures at both sites (109 pM in the forest compared with 109–111 pM in the grassland). Humified fractions at 10‐cm depth (O_a horizon) showed smaller signatures (100–103 pM) in the forest than the equivalent fraction in the grassland soil (106–114 pM). According to a mixing model that takes into account pool size and ¹⁴C signature, the contributions to surface CO₂ fluxes from slow turnover fractions that had resided in the soil for more than one year were greater at the forested site than the grassland site, but contributions from fast‐turnover C fixed within the year prior to study showed the opposite trend. The results, taken together with previous work indicating that both site preparation and clear‐felling lead to a net loss of C, indicate that long‐term fixation in deep soil organic fractions is limited on this soil type under plantation forest over 40–50‐year commercial rotations.     

Phyllocnistis citrella and its parasitoids in three citrus species in Greece

The relative abundance as well as the percentage of parasitism of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) and its parasitoids were studied in a citrus orchard with orange, mandarin and lemon trees in Greece. Infestation of P. citrella on each citrus host, as expressed by the number of mines per leaf, was significantly higher on lemon than on mandarin. The P. citrella parasitoid complex included the native species Neochrysocharis formosa and Pnigalio pectinicornis, as well as the introduced Citrostichus phyllocnistoides. The most abundant of those was N. formosa in all of the citrus species. The average percentage of parasitism was 13.1%, 13.8% and 11.7% on orange, mandarin and lemon, respectively. No significant differences in parasitism rate by each of the three parasitoid species separately were recorded among the three citrus species.     

Red wine making by immobilized cells and influence on volatile composition

Red wine making using yeast cells immobilized in two types of raisin berries, at various temperatures (6-30 degrees C), was studied. A modification of the batch bioreactor was used to separate the grape skins used for color extraction from the biocatalyst and the fermenting grape must. The evaluation of the immobilized biocatalysts was made on terms of productivity and organoleptic quality, including color intensity and formation of volatiles. The immobilized cells were found capable of low-temperature wine making, producing red wines containing more than 11% v/v alcohol in 8 days at 6 degrees C. The quality of wines was examined by gas chromatography (GC) and GC-MS analysis and sensory evaluation. Higher alcohol concentrations were decreased, and ethyl acetate concentrations increased by the drop of temperature. Many esters, alcohols, carbonyls, and miscellaneous compounds were identified in wines produced by immobilized cells, revealing no significant qualitative differences as compared to wines produced by free cells. The sensory evaluation showed that the best red wine was produced at 6 degrees C.