Ice‐‐bacteria as antagonists in biological frost protection

Investigated was the efficacy of 4 ice nucleation‐inactive (ice^‐) bacterial strains (A506, GSPB 1147, 1181, 2357) at 4 ice nucleation active (ice⁺) strains (553, 554, GSPB 1139, 2035) on the surface of 4 culture crops (corn, tomato, bush‐ and field bean). Examinated was the reduction of frost damage at the used culture crops by inoculation with ice⁺ and ice^‐ strains at 4 different variants (A‐D) under laboratory conditions. The ice nucleation activity was determined by the tube‐freezing‐assay. An effective reduction of ice⁺ bacteria was possible, when plant surfaces were preinoculated (3days) with ice^‐bacteria before ice⁺ bacterial strains colonized the surfaces of plants. A statistical comparison of mean values of obtained results showed, the ice crystallization (INT) by inoculation started at ‐3°C and in mean (MNT) below ‐5°C independent of the used ice⁺ and ice^‐ strains. Obtained differences were not significant. As untreated as colonized plants with antagonists started to freeze at ‐5 and ‐6°C and in average at ‐7°C. However, the preinoculation resulted in 1.38 K differences for the temperatures, at which 50% of leaves were frozen (PROZ 50) in favour of preinoculated plants. This difference in freeze temperatures by preinoculation with ice^‐ bacteria was discussed as a possible method of frost protection.     

Updated Italian checklist of Soldier Flies (Diptera,Stratiomyidae)

An updated checklist for Stratiomyidae of Italy is presented. Previous knowledge and information are put together in a comprehensive way, integrated also with results obtained by sampling with Malaise traps in some of the test areas of the LIFE+ project ManFor C.BD.At the time of writing, with 91 known species, the Italian fauna of Stratiomyidae is the richest in Europe. Neopachygaster meromelas (Dufour, 1841) and Zabrachia minutissima (Zetterstedt, 1838) are new to the Italian fauna. A comprehensive key to the European species of Chorisops Rondani, 1856 is given.     

Forest floor photosynthesis and respiration in a drained peatland forest in southern Finland

Background: Although forest floor forms a large biomass pool in forested peatlands, little is known about its role in ecosystem carbon (C) dynamics.

Aim: We aimed to quantify forest floor photosynthesis (P _FF) and respiration (R _FF) as a part of overall C dynamics in a drained peatland forest in southern Finland.

Methods: We measured net forest floor CO₂ exchange with closed chambers and reconstructed seasonal CO₂ exchange in the prevailing plant communities.

Results: The vegetation was a mosaic of plant communities that differed in CO₂ exchange dynamics. The reconstructed growing season P _FF was highest in the Sphagnum community and lowest in the feather moss communities. On the contrary, R _FF was highest in the feather moss communities and lowest in the Sphagnum community. CO₂ assimilated by the forest floor was 20–30% of the total CO₂ assimilated by the forest. The forest floor was a net CO₂ source to the atmosphere, because respiration from ground vegetation, tree roots and decomposition of soil organic matter exceeded the photosynthesis of ground vegetation.

Conclusions: Tree stand dominates C fluxes in drained peatland forests. However, forest floor vegetation can have a noticeable role in the C cycle of peatlands drained for forestry. Similarly to natural mires, Sphagnum moss-dominated communities were the most efficient assimilators of C.     

Policy measures to address bird interactions with power lines – a comparative case study of four countries

Bird mortality caused by electric power lines has been an issue in several countries for more than three decades now. Despite serious efforts by conservationists, government agencies and utility companies assisted by increasing biological and technological knowledge, only a minority of countries has made significant progress in mitigation. In the present article I argue that the policy aspects, which have not been so widely researched so far, have considerable effects on the efficiency of mitigation measures. The problem management methods of four countries—Hungary, Slovakia, South Africa and the USA—are discussed in detail to reveal success criteria. The role of contextual factors, stances and relations of different actors, plus actions and tools applied in the solution process, are demonstrated together with the resulting outcomes. To help strategic planning, I review favourable solution methods (volunteer agreements, legislative steps, mixed solutions, etc.) used in different country-specific contexts, and point out probable consequences of the strategy chosen.     

A Possible Role of Slips in Cytochrome C Oxidase in the Antioxygen Defense System of the Cell

Evidence is available showing that the coupling efficiency of the proton pump in cytochrome c oxidase of mitochondria can under certain conditions decrease significantly below the maximum attainable value. The view is developed that slips in the proton pump of cytochrome c oxidase represent an intrinsic switch mechanism which regulates the relative contribution of energy transfer and respiratory protection against oxygen toxicity by the oxidase.