Ecological factors influencing frequency of Norway spruce butt rot in mature stands in Lithuania

We assess the influence of edaphic, climatic, stand structure and individual tree (stump diameter) factors on incidence of Norway spruce (Picea abies (L.) H. Karst.) butt rot. The data used in the study come from 97 stands, originated from natural regeneration, which were clear-cut. The age of the stands varied between 71 and 130 years old. The climate continentality, site fertility, hydrotop (site humidity index), part of Norway spruce in the stand, stand stocking level (density index) and stump diameter were selected as the factors related with frequency of decay. The study material revealed that selected variables explain 34% of Norway spruce butt rot incidence in Lithuanian forests. Site fertility and stand age influence on butt rot incidence was weak. Higher incidence was related with low stand density, low site humidity (dry sites) and higher part of Norway spruce in stand. More frequent damages were recorded on higher diameter stumps. Our results showed longitudinal distribution of decay incidence in Lithuania—the frequency of decay increasing from West (coast) to East (continent).     

Deposition of 134,137Cs from Chernobyl fallout on Norway spruce and forest soil and its incorporation into spruce twigs

The aims of the present research are to describe the amounts, and the variation with time, of ¹³⁴Cs and ¹³⁷Cs in spruce-twigs (P. abies karst.) and in the soil of a spruce forest in Switzerland following deposition of the Chernobyl fallout. The activity of the twigs was subdivided into 3 compartments: the activity on their surfaces (i.e. the activity which can be removed from the twigs along with their natural wax coating), the activity incorporated into the needles and, finally, the activity incorporated into the wood. These compartments were separately sampled 6 times over a period from 54 to 233 days after the Chernobyl incident. Twigs which sprouted in two successive years (1985, 1986) were sampled and were found to show different behaviours. The activities associated with the 1986 twigs were roughly constant with time, while those of the 1985 twigs decreased exponentially, with half-lives around 150 days. The mean activity associated with 1 g (dry) of 1985 twigs is 724 mBq ¹³⁷Cs g⁻¹, of which 58% is incorporated into the twig wood, 17% into the needles and 25% associated with the adhering aerosol. ¹³⁷Cs on the surface of the needles was found to be water-insoluble. It is believed to be strongly adsorbed on to the soil-derived fraction of the aerosol residing on the needle surface and thus provides a tracer for studying the behaviour of natural aerosols on such surfaces.The same soil profile was measured before and after the Chernobyl incident, allowing direct comparison between nuclear weapons and Chernobyl fallout. The latter is mainly (56%) stored in the litter layer, with only 4% below a depth of 13 cm; it has penetrated into the soil to a much lesser extent than weapons fallout. The forest soil inventory of ¹³⁷Cs showed 2600 Bq m⁻² from nuclear weapons fallout and 6200 Bq m⁻² from Chernobyl.The ¹³⁴Cs/¹³⁷Cs activity ratio of the Chernobyl fallout was found to be 0·58 ± 0·01; the activity ratios in the different compartments investigated prove that incorporation of Cs into spruce occurred exclusively by uptake through the needles. A rough estimate indicates that in a spruce forest the activity stored in the twigs is half that stored in the soil.     

Specific features of seedage in Norway spruce (Picea abies karst.) in the northern Moscow region

Climatic characteristics of the northern Moscow region and the periodicity of seedage in Norway spruce were analyzed retrospectively. The relationship between the intensity of seedage and weather conditions in the period before seedage was revealed.     

Spatial and temporal rainfall variability and its controlling factors under an arid climate condition: case of Gabes Catchment,Southern Tunisia

Environment, Development and Sustainability - Precipitation is the principal component of the hydrologic cycle. This study examines the spatial and temporal rainfall variability in Gabes Catchment...     

Structure and differentiation of spruce populations in the Komi Republic

Groups of spruce populations growing in western and southwestern, central, and northern regions of the Komi Republic significantly differ from each other. Trees with a phenotype intermediate between Norway (Picea abies) and Siberian (P. obovata) spruce prevail in the first group, their proportion in the second group does not exceed 20%, and almost all trees in the third group have the Siberian spruce phenotype.     

Form structure and geographic differentiation of spruce populations in northwestern Russia

Discriminant analysis has been used to analyze the composition of phenotypic forms and geographic differentiation of spruce populations in northwestern Russia in comparison with those of “standard” Norway spruce and Siberian spruce populations. The absolute prevalence of trees with an intermediate Norway-Siberian spruce phenotype has been revealed in almost all populations, except for the northernmost ones. Spruce populations in northwestern Russia may be divided into at least three groups, with the southern group being closer to the Norway spruce, and all other groups, to the Siberian spruce.     

丹江口水库入库水量与气象因子的响应及其预测

利用丹江口水库1959~2016年逐月入库流量及水源区41个气象站同期气象观测资料,通过相关分析确定了影响入库水量的关键气象因子及其影响时效,利用回归分析建立了逐月入库流量预报模型并对误差来源进行了系统分析。结果表明：各月入库水量与前期不同月份降水量呈显著正相关,最大相关系数0.40～0.85,与平均气温呈显著负相关,最大相关系数-0.26～-0.54,其中汛期月份相关性高,影响时效在前1～3个月,冬春季相关性较弱,影响时效在2～6个月。以前期不同月份降水量、气温为预报因子,采用对数变换后的逐步回归模型预报效果最好,各月解释方差在45%～88%之间,汛期月份在75%以上,十折交叉验证月平均绝对误差率20.5%～40.7%,年平均预测误差9.6%。降水的时空分布特征对预测误差具有明显影响,上游汉中、石泉、安康及白河子流域降水偏多,流域边缘降水偏少,预报结果偏低,反之预报结果偏高,同时降水集中或强度大预报结果易偏低,而降水时间分布均匀预报结果易偏高。 关键词： 丹江口水库;入库水量;回归分析;预报误差     

Role of climate risks and socio-economic factors in influencing the impact of climatic extremes: a normalisation study in the context of Odisha,India

Economic costs imposed by climatic extremes have been increasing over the years and are expected to follow a similar trend in the coming years as well. Such costs are incurred due to two factors: (1) natural climate variability and anthropogenic climate change and (2) exposure and vulnerability of socio-economic factors. The impact of these factors as identified separately through a ‘normalisation technique’ is analysed in the existing normalisation studies conducted mostly in developed country contexts; these have produced mixed results. However, one needs to enquire about the influence of the above two factors in a developing country context where the anticipated impacts of climate extremes are significant. This study, therefore, makes an attempt to adjust impact data, in terms of the reported population affected and economic damages of three extreme events, namely cyclones, floods and droughts, together for societal changes between 1972 and 2009 in Odisha in eastern India. Further, the second component is analysed in two ways: (1) assuming that exposed socio-economic factors are equally vulnerable similar to the other normalisation studies, i.e. no adaptation and (2) incorporating adaptation in the existing normalisation methods—which has attracted less attention so far in the literature. The results suggest that: (a) both the natural climate variability and the socio-economic factors influence the increasing damages in the recent decades, and (b) when adaptation is introduced in the normalisation model, economic losses have reduced significantly compared to the estimates using the existing normalisation models.     

Role of hydrological factors in species diversity of algal communities: A case study of the Komarovka River, Primorye, Russia

Studies on the Komarovka River, flowing in the zone of mixed conifer-broadleaf forests in the southwestern Sikhote-Alin Mountains (Primorye, Russia), have shown that the formation of river flow and multispecific phytobenthos communities takes place mainly within 60–70 km² of its catchment area. The summer-autumn runoff rate and taxonomic composition of algae in this river segment are closely correlated with the catchment area. The relative water content of the river decreases downstream because of decrease in the number of tributaries, while changes in the taxonomic diversity of algae depend on river flow velocity and water temperature.     

Growth of northern deciduous trees under increasing atmospheric humidity: possible mechanisms behind the growth retardation

Regional Environmental Change - Increasing atmospheric humidity—a climate trend predicted for northern Europe—will reduce water flux through vegetation. Diminished transpirational water...     

Role of genetic factors in landscape-geographic variation of the water vole (Arvicola terrestris L.)

The geographic variation of the water vole Arvicola terrestris L. has been analyzed with respect to two linear combinations of craniometric characters with the highest additive heritability (h ² = 0.59 and h ² = 0.52). The greatest differences have been revealed between the territorially close montane and piedmont populations. The lowland and montane populations have proved to differ to the smallest extent, despite their spatial and altitudinal separation. Selection under extreme conditions that leads to similar phenotypic results may be based on the common genetic background of these populations, irrespective of considerable distances between them and different environmental conditions in their habitats.     

解悟美国气象经济的发展轨迹和经验

美国政府在引导和规范国内气象经济发展的过程中,始终关注并有效抑制国有气象部门的垄断企图,及时果断地采取措施消除不利于气象事业顺应社会经济和技术发展要求的陈规陋习,适时坚定地扶持充满创造活力的民间资本的竞争努力.可以说,没有这种理智而清醒的管理理念,没有这种不昧于时的前赡眼光和超脱手法,没有这种不拘于内的国际视野和全球战略,是断难有其今天的作为的.我国气象经济的起步较美日等发达国家要晚近40年,更因发展思路不明至今已远远落后于诸多国家.如今面对国内社会经济发展对气象信息日益广泛而精细化的迫切需求,面对全球"气候政治"氛围愈益浓烈的全新形势.特别是"WTO'冲击渡带来的沉重的竞争压力,中国气象经济市场势必将在格局和规则方面进行重大调整.我国在推进气象服务市场化进程中亟需借鉴"美国经验",以确保我国气象事业的健康、协调、可持续发展.     

Environmental occurrence and risk of organic UV filters and stabilizers in multiple matrices in Norway

Eight organic UV filters and stabilizers were quantitatively determined in wastewater sludge and effluent, landfill leachate, sediments, and marine and freshwater biota. Crab, prawn and cod from Oslofjord, and perch, whitefish and burbot from Lake Mjøsa were selected in order to evaluate the potential for trophic accumulation. All of the cod livers analysed were contaminated with at least 1 UV filter, and a maximum concentration of almost 12 μg/g wet weight for octocrylene (OC) was measured in one individual. 80% of the cod livers contained OC, and approximately 50% of cod liver and prawn samples contained benzophenone (BP3). Lower concentrations and detection frequencies were observed in freshwater species and the data of most interest is the 4 individual whitefish that contained both BP3 and ethylhexylmethoxycinnamate (EHMC) with maximum concentrations of almost 200 ng/g wet weight. The data shows a difference in the loads of UV filters entering receiving water dependent on the extent of wastewater treatment. Primary screening alone is insufficient for the removal of selected UV filters (BP3, Padimate, EHMC, OC, UV-234, UV-327, UV-328, UV-329). Likely due in part to the hydrophobic nature of the majority of the UV filters studied, particulate loading and organic carbon content appear to be related to concentrations of UV filters in landfill leachate and an order of magnitude difference in these parameters correlates with an order of magnitude difference in the effluent concentrations of selected UV filters (Fig. 2). From the data, it is possible that under certain low flow conditions selected organic UV filters may pose a risk to surface waters but under the present conditions the risk is low, but some UV filters will potentially accumulate through the trophic food chain.     

Reference populations for discriminant analysis in the continuous range of Norway and Siberian spruces

Reference populations identified within the continuous range of Norway (Picea abies) and Siberian (P. obovata) spuces significantly differ in biometric characters of seed scales, relative position in the same coordinate system (Root 1 and Root 2), phenotypic structure, and mutual taxonomic position (according to the squared Mahalanobis distance). Due to the symmetrically equal positions of the populations relative to each other, they can be used as reference populations in discriminant analysis at a two-, three- or five-class gradation of the test character.     

Endogenous regulation of night-time water relations in hybrid aspen grown at ambient and elevated air humidity

Regional Environmental Change - Although night-time water relations have been studied in different plant species in the last decade, there is limited information about the impact of climate...     

Splenomegaly in small mammals: Prevalence and risk factors

Sources of variation in the relative spleen weight have been studied in small mammals (Rodentia: Muridae, Cricetidae; Insectivora: Soricidae) from the Ural and Fennoscandian forest ecosystems differing in the level of industrial pollution (2004?C2010). Formal threshold indices for the diagnosis of splenomegaly in rodents and shrews have been proposed and substantiated. Effects of several factors on the probability of splenomegaly have been estimated, and the ??normal spleen?? index has been determined.     

Competition factors of edificator tree stand: Quantitative analysis and synthesis

To analyze and quantitatively estimate the contribution of different factors of competition from the edificator tree stand to its effect on plants comprising the lower forest vegetation layer, a set of ecophysiologically based indices of root, light, and integrated competition has been proposed and tested. The results obtained in pine and spruce forests forests of Western Siberia and the Urals show that the growth of the conifer undergrowth is more closely correlated with the index of root competition, and that of heather (Calluna vulgaris (L.) Hull.), with the index of light competition from the edificator tree stand. Moreover, the correlation of their growth with the integrated competition index is 15?C25% stronger than the correlation with the indices of root and light competition, irrespective of forest type.     

Radon exhalation of hardening concrete: monitoring cement hydration and prediction of radon concentration in construction site

The unique properties of radon as a noble gas are used for monitoring cement hydration and microstructural transformations in cementitious system. It is found that the radon concentration curve for hydrating cement paste enclosed in the chamber increases from zero (more accurately - background) concentrations, similar to unhydrated cement. However, radon concentrations developed within 3 days in the test chamber containing cement paste were approximately 20 times higher than those of unhydrated cement. This fact proves the importance of microstructural transformations taking place in the process of cement hydration, in comparison with cement grain, which is a time-stable material. It is concluded that monitoring cement hydration by means of radon exhalation method makes it possible to distinguish between three main stages, which are readily seen in the time dependence of radon concentration: stage I (dormant period), stage II (setting and intensive microstructural transformations) and stage III (densification of the structure and drying). The information presented improves our understanding of the main physical mechanisms resulting in the characteristic behavior of radon exhalation in the course of cement hydration. The maximum value of radon exhalation rate observed, when cement sets, can reach 0.6 mBq kg(-1) s(-1) and sometimes exceeds 1.0 mBq kg(-1) s(-1). These values exceed significantly to those known before for cementitious materials. At the same time, the minimum ventilation rate accepted in the design practice (0.5 h(-1)), guarantees that the concentrations in most of the cases will not exceed the action level and that they are not of any radiological concern for construction workers employed in concreting in closed spaces.