Regional assessment of climate change impacts on maize productivity and associated production risk in Switzerland

A simple model of yield was used along with climate scenarios to assess the impact of climate change on grain maize productivity and associated economic risk in Switzerland. In a first application, changes in the precipitation regime alone were shown to affect the distribution of yield considerably, with shifts not only in the mean but also in the standard deviation and the skewness. Production risk was found to respond more markedly to changes in the long-term mean than in the inter-annual variability of seasonal precipitation amounts. In a further application, yield projections were generated with respect to a full climate scenario, with the emission pathway as specified in the IPCC A2 scenario. Anticipation of the sowing date was found to reduce the negative impact of climate change on yield stability, but was not sufficient to ensure average productivity levels comparable to those observed at present. We argued that this was caused by the reduction in the duration of the growing season, which had a stronger impact than suggested by previous studies. Assuming no change in price relations, the results also revealed a strong increase in production risk with climate change, with more than a doubling in the probability of yield falling short of a critical threshold as compared to today’s situation.     

Natural radioactivity in winter wheat from organic and conventional agricultural systems

The distribution of natural radionuclides was studied in winter wheat plants collected from three sites in Belgium during 2004-2007. Activity concentrations of ⁴⁰K, ²²⁶Ra, ²²⁸Ra and ²²⁸Th in organically and conventionally grown wheat, and in the corresponding soil samples, were determined using ultra low-level gamma-ray spectrometry. The observed soil-to-wheat concentration ratios were calculated for the different parts of the wheat plant (root, stem and grain) in the two agricultural systems (organic and conventional). There were large variations in radionuclide activity concentrations between the sites and fields, but no significant difference between conventionally and organically grown wheat plants was observed.     

Spatial and temporal variation of energy carbon emissions in Yantai from 2001 to 2011

In order to understand the characteristics of spatial and temporal variation, as well as provide effective ideas on carbon emissions and regulatory policy in Yantai, this article analyzed spatial and temporal variation of carbon emissions in Yantai based on energy consumption statistics for a variety of energy sorts together with industrial sectors from 2001 to 2011. The results were as following: First of all, Yantai’s carbon emissions grew by an average of 5.5% per year during the last 10 years, and there was a peak of 10.48 million carbon in the year of 2011. Second, compared with the gross domestic product (GDP) growth rate, the figures for energy carbon emissions growth rate were smaller; however the problem of carbon emissions were still more obvious. Furthermore, carbon emissions in Yantai increased rapidly before 2008; while after 2008, it increased more slowly and gradually become stable. Third, the energy consumption was different among regions in Yantai. For instance, the energy consumption in Longkou city was the largest, which occupied 50% of the total carbon emissions in Yantai; and the energy consumption in Chang Island was generally less than 1% of the Longkou consumption. Finally, there were relative close relationships among the spatial difference of carbon emissions, regional resources endowment, economic development, industrial structure, and energy efficiency.     

Predawn disequilibrium between soil and plant water potentials in light of climate trends predicted for northern Europe

Regional Environmental Change - The study was performed on coppice shoots and 9-year-old saplings of hybrid aspen (Populus tremula L. × Populus tremuloides Michx.) growing at the Free Air...     

Intra-cultivar variability of the soil-to-grain transfer of fallout 137Cs and 90Sr for winter wheat

Differences between the root uptake of fallout radionuclides by different cultivars ('inter-cultivar' variability) growing on the same field may be influenced not only by genetic differences of the cultivars, but also by the spatial variability of the soil-to-grain transfer within the cultivation area of each cultivar. This 'intra-cultivar' variability was investigated in 2001 and 2002 for 137Cs and 90Sr using three winter wheat cultivars with four replicates for each cultivar at three different sites in Bavaria, Germany. The intra-cultivar variability proved to be in the same range as the inter-cultivar variability which was determined earlier at the same sites for both radionuclides. An ANOVA of the 137Cs data set revealed that the variability of the 137Cs soil-to-grain transfer was caused by the soil and climate (year) at the field sites and the interaction of cultivar and field. A significant contribution of the factor 'cultivar' alone to the variability could not be detected. This may be due to the complex environmental conditions to which plants are exposed in field experiments. To find wheat cultivars with minimal uptake of fallout radionuclides it may be better to examine the molecular mechanisms of their root uptake in order to identify targets for breeding "safer" plants.     

210Pb as a tool for establishing sediment chronologies: examples of potentials and limitations of conventional dating models

For aquatic sediments, the use of ²¹⁰Pb originating from the decay of atmospheric ²²²Rn is a well-established methodology to estimate sediment ages and sedimentation rates. Traditionally, the measurement of ²¹⁰Pb in soils and sediments involved laborious and time-consuming radiochemical separation procedures. Due to the recent development of advanced planar (‘n-type’) semi-conductors with high efficiencies in the low-energy range which enable the gamma-spectrometric analysis of the 46.5 keV decay line of ²¹⁰Pb, sediment dating using this radionuclide has gained renewed interest.In this contribution, potentials and limitations of the ²¹⁰Pb methodology and of the models used for estimating sediment ages and sedimentation rates are discussed and illustrated by examples of freshwater and marine sediments. Comparison with the use of ¹³⁷Cs shows that the information which may be gained by these two tracers is complementary. As a consequence, both radionuclides should be used in combination for dating of recent sediments. It is shown that for various sedimentation regimes additional information from other sources (e.g. sediment lithology) may be needed to establish a reliable chronology. A strategy for sediment dating using ²¹⁰Pb is recommended.     

Agronomic adaptation strategies under climate change for winter durum wheat and tomato in southern Italy: irrigation and nitrogen fertilization

Agricultural crops are affected by climate change due to the relationship between crop development, growth, yield, CO₂ atmospheric concentration and climate conditions. In particular, the further reduction in existing limited water resources combined with an increase in temperature may result in higher impacts on agricultural crops in the Mediterranean area than in other regions. In this study, the cropping system models CERES-Wheat and CROPGRO-Tomato of the Decision Support System for Agrotechnology Transfer (DSSAT) were used to analyse the response of winter durum wheat (Triticum aestivum L.) and tomato (Lycopersicon esculentum Mill.) crops to climate change, irrigation and nitrogen fertilizer managements in one of most productive areas of Italy (i.e. Capitanata, Puglia). For this analysis, three climatic datasets were used: (1) a single dataset (50?km?×?50?km) provided by the JRC European centre for the period 1975–2005; two datasets from HadCM3 for the IPCC A2 GHG scenario for time slices with +2°C (centred over 2030–2060) and +5°C (centred over 2070–2099), respectively. All three datasets were used to generate synthetic climate series using a weather simulator (model LARS-WG). Adaptation strategies, such as irrigation and N fertilizer managements, have been investigated to either avoid or at least reduce the negative impacts induced by climate change impacts for both crops. Warmer temperatures were primarily shown to accelerate wheat and tomato phenology, thereby resulting in decreased total dry matter accumulation for both tomato and wheat under the +5°C future climate scenario. Under the +2°C scenario, dry matter accumulation and resulting yield were also reduced for tomato, whereas no negative yield effects were observed for winter durum wheat. In general, limiting the global mean temperature change of 2°C, the application of adaptation strategies (irrigation and nitrogen fertilization) showed a positive effect in minimizing the negative impacts of climate change on productivity of tomato cultivated in southern Italy.     

Distribution and temporal trends of butyltins monitored by molluscs along the Chinese Bohai coast from 2002 to 2005

Thirteen areas around the Chinese Bohai coast, individuals including ten kinds of bivalves and two kinds of snails were collected during the period of 2002-2005 for the investigation of spatial distribution and temporal variations of butyltin compounds (BTs). BTs including tributyltin (TBT) and its derivates, dibutyltin (DBT) and monobutyltin (MBT) were quantified by gas chromatography/flame photometric detection after extraction and Grignard derivatization. BTs compounds were widely existed in the samples and TBT was the dominant composition, indicating recent TBT input along Bohai coast. As a whole, BTs concentration remained high during the sampling years except a slightly decreased in samples from several sites in 2005. The contamination characteristics of BTs in different sampling sites were analyzed using principal component analysis (PCA) method, and the species specific bioaccumulation of BTs was also identified using cluster analysis.     

中国粮食产量变化的驱动效应及其空间分异研究

粮食安全是一个国家和地区经济和社会稳定发展的基础,而粮食产量则是衡量粮食安全的最为重要指标,研究粮食产量变化的驱动效应对于实现其持续稳定增长具有重要意义。综合考虑种植业结构、农林牧渔业结构、农业生产经济收益、农业劳动力等各因素对粮食产量的影响,从农业经济学的视角出发,构建了粮食产量分解的理论框架。基于这一框架,将粮食产量变化分解为种植经济的粮食安全效应、农业结构调整效应、农业劳动力农业经济收益效应、农业劳动力当量效应等4种。采用对数平均迪氏分解模型(LMDI)和粮食生产的空间转移系数,揭示了4种效应对1978—2014年中国粮食产量的时序变化以及2000—2013年全国31省(市、区)粮食产量的空间变化的影响程度。研究结果表明:无论从时间还是空间变化方面,农业劳动力农业经济收益效应都是驱动粮食增产的首要因素,种植经济的粮食安全效应则是抑制粮食增产的首要因素。在政府主导模式下,农业结构调整对粮食增产的负面影响较小,而在农户主导模式下,农业结构调整对粮食产量的负面影响明显增强,这一结果在粮食主产区表现尤为明显。1978—2014年,中国劳动力当量效应对粮食产量变化由正向驱动作用不断向负向抑制作用转变,且其对粮食增产的抑制作用不断增强,这一现象在粮食主产区表现也尤为突出。因此,为促进中国粮食产量持续增长,尤其需要发挥政府在粮食主产区农业结构调整中的主导作用,在确保农民生产粮食基本收益的基础上,加快延伸粮食生产产业链,进一步增加农民收入来源,促进劳动力资源在城乡之间的有效配置。     

吉林省城市紧凑度与城市效率的时空演变及相关性

紧凑城市理念被认为可以有效提高城市经济发展效率,减少城市在开发建设、资源配置等方面的低效率。为探究我国城市紧凑度和城市效率的时空演变及两者间的相关性,本研究以吉林省地级及以上城市为研究对象,研究时间段选择为2000—2013年。研究主要分为三个部分。第一部分,运用熵值法,对吉林省地级及以上城市的紧凑度时空演变特征进行研究,研究发现,吉林省城市紧凑度平均水平较低,并且空间分布极不均衡,受区位和经济发展水平影响较大,高紧凑度城市基本位于哈大城市走廊一线。第二部分运用DEA数据包络模型,对吉林省城市效率演变特征进行研究,结果显示,吉林省城市效率在经过了长期的反复波动后于2012年步入快速增长阶段,受多种因素影响,各城市全要素生产率增长节奏迥异,但都表现出与技术进步一致的变动性,城市经济发展对新技术、新的生产要素投入的依赖较大,资源利用效率整体较低。第三部分运用R语言对吉林省城市紧凑度与城市效率的相关性进行了研究,两者间存在极弱的相关性,接着借助象限图法得出两者在不同时间段内存在一定程度的同步性,紧凑度提升时大部分城市的城市效率会出现提升,紧凑度的下降不一定有效引起城市效率同步下降。     

Spatial and temporal organization of benthic macroinvertebrate communities in Lake Chany,Western Siberia

Communities of benthic macroinvertebrates in drainless Lake Chany, the largest lake in Western Siberia, have been analyzed to estimate the effects of basic abiotic ecological factors (hydrophysical and hydrochemical parameters of water and the type of bottom ground) on their composition, structure, and dynamics. It has been shown that the level of development of these communities depends mainly on the water regime of the lake and also on the type of bottom ground, lake depth, and water mineral content.     

Spatial and temporal distribution of lead-210 in the surface layers of the atmosphere

The levels of ²¹⁰Pb in surface air from about sixty locations and in rainwater from about forty locations, around the globe, are summarised in this report. The spatial, annual and long-term variations in the levels of ²¹⁰Pb are discussed. The concentrations vary as a function of the continentality of the locations and at many stations there is a seasonal variation. There is no significant long-term variation in activity levels, possibly indicating the absence of a major anthropogenic source of this nuclide. The activity ratio of ²²²Rn/²¹⁰Pb is around 6000 in India and varies seasonally depending on air mass source.     

Spatial and temporal distribution of Pu in the Northwest Pacific Ocean using modern coral archives

Historical ²³⁹Pu activity concentrations and ²⁴⁰Pu/²³⁹Pu atom ratios were determined in skeletons of dated modern corals collected from three locations (Chuuk Lagoon, Ishigaki Island and Iki Island) to identify spatial and temporal variations in Pu inputs to the Northwest Pacific Ocean. The main Pu source in the Northwest Pacific is fallout from atmospheric nuclear weapons testing which consists of global fallout and close-in fallout from the former US Pacific Proving Grounds (PPG) in the Marshall Islands. PPG close-in fallout dominated the Pu input in the 1950s, as was observed with higher ²⁴⁰Pu/²³⁹Pu atom ratios (> 0.30) at the Ishigaki site. Specific fallout Pu contamination from the Nagasaki atomic bomb and the Ivy Mike thermonuclear detonation at the PPG were identified at Ishigaki Island from the ²⁴⁰Pu/²³⁹Pu atom ratios of 0.07 and 0.46, respectively. During the 1960s and 1970s, global fallout was the major Pu source to the Northwest Pacific with over 60% contribution to the total Pu. After the cessation of the atmospheric nuclear tests, the PPG again dominated the Pu input due to the continuous transport of remobilised Pu from the Marshall Islands along the North Equatorial Current and the subsequent Kuroshio Current. The Pu contributions from the PPG in recent coral bands (1984 onwards) varied over time with average estimated PPG contributions between 54% and 72% depending on location.     

Climate trends and impacts on crop production in the Koshi River basin of Nepal

Understanding crop responses to climate is essential to cope with anticipated changes in temperature and precipitation. We investigated the climate–crop yield relationship and the impact of historical climate on yields of rice, maize and wheat in the Koshi basin of Nepal. The results show significant impact of growing season temperature and precipitation on crop production in the region. Rice, maize and wheat cultivated at altitudes below 1,100, 1,350 and 1,700 m amsl (above mean sea level), respectively, suffer from stress due to higher temperatures particularly during flowering and yield formation stages. Responses of crop yields to a unitary increment in growing season mean temperature vary from ?6 to 16 %, ?4 to 11 % and ?12 to 3 % for rice, maize and wheat, respectively, depending on the location and elevation in the basin. In most parts of the basin, we observe warming trends in growing season mean temperatures of rice, maize and wheat over the last few decades with clear evidence of negative impacts on yields. However, at some high-elevation areas, positive impacts of warming are also observed on rice and maize yields. If the observed trends in temperature continue in future, the impact is likely to be mostly negative on crop production in the basin. However, crop production may gain from the warming at relatively higher altitudes provided other conditions, e.g., water availability, soil fertility, are favorable.     

The Kinetics of Caesium absorption by roots of winter wheat and the possible consequences for the derivation of soil-to-plant transfer factors for radiocaesium

Caesium (Cs) uptake in roots of winter wheat was found to follow a dual pattern similar to that established for potassium uptake in barley roots. This suggests the operation of two discrete uptake systems for Cs, as for potassium. The ‘System 1’ (low concentration) uptake mechanism for caesium, however, can be resolved into two hyperbolic components which both obey Michaelis-Menten kinetics. The Michaelis-Menten equation was used to derive a function which describes the variation in solution-to-root transfer factor for any element for which the appropriate root uptake constants (K_m andV_max) can be determined. This function successfully described available data for root uptake of caesium and potassium, predicting that the solution-to-root transfer factor decreases in relation to an increase in the substrate concentration of each respective element. At substrate concentrations equivalent to carrier-free radiocaesium concentrations, however, the solution-to-root transfer factor predicted by the function and by empirical data suggests that the relationship between root uptake and solution concentration of caesium is linear. These findings are discussed in relation to the comparative physiology of caesium and potassium uptake by plant roots and with respect to the application of the soil-to-plant transfer factor concept to radioecological studies.     

Comparison of temporal and Spatial Characteristics of Ozone Pollution at Ground Level in the Eastern China

Monitoring data from ozone（O3） automatic stations in three typical cities with different climatic areas in the southern and northern parts of eastern China are used to analyze temporal and spatial characteristics of ozone pollution at ground level. The results show that ozone pollution level has distinct regional differences and the concentration in the suburbs is higher than that in the urban areas. The seasonal variation of ozone concentration in different climatic areas is greatly affected by the variation of precipitation. Ozone concentration in Shenyang and Beijing , in the temperate zone, has one perennial peak concentration, occurring in early summer, May or June. Ozone concentration in Guangzhou, in sub-tropical zone, has two peak values year round. The highest values occur in October and the secondary high value in June. The ozone season in the south is longer than that in the north. The annual average daily peak value of ozone concentrations in different climates usually occur around 3 pm. The diurnal variation range of ozone concentration declines with the increase of latitude. Ozone concentration does not elevate with the increase of traffic flow. Ozone concentration in Guangzhou has a distinct reverse relation to CO and NOx. This complicated non-linearity indicates that the equilibrium of ozone photochemical reaction has regional differences. Exceeding the rate of Beijing＇s lh ozone concentration is higher than that of Guangzhou, whereas the average 8h ozone level is lower than that of Guangzhou, indicating that areas in low latitude are more easily affected by moderate ozone concentrations and longer exposure. Thus, China should work out standards for 8h ozone concentration.     

Spatial and temporal variability of composition of urban effluents in the island of Lesvos, Greece

The spatial and temporal variability in the composition of effluents of the coastal town of Mytilene, island of Lesvos, Greece, was investigated in 8 sewers of the town. Differences were found in the quality of effluents between the old and new parts of the town and were attributed mainly to the different design and construction of the sewers, as well as to the occasional discharge of septage into the sewerage network in parts of the town. During summer the population and water consumption increase, leading to partial dilution of the organic load. However, in the same period (July), the concentrations of dissolved Zn and particulate Pb were enriched. The reasons for such an increase are not clear. At present the seasonal metal peaks (Pb and Zn) are attributed to the increased traffic (Pb and Zn) and to increased corrosion under the prevailing weather conditions of the water supply network, which includes a very large number of galvanized storage tanks (Zn).     

Comparison of temporal and Spatial Characteristics of Ozone Pollution at Ground Level in the Eastern China

Abstract

Monitoring data from ozone(O₃ automatic stations in three typical cities with different climatic areas in the southern and northern parts of eastern China are used to analyze temporal and spatial characteristics of ozone pollution at ground level. The results show that ozone pollution level has distinct regional differences and the concentration in the suburbs is higher than that in the urban areas. The seasonal variation of ozone concentration in different climatic areas is greatly affected by the variation of precipitation. Ozone concentration in Shenyang and Beijing, in the temperate zone, has one perennial peak concentration, occurring in early summer, May or June. Ozone concentration in Guangzhou, in sub-tropical zone, has two peak values year round. The highest values occur in October and the secondary high value in June. The ozone season in the south is longer than that in the north. The annual average daily peak value of ozone concentrations in different climates usually occur around 3 pm. The diurnal variation range of ozone concentration declines with the increase of latitude. Ozone concentration does not elevate with the increase of traffic flow. Ozone concentration in Guangzhou has a distinct reverse relation to CO and NO_x. This complicated non-linearity indicates that the equilibrium of ozone photochemical reaction has regional differences. Exceeding the rate of Beijing's 1h ozone concentration is higher than that of Guangzhou, whereas the average 8h ozone level is lower than that of Guangzhou, indicating that areas in low latitude are more easily affected by moderate ozone concentrations and longer exposure. Thus, China should work out standards for 8h ozone concentration.     

Fate,distribution, and contrasting temporal trends of perfluoroalkyl substances (PFASs) in Lake Ontario,Canada

Lake Ontario water and sediment collected from tributary, nearshore, and open lake sites were analyzed for perfluoroalkyl substances (PFASs), namely perfluoroalkyl carboxylic acids (PFCAs, F(CF₂)_nCO₂⁻; n = 6-11,13) and perfluoroalkane sulfonic acids (PFSAs, F(CF₂)_nSO₃⁻; n = 6,8,10). Survey results of surface sediment and water indicated that shorter chained PFASs were predominant in and near urban/industrial area watersheds, while longer chained PFASs were predominant in fine-grained sediment from major depositional basins. Niagara River suspended solids (1981–2006) demonstrated temporal trends that may have been influenced by recent changes in North American production and use of PFASs. Perfluorooctane sulfonate (PFOS) reached a peak concentration in 2001 of 1.1 ng/g, followed by a decrease from 2001 to 2006 (half-life = 9 years). Perfluorooctanoic acid (PFOA) increased from 2001 to 2006 (doubling time = 2 years) reaching a peak concentration of 0.80 ng/g. In contrast, three sediment cores from western, central, and eastern Lake Ontario showed increasing temporal trends to surface sediment for all PFASs. PFOA and PFOS concentrations increased from 1988 to 2004 (doubling time = ~ 4 years) in the western Lake Ontario core. The observed variations in temporal trends from different environmental compartments may be a result of the physico-chemical properties of PFASs, ongoing emissions, and the environmental transformation and degradation of PFAS precursor compounds.