WATER QUALITY FROM TWO SMALL FORESTED WATERSHEDS IN SOUTHERN ILLINOIS1

Two intermittent streams on oak-hickory watersheds in southern Illinois were gaged with a V-notched weir and sampled with an automatic water sampler. For three years data were collected on flow volume and water quality. Flow volumes show large variations between years and watersheds. Samples were analyzed for Na⁺, K⁺, Ca⁺⁺, Mg⁺⁺, P, and NO^-₃. Water quality was consistently high, although there were significant differences between watersheds. A baseline for water quality has been established for comparison after one of the watersheds is clearcut at a later date.     

Genetic amniocentesis: 505 cases performed before the sixteenth week of gestation

Between May 1987 and November 1988, 505 early amniocentesis within the 15th week of gestation were performed at the First Department of Obstetrics and Gynaecology,‘L. Mangiagalli’ of the University of Milan and at the Department of Obstetrics and Gynaecology of ‘Gaslini’ hospital in Genoa. A total number often abnormal fetal karyotypes were diagnosed. In addition, one case of pseudomosaicism (not confirmed on fetal blood) and one case of osteogenesis imperfecta type II (observed at ultrasound examination) were also detected. Eleven pregnancies were therefore terminated because of an abnormal fetus. Out of 494 pregnancies (excluding terminated pregnancies) there were 16 fetal losses within the 28th week; ten of these occurred in the 2 weeks following the procedure. There were 475 live-births, of which 447 were term deliveries and the other 28 deliveries occurred before the 37th week of gestation.     

Science–policy interface for addressing environmental problems in arid Spain

Science–policy interfaces are avenues for finding solutions for environmental challenges through strengthening collaborations between research disciplines and public administrations. Here we present a methodology for the conduct of science–policy interfaces between scientists and policymakers for addressing day-to-day environmental problems in the southeastern Spanish drylands. A knowledge brokering approach based on six consecutive workshops was used to facilitate mutual understanding and trust between scientists and policymakers. Water policy and biodiversity loss were identified as major environmental concerns in the region, and 12 final environmental problems were agreed as priorities. A graphical tool was used for diagnosing each environmental problem according to the available scientific knowledge, the current regulatory capacity of administrations, and the level of public engagement necessary for addressing the problem. The use of the graphical tool also allowed for (a) the clarification of roles involved in problem solving, and (b) the promotion of a culture of shared responsibility for the implementation of management actions based on collaborative work. We discuss lessons learned and propose recommendations for future experiences.     

WELFARE EFFECTS OF ALTERNATWE WATER RATIONING SCHEMES: A CASE STUDY1

ABSTRACT: Four alternate schemes often used to deal with a water shortage are: physical rationing, lifeline with increasing block rates, rationing with resale, and pure price rationing. Each of these are analyzed using a supply-demand framework. The theoretical results are applied to a representative California water district and the welfare loss is calculated for a hypothetical 20 percent reduction in water supply for six different income classes. We find that reliance on schemes using the price mechanism in one form or another is clearly superior, in terms of welfare loss, as a means of dealing with a water shortage.     

Impacts of agri-environmental policy on land use and nitrogen leaching in Finland

Agri-environmental policies are challenging to be evaluated since they are often implemented in combination with other policies and regulations affecting agriculture. Also input and output markets affect agriculture. We provide impact assessment of agri-environmental scheme implemented in Finland 2007–2013 based on integrated economic and hydrological modelling and counterfactual scenarios. Development of crop specific fertilisation and land use changes, simulated using a multi-regional economic sector model, is included in a nutrient leaching model implemented in a typical agricultural region. Our results on agricultural production, land use, and nitrogen leaching show that the agri-environmental policy successfully mitigates nutrient leaching in intensive production regions but some mitigation potential is lost in less intensive regions.     

关于气溶胶颗粒物沉积率系数平均方法模型的改进研究

气溶胶颗粒物在壁面的沉积率系数模型的研究已经成为现代气溶胶动力学研究的重要课题.本文通过实验腔测量和理论分析相结合,对Koivisto等(2012)提出的平均方法模型(AM)中的关键参数(即时间间隔)的选取和对测量数据量的要求两个问题进行研究.选取目前广泛使用的最小二乘法模型(LSM)和Lai和Nazaroff(2000)提出的理论分析模型进行对比.研究发现,AM模型中的时间间隔这一关键参数,应由目前的50矫正为20;AM模型和LSM模型均要求实验测量数据个数等于或者大于10,但是AM模型在小数据量情况下的预测结果更精确.     

Controlling cyanobacterial blooms by managing nutrient ratio and limitation in a large hypereutrophic lake: Lake Taihu, China

Excessive nitrogen (N) and phosphorus (P) loading of aquatic ecosystems is a leading cause of eutrophication and harmful algal blooms worldwide, and reducing nutrient levels in water has been a primary management objective. To provide a rational protection strategy and predict future trends of eutrophication in eutrophic lakes, we need to understand the relationships between nutrient ratios and nutrient limitations. We conducted a set of outdoor bioassays at the shore of Lake Taihu. It showed that N only additions induced phytoplankton growth but adding only P did not. Combined N plus P additions promoted higher phytoplankton biomass than N only additions, which suggested that both N and P were deficient for maximum phytoplankton growth in this lake (TN:TP = 18.9). When nutrients are present at less than 7.75-13.95 mg/L TN and 0.41-0.74 mg/L TP, the deficiency of either N or P or both limits the growth of phytoplankton. N limitation then takes place when the TN:TP ratio is less than 21.5-24.7 (TDN:TDP was 34.2-44.3), and P limitation occurs above this. Therefore, according to this ratio, controlling N when N limitation exists and controlling P when P deficiency is present will prevent algal blooms effectively in the short term. But for the long term, a persistent dual nutrient (N and P) management strategy is necessary.     

The effects of temperature on decomposition and allelopathic phytotoxicity of boneseed litter

Decomposition of plant litter is a fundamental process in ecosystem function, carbon and nutrient cycling and, by extension, climate change. This study aimed to investigate the role of temperature on the decomposition of water soluble phenolics(WSP), carbon and soil nutrients in conjunction with the phytotoxicity dynamics of Chrysanthemoides monilifera subsp. monilifera(boneseed) litter. Treatments consisted of three factors including decomposition materials(litter alone, litter with soil and soil alone), decomposition periods and temperatures(5–15, 15–25and 25–35°C(night/day)). Leachates were collected on 0, 5, 10, 20, 40 and 60 th days to analyse physico-chemical parameters and phytotoxicity. Water soluble phenolics and dissolved organic carbon(DOC) increased with increasing temperature while nutrients like SO-24 and NO-13 decreased. Speed of germination, hypocotyl and radical length and weight of Lactuca sativa exposed to leachates were decreased with increasing decomposition temperature. All treatment components had significant effects on these parameters. There had a strong correlation between DOC and WSP, and WSP content of the leachates with radical length of test species. This study identified complex interactivity among temperature, WSP, DOC and soil nutrient dynamics of litter occupied soil and that these factors work together to influence phytotoxicity.     

Ozone concentrations, flux and potential effect on yield during wheat growth in the Northwest-Shandong Plain of China

Ozone (O₃) concentration and flux (F_o) were measured using the eddy covariance technique over a wheat field in the Northwest-Shandong Plain of China. The O₃-induced wheat yield loss was estimated by utilizing O₃ exposure-response models. The results showed that: (1) During the growing season (7 March to 7 June, 2012), the minimum (16.1 ppbV) and maximum (53.3 ppbV) mean O₃ concentrations occurred at approximately 6:30 and 16:00, respectively. The mean and maximum of all measured O₃ concentrations were 31.3 and 128.4 ppbV, respectively. The variation of O₃ concentration was mainly affected by solar radiation and temperature. (2) The mean diurnal variation of deposition velocity (V_d) can be divided into four phases, and the maximum occurred at noon (12:00). Averaged V_d during daytime (6:00–18:00) and nighttime (18:00–6:00) were 0.42 and 0.14 cm/sec, respectively. The maximum of measured V_d was about 1.5 cm/sec. The magnitude of V_d was influenced by the wheat growing stage, and its variation was significantly correlated with both global radiation and friction velocity. (3) The maximum mean F_o appeared at 14:00, and the maximum measured F_o was − 33.5 nmol/(m²·sec). Averaged F_o during daytime and nighttime were − 6.9 and − 1.5 nmol/(m²·sec), respectively. (4) Using O₃ exposure-response functions obtained from the USA, Europe, and China, the O₃-induced wheat yield reduction in the district was estimated as 12.9% on average (5.5%–23.3%). Large uncertainties were related to the statistical methods and environmental conditions involved in deriving the exposure-response functions.