Quantifying the ecosystem service of non-native weed seed predation provided by invertebrates and vertebrates in upland wheat fields converted from paddy fields

The extent of post-dispersal weed seed predation in upland wheat fields converted from paddy fields was quantified in Shizuoka Prefecture, central Japan. We investigated the temporal variability in seed predation of Italian ryegrass (Lolium multiflorum Lam.), a non-native winter annual weed in Japan, during summer after the seed shed in both the field interior areas and boundary strips, and estimated the total seed loss due to predation during the summer. Furthermore, the contribution of invertebrates and vertebrates to seed predation was estimated by using exclosures. The total seed loss due to predation during four months (from late June to late October) in the field interior areas and boundary strips was estimated to be 35–43% (the maximum proportion of seed predation per two weeks = 27%) and 42% (25%), respectively. The seed predators in the field interior areas were vertebrates (rodents or birds) and invertebrates (crickets and ground beetles). In contrast, seed predators in the boundary strips were mainly invertebrates (crickets and ground beetles). The results of this study suggest that predators make a substantial contribution in the depletion of post-dispersal seeds of Italian ryegrass in converted paddy fields.     

Cost-effectiveness Analysis of Reducing the Emission of Nitrogen Oxides in Asia

The purpose of this study is to evaluate cost-effective reduction strategies for nitrogen oxides (NO _x ) in the Asian region. The source-receptor relationships of the Lagrangian “puff” model of long-range transportation, ATMOS-N, were used to calculate the wet/dry deposition of the nitrogen (N) in Asia. Critical loads of N deposition in Asia were calculated from the relationships between the critical load of sulfur (S) and balance of N in and out using the data of S critical load of RAINS-ASIA. The cost functions of N reduction of Asian countries were derived by the regression analysis with the data of cost functions of European countries used in RAINS. In order to assess the environmental impact, the gaps between N deposition and critical load of N were calculated. The emission of NO _x was reduced in some cases of this model, and the changes of gaps between N deposition and critical load were observed as well as the changes of the reduction cost. It is shown that a uniform reduction of NO _x emissions by countries in Asia is not cost-effective strategy.     

Light levels used during feeding by primate species with different color vision phenotypes

The intensity of available light is important in determining how well a diurnal animal can distinguish color. Primates with different types of color vision may exhibit behaviors that maximize visual contrast during critical activities such as feeding. We hypothesized that (1) trichromatic taxa will feed in a wide range of light conditions because color constancy permits stabilized color appearance across changes in illumination, and (2) that taxa with a high proportion of dichromatic individuals will tend to feed at higher light levels to increase color contrast. We recorded light levels during feeding bouts of seven primate taxa with varying degrees of color vision: the dichromatic Lemur catta, two polymorphic species, Propithecus v. verreauxi and Ateles geoffroyi, and the routine trichromats, Alouatta palliata, Colobus guereza, Piliocolobus badius, and Cercopithecus ascanius. Results were equivocal for our hypotheses. While routinely trichromatic taxa used varying light levels, the pattern of results did not differ from the dichromatic Lemur catta. However, polymorphic taxa not only sought the highest light, but females, which are the only individuals in polymorphic taxa that can be trichromatic, fed in higher light levels than males when eating non-green foods. This result is consistent with selection operating to maintain a balanced polymorphism in these taxa, though the connection between light levels and color vision type for the females is unclear. Our results further suggest that trichromatic vision may afford a selective advantage because it permits foraging under a greater range of light levels.     

Effect of low dissolved oxygen concentrations on behavior and predation rates on red sea bream Pagrus major larvae by the jellyfish Aurelia aurita and by juvenile Spanish mackerel Scomberomorus niphonius

A shift in outcomes of predator-prey interactions in plankton community may occur at sublethal dissolved oxygen concentrations that commonly occur in coastal waters. Laboratory experiments were conducted to investigate how a decline in dissolved oxygen concentration alters the predation rate on fish larvae by two estuarine predators. Behavior and consumption of larval fish by moon jellyfish Aurelia aurita (103.1±12.4 mm in bell diameter) and by a juvenile piscivore, Spanish mackerel Scomberomorus niphonius (30.1±2.1 mm in standard length: SL), were observed under four oxygen concentration treatments (1, 2 and 4 mg l^–1 and air-saturated: 5.8 mg l^–1). Larvae of a coastal marine fish species, red sea bream Pagrus major (7.21±0.52 mm SL), were used as prey for the experiment. Bell contraction rate of the jellyfish did not vary among the oxygen concentrations tested, indicating a tolerance to low oxygen concentration. Gill ventilation rate of the Spanish mackerel increased and swimming speed decreased as the oxygen concentration decreased, indicating that oxygen concentrations 4 mg l^–1 are physiologically stressful for this species. The number of larvae consumed in 15 min. by jellyfish increased whereas those consumed by Spanish mackerel decreased with the decrease in oxygen concentration. Low oxygen concentrations that are commonly observed in coastal waters of Japan during summer have the potential to increase the relative importance of jellyfish as predator of fish larvae and to change the importance of alternative trophic pathways in estuarine ecosystems.Communicated by T. Ikeda, Hakodate     

Correspondence analysis of paper recycling society: consumers and paper makers in Japan

Paper passes through many hands. In the present paper, key parts of this cycle in Japan were examined, using questionnaire surveys of households and paper makers. The study aimed to examine the paper makers' strategy for paper production and their attitude to recycling, in comparison with those of the consumers. The study especially focused on toilet paper because consumers have a lot of freedom in purchasing toilet paper. A total of 1242 consumers and 60 paper makers responded. The major findings were as follows. First, we compared the criteria of consumers for purchasing toilet paper with the conjectures of paper makers. Brand, advertisements and the appearance of shopping displays received 60% support from paper makers, but less than 12% of consumers selected these criteria even if we exclude those who do not buy toilet paper or do not have any particular criteria. On the other hand, multiple plies and benefit to the earth were selected by moderate numbers (between 20 and 25%) of consumers, while only 16.77 and 5.69%, respectively of paper makers marked these criteria. Paper makers strongly believe that many retailers sell toilet paper as a loss-leader. By comparing those matters considered important for recycling by consumers with those considered important by makers, it was shown that many makers have a clear awareness of the particular problem, the lack of used paper consumption, in the current paper recycling situation in Japan.     

Isomer-specific analysis of chlorinated biphenyls,naphthalenes and dibenzofurans in Delor: polychlorinated biphenyl preparations from the former Czechoslovakia

Technical polychlorinated byphenyl (PCB) preparations--Delors 103, 104, 105, and 106--produced in the former Czechoslovakia were analyzed for their chlorobiphenyl (CB), chloronaphthalene (PCN) and chlorinated dibenzofuran (PCDF) composition and content using high resolution gas chromatography-mass spectrometry techniques. The congener patterns of Delors 103, 104, 105, and 106 resembled Aroclors 1242, 1248, 1254, and 1260. Delors contained PCNs and PCDFs, as impurities, at microgram per gram concentrations. Concentrations of PCNs and PCDFs in Delors were greater than those found in the corresponding Aroclors. The potential for the emissions of PCNs and PCDFs from Delor was estimated to be 3680 and 860 kg, respectively. Non- and mono-ortho PCBs were the major contributors to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents in Delor mixtures.     

四川省卧龙地区土壤中二噁英类化合物和多氯萘的海拔梯度分布及对牦牛的毒性风险评价

初步研究了四川省卧龙地区5个不同海拔高度的表层土壤和2个牦牛样品中二噁英/呋喃(PCDD/Fs)、共平面多氯联苯(co-PCBs)和多氯萘(PCNs)的分布特征、来源、毒性当量以及生态风险状况.土壤样品中总2,3,7,8-PCDD/Fs的含量范围为2.48-4.30 pg·g-1dw,平均3.50 pg·g-1dw,最高含量在海拔3927 m的塘房.co-PCBs的总含量平均为9.14 pg·g-1dw,最高值在海拔4487 m的垭口.总2,3,7,8-PC-DD/Fs和总co-PCBs含量随海拔高度的变化表现出正相关关系.不同海拔高度土壤中的PCDD/Fs和co-PCBs异构体的分布相似,表明具有相同的来源.总PCNs与海拔梯度呈负相关关系,最高含量出现在海拔3345 m的贝母坪,平均21.4 pg·g-1dw,主要以3.氯为主.土壤中PcDD/Fs毒性当量浓度范围为0.29-0.43pg TEQ·g-1dw.牦牛肉和牦牛组织中PcDD,/Fs总浓度分别为27.5和23.6 pg·g-1脂肪,毒性当量浓度为4.04和4.07 pg TEQ·g-1脂肪.结果表明,牦牛中的PCDD/Fg,co-PcBs和PCNs不大可能对卧龙地区人群导致严重的负面效应.     

Perfluorooctane sulfonate (PFOS) and other fluorochemicals in fish blood collected near the outfall of wastewater treatment plant (WWTP) in Beijing

Perfluorinated compounds (PFCs) were measured in zooplankton and five fish species collected from Gaobeidian Lake, which receives discharge from wastewater treatment plant (WWTP) in Beijing, China. The mean total PFCs in five fish were in the order: crucian carp > common carp > leather catfish > white semiknife carp > tilapia. Perfluorooctane sulfonate (PFOS) occurred at the greatest concentrations, with mean concentrations ranging from 5.74 to 64.2 ng/ml serum. Perfluorodecanoic acid (PFDA) was the second dominant PFC in fish samples except for common carp in which perfluorooctane sulfonamide (PFOSA) was dominant. A positive linear relationship (r² = 0.85, p < 0.05) was observed between ln PFOS concentrations (ln ng/ml) and trophic level (based on δ¹⁵N) if tilapia was excluded. The risk assessment showed that PFOS might not pose an immediate risk to fish in Gaobeidian Lake.     

Polychlorinated Biphenyls (Pcbs) Pollution in Sea of Japan

Deep waters of the Sea of Japan and surface waters of the Pacific Coast of Honshu and the northeast Sea of Japan were analysed for polychlorinated biphenyls (PCBs) pollution. the ΣPCB concentrations in solution in the Sea of Japan (50-3000 m) were between 140 and 1230 fg dm_-3. the space-integrated surface water concentration near the Pacific coast of northern Honshu was 140 fg dm_-3and for the surface water of the Sea of Japan was 230 fg dm_-3. Based on these analyses four water masses were deduced in the Sea of Japan during the summer months. It is shown for the first time in the Sea of Japan that polychlorinated biphenyls are excellent chemical indicators of not only the anthropogenic pollution, but also water masses.     

Removal of PCDDs/DFs and dl-PCBs in MWI fly ash by heating under vacuum

Temperature dependence of PCDD/DF and dioxin-like polychlorinated biphenyl (dl-PCB) concentrations in fly ash from a municipal waste incinerator (MWI) heated under vacuum has been investigated as a function of sample temperature ranging from T(s)=425 to 800 K to find out if PCDDs/DFs in fly ash evaporate and are trapped in a liquid nitrogen-cooled trap. The results show that more than 99.98% of PCDDs/DFs in TEQ is removed from fly ash by vacuum heat treatment at T(s)>650 K for 4 h. Almost no PCDDs/DFs were detected in the liquid nitrogen-cooled trap. Homologue distributions indicate that dechlorination/hydrogenation (DCH) reactions proceed in fly ash at T(s)>450 K. Arrhenius rate parameters for the DCH reactions have been determined for each homologue assuming that only DCH reactions occur. The fly ash heated under vacuum at 650 or 800 K was reheated at 573 K (300 degrees C) in a stream of dry or humid air to see how much PCDDs/DFs and dl-PCBs are regenerated. We have found that (1) PCDDs/DFs are regenerated in both 650 K and 800 K treated fly ash, whereas dl-PCBs are regenerated in 650 K treated fly ash, (2) formation of PCDFs predominates over that of PCDDs or dl-PCBs, and (3) less chlorinated homologues are abundant for PCDDs/DFs and dl-PCBs.