生物有机除草剂防除水田杂草试验研究

采用田间试验方法,进行了生物稻壳粉、生物稻草粉2种生物有机除草剂对水田杂草的防效试验。结果表明,2种生物有机除草剂对水田杂草均有不同程度的防效,其中生物稻壳粉防效最好、经济效益最高,生物稻草粉防效和经济效益次之。该试验研究为生产有机水稻提供了新的除草方法。     

Incorporating Social and Cultural Significance of Large Old Trees in Conservation Policy

In addition to providing key ecological functions, large old trees are a part of a social realm and as such provide numerous social‐cultural benefits to people. However, their social and cultural values are often neglected when designing conservation policies and management guidelines. We believe that awareness of large old trees as a part of human identity and cultural heritage is essential when addressing the issue of their decline worldwide. Large old trees provide humans with aesthetic, symbolic, religious, and historic values, as well as concrete tangible benefits, such as leaves, branches, or nuts. In many cultures particularly large trees are treated with reverence. Also, contemporary popular culture utilizes the image of trees as sentient beings and builds on the ancient myths that attribute great powers to large trees. Although the social and cultural role of large old trees is usually not taken into account in conservation, accounting for human‐related values of these trees is an important part of conservation policy because it may strengthen conservation by highlighting the potential synergies in protecting ecological and social values. Incorporación del Significado Social y Cultural de Árboles Añejos a Políticas de Conservación     

Modeling channel management impacts on river migration: a case study of Woodson bridge state recreation area,Sacramento river,California, USA

Understanding how hydraulic factors control alluvial river meander migration can help resource managers evaluate the long-term effects of floodplain management and bank stabilization measures. Using a numerical model based on the mechanics of flow and sediment transport in curved river channels, we predict 50 years of channel migration and suggest the planning and ecological implications of that migration for a 6.4-km reach (river miles 218–222) of the Sacramento River near the Woodson Bridge State Recreation Area, California, USA. Using four different channel management scenarios, our channel migration simulations suggest that: (1) channel stabilization alters the future channel planform locally and downstream from the stabilization; (2) rock revetment currently on the bank upstream from the Woodson Bridge recreation area causes more erosion of the channel bank at the recreation area than if the revetment were not present; (3) relocating the channel to the west and allowing subsequent unconstrained river migration relieves the erosion pressure in the Woodson Bridge area; (4) the subsequent migration reworks (erodes along one river bank and replaces new floodplain along the other) 26.5 ha of land; and (5) the river will rework between 8.5 and 48.5 ha of land in the study reach (over the course of 50 years), depending on the bank stabilization plan used. The reworking of floodplain lands is an important riparian ecosystem function that maintains habitat heterogeneity, an essential factor for the long-term survival of several threatened and endangered animal species in the Sacramento River area.     

The Transboundary River Nestos and Its Water Quality Assessment: Cross-Border Cooperation between Greece and Bulgaria

Transboundary water resources require the cooperation of the countries involved, not only on the various uses of the water, but also on overall water quality and the protection of ecosystems. Transboundary rivers and their management constitute a contemporary issue of great significance. Cooperation between neighboring countries is not always easy, due to different socio-economic and political conditions. Therefore, the different needs and priorities between the countries involved need to be solved first. Since pollution does not stop at a State border, it is an example of something that can be solved only at the cross-border level. This paper presents the cross-border cooperation between two transnational Institutions; the Aristotle University of Thessaloniki (Greece) and the University of Sofia (Bulgaria), within the framework of Interreg programs. The first collaborated attempt was to carry out a coordinated program for monitoring the pollution of the Nestos River. The second was the protection and restoration of the ecosystem through the education of young engineers and the transfer of experiences and scientific knowledge across the borders.     

Watershed scale assessment of nitrogen and phosphorus loadings in the Indian River Lagoon basin,Florida

There is a growing evidence that the ecological and biological integrity of the lagoon has declined during the last 50 years, probably due to the decline in water quality. Establishment of a watershed scale seagrass-based nutrient load assessment is the major aim of water quality management in the Indian River Lagoon (IRL). Best estimate loadings incorporate wet and dry deposition, surface water, groundwater, sediment nutrient flux, and point source effluent discharge data. On the average, the IRL is receiving annual external loadings of 832, 645 and 94,476kg of total nitrogen (TN) and total phosphorus (TP), respectively, from stormwater discharges and agricultural runoff. The average internal cycling of TN and TP from sediment deposits in the IRL was about 42,640kg TN and 1050kg TPyr(-1). Indirect evidence suggests that atmospheric deposition has played a role in the ongoing nutrient enrichment in the IRL. The estimated total atmospheric deposition of TN and TP was about 32,940 and 824kgyr(-1), while groundwater contribution was about 84,920 and 24,275kgyr(-1), respectively, to the surface waters of the IRL. The estimated annual contribution of point effluent discharge was about 60,408kg TN and 7248kg TP. In total, the IRL basin is receiving an annual loading of about 1,053,553kg TN and 127,873kg TP. With these results, it is clear that the current rate of nutrient loadings is causing a shift in the primary producers of the IRL from macrophyte to phytoplankton- or algal-based system. The goal is to reverse that shift, to attain and maintain a macrophyte-based estuarine system in the IRL.     

THE MILWAUKEE POLLUTION CASE - IMPLICATIONS FOR WATER RESOURCES PLANNING1

ABSTRACT: The Illinois v. Milwaukee Federal District Court decision is the most far reaching application yet of the federal common law of nuisance to interstate water pollution conflicts. Although a Federal Appelate Court recently rescinded part of the district court decision, Milwaukee must still upgrade its metropolitan sewage system to a level beyond that required by federal and state regulations. The improvements must be completed with or without federal aid. The case points out the apparent inability of the Clean Water Act, the most comprehensive federal legislation affecting the nation's water quality, to deal with certain interstate water quality conflicts. The Milwaukee decision could set a precedent for similar settlements elsewhere which may in turn affect the U.S. Environmental Protection Agency's water quality clean up program. A more integrated, ecosystem conscious approach to management of shared water resources (e.g., the Great Lakes) would help reduce the need for court decisions like Illinois v. Milwaukee.     

长江三角洲跨界流域生态产品交易机制——以天目湖流域为例

生态价值多元化实现是落实区域一体化生态保护格局的经济政策保障。针对当前生态产品交易制度不完善与市场活跃度问题,以天目湖流域水质净化服务产品为例,提出一条生态保护市场化与生态产品增值的双向促进道路：基于长序列监测数据与水文水质过程模型,提出流域生态保护基准概念及其约束下生态产品交易边界,精准核算基准年水质净化产品的可交易量为1.37 t,基准价格为1186.71万元/t/年;面向近10年产品实际供需主体的内在联系,揭示了“三类五种”生态产品交易机制类型,并选择设计了低端产品退出—高端产品激励的典型交易模式。生态产品交易实施为研究区生态价值实现提供市场化路径,为国内同类地区一体化生态保护格局保障提供思路。     

Temporal dynamics of arsenic uptake and distribution: food and water risks in the Bengal basin

Abstract

Contaminated food chain is a serious contender for arsenic (As) uptake around the globe. In Nadia, West Bengal, we trace possible means of transfer of As from multiple sources reaching different trophic levels, and associated seasonal variability leading to chronic As uptake. This work considers possible sources-pathways of As transfer through food chain in rural community. Arsenic concentration in groundwater, soil, rice, and vegetable-samples collected detected in different harvest seasons of 2014 and 2016. Arsenic level in shallow groundwater samples ranged from 0.1 to 354?µg/L, with 75% of the sites above the prescribed limit by WHO (10?µg/L) during the boro harvest season. High soil As content (～20.6?mg/kg), resulted in accumulation of As in food crops. A positive correlation in As conc. with increase over period in all sites indicating gradual As accumulation in topsoil. Unpolished rice samples showed high As content (～1.75?mg/kg), polishing reduced 80% of As. Among vegetables, the plant family Poaceae with high irrigation requirements and Solanaceae retaining high moisture, have the highest levels of As. Contaminated animal fodder (Poaceae) and turf water for cattle are shown to contaminate milk (0.06 to 0.24?µg/L) and behoves strategies, practices to minimize As exposure.     

西藏森林生态系统服务价值

森林生态系统作为可再生的自然资源,具有公共物品的属性,随着环境污染和资源危机的加剧,具有可持续意义的森林生态服务价值受到人类的重视。论文采用产量-价格法、直接市场法、影子工程法、机会成本法等主要研究方法,核算了西藏森林生态系统价值,结果表明:西藏森林生态系统服务价值中碳库、木材和生物多样性存量价值为44543.5×10⁸元,其中生态价值是直接经济价值的2.24倍;在流量中,年流量价值1738.3×10⁸元,其中年生态价值为1565.9×10⁸元,是直接经济价值172.4×10⁸元的9倍,社会价值只有9.5×10⁸元。论文旨在强调森林的生态功能,为西藏的生态补偿、绿色GDP核算奠定良好的基础。     

南方涝渍地区退田还渔的一个实例分析

以江汉平原四湖涝渍地区的一个经围湖造田形成的典型农业微域为研究对象,在对其土壤和作物生长状况进行调查的基础上,探讨了退田还渔的必要性与具体方案。结果表明,对小型湖泊通过围湖造田所形成的农业微域,在人工排水和土地平整不充分的情况下,其地貌和土壤还残留有原有湖泊的影响,处于原湖泊低处的土壤表现出明显的沼泽化和严重潜育化的特征。在该地区种植水稻产量比正常地区减产达16%～26.8%。利用数量化理论Ⅰ确定了该地区适宜退田还渔的具体位置和面积。按照这一方案实施的结果,该地区从1997～2001年的5年中精养鱼塘面积增加9倍,养鱼的效益比种植水稻高5～10倍,还减轻了该地区夏季和冬季的排水压力。