Effect of grass cover on water and pesticide transport through undisturbed soil columns, comparison with field study (Morcille watershed, Beaujolais)

The purpose of this work is to assess the effectiveness of two grass covers (buffer zone and grass-covered inter-row), to reduce pesticide leaching, and subsequently to preserve groundwater quality. Lower amounts of pesticides leached through grass-cover soil columns (2.7-24.3% of the initial amount) than the bare soil columns (8.0-55.1%), in correspondence with their sorption coefficients. Diuron was recovered in higher amounts in leachates (8.9-32.2%) than tebuconazole (2.7-12.9%), in agreement with their sorption coefficients. However, despite having a sorption coefficient similar to that of diuron, more procymidone was recovered in the leachates (10.2-55.1%), probably due to its facilitated transport by dissolved organic matter. Thus even in this very permeable soil, higher organic matter contents associated with grass-cover reduce the amount of pesticide leaching and limit the risk of groundwater contamination by the pesticides. The results of diuron and tebuconazole transfer through undisturbed buffer zone soil columns are in agreement with field observations on the buffer zone.     

Effect of vegetative filter strips on herbicide runoff under various types of rainfall

Narrow vegetative filter strips proved to effectively reduce herbicide runoff from cultivated fields mainly due to the ability of vegetation to delay surface runoff, promote infiltration and adsorb herbicides. A field trial was conducted from 2007 to 2009 in north-east Italy in order to evaluate the effectiveness of various types of vegetative filter strips to reduce spring-summer runoff of the herbicides mesotrione, metolachlor and terbuthylazine, widely used in maize, and to evaluate the effect of the rainfall characteristics on the runoff volume and concentration. Results show that without vegetative filter strip the herbicide load that reaches the surface water is about 5-6 g ha⁻¹ year⁻¹ for metolachlor and terbuthylazine (i.e. 0.5-0.9% of the applied rate), confirming that runoff from flat fields as in the Po Valley can have a minor effect on the water quality, and that most of the risk is posed by a few, or even just one extreme rainfall event with a return period of about 25-27 years, causing runoff with a maximum concentration of 64-77 μg L⁻¹. Mesotrione instead showed rapid soil disappearance and was observed at a concentration of 1.0-3.8 μg L⁻¹ only after one extreme (artificial) rainfall. Vegetative filter strips of any type are generally effective and can reduce herbicide runoff by 80-88%. Their effectiveness is steady even under severe rainfall conditions, and this supports their implementation in an environmental regulatory scheme at a catchment or regional scale.     

Factors influencing acquisition of ecological and exposure information about hazards and risks from contaminated sites

Considerable research indicates that a wide range of socio-economic factors influence attitudes and perceptions about environmental hazards and risks, and that social trust in those who manage a hazard is strongly correlated to judgements about risks and benefits. We suggest that there are three steps that lead to environmental risk perceptions: acquisition of information, interpretation and synthesis of different pieces of information, and understanding of that information in light of previous knowledge, perceptions, or attitudes. In this study we presented 211 college students in the sciences and non-sciences with ecological and exposure information using text, tables and maps to examine the factors that affect information acquisition and interpretation concerning ecological issues at a fictitious hazardous waste site. Students were allowed about an hour to read the materials and answer questions. The percent of students answering each question correctly varied from 4 to 82%, indicating that some questions were extremely difficult to answer. We attributed these differences to variations in the number of places information was presented (in text, tables, maps, or a combination) and the complexity of the information (how many pieces of information were required to answer the question correctly). The correlation between the number of students answering each question correctly and these combined measures (frequency, complexity) was −0.72. Thus, although there were differences in accuracy concerning ecological information as presented in this study, the major differences were accounted for by how the information was presented, and how much information was required. This suggests that risk communicators should carefully determine which ecological information is critical for the target audience, and ensure that it is presented several times (in different forms). That a lower percentage of people correctly answered questions that required synthesizing several pieces of information suggests that this complexity should be reduced where possible, or that the pieces of information should be tied clearly to the conclusion. Self-declaration of effort and perceptions of safety of the site did not markedly influence the relationship between accuracy, difficulty of finding information, and complexity of information. Other possible confounding variables (i.e., science vs non-science major) only accounted for about 27% of the variation in student’s overall score on ecological questions; age, ethnicity, and gender did not enter as significant variables. We cannot manage environmental hazards with appropriate stakeholder input unless we understand how to present environmental information to achieve a full understanding. Protection of human health and the environment requires that people understand ecological and exposure information, particularly on buffer lands.     

官厅水库库滨带非点源污染控制效应的遥感分析

选取官厅水库库滨带为研究区域,应用SPOT5遥感数据对其结构进行了解析,建立了高分辨率的Quick Bird遥感数据与SPOT数据的尺度转化关系,对SPOT信息提取结果进行了校核,以提高SPOT卫星对库滨带结构的解译精度;最后结合点上的实验结果对流域尺度上的库滨带的环境效益进行了分析.研究结果表明:(1)官厅水库陆相库滨带的结构不利于非点源污染的防治,应该适当增加林地的比例,同时提高林地、草地的植被覆盖度;(2)按照官厅水库流域非点源区年均TN量为188.1×104 t、TP量为101.2×104 t计算,库岸库滨带对TN、TP的去除率分别为11.6%和0.4%;(3)为了有效地防止官厅水库流域的非点源污染,必须加强水库流域的农业管理和库岸库滨带的科学建设与管理.     

US National Park Buffer Zones: Historical, Scientific, Social, and Legal Aspects

/ This review will trace the evolution of beyond boundary/buffer zone thinking and policy responses in the US National Park Service (NPS); address buffer zone science, benefits, and limitations; examine pertinent legal and social concerns; highlight some agency attempts to create buffer zone-like areas; and propose highlights of a protected area strategy, with buffer zones and corridors as one component. Some findings follow. The need to expand national parks to accommodate large ungulate movement began in the late 1800s, but the recognition that such land was also needed to thwart human impacts such as poaching surfaced in the 1930s. External park buffer zone recommendations by 1930s park scientists were not implemented, and other related adopted policy forgotten, supporting the belief that great insight can be discovered in forgotten institutional history. Buffer zones can remedy some impacts but not others, but their benefits are multiple and underappreciated. The science of buffer zones is very immature and deserves more attention. A present primary obstacle to creating park buffer zones and connecting corridors is a social climate opposing federal initiatives that may intrude on the rights of private landowners. Some proactive NPS bufferlike activity examples are reviewed, but there were none where permanent, complete, effective nonlegislated park buffer zones, derived from nonfederal property, circumscribed large natural area parks. The need for buffer zones and corridors may be a symptom of inadequate regional planning. Options to create buffer zones from private and federal land are outlined. A comprehensive, overall protected area strategy must include more than just buffer zones, with highlights provided. Because optimal regional planning for US national parks is now thwarted by land-use politics, American society must soon decide what is most crucial to future well-being. KEY WORDS: Buffer zone; Reserve; Boundary; Policy; Planning     

Contaminant Retention Potential of Forested Filter Strips Established as SMZs in the Piedmont of Georgia1

Abstract: It is common practice in the United States and elsewhere to maintain vegetated filter strips adjacent to streams to retain contaminants in surface runoff. Most research has evaluated contaminant retention in managed agricultural field strips, while relatively few studies have quantified retention in forested filter strips, particularly for dissolved contaminants. Plot‐scale overland flow experiments were conducted to evaluate the efficiency of natural forested filter strips established as streamside management zones (SMZs) for retaining phosphorus (P), atrazine, and picloram transported in runoff. Retention was evaluated for five different slope classes: 1‐2, 5‐7, 10‐12, 15‐17, and 20‐22%; two cover conditions: undisturbed forest floor (O horizon intact) and forest floor removed by raking; and two periods with contrasting soil moisture conditions: summer‐dry and winter‐wet season. Surface flow was collected at 0, 2, 4, 6, and 10 m within the filter strip to evaluate changes in solution concentration as it moved through the O horizon and the surface soil horizon mixing zone. On average, a 10 m length of forested SMZ with an undisturbed forest floor reduced initial solution concentration of total dissolved P by 51%, orthophosphate P by 49%, atrazine by 28%, and picloram by 5%. Percentages of mass retention through infiltration of water plus concentration reductions in runoff were 64% for total dissolved P, 62% for orthophosphate P, 47% for atrazine, and 28% for picloram for undisturbed forest floor conditions. Lower retention occurred following forest floor removal, particularly for P. Average dissolved P retention was 16% lower following forest floor removal. For undisturbed sites, differences in retention were more closely related to forest floor depth than to slope or antecedent soil moisture. These results indicate that forested SMZ filter strips provide a significant measure of surface water protection from dissolved P and herbicide delivery to surface water.     

污染负荷及植被生物量变化对缓冲带污染物净化效果的影响

模拟上海地区农业面源污染和降雨特征,进行缓冲带污染物净化效果和植被生物量监测试验研究。结果表明：植被缓冲带对径流污染物质的净化效果明显高于空白对照,百慕大缓冲带SS截留率最高,达到74％;白花三叶草对TN、TP的净化效果最好,去除率分别为28％和25％;百慕大和白花三叶草生物量最大,栽种当年9月份,两者地上部分的生物量鲜重分别达到了6.14和6.49 kg/m²,百慕大生长速度最快,当年9月份生物量几乎达到5月份的6倍;植被生物量增长明显提高了缓冲带截留径流污染物的效果,缓冲带SS截留率与生物量成显著线性相关,而污染负荷变化对缓冲带污染物净化效果的影响很小,明显弱于植被种类和生物量的变化。     

Beyond buffer zone protection: a comparative study of park and buffer zone products' importance to villagers living inside Royal Chitwan National Park and to villagers living in its buffer zone

Even after 30 years of strict de jure protection, today's de facto extraction of products from Nepal's Royal Chitwan National Park (RCNP) and their great economic importance to local households suggests that this reality should be explicitly internalised in managing this world heritage park. Several studies have quantified local people's use of protected areas and estimated the value of such areas to them. However, few studies incorporate economic analyses to investigate the effect of management interventions on local communities' resource use and collection behaviour. In Nepal, buffer zones and especially buffer zone community forestry are seen as means to define and demarcate places, where local people may legally extract goods that are either identical to or relevant substitutes for products that are collected in protected areas. The intention is to resolve park-people conflicts over resource use. This article presents the findings of an in-depth study of the importance of natural resources to the livelihoods of 18 households. One village was located inside RCNP with no realistic alternatives to Park resources, while the other is located in the buffer zone with equal distance to the Park, a national forest and their community forest. For each household, the collection of products, allocation of time, and purchase and sale of goods were recorded daily through 12 consecutive months and economic values were calculated on the basis of local market prices and recorded quantities. The study shows that products from RCNP are of great importance to the livelihoods of local people. Furthermore, we find that products collected in the national forest substitute products from the Park, while the substitution effect of the community forest is small. Accordingly, the study illustrates that, irrespective of buffer zone community forestry, there is still a gap between local people's need for supplementing natural resources and their rights to satisfy them on a legal basis, which is likely to be unsustainable in the longer term. This calls for a thorough evaluation of actual park-people relations and how these may be improved through local participation that goes beyond the current form of buffer zone community forestry and the admitted 7-14 annual days of open access grass cutting within the park.     

Rehabilitation and improvement of Guilin urban water environment：Function-oriented management

Economic development and population growth have deeply damaged the urban water environment of Guilin City, China. Main problems involved structural damage and functional deterioration of the urban waters. An integrated technical scheme was developed to rehabilitate the urban water environment and to enhance the waters' functions during 1998-2008. Improvement of waters' functions included water system reconstruction, water pollution control, water safety assurance, and aquatic ecological restoration. The water system was reconstructed to connect different waters and clean water supplies to the lakes. Moreover, water pollution was controlled to improve water quality by endogenous pollutant elimination and extraneous pollutant interception. In addition, ecological measures put in place serve to enhance water system functions and better benefit both nature and humans. The project has brought about sound ecological, economic and social benefits in Guilin City, which can potentially be extended to similar cities.     

抚仙湖缓冲带污染负荷分析及治理方案

对云南高原湖泊抚仙湖及其缓冲带进行了概述,对缓冲带内污染负荷的产生量、排放量、入湖量进行了计算、分析,总结了主要环境问题,并提出治理方案。结果表明:农村生活污水和农田面源成为缓冲带内主要污染源,污染物入湖量COD为578.89t/a、TN为120.61t/a、TP为13.04t/a、NH3-N为43.64t/a。在缓冲带村落污染得到有效控制的基础上,进行自然修复为主、人工为辅的自然缓冲带生态建设,实施环湖低污染水净化工程建设,强调污染截蓄、水质净化等方面的环境效益的最大体现,并提出当地旅游在限制中有序开发的管理方案。