西南典型碳酸盐岩高地质背景区农田重金属化学形态、影响因素及回归模型

土壤重金属化学形态是决定重金属生物活性和生物毒性的重要因素,是科学评价西南碳酸盐岩高地质背景区土壤重金属生态风险的关键.为了探明碳酸盐岩高地质背景区土壤重金属化学形态分布情况,选择贵州省典型碳酸盐岩分布区,以第二次全国土壤普查图斑为采样单元,在农田中采集土壤表层样品309件,利用改进的Tessier七步顺序提取法,分析了As、Cd、Cu、Hg、Ni、Pb和Zn等7种重金属的水溶态（F1）、离子交换态（F2）、碳酸盐结合态（F3）、弱有机结合态（F4）、铁锰氧化物结合态（F5）、强有机结合态（F6）和残渣态（F7）这7种化学形态.结果发现,土壤中重金属As、Cu、Hg、Ni、Pb和Zn残渣态比例均超过50%,有效组分（F1~F3）比例均小于5%,潜在生物有效组分（F4~F6）比例低于45%,活性较低,生态风险不高.Cd的有效组分和潜在生物有效组分占比分别为55.49%和29.37%,远高于其他重金属,基于土壤重金属形态的生态风险远小于基于土壤总量的生态风险.逐步回归方程可以有效建立Cd、Cu和Pb生物有效组分与影响因素之间的关系.重金属全量和pH值是影响碳酸盐岩高地质背景区土壤重金属化学形态的重要因子,受研究区长期土法炼锌活动和碳酸盐岩风化成土过程中重金属元素倾向于在残渣态中富集的影响,土壤有机质（OM）和氧化物含量对土壤重金属化学形态影响相对较小.     

Striking a Balance between Biodiversity Conservation and Socioeconomic Viability in the Design of Marine Protected Areas

Abstract: The establishment of marine protected areas is often viewed as a conflict between conservation and fishing. We considered consumptive and nonconsumptive interests of multiple stakeholders (i.e., fishers, scuba divers, conservationists, managers, scientists) in the systematic design of a network of marine protected areas along California's central coast in the context of the Marine Life Protection Act Initiative. With advice from managers, administrators, and scientists, a representative group of stakeholders defined biodiversity conservation and socioeconomic goals that accommodated social needs and conserved marine ecosystems, consistent with legal requirements. To satisfy biodiversity goals, we targeted 11 marine habitats across 5 depth zones, areas of high species diversity, and areas containing species of special status. We minimized adverse socioeconomic impacts by minimizing negative effects on fishers. We included fine‐scale fishing data from the recreational and commercial fishing sectors across 24 fisheries. Protected areas designed with consideration of commercial and recreational fisheries reduced potential impact to the fisheries approximately 21% more than protected areas designed without consideration of fishing effort and resulted in a small increase in the total area protected (approximately 3.4%). We incorporated confidential fishing data without revealing the identity of specific fisheries or individual fishing grounds. We sited a portion of the protected areas near land parks, marine laboratories, and scientific monitoring sites to address nonconsumptive socioeconomic goals. Our results show that a stakeholder‐driven design process can use systematic conservation‐planning methods to successfully produce options for network design that satisfy multiple conservation and socioeconomic objectives. Marine protected areas that incorporate multiple stakeholder interests without compromising biodiversity conservation goals are more likely to protect marine ecosystems.     

Relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan, China

This paper studied the relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan, China. 50 herbaceous plant samples of 9 plant species from 4 families and 50 soil samples were collected and then ana1yzed for the tota1 concentrations of Pb, Cd, and Zn. The results showed that the average concentrations of Pb, Cd, and Zn in soil samples were 3772.83, 168.81, and 5385.65 mg/kg, respectively. The average concentrations of Pb, Cd, and Zn were 395.68, 28.14, and 1664.20 mg/kg in the shoots, and 924.12, 57.25, and 1778.75 mg/kg in the roots, respectively. Heterospecific plants at the same site and conspecific plants at various sites had different average levels of Pb, Cd, and Zn, both in the shoots and the roots. Enrichment coefficients of Pb, Cd, and Zn were greater than 1 in 2, 3, and 9 herbaceous plant samples, respectively. Translocation factors of Pb, Cd, and Zn were greater than 1 in 10, 17, and 25 herbaceous plant samples, respectively. In all 50 samples, the concentrations of Pb, Cd, and Zn between the shoots and the roots, the shoots, and the soils, and the roots and the soils had significant positive relationships.     

山区二级公路运营期常态交通风险评价

为客观准确地评价山区二级公路常态交通风险,将风险源分为动态风险源和静态风险源.首先,基于白化权函数的综合评价法建立事故后果模型,基于历史事故数据建立事故概率模型,以评价静态风险;其次,结合白化权函数和层次分析法(AHP)建立事故后果模型,采用有序Logit模型建立事故概率模型,以评价动态风险;最后综合动静态风险结果评价...     

快速城镇化进程中农村生态治理

我国不断加快城镇化的步伐,但在这过程中,农村的生态污染越来越严重,但是往往政府主要将着眼点放在城镇生态环境的建设,对农村生态治理重视不足,因此本文对此展开研究,分析目前农村生态治理面临的形式,探讨生态治理中有哪些问题,并提出相应的解决对策。     

空间贫困分异特征、陷阱形成与致贫因素分析

消除贫困是中国共产党的一项重要历史使命。目前,中国脱贫攻坚进入关键的决战决胜阶段,精准脱贫成为实现乡村振兴及全面建成小康社会的关键问题。本文以贫困突出的江西革命老区为例,采用ESDA空间探索性分析和空间计量模型,探究其空间贫困分异特征、陷阱形成机制及影响因素,发现:①从时间维度看,2000—2016年,受国家贫困标准线大幅调整影响,江西革命老区贫困人口和贫困发生率呈现三个断点下降时期,总体脱贫进程加快。②从空间维度看,江西革命老区各县(市、区)的贫困人口和贫困发生率明显减少,贫困分异特征表现为高贫困地区集聚于南部的集中连片区或国家级贫困县,低贫困地区主要集聚于北部的非贫困区。③进一步通过空间检验发现,江西革命老区贫困以"高-高"集聚模式为主,并形成"空间贫困陷阱",均属于集中连片特困区或国家级贫困县;少数地区的贫困还存在"低-低"集聚模式,形成"脱贫溢出效应",均属于非贫困区。④实证结果表明,城乡收入之比和中学教师负担学生数显著加剧了江西革命老区贫困水平;而农民人均纯收入、卫生技术人员比例和农业机械化水平对减贫具有显著正向作用;贫困空间滞后项的显著为正也再次验证了江西革命老区"空间贫困陷阱"及"脱贫溢出效应"的存在性;相邻地区的农民人均纯收入和卫生技术人员比例的减贫效果存在显著的空间溢出效应。为此,本文提出实现江西革命老区精准脱贫建议。     

云南森林生态功能区农户生态补偿支付意愿(WTP)影响因素及差异性分析

生态补偿是协调经济与资源环境和谐发展,化解生态环境与经济增长矛盾的有效手段,对推进生态文明建设意义深远。基于云南省5个州市农户调查数据,运用二元Probit模型,分析了云南森林生态功能区农户生态补偿支付意愿的关键影响因素及其差异性。研究表明:大部分农户愿意为生态补偿付费,影响其支付意愿的主要因素是性别、年龄、是否兼业、家庭人口数、非农收入比重、生态补偿重要性认知、森林经济效益是否比生态效益重要、生态环境满意度、政府是否对生态环境保护宣传、政策执行信任度以及信息获取难易程度;其中年龄、家庭农业劳动力人数和信息获取难易程度对专业户支付意愿有重要影响,而家庭人口数、非农收入比重以及获得政府补偿的情况对兼业户支付意愿有重要影响;是否兼业、非农收入比重、对生态补偿了解程度以及信息获取难易程度对传统散户支付意愿影响较大;对政策执行的信任程度和产业发展程度对种植大户支付意愿有重要影响。基于此,提出了完善政府农村就业服务职能,鼓励农户非农就业、创业;完善生态功能区环境教育体系和宣传制度建设,强化农户环保意识;强化政府职责及其政策推广、执行力度,构建综合、完善的生态补偿宣传媒介;制定并实施差异化的生态补偿措施等具体对策建议。     

国家行政征用海域使用权补偿标准法律问题探讨

根据2002年开始实施的《中华人民共和国海域使用管理法》,在海域使用管理法中关于国家行政征用海域使用权、进行清海补偿标准的未作规定,只在渔业管理法中规定参照土地管理法的补偿标准进行补偿,因此,各沿海地区确定征用补偿标准缺乏统一标准。本文根据国家行政征用海域使用权补偿存在的无专门系统的行政征用补偿法、海域征用补偿程序混乱、海域征用补偿救济手段不完善、海域管理适用法律冲突和安置补偿与生产损失补偿混淆在一起等问题进行了探讨,对于完善国家行政征用海域补偿制度提出了法律建议。     

Factors influencing farmers' concerns regarding bovine tuberculosis in wildlife and livestock around Riding Mountain National Park

Despite intensive efforts over the last century to eradicate bovine tuberculosis (TB) in North America, several hotspots of infected wildlife and livestock remain, raising concerns that the disease will never be eradicated. The stress and frustration for a farmer caused by having a herd test positive for TB or living in an infected region can be substantial. The goal of this study was to investigate the concerns of farmers around Riding Mountain National Park (RMNP) regarding the presence of TB in wildlife and livestock and conduct an exploratory analysis of causal factors. Data were collected from 786 farmers within 50 km of RMNP using a mail-back questionnaire. Overall, farmers indicated a high level of concern toward diseases in both wildlife and cattle relative to other concerns. The spatial variables that had the greatest influence on TB concern were both the distance of farms to the RMNP boundary and distance of farms to previous cases of TB. The most important aspatial factor associated with high TB concern was the frequency with which farmers observed elk on their land. These results underscore the important differences between 'objective' measures of risk, such as epidemiological estimates of disease prevalence, and subjective measures of disease concern, such as risk perception and acceptability of management actions. Written responses suggest that concerns regarding disease may affect how farmers view wildlife on their land and their relationship with neighbouring protected areas. Management activities that reduce the frequency of elk interactions with farms, but also recognize the complex relationship that farmers have with wildlife and protected areas, will be most effective in mitigating farmer concern regarding this important problem.     

Improving Community-Based Conservation Near Protected Areas: The Importance of Development Variables

Community-based conservation projects implemented in conjunction with protected area management often struggle to meet expectations. This article argues that outcomes will improve if project leaders pay closer attention to four development indicators—rights, capacity, governance, and revenue—that are often taken for granted or considered beyond the scope of local conservation projects. I make the case for focusing on these variables in four steps. First, I distinguish community-based conservation linked to protected area management from community-based institutions studied by scholars of the commons. Second, I draw on the theory and practice of international development to highlight the central relevance of the variables highlighted in this article to development projects at all levels. Third, I discuss the four variables in some detail, considering problems of definition and measurement and reviewing possible interactions among them. Fourth, to illustrate the influence of the variables in particular cases, I review outcomes from community-based conservation projects implemented near protected areas in El Salvador and Zimbabwe.