林地外部效应评估研究势在必行

目前,国内外对林地外部效应评估的研究十分缺乏。此项研究不但有利于建立森林环境资源产业,完善国民经济核算体系,而且为合理确定林地资源效益补偿标准提供依据,并促进广义的森林环境资源市场体系的建立和林地资源的最佳配置。     

林地细碎化、林地流转对林地资源配置效率的影响分析

我国集体林权制度改革之后,林地细碎化程度不断加剧,农户的林地经营难度有所增加。林地细碎化、林地流转对林地资源配置效率的作用方式如何?基于福建省235户农户的调查数据,从林地细碎化、林地流转的角度分析了对林地资源配置效率的影响。结果表明:林地细碎化、林地流转对林地资源配置效率具有正向影响,户主年龄、户主身份、投资营林风险大小、林业劳动力占比、家庭总收入、林业收入占比、林地质量、申请采伐限额指标难易程度对林地资源配置效率具有显著的影响。     

林地生计依赖性测算及其与农户林地流转意愿关联性研究

农户对林地的生计依赖性同时受到农户家庭因素与外部社会环境的共同影响,由此构建了农户对林地生计的依赖性测算模型,并考察了农户对林地生计的依赖性与农户对林地流转意愿的关联性。利用福建省的农户调查数据,得到农户对林地生计的依赖度,并基于此对农户对林地生计的依赖性与他们对林地流转意愿的关联性进行了实证探讨。结果表明:农户对林地生计的依赖度在不同区间内的分布较不均衡,且农户对林地生计的依赖性较弱的农户数量所占的比重较高。同时,农户的林地流转意愿与他们对林地生计的依赖性表现出了较强的相关关系。这一研究结果证实了文中的两个基本假设:农户对林地的生计依赖性越强,农户的林地流入意愿越强,流出意愿越弱;农户对林地生计的依赖性越弱,农户对林地流出意愿越强,流入意愿越弱。     

厦门市污水林地生态处理工程

文章介绍了厦门市狐尾山原生生活污水林地生态处理工程依循“污水-土壤-植物”资源再生机制，提出了“截流井＋氧化塘（调节池）＋污水动力输送、管网投配＋林地＋城市景观林地”的基本模式。     

集体林地使用权市场制度的建立与完善

集体林地使用权市场将是我国南方集体林区土地市场发展的主要内容,它的健康发展需要一套制度来保障.在介绍集体林地使用权市场类型的基础上,分析了我国集体林地使用权市场制度的建设状况,并提出了今后急待建立和完善的林地使用权市场制度的主要内容.     

基于农地金融的林地经营权抵押贷款模式研究

与农地相比,林地具有经营投入成本大、周期长,收益慢等特点,导致林地经营权抵押难以变现,严重影响了林地经营权抵押贷款的发展。现阶段国内外对农地抵押贷款的研究较成熟,而在林地方面还未形成完整的体系。通过梳理国内当前主要的农地经营权抵押贷款模式理论框架,对比分析三种主要模式,结合林地的特点,提出适合林地的经营权抵押贷款模式构建框架。该模式由贷款申请、资金补给、抵押品处置三个系统构成,克服了抵押品处置难、农信社贷款意愿低、资金来源渠道少等难题,提出了构建该模式的相关建议。     

林地征占用中健全生态补偿机制的研究

通过分析当前森林生态补偿机制的各层面立法现状以及实践中形成的公益林登记模式与补偿资金专户管理模式,总结出在林地征占用中健全生态补偿机制的共有逻辑,并由此提出补充林地征地法律规范、规范相关程序、落实林地补偿分配机制等符合林地征占用补偿需求的生态补偿机制的应然路径。     

森林可持续经营的林地产权政策研究--以临安示范林为例

林地产权政策是决定资源配置效率的基础条件。对临安示范林地区研究基点河桥乡的林地产权政策、林地流转的基本情况及农户对林地产权的意愿进行了介绍，找出了现行政策存在的问题，并提出了一套科学合理的适合当地水平的林地产权政策方案。     

晋西北黄土丘陵区植被类型林地土壤有效水和持水能力刍议

以晋西北黄土丘陵区岚县不同人工林地土壤水分为研究对象,分析了杨树、杏树、核桃3种不同树种的土壤水含量在垂直剖面的变化特征。研究表明,在0～600 cm深度的土壤中,随着土壤深度的增加,3种林地土壤水分含量呈现迅速减少然后缓慢增加再减少的波动趋势,土壤水分含量总体具有核桃林地杏树林地杨树林地;杨树林地土壤水分缺失度较大,核桃林地水分缺失度相对最小;干层发育严重程度表现为杨树林地杏树林地核桃林地。从3种植被对土壤水分的利用和破坏方面来看,核桃树更适宜作为该区商品林地的种植树种。     

“三权分置”视野下的林地使用权价值饱和研究

学术界从不同角度对十八届三中全会以来的"三权分置"改革展开了讨论、研究,然而对"三权分置"的界定仍众说纷纭、缺乏共识,其背后潜在的问题与风险亦值得关注。林地是土地的重要组成部分,应坚持集体林地所有权,保护林地,保障林农的利益。但林地使用权"价值饱和"存在权属不清、流转不规范、主体单一等问题。通过"三权分置"制度的改革,对经营主体进行规制,明晰相关的权利属性,规范程序、完善司法救济,可最终实现林地使用权"价值饱和"。     

BIOLOGICAL INDICATORS AND BIOLOGICAL EFFECTS OF ESTUARINE/COASTAL POLLUTION1

ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.     

电子设备的安全性设计

本电子设备安全性设计的目的就是通过识别、分析、评价系统中存在的危险性,预计事故对人员、设备和环境的破坏的可能性和严重性,根据其结果调整工艺、设备、操作、管理、生产周期和投资等因素,提出消除、减少、控制危险及危险事件的措施,以便使事故在发生之前得到控制,降低系统运行的风险。     

Ethical Issues Related to Food Sector Evolution in Developing Countries: About Sustainability and Equity

After a century of major technicaladvance, essentially achieved by and for theindustrialized countries, the evolution of thefood sector in southern countries should nolonger be thought of in terms of a ``headlongpursuit.'' In the present context of demographicgrowth, urbanization, poverty and disparities,environmental degradation, and globalization oftrade, new priorities have emerged, and newethical questions have been raised, mainlyrelated to sustainability and equity. Thispaper analyses these ethical concerns in thefollowing terms: can the model of food sectordevelopment initiated by the industrializedcountries be applied to the entire world on asustainable and equitable basis, given theeffects of this development with regard to theenergy consumed, the changes in dietarybehavior and related nutritional problems, thenew demands in terms of food safety, thequestions of biodiversity, ownership ofknowledge, cultural identities, gender issues,and Man's relationship to food and Nature?     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Study of the saltwater pond at Capoterra,southern Sardinia: General characteristics

Capoterra Pond in southern Sardinia is described and analyzed with respect to its morphological, meteorological, physical and chemical characteristics, and its zoobenthic, zooplankton, and phytoplankton biocenoses. The birdlife, flora, and riparian associations of vegetation are studied in order to draw international attention to the importance of this lagoon, the precariousness of its ecosystem, the seriousness of current attempts to destabilize it, and the need to encourage the Sardinian authorities to initiate conservation measures, especially as rare birds have found their niches there.     

University of Benin water supply system: Microbiological and physico-chemical assessments

The microbiological and physico-chemical characteristics of the drinking water supplied by the Central Borehole at the University of Benin, Ugbowo Campus were investigated. The investigation entailed assessment of the pH, turbidity, total suspended solids, total dissolved solids, dissolved oxygen, temperature, salinity, conductivity, nitrate, nitrite, phosphate, sulphate, chloride, N-nitroso compounds, cadmium, chromium, nickel, lead, zinc, manganese, iron, coliform count, BOD₅ and COD of the water at the Central Borehole and at ten residential quarters. The assessment indicated that the water was fit for drinking and other domestic applications. Results were also compared with WHO, EU and Nigeria FEPA standards. The results showed that the pH values of the water (5.01–5.86) and total coliform count (1–2/100 ml) expressed as MPN were outside the limits set by the WHO, EU and FEPA. The data also showed that the other water quality parameters assessed were within WHO, EU and FEPA permissible limits. The results of ANOVA showed that significant changes occurred during distribution.     

绕城高速公路走廊的产业发展策略分析——以济南市东绕城高速走廊为例

随着绕城高速公路的建设,国内大城市高速走廊效应日益显著.以山东济南市东绕城高速公路为例,利用SWOT分析方法阐述了绕城高速公路走廊发展的基础条件,明确了产业发展的思路和定位.最后,在总结分析结构提升、重点突破、组团布局、集群发展、品牌联动五大战略的基础上,提出了产业走廊发展所需的人才、科技、投资、资源、基础设施等六大支撑体系.     

环境行政执法工作中存在的问题及对策分析

近年来，我国虽然不断加大环境执法的力度，但由于在立法、体制、机制与执法监管能力等方面存在的弊端，执法效果不显著，这在一定程度上影响了环保法制建设的进程，降低了环保部门行政执法的能力。本文针对现实障碍，提出了尽快修订和完善法律体系，完善环境管理体制，扩大执法的权限，提高环境执法及应急能力等相应对策。     

Women and natural resource management: Illustrations from India and Nepal

This article attempts to delineate women's roles in natural resource management by highlighting their roles in management of water, agriculture, livestock, forestry and fishery. The article is based on the findings of case studies in rural areas of India and Nepal done during 2003 and 2004 by the author as well as by other researchers. Taking women as primary respondents, empirical work used participatory techniques, such as in‐depth surveys, focus group discussions and participant observation. Findings suggest that women clearly outdo men in terms of their involvement in use and management of all the studied sectors, i.e., water, agriculture, livestock, forestry and fishery. Yet, they face categorical exclusion and denial of equal sharing of benefits from natural resources. In order to ensure sustainable use of these resources, the article recommends that policy makers, planners and development workers must have a better understanding of the relative and often shifting roles of men and women in natural resource management, including division of labour, access to resources, decision‐making and traditional knowledge and practices. The article concludes with sector‐specific recommendations.     

Control of Tamarix in the Western United States: Implications for Water Salvage, Wildlife Use, and Riparian Restoration

Non-native shrub species in the genus Tamarix (saltcedar, tamarisk) have colonized hundreds of thousands of hectares of floodplains, reservoir margins, and other wetlands in western North America. Many resource managers seek to reduce saltcedar abundance and control its spread to increase the flow of water in streams that might otherwise be lost to evapotranspiration, to restore native riparian (streamside) vegetation, and to improve wildlife habitat. However, increased water yield might not always occur and has been substantially lower than expected in water salvage experiments, the potential for successful revegetation is variable, and not all wildlife taxa clearly prefer native plant habitats over saltcedar. As a result, there is considerable debate surrounding saltcedar control efforts. We review the literature on saltcedar control, water use, wildlife use, and riparian restoration to provide resource managers, researchers, and policy-makers with a balanced summary of the state of the science. To best ensure that the desired outcomes of removal programs are met, scientists and resource managers should use existing information and methodologies to carefully select and prioritize sites for removal, apply the most appropriate and cost-effective control methods, and then rigorously monitor control efficacy, revegetation success, water yield changes, and wildlife use.