中国农业生态补偿法律制度建设研究

2014年通过的《环境保护法》第31条规定:国家建立、健全生态保护补偿制度.紧随其后,2014年5月苏州市人大常委会正式批准了《苏州市生态补偿条例》,彰显了国家和地方政府对于生态补偿这一法律制度的重视.农业生态补偿作为生态补偿的一个具体分支,法律制度的建设,将对当前中国日趋严重的农业面源污染问题,提供一个现实的解决路径.文中找出农业生态补偿法律制度存在的问题,并提出具体的建设意见,为中国农业生态补偿法律制度的建设提供理论上的支撑.     

Floodplain Trapping and Cycling Compared to Streambank Erosion of Sediment and Nutrients in an Agricultural Watershed

Floodplains and streambanks can positively and negatively influence downstream water quality through interacting geomorphic and biogeochemical processes. Few studies have measured those processes in agricultural watersheds. We measured inputs (floodplain sedimentation and dissolved inorganic loading), cycling (floodplain soil nitrogen [N] and phosphorus [P] mineralization), and losses (bank erosion) of sediment, N, and P longitudinally in stream reaches of Smith Creek, an agricultural watershed in the Valley and Ridge physiographic province. All study reaches were net depositional (floodplain deposition > bank erosion), had high N and P sedimentation and loading rates to the floodplain, high soil concentrations of N and P, and high rates of floodplain soil N and P mineralization. High sediment, N, and P inputs to floodplains are attributed to agricultural activity in the region. Rates of P mineralization were much greater than those measured in other studies of nontidal floodplains that used the same method. Floodplain connectivity and sediment deposition decreased longitudinally, contrary to patterns in most watersheds. The net trapping function of Smith Creek floodplains indicates a benefit to water quality. Further research is needed to determine if future decreases in floodplain deposition, continued bank erosion, and the potential for nitrate leaching from nutrient‐enriched floodplain soils could pose a long‐term source of sediment and nutrients to downstream rivers.     

Is this trail too crowded? A choice experiment to evaluate tradeoffs and preferences of park visitors in Garibaldi Park,British Columbia

Large crowds in parks can be a problem for park managers and visitors. However, perceptions of crowding are difficult to measure due to coping mechanisms deployed by park visitors. Furthermore, perceptions of crowding should not be measured in isolation, but rather as part of a suite of conditions that comprise the visitors’ outdoor experience. We used a dichotomous choice experiment with visual images and eight attributes to estimate park users’ utilities associated with their visitor experience in Garibaldi Provincial Park in British Columbia, Canada. Our visual method allowed us to control for background view and compare user preferences on hiking trails with preferences at final destinations. We find that utilities are more sensitive to crowding at viewpoints than to other aspects of the outdoor experience. Thus, visitor satisfaction and crowding perceptions are more likely to be defined by where visitors have these encounters rather than the total number of encounters.     

马克思恩格斯关于依靠科学技术发展生态农业的思想及其当代启示

马克思恩格斯虽然没有专门论述生态农业的著作,但在他们的理论文本中蕴涵着深刻的生态农业思想。在马克思恩格斯看来,依靠技术,改良耕作方法,可以保持和改良土质;通过在农业中利用现代科学技术能够提高农业生产率,促进农业发展。马克思恩格斯关于依靠科学技术发展生态农业的思想,为我国的农业发展指明了方向。     

我国节水农业发展现状研究

中国的灌溉水利用系数只有45%,大大落后于发达国家的70%;全国农业用水效率较低,单位粮食产量耗水量比发达国家高2.5～3倍。所以我国发展节水农业具有至关重要的意义。本文根据我国农业发展现状,结合我国节水农业发展布局,重点分析5大节水农业区在技术、制度、资金和政策等方面的节水农业现状,总结交流发展节水农业的成功经验,分析其存在的不足,从而提出更好的促进节水农业发展的路径。     

海南省农业能值分析

应用ＯｄｕｍＨＴ创立的能值分析理论和方法,对海南省农业进行了分析和评价,结果表明：由于自然条件得天独厚,环境资源对农业的贡献很大,环境资源能值占能值利用率的３０％,高于全国平均值（１３％）;净能值产出率为１．２７,高于日本和意大利,可以作为一种能值来源;农牧渔业产品的宏观经济价值远大于市场价值,农业生产中有相当大一部分环境资源无偿投入;环境承载指标为２．４４,远低于日本和意大利,环境压力较小,发展潜力很大。进而提出促进农业持续发展的有关建议与设想。     

Amounts of pesticides reaching target pests: Environmental impacts and ethics

Less than 0.1% of pesticides applied for pest control reach their target pests. Thus, more than 99.9% of pesticides used move into the environment where they adversely affect public health and beneficial biota, and contaminate soil, water, and the atmosphere of the ecosystem. Improved pesticide application technologies can improve pesticide use efficiency and protect public health and the environment.     

徒步休闲制约因素的类型与差异研究--以宁波市北山游步道为例

基于浙江省宁波市北山游步道的调研数据,综合采用探索性因子分析、验证性因子分析和方差分析等方法,对徒步休闲制约因素的类型及其差异进行了研究。结果表明:①北山游步道徒步休闲的制约因素共有7种类型,分别为休闲设施、闲暇时间、环境状况、经济因素、个人内在因素、交通可达性、人际间因素。②7种徒步休闲制约因素在性别、年龄、学历、职业、收入、婚姻状况、孩子个数等人口统计学变量上呈现出差异。研究结果可为当地制定徒步休闲政策提供参考。     

中国农业净碳汇时空演化特征分析

论文以全国范围县级单元为研究对象,对1991—2011年长达21 a的农业净碳汇时空格局变化规律展开了深入分析。研究表明：1）从时间变化角度可以发现,整体上我国农业在长达21 a内均以净碳汇为主,并且总体上处于波动上升趋势,农业净碳汇净增93.7%;2）我国农业碳汇结构相对比较稳定,稻谷、小麦和玉米三者共同占到了80%左右,而碳源结构则在1991—2011年间发生了较大变化,由1991年农药为主,化肥、牛为辅转变成为化肥为主,农药、地膜、牛为辅的结构;3）空间分布方面,我国县域农业净碳汇量地区间差距在不断缩小,存在4种农业碳生态类型区;4）1991—2011年间净碳汇为负值的县级单元数量增多,并且在空间上主要分布于西南地区与内蒙古。农业种植量相对较小,作物生长碳吸收不明显,单位产量农业投入要素多以及农业类型以畜牧业为主是这些地区农业净碳汇为负值的主要原因。