山地生态农业研究

文章从我国山区地貌地特点和山区农业发展问题入手,分析了山地农业的发展方向,并提出了作为山地农业最佳选择的山地生态农业构建原则的实施途径。     

可持续发展中的公平与效率问题

在传统增长方式中,公平与效率之间存在着巨大的冲突,由于可持续发展的出现,才第一次把两者纳入到可以相互补充、相互协调的框架之内,从而构成了整个社会得以生存与发展的必要张力。如何在公平的价值观念下效率,如何在有效的市场中保证公平,成为环境与发展问题相并列的当代经济理论、经济伦理思想以及可持续发展观的重要课题。     

流域尺度土地利用调蓄视角的雨洪管理探析

发达国家雨洪管理焦点历经管网设计、不透水面阈值控制、低影响开发及土地利用管理等过程,呈现"多尺度多视角衔接"趋势。本文聚焦太湖流域土地利用调蓄功能变化机制及管理应用,揭示了1985-2015年来建设占用耕地是调蓄功能降低的主要原因;发现基于小流域的调蓄功能变化与建设用地强度整体低关联,但局部高相关,高相关的地区位于大城市或某些乡镇周边的建设增长热区,而这些热区的建设用地与调蓄空间规模较大且接触机会更多,是开发之前调蓄空间保护、开发控制以及开发之后综合管理等3个土地利用调蓄目标因子协调不当的结果;最后提出流域尺度土地利用调蓄视角的雨洪管理"345"模式,即以3个目标因子和5类控制要素为基础,实施土地利用调蓄创建、防御、拓展与保护等4类差别化战略模式,从更大尺度认识老城区和新区的雨洪关联,拓展海绵城市建设的本土认知和视野。     

兰州大学(盘旋路校区)2003年生态足迹调查分析

人均消费产品的数量是计算区域人均生态足迹关键和基础的一步。通过实地问卷调查，运用自下而上法收集资料，计算小尺度生态足迹。兰州大学(盘旋路校区)2003年的生态足迹计算结果为：人均生态足迹0．892hm^2，男、女生的人均生态足迹分别为0．976hm^2和0．788hm^2。这些数据与全国或者西部的人均生态足迹相比明显偏低，但总生态足迹为4119．3hm^2，是校园面积的73．7倍。因此，应合理利用自然资源，减少学生的生态足迹，真正做到可持续发展。     

Patterns of Irrigated Agricultural Land Conversion in a Western U.S. Watershed: Implications for Landscape-Level Water Management and Land-Use Planning

In irrigated agricultural landscapes, land-use conversion may have landscape-level social, hydrological, and ecological effects. We used geographic information systems (GIS) and interviews to analyze development effects on irrigation in the Henry's Fork Watershed, Idaho. Farmers developed irrigation there in the 19th century, and incidental recharge from canal seepage and flood irrigation raised groundwater levels and expanded wetlands. Cohesive culture in agricultural communities sustained irrigation systems until amenity-driven demographic shifts beginning in the 1970s led to development approved by local governments with land-use planning but no water-management authority. Although only 5% of irrigated land has been converted, development has fragmented irrigated landscapes and made canal-system operation more difficult, potentially reducing groundwater levels, wetland extent, and return flows critical to downstream irrigators and fish and wildlife. We discuss future scenarios, highlighting the need for increased communication among local and state governments regarding land use and water management in irrigated landscapes across the West.     

农业景观保护路径历史回顾及启示

农业景观保护是实现农业景观可持续发展的重要举措,关系到中国粮食安全保障、农耕文明传承、乡村风貌维系、生态安全格局构建乃至社会经济稳定发展.本文借助对发达国家农业景观保护路径的长时间尺度历史回顾,总结归纳出农业景观保护路径发展的一般规律,即其在社会经济发展进程中一般经历传统保护、应对保护、管制保护、治理保护和管护保护五个...     

试论少数民族地区的生态化旅游开发

生态化旅游开发是有别于传统的旅游开发的一种可持续开发与发展的理念，它追求的是生态、社会和经济综合效益的最大化，应该成为旅游开发与旅游业发展的主要方向。民族地区的旅游开发具有特定的区域生态特征。其生态化旅游开发的核心问题是旅游环境容量的确定与旅游环境的保护、民族特色与民族文化的弘扬以及注重旅游经济发展过程中旅游业的拉动效应及其依托性之间的关系处理等。     

Comparisons between the reproductive biology of black bream Acanthopagrus butcheri (Teleostei: Sparidae) in four estuaries with widely differing characteristics

The reproductive biology of Acanthopagrus butcheri has been studied in the permanently open Swan River and intermittently open Moore River estuaries on the lower west coast of Australia (31--32 °S) and in the permanently open Nornalup Walpole and normally closed Wellstead estuaries on the southern coast of Western Australia (34--35 °S). Trends exhibited by gonadosomatic indices, gonadal maturity stages and the sizes and developmental stages of the oocytes demonstrate that A. butcher typically spawns in spring and early summer. However, spawning occurred in salinities ranging from as low as 3.5-8 g L^–1 in the Moore River Estuary to as high as 41-45 g L^–1 in the Wellstead Estuary. Furthermore, water temperatures during spawning were greater in the two northern estuaries (19.7--28.5 °C) than in the two southern and cooler estuaries (17.5--23.4 °C). Histological studies strongly indicate that A. butcheri spawn more than once in a breeding season and demonstrate that the development of its oocytes exhibits group synchrony sensu de Vlaming (1983). The ages and total lengths at which, on average, female and male A. butcheri both first attain maturity in the Swan River Estuary were ca 2 years and ca 215 mm. However, the age at which individual fish in that system reach maturity was influenced by body size. This suggests that the attainment of first maturity at an older age but smaller length in the Moore River and Nornalup Walpole estuaries than is the case in the Swan River Estuary is a consequence of the slower growth rates of A. butcheri in those estuaries. The combination of the young age (ca 2 years) but small length (ca 145 mm) at which maturity is first attained in the Wellstead Estuary could have resulted from selection pressures brought about by high mortality rates and/or heavy fishing pressure in this estuary. The mean fecundity of A. butcheri, based on the combined number of yolk vesicle and yolk granule oocytes found in ovaries just prior to the onset of spawning, was 1580 × 10³. The significance of the sizes at first maturity, minimum legal length for capture, mesh selectivity data and closure of certain regions of estuaries to fishing for the management of the recreational and commercial fishery for A. butcheri is discussed.     

典型农区农用地承包经营权流转价格及对策研究(英文)

河南既是农业大省又是中国重要的粮食主产区,农用地流转顺畅及适度规模经营对区域经济发展和国家粮食安全产生重要影响。借助于土地使用权评估的基本方法,并使用土地承包经营权的权属特性进行修正,构建了土地承包经营权流转价格模型,并对典型区域沁阳市西万村进行了实证分析。结果表明,土地承包经营权流转价格应该包括经济价格、社会价格和修正价格。价格模型的应用,应甄别理论价格和实际流转费用的区分,农用地流转后经营项目没有转变,流转价格为经济价格和社会保障价格是总和。农用地流转后经营项目发生转变,比如耕地改种经济作物,流转价格则是经济价格、社会价格与修正价格三者的总和。收益分配格局存在复杂性,流转收益应在流出方、流入方、管理者和所有者之间合理、公平分配。政府应建立合理有序的农用地承包经营权流转市场,并以农用地流转市场为载体,构建农用地流转价格体系。     

昆明城市基础设施建设与城市管理问题与对策

城市的基础设施建设是一个城市的血脉和生命。它代表着一个城市的政治、经济和文化品位,代表着市民的社会公德素质和文化素质,代表着一个城市的城市精神。在面临今天大开发、大发展的新形势下,昆明的城市基础设施的建设和管理存在着一些问题：重建设轻管理、建设与管理主体不统一、管理的落后等。针对这些问题,围绕项目全生命周期管理,转变政府职能等理念,提出了引入市场竞争机制;建立城建资金良性循环机制等相应的对策。