山西云顶山亚高山草甸优势种群和群落的格局分析

应用DCA排序与双项轨迹方差法相结合的方法,对云顶山亚高山草甸优势种群和群落的分布格局进行了分析.结果表明,群落格局与其优势种的格局关系密切,披针苔草 车前群系、披针苔草 蒲公英群系和嵩草 车前群系的格局差异明显,种群和群落的分布格局不仅受种的生物学特性影响,还受环境因子制约.图4表1参19     

山区资源开发的一些经验

本文分析了山区贫困的一般原因。讨论了山区有效资源不足和“单向流失”现象与山区贫困化的关系,并列举了山区工作中的历史失误。本文总结了一些地区采用“长短结合、以短养长”的发展战略,开发优势资源所取得的成功经验,并提出了区域经济、社会、生态协同发展的目标。     

春季沙尘过程对华东高山背景区域颗粒物中水溶性无机离子的影响

于2014年3—5月在国家大气背景监测福建武夷山站采集了PM2.5及PM2.5~10样品,利用离子色谱对其中的水溶性组分进行分析,并同步收集气象因子及污染物质量浓度数据,结合后向气流轨迹,分离出受沙尘影响的样品,探讨了春季沙尘过程华东高山背景区域颗粒物中水溶性组分的特征.结果表明,春季武夷山背景点沙尘影响期间颗粒物质量浓度及各水溶性离子浓度均比非沙尘期高,在粗粒子中表现更为明显;沙尘期间NO-3在粗粒子中明显富集,NO-3浓度显著升高;受沙尘影响,粗粒子中阳离子与阴离子的当量浓度比及NO2的二次转化率均明显升高.     

Using Soil and Water Conservation Contests for Extension: Experiences from the Bolivian Mountain Valleys

Soil and water conservation (SWC) contests among farmer groups were organized in five rural villages in the Bolivian mountain valleys. The contests were aimed at quickly achieving widespread sustainable results. This article analyzes the effectiveness of these contests as an extension tool. Mixed results were obtained. In three villages, participation rates in the SWC activities introduced in the contests were still high even 2 years after project withdrawal. These were all villages where a solid foundation for sustainable development had been laid before the contests were held. Two years later, most families were still involved in maintenance of the SWC practices introduced in the contests, and many farmers had started to experiment with different soil management practices. However, replications of these SWC practices were not widespread, Conservation Leaders did not continue with their training activities, and the quality of maintenance of the practices was often not satisfactory. In order to become a more effective extension tool and achieve widespread impact, SWC contests must receive continued support by a catalyst agency. Moreover, other SWC contests should also be organized in which practices are not predefined. Given that SWC contests are a low-budget extension tool, local municipalities could become more actively involved.     

Laying a solid foundation for sustainable development in Bolivian mountain villages

In Bolivia, recent decentralisation policies have broadened the participation of local actors in development processes. However, development is far from sustainable, and poverty and natural resources degradation still increase. The challenge is to develop strategies that achieve the genuine participation of poor farmers in natural resources management and sustainable development. The logical strategy, which was developed and validated in five Bolivian mountain villages, is an example. In this strategy, first a solid foundation for sustainable development is laid, with activities focussing on five basic conditions for sustainable development in rural villages: leadership and organisation, responsible participation, effective collaboration, mutual trust and environmental awareness. The results show that the existence of a solid foundation is crucial for the success of other development activities, such as soil and water conservation activities. However, given that 2 years after the project’s withdrawal the firmness of the foundation had slightly weakened, it was concluded that a better integration of these villages in local development processes is essential to profit from the new dynamics. This is especially true for soil and water conservation. To achieve this integration, municipalities—with the support of international development agencies—must be encouraged to invest in laying this solid foundation in rural villages and in facilitating follow-up activities to keep the dynamic process going. This study shows that such investments result in better organised villages, more equality, and the genuine participation of more people in sustainable village development. Effective collaboration and accountability at institutional level are, however, required.     

RHODAMINE WT DYE LOSSES IN A MOUNTAIN STREAM ENVIRONMENT1

ABSTRACT: A significant fraction of rhodamine WT dye was lost during a short term multitracer injection experiment in a mountain stream environment. The conservative anion chloride and the sorbing cation lithium were concurrently injected. In-stream rhodamine WT concentrations were as low as 45 percent of that expected, based on chloride data. Concentration data were available from shallow‘wells’dug near the stream course and from a seep of suspected return flow. Both rhodamine WT dye and lithium were nonconservative with respect to the conservative chloride, with rhodamine WT dye closely following the behavior of the sorbing lithium. Nonsorption and sorption mechanisms for rhodamine WT loss in a mountain stream were evaluated in laboratory experiments. Experiments evaluating nonsorption losses indicated minimal losses by such mechanisms. Laboratory experiments using sand and gravel size streambed sediments show an appreciable capacity for rhodamine WT sorption. The detection of tracers in the shallow wells and seep indicates interaction between the stream and the flow in the surrounding subsurface, intergravel water, system. The injected tracers had ample opportunity for intimate contact with materials shown in the laboratory experiments to be potentially sorptive. It is suggested that in the study stream system, interaction with streambed gravel was a significant mechanism for the attenuation of rhodamine WT dye (relative to chloride).     

INFLUENCES OF A FOREST ON THE HYDRAULIC GEOMETRY OF TWO MOUNTAIN STREAMS1

ABSTRACT The influence of a forest on the formation of steps in two small streams of the Colorado Rocky Mountains was studied. Steps provided by logs fallen across the channel added to flow energy reduction. The streams required additional gravel bars to adjust to slope. Average step length between logs and gravel bars was strongly related to channel gradient and median bed material size. Based on the average number of log steps per 50 feet of channel, an average of 116 percent of gravel bars were added at Fool Creek and 60 percent at Deadhorse Creek. The latter had 52 percent more logs in the channel and therefore required less bed material movement than the former. Although these are “rushing mountain streams,” most flow velocities ranged between 0.5 and 2.5 f.p.s. Exponents of a function relating rate of change of depth or velocity to discharge indicated that dynamic stream equilibrium was attained. Implications for forest management are that sanitation cuts (removal of dead and dying trees) would not be permissible where a stream is in dynamic equilibrium and bed material movement should be minimized.     

生态旅游:实现山区可持续发展的理想途径--以临安市为例

以临安市生态旅游发展实践为例,通过参与性农村快速评估方法(PRRA),实证分析了生态旅游对开发企业、当地农民和政府带来的经济效益,以及对改善生态环境、增加就业、提高农民素质等方面发挥的生态效益与社会效益,指出准确的市场定位、参与式市场运作、政府重视和支持是临安生态旅游发展的成功经验.说明生态旅游业作为最终需求产业,在具备一定资源优势和区位优势的山区,是实现山区经济、生态、社会协调发展的理想途径.     

大巴山区野生腊梅资源的保护与开发利用

达州市是我国野生腊梅三大主产区之一,野生腊梅资源极具开发价值.介绍了大巴山野生腊梅资源的研究状况,提出了加强资源保护、制定开发战略、强化基础研究、集成科研创新的建议.     

云台山生物资源的开发利用与保护

作为国家级风景区的云台山蕴藏着丰富的生物资源,本文从生物资源的可持续开发和经济学角度出发,对合理利用云台山的生物资源作了初步探讨。