Qualitative and quantitative effects of reintroduced beavers on stream fish

Reintroduction of beaver (Castor spp) may facilitate rehabilitation of freshwater habitats providing a cost‐effective sustainable means of improving ecological conditions. Despite extensive research, debate and consultation, a general consensus on the impact of beaver on fishes has proven elusive because of variability in biological response. This paper provides a systematic review of the impacts of beaver dams on fishes and fish habitat based on a meta‐analysis of the literature and expert opinion. Research is regionally biased to North America (88%). The most frequently cited benefits of beaver dams were increased habitat heterogeneity, rearing and overwintering habitat and flow refuge, and invertebrate production. Impeded fish movement because of dams, siltation of spawning habitat and low oxygen levels in ponds were the most often cited negative impacts. Benefits (184) were cited more frequently than costs (119). Impacts were spatially and temporally variable and differed with species. The majority of 49 North American and European experts considered beaver to have an overall positive impact on fish populations, through their influence on abundance and productivity. Perceived negative effects related to the movement of aquatic organisms in tributary streams, including upstream and downstream migrating salmonids, and the availability of suitable spawning habitat.     

基于居民感知的旅游城镇化影响研究--以武汉市黄陂区为例

旅游城镇化是以旅游业为主要推动力的城镇化类型,是新型城镇化的重要路径之一,其过程更加注重"人的城镇化"。在旅游城镇化的进程中,当地居民对旅游城镇化的影响感知强烈并有其独特性。笔者以旅游业快速驱动城镇化发展的武汉市黄陂区为案例,通过对黄陂区居民旅游城镇化感知的调查实证分析旅游城镇化的积极影响和负面影响。研究发现,旅游城镇化的积极影响主要体现在促进其经济发展;提升当地的旅游业的整体实力;强化城镇辐射功能,推动村落变化。而其消极影响则体现在不同区位条件的居民从旅游业发展中获益不均且居民的部分旅游收入合法权益得不到保证,缺乏长期稳定收入;旅游城镇化的发展加速乡村环境及景观的破碎化以及对当地的生态环境产生消极影响。     

Effects of bioenergy extraction on visual preferences in boreal forests: a review of surveys from Finland,Sweden and Norway

Increased forest biomass production for bioenergy will have various consequences for landscape scenery, depending on both the landscape features present and the character and intensity of the silvicultural and harvesting methods used. We review forest preference research carried out in Finland, Sweden and Norway, and discuss these findings in relation to bioenergy production in boreal forest ecosystems. Some production methods and related operations incur negative reactions among the public, e.g. stump harvesting, dense plantation, soil preparation, road construction, the use of non-native species, and partly also harvest of current non-productive forests. Positive visual effects of bioenergy production tend to be linked to harvesting methods such as tending, thinning, selective logging and residue harvesting that enhance both stand and landscape openness, and visual and physical accessibility. Relatively large differences in findings between studies underline the importance of local contextual knowledge about landscape values and how people use the particular landscape where different forms of bioenergy production will occur. This scientific knowledge may be used to formulate guiding principles for visual management of boreal forest bioenergy landscapes.     

基于居民感知的漓江流域生态旅游影响研究

基于居民感知视角,采用问卷调查方法进行数据收集,通过因子分析将测量居民感知的26个指标归纳为经济影响、环境影响、社会影响和文化影响4大类。研究表明,漓江流域生态旅游发展主要给社区带来以下影响:1）经济效益显著,但一定程度上引起物价上涨和贫富差距拉大;2）自然环境遭受破坏,环境污染加重;3）增加了娱乐场所和机会,但居民关系不及从前;4）促进居民文化素质提高和当地与外界的交流,但传统文化受到冲击等。     

The Probe of Environment Lighting in Commercial Pedestrian Streets Based on Principles of Visual Perception

Expect to satisfy basic visual task,the chief purpose of lighting in commercial pedestrian streets is to create more comfortable,more active and interesting environment.This paper analyzes main characteristics of visual perception,such as the attributive stage,expectations of perception and final response to the environment,and tries to discuss object and demand of lighting in commercial pedestrian street based on principles of visual perception.In this paper,first,frame of reference about visual perception is presented;then,the cause of lighting environment design is put forward;finally,some elements of lighting design in commercial pedestrian streets are ascertained.     

宝鸡山区居民的旱灾认知研究

采用多级分层抽样、部分区域采取滚雪球抽样,并与重点目标调查相结合,主要从旱灾产生原因及影响的重视程度、抗旱防旱态度和行为趋向等方面入手,对宝鸡山区居民的旱灾感知进行了问卷和访谈调查。结果显示:(1)宝鸡山区的干旱是相对的,总体上当地居民对旱灾现状的感知程度相对较高,对减灾持积极态度,87%以上居民愿意通过个人和政府的努力减缓旱灾的发生;(2)居民对旱灾产生原因及影响的认识不够深入,相对于抗旱减灾态度,在减灾行为方面存在一定的滞后性。在建设水利工程、引进抗旱作物及按规划开展减灾工作方面表现出心有余而力不足;(3)在防旱抗旱行为上,居民期望政府给予的指导和帮助与实际有较大差距。     

基于三星S5PV210的智能割草机控制系统设计

为了满足割草机全自动的作业需求,提出了一种基于三星S5PV210的智能割草机控制系统。该系统融合了机械设计、环境感知、智能控制、路径动态规划和行为决策等技术,能够自主地对目标草坪进行作业。试验结果表明:该智能收割机能够实现整个目标草坪的割草作业,且路径规划路线最优,割草机成功避开了障碍物,在整个过程没有发生碰撞行为,具有高实时性和高可靠性,应用前景广阔。     

Farmers' participatory selection of new rice varieties to boost production under temperate agro-ecosystems

In mountain agriculture, early maturity, high grain yield and high biomass are generally considered as farmer preferred traits in rice crop in addition to a multiple set of traits collectively responsible for variety adoption or rejection. The varieties tested only on station evaluation trials without taking the data from the farmers' fields by not including farmers as partners for variety evaluation are the reasons of low adoption of varieties. In this regard, a participatory methodology was followed by conducting a number of participatory trials in the farmers' fields during 2012–2014 in six districts of Kashmir Valley, India. The mother trials in the farmers' fields showed that the test variety SKUA-408 consistently and significantly out yielded Jhelum and farmers' variety followed by Shalimar rice 3(SR3). The other released varieties like SR1 and SR2 could not perform nicely in the farmers' fields because of late maturity. After making the t-test comparison of baby trials(paired plots), the mean yield superiority of test varieties SKUA-408, SR3, and SKUA-403 over farmers' variety during 2013 was around 23, 25, and 22%, respectively, whereas in 2014 the respective yield advantage was recorded as 16.3, 17.7, and 16.2%. In all districts, SKUA-408 and SR3 were significantly preferred by farmers(P0.05 or 0.01) in terms of pre-harvest traits namely, tillering ability and general phenotypic acceptability, early maturity and biomass and for post-harvest traits such as general cooking quality besides, the intention to grow the variety for next year. Adoption and dissemination of SKUA-408 began in 2014 from the farm-saved seed in the form of farmer to farmer seed exchange. Farmers are the end users of a variety so the decision by the farmers while judging the variety should be taken into consideration to make the varietal choice more effective for its widespread adoption.     

西部社区山地灾害风险认知与应急管理能力评价——以四川省彭州市小鱼洞镇为例

[目的]探讨山区留守人员对地质灾害(如崩塌、滑坡与泥石流等)的减灾防灾的认知情况以及对当地政府的应急管理能力进行评价。[方法]选取受泥石流等山地灾害威胁的彭州市小鱼洞镇为研究区,基于实地问卷调查数据,并用SPSS与Microsoft Excel软件进行描述性分析,获得了受访人员对有效减灾防灾措施的认可度。[结果]留守人员对于减灾防灾的基本理论知识和应急反应能力是有限的,公众对防灾减灾的认知有一定的错误和曲解;通过已有的评价模型对小鱼洞镇地质灾害应急管理能力进行评价,评分为84,表明该区域应急管理能力较强,当地人民也较为满意。[结论]在起草紧急计划之前,政府应该更多的考虑留守群体的期望和实际的疏散能力,而不是靠想象中的情况来完成计划好的工作,同时加强应急管理能力的建设,提高突发地质灾害应对能力。