Habitat loss, Fragmentation, and Alteration – Quantifying the Impactof Land-use Changes on a Spanish Dehesa Landscape by Use of Aerial Photography and GIS

Mediterranean agroforestry landscapes, dehesas, experience significant structural changes that affect their ability to support habitats for a rich biodiversity. The goal of this study is to provide quantitative information on loss, fragmentation, and alteration of holm oak (Quercus ilex) stands over a 42-year period, based on two sites in the lowlands of Cáceres province, Spain. Aerial photography and orthoimages from 1956, 1984, and 1998 were processed in a geographic information system (GIS). Important changes in demography and land-use were rural depopulation, abandonment of traditional agricultural activities, and a sharp increase in livestock stocking levels. These were related to intensification and extensification of land-uses determined by national and EU agricultural policies. Results of the land cover analysis indicated that dehesas suffered an annual 0.27% and 0.04% decrease in cover in the two sites. From 1984 loss rate had markedly accelerated (0.83% and 0.30%). Most dehesas were lost by shrub encroachment or conversion to open grassland. Fragmentation through roads increased by 28% and 45%, while rural buildings decreased by 17% and 50% from 1956 to 1998. Mean tree density decreased from 1956 to 1984, but a recovery was found since 1984. Significant factors determining stand densities in most time points were altitude (related with different land-uses and geological substrates), ownership, and proximity to villages. This suggests that stand structure is controlled both by human interventions and ecological settings. The findings support the view that opposite trends of land abandonment and intensification of land-uses arise in most northern Mediterranean countries as an effect of the EU Common Agricultural Policy.     

Simulating the cumulative effects of multiple forest management strategies on landscape measures of forest sustainability

While the cumulative effects of the actions of multiple owners have long been recognized as critically relevant to efforts to maintain sustainable forests at the landscape scale, few studies have addressed these effects. We used the HARVEST timber harvest simulator to predict the cumulative effects of four owner groups (two paper companies, a state forest and non-industrial private owners) with different management objectives on landscape pattern in an upper Michigan landscape managed primarily for timber production. We quantified trends in landscape pattern metrics that were linked to Montreal Process indicators of forest sustainability, and used a simple wildlife habitat model to project habitat trends. Our results showed that most trends were considered favorable for forest sustainability, but that some were not. The proportion of all age classes and some forest types moved closer to presettlement conditions. The trend for the size of uneven-aged patches was essentially flat while the average size of patches of the oldest and youngest age classes increased and the size of patches of the remaining age classes decreased. Forest fragmentation generally declined, but edge density of age classes increased. Late seral forest habitat increased while early successional habitat declined. The owners use different management systems that cumulatively produce a diversity of habitats. Our approach provides a tool to evaluate such cumulative effects on other landscapes owned by multiple owners. The approach holds promise for helping landowner groups develop and evaluate cooperative strategies to improve landscape patterns for forest sustainability.     

非电类工科专业《电子技术》课程教学改革的探究

对当前非电类工科专业在《电子技术》课程教学中存在的问题进行了阐述，并结合作者自己的教学经验探讨了非电类工科专业《电子技术》课程的内容设簧和教学方法。提出了教学内容应与所学专业相结合，提高学生学习的积极性与自觉性。并介绍了一些具体的改革方法，实践证明其改革效果较好。     

Urban forests as compensation measures for infrastructure development

Sustainable development requires, among other things, that development projects not result in the degradation of natural resources for outdoor recreation. There has been a rapid increase in knowledge regarding the importance of the external environment to our health and well-being. Stress is reduced significantly when people are exposed to health-promoting nature and landscape values. Many people are actively choosing to reduce their stress. Doctors today prescribe outdoor walks in peaceful environments for the same purpose. A high level of traffic noise increases stress. This paper discusses the application of silent values in an infrastructure development project, the extension of Sturup Airport, east of Malmö, Sweden and Copenhagen, Denmark. Through estimating the change in noise resulting from the development, it is possible to integrate mitigating and compensating measures in the planning process discussions. Such measures can be negotiated as conditions for authorization of the project. The airport is situated in an area rich in nature values for recreation. The airport expansion will mean both new noise impacting "silent" areas and increasing noise levels in already noise-affected areas. In this study, we have taken a positive stand on the silent areas, mostly agriculture land, where compensation measures could be taken, thus balancing the loss of silent nature values for recreation. Silent areas that will not be affected are suitable and feassible for compensation measures thus can be called compensation areas. In this way the development of new recreational areas, preferably designed as urban forests, are critical preconditions for the negotiations for the airport extension. The conclusion is that urban forest investments for health and well-being can be an important part of strategic decisions in spatial planning. As preconditions for a permit, the development and financing of new urban forests and green areas can be part of the total development plan. This is an issue of global interest, as many countries are in a process of rapid urbanization, and urban greening and urban forestry have an important role to play in the process of promoting quality of life and improving environmental quality.     

城市高密度居住区的绿化景观营造

介绍了大城市中高密度居住区的环境条件,分析了当前面临的生态环境问题,阐述了高密度居住区绿化景观营造模式,为居住区环境绿化的建设提供借鉴。     

从育人角度谈校园景观设计

校园环境是与学生密切接触的环境,对学生成长起到潜移默化的作用,因此校园环境景观应强调其育人功能。在校园环境景观中纳入以教育为主题的景观,可为学生提供健康的学习环境,培养学生的学习兴趣,扩展学校的实习基地,突出学校的办学特色。以教育为主题的景观有历史人文类、科学知识类、思想道德教育及时事展示类,具有教育的间接性、对外的开放性、受众需求多样性等特点。笔者通过例举实例说明了教育主题景观在校园景观和学校的教育氛围中发挥的重要作用,提出教育主题的校园景观设计需要科学合理地总体规划、细致充分地调查研究、多种教育题材和设计手法,从而营造出可以引导学生学习兴趣、参与性的,与周边建筑协调的,使用功能完善的教育主题景观,以期为今后校园环境中教育主题景观设计提供思路。     

办好农业技术类期刊的方法探讨

本文在信息化时代背景下如何办好农业技术期刊进行了深层次探讨,结合《现代农村科技》的成功经验,提出打造品牌、准确定位、贴近读者、健全网络、强化管理、扩展广告、开放办刊等一系列措施。     

科技小院创新发展：现实需要、功能定位与运行保障机制

科技小院是现代农业发展的创新组织模式,也是推进乡村振兴的重要科技支撑。本文基于宏观和微观层面阐释科技小院产生的现实需要,结合实地调研系统分析其发展演变与功能定位,探讨其运行保障机制与取得的实践成效,提出引导科技小院高质量发展的思路与建议。研究表明,科技小院的产生顺应了微观层面农户对先进农业技术需求增加,以及宏观层面现代农业发展对农业科技进步依赖加大的现实需要,在发展过程中演绎出“自下而上”式农业科技创新、“科普志愿”式农业社会服务和“产教融合”式农业人才培养三重功能,且三重功能定位以科学技术为纽带,形成了激励相容关系。科技小院以高校科研院所为内核,各主体之间形成了不同目标导向的利益联结机制,其中正式制度施加规范约束、服务互动融入社会规范、多方支持构成物质保障,推动科技小院有效运行。科技小院创新了农业技术推广模式、促进了现代农业高质量发展、提高了农民综合素质水平、开创了农业人才培养新模式,取得了显著的综合效益。因此,未来科技小院发展应深入明确功能定位、强化制度约束、加强组织创新和推广经验典型,走错位发展、规范发展、融合发展和共享发展之路。     

区域土地利用变化与景观格局分异研究

以1975年和2005年的土地利用图为基础图件,以各个县市为研究单位,提取各个县市的土地利用数据,分析三峡库区近30年来土地利用动态度的变化、土地利用程度的变化;然后接合景观生态学的理论,引入了斑块平均面积、景观的多样性与景观破碎度,寻找分异特征。研究表明,三峡库区近30年各类建设用地的变化速度>河流水域的变化速度>林地、草地的变化速度>耕地的变化速度;各县市土地利用程度在增加;各个景观指数的变化在各个地域分布上的变化趋势是不一样的,土地利用对景观格局的影响比较和缓,三峡库区景观的多样性在减少。     

提高粮食综合生产能力的技术路径——以河南省为例

[目的]根据河南省情和生产实际,探讨提高粮食生产能力的技术路径。[方法]对河南省粮食产量的现状与动态进行整体分析。[结果]河南省粮食总产量的变化呈现上升态势。2010年粮食总产5437万t是1978年粮食总产2097.40万t的2.5倍。粮食总产的增长越来越依赖于单产的提高。[结论]该研究为河南省乃至全国粮食增产提供理论依据。