Understorey vegetation as an indicator of water content in till soils in Finnish Lapland

Artificial regeneration of Scots pine (Pinus sylvestris L.) has been applied to a variety of forest site in Lapland. Occasional failures in regeneration have been observed on sites with high soil moisture contents and originally dominated by Norway spruce (Picea abies (L.) Karst). Understorey vegetation was studied on four naturally pine-dominated and eight spruce-dominated sites to determine suitable indicator plants for assessing soil moisture regimes. Soil moisture contents were estimated using the in situ dielectric measurements with radar surface arrival detection targeted to a depth of 0-50 cm. The abundance and frequence of plant species were analysed using logistic regression. The most reliable indicators were found to be Stereocaulon and Cladonia lichens for the dry regime (θv<25%), and Polytrichum commune Hedw. and Carex globularis L. for the wet regime (θv>25%). It was concluded that the indicator plants found in this study provide an alternative to the traditional Finnish forest site type approach in recognizing high soil moisture regimes.     

森林对降水的影响概述

森林能否增加降水,这是植树造林、美化环境等工作中必然要考虑的问题。文章总结了国内外相关文献,就森林对降水的影响做了阐述。综合现有研究结果来看,森林对降水有无影响目前还没有普遍性的结论;对于局地森林对降水的影响应持保守态度,既不能说"有",也不能说"无"。明确的结论必须结合当地地形、天气、气候条件做具体的研究分析后才能得出,这样的结论才更科学,更具指导意义。因此关于宁夏植树造林是否对宁夏的区域气候产生影响,以及有什么样的影响,目前还不清楚。另外一个主要问题就是森林的尺度,即多大面积的森林才会对区域降水产生影响,因为如果森林的面积很有限,对区域降水的影响是否也很有限等等,这些问题都需要进一步深入研究和探讨。     

浅析森林资源管理信息系统研究现状及发展

21世纪是信息时代,在信息社会中,随着网络技术的不断发展,科学技术的迅速发展,特别是"3S"技术在林业上广泛应用,森林资源的科学管理和高效应用是非常重要的,传统的森林资源管理模式已经不能适应时代的发展,因此,实现信息化管理势在必行。     

Environmental Change and the Sustainability of European Forests

Summary

It is some years now since forest decline was a major public concern in Europe and was one of the principal environmental issues around which international research programs were focused. A number of internationally coordinated activities were initiated in the 1980s and 1990s and have continued until now; these contributed significantly to our current understanding of forestry and to the way in which forestry policies have developed. In short, the concept of sustainable development has had an increasing influence and is now of immeasurable value in forest policy, with sustainable forest management well established as its guiding principle. This sequence of events is examined here. The extent to which understanding has advanced is remarkable; much has changed. Arguably this period gave the first indication of the extent to which forests and ecosystems globally are threatened by environmental change. On the basis of the last 20 years, it is tempting to conclude that we now have an effective institutional framework and have made excellent progress. However, some of the recorded ecosystem responses seem anomalous; there are surprises in system responses, e.g., the linkage between sulphur and nitrogen depositions and forest growth. Even more importantly some specific pollutant problems remain and will intensify, and climate change has become an environmental issue of overwhelming importance.     

The genetic diversity and structure of 18 sheep breeds exposed to isolation and selection

The phylogenetic layout of the genotyped (30 microsatellite) 18 sheep breeds in this study demands and provides the opportunity to evaluate both neutral and adaptive components of genetic diversity in a naturally and artificially selected and subdivided sheep population. Seven Pramenka strains from Bosnia and Herzegovina and Croatia characterized by a very low intensity of artificial selection, preserved the highest neutral genetic variability. Eight central and north‐western European breeds under considerable artificial isolation and selection preserved the lowest genetic variability. Only combinations of various phylogenetic parameters offer a reasonable explanation for underlying evolutionary forces working in the investigated island and mainland sheep breeds under variable natural and artificial selection. More than 60% of total genetic, diversity was allocated to virtually unselected Pramenka strains, and an additional 25% to native moderately selected Graue Gehoernte Heidschnucke and intensively selected Ostfriesische Milchschafe. Some economically very important breeds and strains did not contribute to a pool with maximal genetic diversity, while they play an important role in the cultural heritage of respective countries.     

酶制剂在农业中的应用及生物技术改良

酶是由多种氨基酸、维生素及矿物质等构成的活性蛋白质,广泛地存在于自然界。酶制剂工业是生物工程的重要组成部分,其应用非常广泛。主要从畜禽养殖、水产养殖、农药残留降解、生物农药、作为抗生素替代品和农业食品加工以及生物技术在该领域应用进行简短的综述。     

提高农业科技服务能力 推进农村小康社会建设

中国全面建设小康社会重点在农村，难点在如何增加农民收入，很大程度上取决于如何为八亿农民提供农业科技服务，促进农业技术创新和科技成果转化为现实生产力。本文从中国农业生产的现状、科技服务“缺位和滞后”和力量不足等问题入手，提出改革现行的农业科技运行和转化机制、开展科农携手共建利益共同体、发挥示范榜样作用、提高劳动者的科技素质等对策，促进科学研究面向生产第一线和科技成果直接应用于生产，为农民提供全方位、多层次、多领域的科技服务，推进农村全面建设小康社会进程。     

坚持和落实科学发展观 努力破解农民增收难题

以科学发展观为指导，针对安徽省农民增收和农业发展中存在的资源约束等问题进行分析，提出了抓住时机，依靠政策调动、布局优化、市场带动、科技拉动，提高农民增收的稳定性和持续性,大幅度提高农民增收的对策和发展思路。     

A model of decision-making and information flows for information-intensive agriculture

This paper describes the development of a systems based model to characterise farmers’ decision-making process in information-intensive practices, and its evaluation in the context of Precision Agriculture (PA). A participative methodology was developed in which farm managers decomposed their process of decision-making into brief decision statements along with associated information requirements. The methodology was first developed on a university research farm in Denmark and further revised during testing on a number of research and commercial farms in Indiana, USA. Twenty-one decision-analysis factors were identified to characterise a farm manager’s decision-making process. Then, a general data flow diagram (DFD) was constructed that describes the information flows “from data to decision”. Illustrative examples of the model in the form of DFDs are presented for a strategic, a tactical and an operational decision. The model was validated for a range of decisions related to operations by three university farm managers and by five commercial farmers practicing PA for cereal, corn and soybean production in Denmark and in Indiana, USA.     

试论农业机械化在建设社会主义新农村中的重要作用

建设社会主义新农村,是党中央从贯彻落实科学发展观、构建社会主义和谐社会的全局出发作出的重大战略部署,农业机械化发展必须适应农业现代化和建设社会主义新农村的需要,为我国实现农业现代化、解决“三农”问题,建设社会主义新农村作出农业机械化应有的贡献。