全文获取类型
收费全文 | 114篇 |
免费 | 18篇 |
国内免费 | 2篇 |
专业分类
林业 | 40篇 |
农学 | 3篇 |
基础科学 | 2篇 |
18篇 | |
综合类 | 21篇 |
农作物 | 1篇 |
水产渔业 | 7篇 |
畜牧兽医 | 31篇 |
园艺 | 6篇 |
植物保护 | 5篇 |
出版年
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 2篇 |
2013年 | 8篇 |
2012年 | 11篇 |
2011年 | 6篇 |
2010年 | 6篇 |
2009年 | 19篇 |
2008年 | 9篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有134条查询结果,搜索用时 15 毫秒
1.
[目的]分析德国推行近自然森林经营20年来的经营效果,总结德国推行近自然森林经营的经验。[方法]在明晰近自然森林经营原则的基础上,基于两期(间隔期10年)资源清查数据对比,对德国大面积推行近自然森林经营20年的经营效果进行分析。[结果]两期资源清查数据表明,德国采用近自然经营20年后,针叶林如挪威云杉和欧洲赤松的面积显著减少,阔叶林和针阔混交林面积持续增加;阔叶树种蓄积平均增长量约为15 m~3·hm~(-2),针叶树种蓄积平均增长4 m~3·hm~(-2),挪威云杉是唯一蓄积下降的树种,下降了5 m~3·hm~(-2);近自然度等级变化表明,人工林面积在减少,而近自然森林的面积在增加,甚至符合原始林等级的森林面积也在增加。[结论]实现近自然森林经营的目标是一个长期的过程,联邦政府促进和保护森林的政策以及林场主所采用的先进的森林经营技术也是德国森林每公顷蓄积达到336 m~3的重要原因;在近自然森林经营的原则下,德国森林中针阔混交林比例显著增加;将近自然程度不高的人工林经营转化为近自然的森林生态系统是德国森林经营所面临的主要问题。 相似文献
2.
3.
德国林业、环境保护和林业管理体制 总被引:1,自引:0,他引:1
介绍了德国:①先进的林业理论和高度发达的林业现状;②公民良好的环境保护意识和环境保护政策;③目前林业的管理体制、管理机构、管理方式以及林业政策的目标和原则。 相似文献
4.
5.
德国的森林生态环境建设及其启示 总被引:3,自引:0,他引:3
介绍了德国林业在"近自然林业"理论指导下的森林生态环境建设的历程、特点和成效,以及对我国林业工作的启示. 相似文献
6.
Participatory National Forest Programmes (NFPs) intend to democratise forest sector policy, but they may suffer from a fundamental democratic legitimisation deficit since the stakeholders involved are neither democratically authorised nor accountable to the population. In order to scrutinise the empirical relevance of this problem in the case of the German NFP, it is analysed how the German population on the one hand and the NFP participants on the other hand assess central forest policy aims of the NFP, and how far both assessments coincide. Two surveys based on identical questionnaires are used as the data base. The respondents assessed the importance of the respective aims as well as at their implementation. Results show that the population considers the majority of the NFP aims to be generally relevant, but assesses the majority of the aims significantly differently from the stakeholders. The formal legitimisation deficit of the German NFP therefore also matters in terms of content. Discussing the NFP among the elected representatives and in the public seems indispensable.Moreover, the differences in the assessment of some policy aims are significantly dependent on how people judge the image of forest enterprises between the opposing poles of profit orientation and nature protection. Public acceptance of those aims could be furthered more appropriately by adjusting the partly incorrect image of forestry rather than by providing more information about the particular aims and their background. 相似文献
7.
Ulrich Schraml 《European Journal of Forest Research》2006,125(1):79-88
The changes to the forest ownership structure of small private forests in recent times have opened up an intensive field of
research throughout Europe. Most of the studies completed to date adhere to the classic survey model and describe the behaviour
and attitudes of forest owners. The research presented in this article analyses the changes to small private forests with
the aid of data collected from focus groups comprised of forestry extension officers in Germany. Through the reconstruction
of the experiences gleaned by the consultants, it was possible to describe the manner in which they characterise their clientele,
and the changes they have observed, against the backdrop of changes occurring across rural areas. The consultants’ strategies
for describing forest owners are presented. The orientation pattern presented by the extension officers is compared with the
urban orientation of forest owners’ model developed by social scientists. 相似文献
8.
德国林业体系及森林经营技术与管理 总被引:9,自引:0,他引:9
通过德国的培训考察,对其林业管理体系与政策、森林经营与理念、生物圈保护、森林公共教育等方面归纳叙述。 相似文献
9.
Nicole?WellbrockEmail author Winfried?Riek Barbara?Wolff 《European Journal of Forest Research》2005,124(4):261-271
Based on the results of the atmospheric deposition classification of the year 1989, a methodical approach should be introduced,
which—based on the modelled total deposition rates—enables us to characterise the input situation of forest monitoring plots
and to delimit load areas in Germany. In 1989, the deposition situation in nearly 1,800 forest monitoring sites (BZE/extensive
Soil Condition Inventory) in Germany could be explained by four factors (or three, excluding sea salt impact) with the help
of a factor analysis. The factor values were grouped into six deposition types with typical compounds and regional patterns.
The classified input rates of the soil inventory plots adequately represent the stress situation and deposition changes in
Germany. The application of the statistical approach on the level of Brandenburg clarifies the special local input situation.
Due to the special combination of deposed elements, the sources of emissions can be characterised as well. When the soil inventory
is repeated, a project planned for 2006, this approach can be used in order to determine homogenous areas for stratified data
evaluation. 相似文献
10.
Long range (or strategic) planning is an important tool for forest management to deal with the complex and unpredictable future.
However, it is the ability to make meaningful predictions about the rapidly changing future that is questioned. What appears
to be particularly neglected is the question of the length of time horizons and the limits (if any) to these horizons, despite
being considered one of the most critical factors in strategic planning. As the future creation of values lies within individual
responsibility, this research empirically explored the limits (if any) of individual foresters’ time horizons. To draw comparisons
between countries with different traditions in forest management planning, data were collected through telephone surveys of
forest managers in the state/national forest services of the Netherlands and Germany. In order to minimize other cultural
differences, the research in Germany concentrated on the federal state of Nordrhein-Westfalen, which has considerable similarities
with the Netherlands, e.g. in topography, forest types and forest functions. The results show that, in practice, 15 years
appears to be the most distant horizon that foresters can identify with. This is in sharp contrast to the time horizons spanning
decades and even generations that are always said to exist in forestry. The “doctrine of the long run”—the faith in the capacity
of foresters to overcome the barriers of the uncertain future and look ahead and plan for long-range goals—which in many countries
still underlies traditional forest management, can therefore be rejected.
相似文献
Heiner SchanzEmail: |