首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
城市森林规划的指导原则   总被引:8,自引:1,他引:8  
以生态学原理为指导,以建立稳定高效的城市森林生态系统、优化人居环境、达到人与自然和谐共存、实现可持续发展为目标,提出了城市森林规划的一系列指导原则,其中着重阐述了如何贯彻生态优先和体现地方特色。  相似文献   

2.
城市森林建设的景观生态学思考   总被引:2,自引:0,他引:2  
应用景观生态学的原理和方法.评述了城市森林的景观生态特点,以及城市森林的建设原则,提出在城市森林建设中要以城市为对象进行布局,尊重城市自然地理布局进行复合交错式林业体系建设;普及森林知识,建设开放型的城市森林;强调充分考虑城市森林类型的特点和发展趋势,促进城市森林经济效益与生态效益的共同发展.  相似文献   

3.
城市森林系统评价指标体系研究   总被引:2,自引:0,他引:2  
城市森林建设是人与自然和谐的重要内容之一,是实现森林城市的重要途径。针对近年来全国不少城市提出“城市森林”、“森林城”的建设目标,作者以森林生态学、景观生态学、城市生态学等理论为指导,在系统分析国内外现有城市森林的基础上,探讨了城市森林的评价指标体系,并介绍了指标的内涵及选取评价指标的原则,旨在为城市森林规划建设提供科学合理的量化依据。  相似文献   

4.
树种选择的正确与否关系到城市森林建设的成败.以生态学原理为指导,阐述了城市森林建设中树种选择必须坚持的6项原则,即适地适树原则、生态优先原则、多目标兼顾原则、生物多样性原则、以乔木为主原则和重视乡土树种原则等.同时,拓展和丰富了适地适树的内涵,并就当前城市森林树种选择存在的一些问题进行探讨,提出解决问题的思路.  相似文献   

5.
在实地考察调研的基础上,运用森林生态学、景观生态学的方法和理论,提出了建设云龙示范区城市森林生态系统的原则。意在为该区建设成为生态环境优良、城市景观丰富、生态效益良好的两型生态城市提供参考。  相似文献   

6.
在实地考察调研的基础上,运用森林生态学、景观生态学的方法和理论,提出了建设云龙示范区城市森林生态系统的原则。意在为该区建设成为生态环境优良、城市景观丰富、生态效益良好的两型生态城市提供参考。  相似文献   

7.
回顾森林游憩发展的历史,探讨现代森林游憩建设中存在的法律法规不健全、开发利用不合理、景观管理薄弱等问题,认为应该通过景观生态规划使之不断完善,并从森林景观生态学基础研究、森林风景区景观生态评价、森林风景区景观生态规划模型和森林风景区景观管理4个方面综述国内外景观生态规划研究的成果,指出森林风景区景观生态规划研究发展的趋势,认为单纯的景观生态学的研究已经不能适应景观生态规划研究多学科的需要,森林风景区景观生态规划的研究应该大力加强与其他学科,诸如经济学、社会学和公共管理学的联系,并在此基础上,提出在未来森林风景区景观生态规划研究中,需要在理论研究、方法探讨和技术支撑方面进行全面的革新.  相似文献   

8.
生态学理念在城市森林景观规划中的应用探讨   总被引:1,自引:0,他引:1  
对城市森林作用及城市生态环境的特殊性进行分析的基础上,运用生态学原理进行城市森林景观规划,提出了城市森林景观规划建设的原则和方法,对我国正在开展的城市森林规划与建设具有理论和实践意义。  相似文献   

9.
该文综述了我国森林景观生态规划研究的3个方面的主要内容:森林景观生态规划研究方法的提出及实践、森林景观空间结构与生态学过程分析、森林景观动态模型的应用。并阐述了我国森林景观生态规划研究领域中存在的问题:森林景观规划研究力度不够、研究成果有限、景观规划软件缺乏。同时,还提出了今后我国森林景观生态规划研究的主要动态方向。  相似文献   

10.
分析城市景观的结构、功能,从生态学的角度阐述城市景观规划设计与生态学结合的必然性,总结城市景观规划的生态学原则和方法,强调城市绿地景观规划及城市道路景观规划是城市景观生态规划的两个方面。  相似文献   

11.

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.  相似文献   

12.

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.  相似文献   

13.

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.  相似文献   

14.

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.  相似文献   

15.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。  相似文献   

16.

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.  相似文献   

17.
18.

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.  相似文献   

19.
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.  相似文献   

20.
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号