湖北省国有林场改革发展现状与对策——以十堰、襄阳、随州、孝感四市为例

指出了国有林场是湖北省林业的重要组成部分,但近年来国有林场经济发展面临着各种困难和挑战,介绍了湖北省十堰市、襄阳市、随州市、孝感市4市的国有林场发展现状,分析了国有林场生存和发展中存在的主要问题,并提出了相应的对策和建议。     

景洪市国有林场经济发展现状与前景

国有林场是生态文明建设中的重要组成部分,而国有林场经济发展关系到国有林场的建设。为了更好的推动国有林场的发展,结合景洪市国有林场实际情况,根据现阶段景洪市国有林场发展的困难,实践分析了景洪市国有林场改革后的林区经济发展因素,提出实现景洪市国有林场经济发展和乡村振兴的策略和建议。     

湖北国有林场改革中发展模式适宜度 指标体系建立与分析

国有林场是国家培育和保护森林资源的林业生产性事业单位,在国家生态文明建设和绿水青山就是金山银山的发展战略的背景下,国有林场又被赋予了更重要的生态使命。湖北省森林资源丰富,国有林场在湖北省林业生态建设和森林经营管理中承担关键角色。在这一背景下,了解湖北省国有林场的现状与改革成效有助于揭示生态文明建设背景下国有林场改革与体制创新的机制,也是当前湖北省林业生态建设中面临的重要挑战之一。为此,选择了通山县大幕山林场、南漳县七里山林场、咸宁市潜山林场、枣阳市大阜山林场和咸安区小岭林场等5个国有林场作为研究样本,采用层次分析法和等权重方法分析国有林场改革中通过建立适宜度指标体系,来确定林场的改革发展模式。     

国有林场改革问题及对策探讨

指出了近年来我国国有林场改革在取得了一系列成绩的同时,在改革探索过程中还存在一系列的问题,影响了国有林场的改革进程。探讨了国有林场改革的方向,结合目前国有林场改革实际分析了国有林场改革存在的问题,提出了我国国有林场改革的路径,旨在加快发展我国国有林场改革步伐,促进国有林场健康可持续发展。     

制约湖北国有林场发展的主要因素及发展思路浅探

制约湖北国有林场发展的主要因素及发展思路浅探彭行荣目前，湖北省现有的１７０余个国有林场，在其发展中面临着一些带有普遍性质的急待解决的问题、困难。笔者就此作了一些粗浅的分析探讨：１．制约国有林场发展的主要因素从总体上看，制约、影响我省国有林场发展的因素...     

关于泗洪县国有林场发展规划的研究

文章在总结泗洪县国有林场面临的困难和问题的基础上,提出了未来五年的总体目标、规划布局,研究了林业生态工程、林业产业工程、基础设施建设等3个方面的规划,结合当前全国范围内开展的国有林场改革,提出了加快泗洪县国有林场发展的组织、科技、政策、机制等4个方面的保障措施。     

安徽省国有林场的困惑与发展对策

当前安徽省国有林场的发展面临诸多困难,造成这些困难的因素既有主观方面的不思进取和思而不进,又有客观方面的各种制约和限制。解决国有林场发展问题关键在于改革。惟有加快改革,才能实现新世纪之初国有林场的跨越式发展。     

秭归九岭头林场发展现状与对策研究

国有林场改革是当前林业改革进程中的一项重要内容.通过对秭归县国有九岭头林场发展现状的调查,分析了当前影响林场发展的制约因素和有利条件,并结合其它地区国有林场发展的成功经验,提出了相应的发展对策,为进一步推进国有林场发展提供参考.     

湘西州国有林场改革与发展探讨

探讨了湘西州7个国有林场改革目前存在的问题,分析了国有林场的改革成效,结合湘西州实际,从更加注重生态功能的改善和生态效益的提高、更加注重公益性方向发展、更加注重森林资源培育、更加注重森林生态旅游和发展林下经济4个方面提出了湘西州国有林场未来的发展方向,为湘西州国有林场改革提供参考依据。     

试论国有林场的改革与发展

介绍了国有林场发展改革的历程,从基础设施、债务、人员等方面分析了国有林场发展改革存在的问题,探讨了加快国有林场发展的主要措施.     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

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.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

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.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

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.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

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.     

CAD与建筑设计的关系

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。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

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.     

Risk Perception Among Non-industrial Private Forest Owners

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.     

Interactions in decomposition and N mineralization between tropical legume residue components

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.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

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.