浙江省生物防火树种研究现状及发展对策

总结了当前国内外生物防火树种的研究进展,分析评价了当前生物防火树种选择的主要研究方法,概括了浙江省生物防火树种包括针叶林、阔叶林和经济林树种的研究进展,指出浙江省生物防火树种研究存在树种选择范围狭窄、防火性能综合评判尚不全面和树种配置模式研究较少等问题,提出了对浙江省阔叶树种进行大范围选择研究,建立防火综合评价数学模型和针对不同范围、不同立地条件确定合适的配置模式的建议。     

石家庄市园林绿化树种的选择与配置

本文对石家庄市园林绿化树种的选择和配置进行了阐述,认为树种的选择和配置应以乡土树种、速生树种、乔木树种为主,同时注重选择环保型、彩叶型、果树型树种,并加强野生树种、引进树种的研究和开发力度,加强苗圃建设和苗木培育工作。     

石家庄市园林绿化树种应用研析

该文对石家庄市园林绿化树种的选择和配置进行了阐述,认为树种的选择和配置应以乡土树种、速生树种、乔木树种为主,同时注重选择环保型、彩叶型、果树型树种,并加强野生树种、引进树种的研究和开发力度,加强苗圃建设和苗木培育工作。     

浅谈乡土树种在园林中的应用

文章根据乡土树种应用现状,指出乡土树种没有能够在园林建设中很好的应用不仅因为其生长缓慢、投资回报低等表面现象,更主要的是乡土树种园林应用技术研究体系不健全,提出乡土树种应用研究应该针对城市园林的环境特点和要求,加强新优乡土树种的种源评价和选育种研究、繁殖技术研究、栽培营养和促生技术研究、适应性和抗逆性评价。     

大田县主要造林树种水土保持分析与研究

研究构建大田县耐干瘠水土保持造林树种选择综合评价指标体系,并运用层次分析法确定各指标权重,提出了研究区水土保持造林树种选择数量化评价模型。应用该评价模型对21个初选树种进行了综合评价,并依据最优分割法将参选树种划分成3个等级。树种的综合指数通过树种对逆环境的抗性、树种的水土保持功能及树种的社会经济效益的评定得出。结果表明;青冈、枫香、马尾松等5个种综合指数较高,为大田县水土保持一级树种;板栗、光皮桦、细柄阿丁枫等9个种为大田县水土保持二级树种;檵木、楠木等7个种综合评分较低,为大田县水土保持三级树种。     

激光雷达和高光谱遥感技术在树种识别中的应用

快速准确识别树种是研究和保护森林资源的基础,通过遥感技术进行树种识别已成为森林调查重要手段之一。激光雷达数据可以提供森林垂直结构的信息,而高光谱遥感数据可以提供树木详细的光谱信息,因此联合激光雷达和高光谱数据能够提高树种分类精度。文中阐述了激光雷达和高光谱遥感在森林树种识别中的研究现状,总结了单一遥感源进行树种识别的优缺点,介绍了联合激光雷达和高光谱遥感数据的树种识别方法,最后从数据平台、数据提取、数据融合及识别模型等4个方面探讨了当前树种识别研究中面临的问题以及未来的研究方向,旨在为提高树种识别精度提供参考。     

呼和浩特市哈拉沁沟木本植物群落景观优势树种园林应用前景预测

为扩展呼和浩特市优良乡土园林树种的选用范围及优化其配植,对当地天然植物群落景观优势树种的园林应用前景进行预测。选取大青山哈拉沁沟为研究地,以研究地野生树种为研究对象,采用典型取样、现场实测及景观重要值分析等方法,探明了该区域景观优势树种;参照该市园林树木现状调查结果,筛选出绿地利用率低的优势种;以前期研究为基础,选用AHP法对已筛选树种进行景观价值定位,并以此作为预测基础,以树种的城市环境适应性为前提,结合绿地现状及当前政策,同时考虑树种的核心景观价值,进行多角度分析预测。结果表明:研究地树种共计32种,依据预测结果,其中10种树种园林适用广泛,发展前景优良。     

试论哈尔滨市开展造林树种固碳能力研究的意义

环境保护背景下,优良固碳树种引种培育可丰富树种资源、提高绿化水平、促进碳汇交易发展,有着社会、经济、生态三大效益,固碳树种的培育与推广关系到未来低碳社会的建设与发展。文章介绍了哈尔滨市固碳树种研究的背景,分析了研究区的自然条件、树种来源、技术路线,并对树种引进结果与意义进行了评价,希望能为东北地区碳汇林的培植发展提供帮助。     

兰州地区水土保持树种抗旱生理指标测定初报

在黄土高原半干旱、干旱地区营造水土保持林,需要选择耐旱的树种。为了给这些地区的树种选择提供科学依据,我们对一些当地乡土树种及由外地沙区引进的乔灌木树种,进行了抗旱生理指标的测定,现将初步结果报导如下。研究的树种及方法一、研究树种我们重点测定耐旱的灌木,尤其对过去缺少研究的蒙古莸花、木地肤等新种更加注意.     

太行山中段造林树种选择研究

造林树种选择的适当与否是造林工程成败的关键。通过对当前太行山中段生态工程中树种选择存在的问题进行研究,提出造林树种选择应遵循适地适树、适时适树、适的适树的原则。遵循该原则,研究了太行山中段主要造林树种的生态学特性,及各宜林类型组可选择的造林树种。     

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。     

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.     

Key Habitats in the Norwegian Production Forest: A Case Study

This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes.