林木非生物胁迫抗性基因工程研究进展

干旱、极端温度和盐害等非生物胁迫因子是制约林木生长的重要因素。由于林木生长周期长, 且抗逆机制极为复杂, 长期以来, 如何改良林木对非生物胁迫的抗性一直是育种学家的难题。然而, 随着基因工程技术的发展, 人们可以在基因水平上改造林木, 提高其抗逆能力。文中主要介绍了林木抗逆基因工程的研究进展, 探讨了目前基因工程技术应用于林木抗逆育种研究存在的问题, 并对其应用前景进行了展望。     

抗旱节水制剂在沙地针叶树播种育苗中的应用

在沙地针叶树播种时使用"科瀚98"、FA旱地龙2种抗旱节水制剂,分别采用浸种和拌种进行种子不同处理试验,结果表明,4种处理在不同程度对不同苗木的生长有促进作用,同时促进了樟子松、油松苗木的干物质累积;同时,在一定程度上减轻土壤的酸化,增加土壤有机质,提高土壤的肥力和蓄水力,增加抗旱节水、增效节支作用.建议在沙区针叶树育苗中根据实际情况推广应用.     

河南新县古树名木资源评价及保护

新县境内现存古树名木资源16科26属28种,计3349株,为河南省古树资源较丰富的县;在分析评价该县古树名木资源的基础上,提出科学保护的建议。     

张家口市园林树木害虫危害规律与防治对策

为全面了解张家口市区园林树木害虫的种类、分布及其危害规律,给防治提供理论依据,作者采用踏查和标准地调查的方法对张家口市区内主要街道、公园及城郊周边绿化的园林树木害虫进行了全面调查。结果表明,张家口园林树林害虫群落共有5个目20个科38种,优势种集中于天牛、蚧虫、卷叶蛾等类群及天幕毛虫、舞毒蛾等。并对不同类群的害虫提出了综合防治对策。     

Effects of previous forest types and site conditions on species composition and abundance of naturally regenerated trees in young <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> plantations in northern Japan

Naturally regenerated trees in young Cryptomeria japonica plantations were investigated in 141 quadrats of 10 × 50 m within a watershed of 1,000 ha, and factors affecting their composition and abundance were examined. The species composition of naturally regenerated trees was classified into four types. Dominant species were Swida controversa, Magnolia hypoleuca and Pterocarya rhoifolia in Type A1, Betula maximowicziana, M. hypoleuca, Quercus crispula and Castanea crenata in Type A2, Q. serrata and C. crenata in Type B1, and Pinus densiflora in Type B2. The results of path analysis showed significant influences of previous forest type and geology among the factors that correlated with the species composition of naturally regenerated trees; previous forest type in particular showed a higher absolute path coefficient value. Species composition types of naturally regenerated trees corresponded to the previous forest types: Types (A1 and A2) corresponded to the natural forests composed of Thujopsis dolabrata var. hondai, Fagus crenata, Aesculus turbinata, etc., Type B1 corresponded to the secondary Q. crispula and Q. serrata forest, and Type B2 corresponded to the secondary P. densiflora forest, respectively. The abundance of naturally regenerated trees was strongly affected by geology; i.e., plantations on soft-sedimentary dacitic tuff contained great amounts of colonizing P. densiflora trees.     

Effect of wide spacing on tree growth, branch and sapwood properties of young Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in south-western Germany

The influence of stand density on Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] is conceptually understood, but for wide spacings not well quantified, particularly in Europe. This study used 41 trees from 7 different locations in south-western Germany to compare important tree- and branch-level attributes across three different densities, namely 100, 200, and 1,200 stems ha⁻¹. In general, there were only a few tree and branch attributes that were significantly different between the 100 and 200 ha⁻¹ densities. Crown projection area and diameter of the thickest branches were the most important differences between the 100 and 200 ha⁻¹ densities. The most obvious and significant differences in this study were between 100 and 1,200 ha⁻¹ densities, where nearly every examined tree and branch attributes were statistically significant. However, relative sapwood area, the number of branches, branch angle, and the occurrence of spike knots were insensitive to stand density. Although the two lowest stand densities in this study represent rather extremely wide spacings, these results still have important implications for the development of effective thinning regimes for Douglas-fir in south-western Germany. Important management recommendations from this study include thinned stands should be maintained to at least 200 stems ha⁻¹ to maintain high log quality and stand stability. Furthermore, even at stand densities exceeding more than 1,200 trees ha⁻¹ planted trees, artificial pruning may even be necessary to produce high quality logs.     

古镇民宅家具与现代家具造型特点视觉特性的对比

对古镇民宅家具和现代家具的造型特点进行量化,利用主观评价的方法分析家具造型特点与视觉心理量之间的关系,找出他们之间的相关系数,为建立家具造型特点的定量化描述区分体系提供科学依据,同时讨论了古镇民宅家具和现代家具造型视觉特性之间的差异。     

古代黄河三角洲海岸带建成芦苇湿地循环经济

结合古代黄河三角洲海岸带的立地环境与气候条件,介绍了潮上带重盐碱荒地发展为人工芦苇湿地的具体情况,肯定了取得的效益并提出了维持湿地良性发展的建议。     

乡土建筑历史文化特色的保护与延续——以临沣寨为例

古村落是历史长河中文化多样性的物质表现,它具有深厚的历史文化内涵,一方面体现了人与自然环境和谐的人居环境;另一方面体现了传统文化的固有价值。临沣寨,作为河南中部平原低洼地区的一个小村落,有着小巧精致、保存完好的特色,是一定时期该地区常见的村寨形式,具有很好的历史、文化价值。     

毛竹纯林留养阔叶树后土壤理化性质的研究

对闽侯县荆溪镇仁洲村毛竹纯林留养阔叶树林与毛竹纯林的土壤理化性质的分析研究结果表明：毛竹留养阔叶树后,土壤容重、毛管持水量、总孔隙度及非毛管孔隙度等物理性状都得到了改良;林地土壤有机质含量增加,土壤全氮、水解氮及有效磷等养分指标普遍比毛竹纯林土壤高。由此可知毛竹留养阔叶树能更好的培肥土壤,提高林分水源涵养力,改善土壤的理化性质。