国外木材工业现状及发展趋势

本文介绍世界木材消费结构、木材工业结构、发展趋势和木材工业布局与工厂规模及世界１２个地区标准工业人工林轮伐期、生长量和产量。     

我国家具业的发展状况与思考

介绍了我国家具业的发展，对我国家具业的市场容量、产品结构、所用材料及现有问题进行了分析和思考，并提出了解决办法。     

太行山石质山地植被结构优化评价

以太行山石质砂岩区山地植被为研究对象,在对典型植被类型综合调查的基础上,提出了评价山地植被水土保持效益的10项指标,并通过不同植被类型的水源涵养效能指标测定和径流小区泥沙对比分析,认为人工-天然复合植被类型的水土保持效果最好,乔木林最适郁闭度为0．6～0．7。阐述了突出水土保持、水源涵养功能的植被优化结构建设是太行山石质山地植被恢复的根本途径和防护林体系建设的重要内容。     

N,N′-二（对硝基苯基）-2,2-′（对苯二氧基）二乙酰胺的合成、结构及计算

以对硝基苯基氯乙酰胺和对苯二酚为原料,在丙酮溶液中反应合成了N,N′-二(对硝基苯基)-2,2-′(对苯二氧基)二乙酰胺.在室温下采用自然扩散溶剂DM F和乙醇混合溶液(1∶20,体积分数)得到了适合于X射线衍射分析的单晶体.依据晶体结构数据建立了分子结构模型,并利用量子化学半经验PM 3方法进行结构优化计算和频率分析.M u lliken电荷布居分析表明分子中醚氧原子和羰基氧原子上都带有大量负电荷,并且与分子内的氢原子之间有氢键作用.     

Severe hail damage to mangroves at Port Curtis, Australia

A hailstorm in October 1994 was found to have moderately or severely impacted on 5.3% of the mangrove forests in Port Curtis. All mangrove species showed evidence of hail damage, including the three most common species (Rhizophora stylosa, Ceriops tagal and Avicennia marina). Physical effects of hail damage included stripping of leaves from plants, holes punched through leaves, bruising to bark, divots removed from bark, branch and plant death. Speciesspecific differences in vulnerability to the effects of hail were observed with C.tagal experiencing relatively higher mortality rates than the other two common mangrove species. A delayed pattern of mortality was observed in two species _ C.tagal and A.marina. Alterations to mangrove community structure included: (1) reductions in stem density, stem diameter and basal area, (2) reductions in canopy cover (based on a photographic index of foliage projective cover) and (3) changes in relative abundance of species in mangrove zones. Recovery was observed in some stands but others had not recovered to prehail levels of canopy cover two years after the hailstorm. Recovery had occurred by regeneration of fresh leaves but no recruitment of young plants had been observed during the study. The forests in the impact area were dominated by either Ceriops tagal or Rhizophora stylosa with Avicennia marinaas a subdominant in places. C.tagal dominated forests within the impact area were relatively more severely affected (41.8% in the severe category) than R.stylosa dominated communities (only 17.4% in the severe category). This indicated that C.tagal dominated forests were more vulnerable to the effects of hail damage than R.stylosa dominated forests. In addition, hailimpacted C.tagal dominated forests represented a relatively high percentage of the area of C.tagal dominated forests in Port Curtis (44.3%). This percentage was much higher than hailimpacted R.stylosa dominated forests in Port Curtis (2.7%). These two factors – relatively severe impact on C.tagal communities and a relatively higher percentage affected within the Port Curtis area – illustrate that hailstorms, as a form of natural disturbance, are an important influence on the forest ecology of mangrove ecosystems in this region.     

祁连山北坡青海云杉中龄林结构随海拔的变化

在祁连山北坡中段的大野口流域,沿海拔梯度(2 500~3 300 m)调查了青海云杉中龄林的结构,并分海拔段(每100 m)进行统计。结果表明:1)研究区森林密度较大但树木个体较小,密度、胸径、树高和冠幅直径(平均值±SD)分别为1 550±628 株·hm^-2、13.9±6.2 cm、8.1±3.7 m和3.3±1.7 m。随海拔升高,密度降低、平均胸径和冠幅直径增加,平均树高呈"单峰"变化,峰值在海拔2 800~2 900 m。2)研究区森林的径级组成以小树(DBH: 5~12.5 cm)和中树(DBH: 12.5~22.5 cm)为主,树高(H)以6~12 m的树木为主。随海拔升高,林内幼树(DBH≤5 cm)比例基本稳定,小树比例略有下降,中树比例呈"单峰"变化,峰值在2 800~2 900 m,大树(DBH>22.5 cm)比例增加。H≤6 m的树木比例呈"V"字型变化,在海拔2 800~2 900 m最低,H为6~12 m和H>12 m的树木比例均呈"单峰"变化,峰值分别在海拔2 600~2 700 m和海拔2 800~2 900 m。3)林分高径比介于0.45~0.73,胸高断面积介于7.86~33.32 m²·hm^-2,随海拔升高两者均呈"单峰"变化,峰值在海拔2 800~2 900 m。分析表明,随海拔升高,青海云杉林的结构呈明显变化,并在中间海拔区(海拔2 800~2 900 m)达到最优。因此,分海拔区段建立森林结构与水文过程的定量关系并进行生态水文模型的参数设置十分必要。     

白马雪山自然保护区德钦分局辖区鸟类多样性及保护管理对策

白马雪山自然保护区德钦分局辖区内鸟类资源十分丰富,至2005年底共记录到鸟类328种。其中留鸟204种,占总数的62.2%;夏候鸟和繁殖鸟76种,占23.2%;旅鸟和冬候鸟48种,占14.6%。以区系成分分,东洋界106种,古北界48种,广布种68种。针对分布鸟类多样性资源受威胁及限制因子,提出相应的对策。     

五营林业局杨树河林场林种结构调整

在建立ArcViewGIS平台的杨树河林场地理信息系统的基础上,通过建立杨树河林场二维坡向图和坡度图、三维地面模型、二维河流、公路、城镇和林型分布专题图,用缓冲分析方法进行护岸林,护路林,环境保护林,水源涵养林等公益林的规划;商品林和一般用材林用蓄积等值图规划,在空间尺度上进行合理的划分林种,对杨树河林杨植物群落生长的立地条件进行研究。最后经过调整林种结构和林龄结构,以达到提高森林可持续经营能力的目的。     

The effects of Douglas-fir on tree-specific arthropod communities in mixed species stands with European beech and Norway spruce

The ecological effects of planting exotic Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in Central Europe are still poorly understood. The aim of this study was to answer the question of whether Douglas-fir affects tree specific arthropod communities in different mature forest types (Douglas-fir, spruce and beech dominated) in Southern Germany. Therefore, arthropod communities of stem and tree crown strata of Douglas-fir and spruce (Picea abies L.) were sampled in the years 1999–2001 using arboreal photo-eclectors and flight interception traps. Statistical analysis was conducted for all species and focused on conifer specialists at three levels: (1) species diversity, (2) guild structure and (3) community structure. Within the stem stratum, species diversity was significantly higher on spruce than on Douglas-fir independent of year and stand composition. This could not be explained by a single feeding guild, rather by species changing strata during the vegetation period. In contrast, species diversity in tree crowns was approximately the same for both conifer species. However, communities in Douglas-fir crowns were conspicuously different from those in spruce crowns, especially in the Douglas-fir dominated stand type. While zoophagous insects exhibited higher activity on Douglas-fir in 2000, xylophagous beetles were more abundant on spruce in 2001. In European beech stands with widely spaced Douglas-fir trees, the site specific and broad-leaved tree related fauna might be maintained. In addition, Douglas-fir with its resource of Adelges cooleyi and crowns that overtop the broad-leaved tree canopy, offer additional resources for several aphidophagous and thermophile species.