生态文明社会需构建城乡统筹的生态绿地系统

2007年10月,胡锦涛总书记在中国共产党第17届代表大会的工作报告中提出:建设生态文明,基本形成节约能源资源和保护生态环境的产业结构、增长方式、消费模式,使生态环境质量明显改善。生态文明观念在全社会牢固树立。       

河西走廊城镇绿化树种引种栽培试验

十多年来,河西走廊引进各类观赏树种品种120余个,并对其生物学特性、栽培区划、繁育技术、水肥管理、越冬技术、造型和混交栽植等方面进行了研究,初步筛选出适于河西走廊城镇绿化的优良适生品种50多个。       

A family of segmented polynomial functions for modelling the border effect on the diameter growth of Ayous (Triplochiton scleroxylon K. Schum)

This paper introduces a family of four segmented (or grafted) polynomial functions for modelling the decrease in the diameter of Ayous (Triplochiton scleroxylon K. Schum) with distance from the border of the plantation. The functions, each comprising two segments of second degree or less, were fitted to data collected in the Cameroon rain forest. A comparative assessment of the fit was carried out using criteria such as mean deviation, root mean squared deviation, and fit index.

The border effect extended to 10 m inside the plantation where a 50% decrease in diameter occurred. Beyond that distance, the diameter appeared to be stable except for random variation. The estimated functions performed equally well as they all provided a good fit to the data, with a small bias. Most importantly, they proved to be flexible and thus adaptable to a wide variety of situations.

Recommendations are made concerning setting up a guard area and ways of improving the silviculture of Ayous. Also, the possibilities for an agrisilvipastoral system are explored.     

惠安——一颗璀灿的海湾绿色明珠

沿海防护林体系建设关系到保护我国70%以上大中城市1.25亿人口和全国60%以上国内生产总值及生态安全。全国海防林建设虽然取得不小成绩,但由于我们工作不扎实,又遭受严重的人为破坏,其总量不足,基干林尚未合拢,红树林面积骤减7成(由6万hm2减至目前的2万hm2),试想一旦有海啸发生后果将不堪设想!在此严峻形势下,我们在福建惠安却看到另一番景象。基干林带基本合拢、红树林面积大幅度增加,两个生态屏障(海上木麻黄+红树林)和陆上山地生态保护林带基本建成,一个海湾型县级城市森林生态系统已见雏型。惠安经验对全国沿海城市生态林建设具有典型意义。惠安的一批像林竑斌式的青年科技人员,长年坚持在有异味的海水里大造红树林;惠安有一批陈丽英式的惠安女,35年来坚持奋战在盐碱海滩上,百折不挠,终于建成一条136 hm2的沿海木麻黄林带;惠安有一批统领全局求真务实的各级领导班子。我们采访并编撰了这组文章,希望对您有所启迪。       

加快绿色发展 构建和谐社会——在“人与自然和谐发展”绿色论坛开幕式上的致辞

在"人与自然和谐发展"绿色论坛隆重召开之际,请允许我代表全国绿化委员会和国家林业局,代表论坛组委会,对论坛的成功举行表示热烈祝贺!向出席今天论坛开幕式的各级领导和国内外专家,表示热烈的欢迎!       

建设生态绿城 构筑和谐东莞

东莞市在2005年公布的中国GDP排名前100位城市生活质量排名中名列第2位(仅次于深圳,超过上海和北京),这一骄人成绩与东莞市近年来大力推进绿色生态建设分不开。现将东莞市人民政府副市长李小梅在第二届中国城市森林论坛上的讲话摘发于下,以飨读者。       

Determination of fiber length and juvenile and mature wood zones in Acer velutinum Boiss. trees grown in Iran

In our investigation we studied fiber lengths and the transition age from juvenile to mature wood in Acer velutinum Boiss. For this purpose, samples from three normal maple trees at a Noshahr site in northern Iran were selected. Disks were cut at breast height. Test samples were taken along a radial direction from the pith to the bark, accounting for every ring during a 48-year period. We used the Franklin method to distinguish between fibers of juvenile and mature wood. The results show that the fiber length increased along the radial direction from the pith to the bark. The transition age between juvenile and mature wood was determined at the 14th annual ring from the pith.     

Carbon Accumulation and Fossil Fuel Substitution During Different Rotation Scenarios

Accumulation of carbon (C) in biomass and soil, and using forest residues for bioenergy are examples of forestry’s contribution to reducing the enhanced concentration of greenhouse gases in the atmosphere. The aim of this report was to study the effect of rotation length on carbon accumulation in biomass and soil, and on the amount of forest residues that could substitute fossil fuel during 2000–2100. Two models, based on inventory data from the Swedish National Forest Inventory, were used to simulate the effects of a changed rotation length in the region of Dalarna (1.8 × 10⁶ ha), in central Sweden. During the studied period, the accumulation of carbon in biomass was 32 kg C ha^?1 yr^?1 larger for the prolonged rotation period and 105 kg C ha^?1 yr^?1 smaller for the shortened rotation period compared with the base scenario. The build-up of carbon in forest soil was 23 kg C ha^?1 yr^?1 larger for the prolonged rotation than for the base scenario, whereas the shortened rotation was 24 kg C ha^?1 yr^?1 smaller than the base scenario. The potential to substitute fossil fuel was 37 kg C ha^?1 yr^?1 larger for the shortened rotation and 17 kg C ha^?1 yr^?1 smaller for the prolonged rotation compared with the base scenario. The annual accumulation of carbon in biomass decreased in all scenarios, which resulted in a prolonged rotation scenario possibly being a poor long-term solution (> 100 yrs). The amount of forest residues that could substitute fossil fuel increased in all scenarios during the studied period.     

Comparison of aluminium tolerance in the brassicas and related species

The aluminium tolerance of 31 varieties within 11 species in six genera of the Cruciferae was determined by measuring root length under aluminium stress. Variance analysis indicated highly significant differences of aluminium tolerance among the species compared. Raphanus sativus (2n= 18, RR) had the highest aluminium tolerance, followed by Brassica carinata (2n= 34, BBCC), Brassica oleracea (2n= 18°C) and Brassica napus (2n= 38, AACC), which had the C genome. There might be more than one gene for aluminium tolerance in the R and C genomes. Those species such as Brassica campestris (2n= 20, AA), Brassica nigra (2n= 16, BB), Brassica juncea (2n= 36, AABB), Arabidopsis thaliana (2n= 10, arar), Sinapis alba (2n= 24, alal), Cheiranthus cheiri (2n= 12, chch) and Orychophragmus violaceus (2n= 24, OO) that did not include the R or C genome had lower aluminium tolerances. Transfer of aluminium tolerance from R. sativus into the cultivated brassicas seems possible by intergeneric hybridization and the production of addition, substitution or translocation lines.     

The Identification of QTL Associated with Cotton Fruit Branch Length Suitable for Mechanized Harvest Utilizing BSA-seq

[Objective] This study aims to identify quantitative trait loci (QTLs) associated with cotton fruit branch length by using the combination of bulked-segregant analysis (BSA) and next-generation sequencing (NGS) method. [Method] In this study, the cotton F₂ segregating population was developed with the short branch line Sujimian 125 and long-branch variety Sikang 1 as cross parents. According to the average internode length of fruit branches in middle, extreme individuals in F₂ population were divided into two groups to generate the bulked DNA samples. The whole-genome resequencing of two DNA bulks was applied to analyze the single nucleotide polymorphism (SNP) and insertion-deletion (InDel) between two groups, and the fruit branch internode length related QTLs were detected using Euclidean distance (ED). [Result] With SNP data obtained from sequencing, a 0.8 Mbp range associated region on chromosome A3 was identified; with InDel data obtained from sequencing, a 1.09 Mbp range associated region on chromosome A3 was identified. Two regions overlapped, and the overlapped range was 0.77 Mbp. [Conclusion] This result suggested that the difference between I-type fruit branch and zero-type was due to different genetic locus and pattern rather than dosage effect of the same gene.