广东林木种苗工程项目资金使用管理的问题与对策

概述了广东省林木种苗工程项目资金使用与管理现状,分析了其存在的主要问题,并提出解决问题的相关建议。     

雅安市主要造林树种苗木质量的分级研究

对2006年雅安各县苗圃主要造林树种苗木进行调查,以地径(D)和苗高(H)作为质量指标,采用逐步聚类分析对苗木质量进行分级,结合生产实际探讨了雅安市主要造林树种苗木标准。其中有些树种的苗木分级标准为首次研究。标准中各指标均大于现行国家标准,能较好地反映实际生产水平,为育苗生产和制定地方标准提供了参考。     

速生耐寒邓恩桉在桉树分布北缘区的适生性

桉树E uca lyp tus为世界热带、亚热带地区的极有价值的造林树种.对邓恩桉在湘中地区引种后的生长情况进行调查.结果表明:在桉树引种北缘区,邓恩桉年平均高生长为2.3~3.0 m,胸径生长2.2~3.0 cm,表现出一定的抗瘠薄能力、抗寒耐寒性和速生性.扼要地总结了邓恩桉种苗繁殖技术的进展,并就存在的问题提出了解决方法.     

长春市广场树木生长状况与园林植物多样性相关关系的研究

对长春市广场树木生长状况和园林植物多样性之间的关系研究表明:广场树木生长状况的数量化值与用Shannon-Wiener指数表示的园林植物多样性之间有良好的相关关系,相关方程为:G=1.972 2 2.667 86Ht-0.644 7Ht2,相关系数R=0.908 57,估计可靠性P=99.9%。     

四川桤木优株扦插繁育技术初报

引种栽培四川桤木4年后进行优株选择,在此基础上取优株1年生健壮穗条,采用不同浓度的GGR生根剂处理,在相同立地条件和培管措施下,分2、3、5、9月四个季节进行扦插育苗对比试验,结果表明:扦插季节对育苗成苗率有较大影响,运用200×10-6浓度的GGR处理穗条30 m in,成活率为91.33%,成苗效果最佳。     

26种乡土树种苗木生长规律及育苗技术的系统研究

通过对省沽油科圆齿野鸦椿、壳斗科8种、木兰科2种、冬青科2种、山茶科4种、蔷微科2种、桃金娘科的赤楠、八角科的莽草、槭树科的五裂槭、交让木科1种、金缕梅科3种等26种亚热带乡土树种的种子预处理、种子主要播种品质参数测定、对苗木的苗高、地径、主根长、大于5cmI级侧根数、根幅、冠幅、鲜叶重、鲜干枝重、鲜根重的测定,以及对苗木物候、苗木生长节律进行研究,从而得出上述树种的较为系统的育苗技术。     

Effects Of Thinning In a Water-Limited Holm Oak Forest

ABSTRACT

A natural holm oak forest was selectively thinned to test thinning as a tool to reduce tree mortality, increase productivity, and reverse the recent regression of the dominant species (Quercus ilex) induced by climate change. Thinning increased aboveground productivity and reduced stem mortality in this Mediterranean forest during four years just after thinning, contributing to the maintenance of forest functioning under changing climatic conditions. Q. ilex was the only species positively affected by the thinning: stem growth increased for all stem sizes, and mortality was significantly lower in thinned plots. On the contrary, mortality rates of Phillyrea latifolia and Arbutus unedo were not significantly lower. Stem growth increased for P. latifolia only in the smallest stem-size class. Our results highlight the suitability of selective thinning for improving the forest productivity and ensuring the conservation of Mediterranean coppices. Other benefits of selective thinning, such as a decrease in the risk of fire dispersion and an increase in the water supply for human populations, are also discussed.     

两种混交度的比较分析

混交度是描述混交林中树种混交程度的重要空间结构指数。由于传统混交度仅以对象木与最近邻木之间的树种异同为基础,并不考虑最近邻木之间的树种差异,不能完全反映树种的空间隔离程度。本文在传统混交度的基础上,提出一种新的混交度即树种多样性混交度。通过比较,树种多样性混交度更能反映树种相互隔离程度,是一个较好的林分空间结构指数。     

Genetic diversity of sea buckthorn (Hippophae rhamnoides) populations in northeastern and northwestern China as revealed by ISSR markers

As a N₂-fixing tree species, sea buckthorn (Hippophae rhamnoides) is well adapted to arid regions and is utilized for multiple purposes in China. Current knowledge of genetic variability of H. rhamnoides is limited in terms of rangewide distributions. Eleven natural populations of sea buckthorn in northeastern and northwestern China were analyzed to detect genetic variation among and within populations, by use of ISSR (inter-simple sequence repeats) markers. Using eight primers, 207 polymorphic loci were observed, ranging in size from 250 to 2500 bp. The coefficient of gene differentiation (Gst = 0.0679) showed that the total molecular variance of 11 populations was mainly existed within populations. The genetic variation within and among the 11 populations was 93.21 and 6.79%, respectively. No significant correlation between genetic and geographic distances of the populations was found using ISSR markers. Our study provides a population-level genetic profile for further investigation and conservation of genetic diversity of sea buckthorn.     

The process of decline of an endangered tree species,Pinus armandii Franch. var.amamiana (Koidz.) Hatusima, on the southern slope of Mt. Hasa-dake in Yaku-shima Island

The process of decline of an endangered tree species,Pinus armandii var.amamiana, was monitored on the southern slope of Mt. Hasa-dake in Yaku-shima Island from 1994 to 1998. There are 163 trees ofP. armandii var.amamiana over 1.3 m in height. They are distributed on steep ridges and rocks with a thin soil layer mostly consisting of friable granite. During the monitoring period, 21 trees ofP. armandii var.amamiana died and the mortality rate was 12.9%. Dead trees were categorized into three types: standing, uprooted and landslide. The uprooted- and landslide-typed dead trees were found only after a severe typhoon struck Yaku-shima Island. This suggests that the combination of fragile site conditions and severe typhoons play an important role in the process of decline ofP. armandii var.amamiana. The standing-typed dead trees were presumed to have been killed by pine wilt disease, accounting for 71.4% of the dead trees. However,Bursaphelenchus xylophilus, the cause of pine wilt disease, was not detected from any of the wood chips or branch samples from the standing-typed dead trees ofP. armandii var.amamiana. This might indicate that some factor(s) other than pine wilt disease could be responsible for the standing-typed death ofP. armandii var.amamiana in natural habitats. A part of this paper was presented at the 109th Meeting of the Japanese Forestry Society.