矩形区组方“RBS”设计及其在树木育种中的应用Ⅰ.单个“RBS”设计统计分析

本文介绍矩形区组方"RBS"设计的基本方法,单个"RBS"设计方差分析的数学模型,处理平均数效应,期望均方分解,遗传力及其遗传变异系数估值,并举例介绍"RBS"在树木育种中的应用。     

云南地方栽培木豆群体数量性状变异分析

对云南省8个地方栽培木豆群体进行调查,对木豆株高、地径、冠幅、单株荚数、虫荚率、单株粒质量及百粒质量等数量性状变异进行分析,结果表明7个性状不论是群体间还是群体内个体间均存在丰富变异。性状相关性分析表明,单株粒质量与单株荚数呈高度正相关,与株高、地径呈弱正相关。单株荚数、虫荚百分率、百粒质量对产量构成贡献最大,通径系数分别为0．8551、-0．2374、0．1799。若将三个性状相结合,选择单株荚数多、粒大、虫荚少的单株,则后代产量可望有明显增加,有可能育成高产高抗虫性品种。     

生物措施治理水土流失项目管理信息系统研发浅议

研制开发生物措施治理水土流失项目管理信息系统,可以利用现代技术提升项目管理工作,对项目建设和推广有着十分重要的意义。本文介绍了生物措施治理水土流失项目管理信息系统研发的目的任务、技术思路、运行环境及系统的主要功能。     

Above- and belowground biomass measurements in an unthinned stand of Sitka spruce (<Emphasis Type="Italic">Picea sitchensis</Emphasis> (Bong) Carr.)

Reporting carbon (C) stocks in tree biomass (above- and belowground) to the United Nations Framework Convention on Climate Change (UNFCCC) should be transparent and verifiable. The development of nationally specific data is considered ‘good practice’ to assist in meeting these reporting requirements. From this study, biomass functions were developed for estimating above- and belowground C stock in a 19-year-old stand of Sitka spruce (Picea sitchensis (Bong) Carr.). Our estimates were then tested against current default values used for reporting in Ireland and literature equations. Ten trees were destructively sampled to develop aboveground and tree component biomass equations. The roots were excavated and a root:shoot (R) ratio developed to estimate belowground biomass. Application of the total aboveground biomass function yielded a C stock estimate for the stand of 74 tonnes C ha⁻¹, with an uncertainty of 7%. The R ratio was determined to be 0.23, with an uncertainty of 10%. The C stock estimate of the belowground biomass component was then calculated to be 17 tonnes C ha⁻¹, with an uncertainty of 12%. The equivalent C stock estimate from the biomass expansion factor (BEF) method, applying Ireland’s currently reported default values for BEF (inclusive of belowground biomass), wood density and C concentration and methods for estimating volume, was found to be 60 tonnes C ha⁻¹, with an uncertainty of 26%. We found that volume tables, currently used for determining merchantable timber volume in Irish forestry conditions, underestimated volume since they did not extend to the yield of the forest under investigation. Mean stock values for belowground biomass compared well with that generated using published models.     

Morphological variance and natural types' division of plus trees ofLarix principis-rupprechtii Mayr.

The phenotypic characteristics of the plus trees ofLarix principis-rupprechtii such as stem form, branch angle, branch/stem ratio, branch density, the crown width, crown length, number of short branch over 5-cm branch segment in length, and the leaf number of each short branch were investigated in seed orchard in the Changcheng Mountain, Shaanxi Province. According to the morphological characters, the plus tree clones ofLarix principis-rupprechtii were classified into 4 natural types: the narrow-dense-crown type, wide-dense-crown type, wide-sparse-crown type, and the narrow-sparse-crown type. The result of the cluster analysis showed there was a very significant difference in tree growth among the four natural types. While comparing the tree growth of four natural types for the last ten years, it was found that the performance order of various types from good to bad is as follows: the narrow-dense crown type > the wide-dense crown type > the wide-sparse crown type > the narrow-sparse crown type. The plus trees of narrow-dense-crown, as a fine type, should be paid great attention to production and prepared to popularize. Biography: ZHANG Xin-bo (1956-), male, Senior engineer of Shanxi Academy of Forestry Science and Northern Research Institute of Forestry of China, Taiyuan 030012, P. R. China Responsible editor: Chai Ruihai     

Variation in juvenile traits of natural black poplar (Populus nigra L.) clones in Turkey

Natural black poplar (Populus nigra L.) clones sampled from river courses were tested in the arid southeast region of Turkey, using a randomized complete block field design with four replications. Clones were laid out in row plots of eight ramets each. Height and apical dominance were assessed at age one year; diameter, survival, bole straightness and branchiness were measured at age two years. Clones differed significantly in survival, growth and quality traits. The results showed that promising clones exist in natural populations. Two commercial clones out of four did not grow as fast as the top new selection clones. For bole straightness, three commercial clones had significantly lower grading scores than the top best 14 clones. Principal components analysis indicated that growth, apical dominance and branching are the most important traits distinguishing black poplar clones. Diameter had a moderate correlation (0.34) with bole straightness. Relationships between geographic variables (elevation, latitude and longitude) with growth and stem quality traits were weak. Considerable genetic variation was observed among clones for all the traits. Genetic differences among the clones accounted for 27% (survival, bole straightness) to 39% (height) of the total variance. Broad-sense individual heritability ranged from 0.27 (survival) to 0.37 (apical dominance). Clonal mean heritabilities were higher than individual heritabilities and ranged from 0.60 (survival) to 0.82 (diameter), implying considerable gain could be realized via selective improvement methods.     

目前我国森林环境价值评价的难点及对策

概述了目前我国森林环境价值评价的理论基础和评价方法，并对其难点进行了分析，阐述了构建我国特色的评价理论框架及评价体系的必要性，指出只有建立森林生态环境定位观测站及其动态监测体系，才能科学计量、评估森林生态环境价值.     

SPSS软件在林业试验数据方差分析中的应用

简介SPSS软件及其方差分析功能。举例阐述单向分组、两向分组、系统分组及多元数据方差分析的数据录入及分析过程,认为SPSS软件的应用可提高林业科学试验数据统计分析的质量和效率。     

森林枯落物的水文功能

从森林枯落物的蓄水量、雨水截留量、阻延径流流速、改善土壤结构、减沙减流作用5个方面,叙述了森林枯落物的水文功能,提出森林经营中,应采取措施,促进林分森林枯落物的积累。     

Estimates of genetic variance and variance of predicted genetic merits using pedigree or genomic relationship matrices in six Brown Swiss cattle populations for different traits

The amount of variance captured in genetic estimations may depend on whether a pedigree‐based or genomic relationship matrix is used. The purpose of this study was to investigate the genetic variance as well as the variance of predicted genetic merits (PGM) using pedigree‐based or genomic relationship matrices in Brown Swiss cattle. We examined a range of traits in six populations amounting to 173 population‐trait combinations. A main aim was to determine how using different relationship matrices affect variance estimation. We calculated ratios between different types of estimates and analysed the impact of trait heritability and population size. The genetic variances estimated by REML using a genomic relationship matrix were always smaller than the variances that were similarly estimated using a pedigree‐based relationship matrix. The variances from the genomic relationship matrix became closer to estimates from a pedigree relationship matrix as heritability and population size increased. In contrast, variances of predicted genetic merits obtained using a genomic relationship matrix were mostly larger than variances of genetic merit predicted using pedigree‐based relationship matrix. The ratio of the genomic to pedigree‐based PGM variances decreased as heritability and population size rose. The increased variance among predicted genetic merits is important for animal breeding because this is one of the factors influencing genetic progress.