我国森林碳汇市场培育的路径选择

在分析2010年全球森林碳汇市场特征的基础上, 结合我国森林碳汇市场的现状, 提出我国森林碳汇市场培育的路径选择:加强国际森林碳汇项目推广合作, 推动森林碳汇市场的发展; 发展一级市场交易, 稳步推动金融市场的建设; 立足国内市场, 推动森林碳汇的国内市场的形成; 将自愿减排作为目前发展的优先安排。     

浅析营建生态景观林带的效益和设计路径

生态景观林带是重要的景观资源和生态屏障,是展示区域形象的重要载体,也是城乡经济社会发展的重要标志.生态景观林带建设是发展现代林业的新领域,是广东林业生态建设的重点项目.文章重点探讨营建生态景观林带的背景、意义、效益分析和设计路径,提出建设立体、复合的生态景观林带,构建区域生态安全体系.     

Phenotypic character gradient variation of Melia azedarach

Canonical Correlation Analysis (CCA) was applied on the research data of five geographical-climatic factors and 18 phenotypic characters of 729 trees of 24 populations of Melia azedarach distributed in China. The eigenvalue of the first canonical variable is 0.997 9 (significant at 0.01 level), accounting for 78% of all eigenvalues. A study on the principal component analysis (PCA) was done, taking the first canonical variable coordinate values as the phenotypic character gradient axes (PCGA). The isogram of the PCGA was drawn out with 0.2 contours, which showed a geographical model with a northeast-southwest variation trend of the phenotypic characters of M. azedarach. Meanwhile, the path analysis results show the direct and indirect effects of phenotypic characters with phenotypic character gradient values, which prove that the propagative organs, are steadily changing. __________ Translated from Scientia Silvae Sinicae, 2006, 42(5): 29–34 [译自: 林业科学]     

Variability and divergence in <Emphasis Type="Italic">Pongamia pinnata</Emphasis> for further use in tree improvement

A total of 24 candidate plus trees (CPTs) of Pongamia pinnata (L.) Pierre. were selected to elucidate their variation and diversity based on thirteen quantitative traits (4 pod traits, 6 seed traits of parent trees and 3 progeny traits) at Forest Research Centre, Institute of Forest Productivity — Mandar, Ranchi district during 2005–2007. The results show that, CPT-19 had maximum for seven traits viz, pod length (65.6 mm), 100-pod weight (542.4 g), seed 2D (two dimension) area (351.2 mm²), seed length (27.9 mm), seed breadth (17.4 mm), 100-seed weight (217.9 g) and plant height (164.3 cm). The traits, 100-pod weight and 100-seed weight had a high heritability (98.4%, 96.9%) accompanied with high genetic advance (46.0%, 34.9%). There is a positive significant correlation between 100-pod weight and 100-seed weight traits at both genotypic and phenotypic levels with plant height, collar diameter and volume index at 30 MAS (months after sowing). Volume index expressed a moderate heritability (47.4%) accompanied with high genetic advance (48.4%), indicating that the character is governed by additive gene effects. In divergence study, 24 accessions were grouped into 6 clusters on the basis of non-hierarchical euclidian cluster analysis. The genotypes in cluster IV (CPT-5, CPT-6, CPT-7, CPT-12, CPT-16, CPT-18, CPT-22) and cluster III (CPT-4, CPT-8, CPT-9, CPT-20, CPT-21) were most heterogeneous and can be best used within group hybridization. The wide diversity exists between the cluster V and II, followed by cluster II and I and crosses between CPTs of these clusters may result in substantial segregates. It is revealed that the existence of substantial variation and diversity can be utilized for genetic resource conservation and further tree improvement programmers of the species.     

太行山片麻岩山地坡面土壤含水率及其影响因子——以河北省阜平县为例

为了解决太行山干旱片麻岩山区极度缺水问题,以河北省太行山片麻岩山区的典型地区阜平县为试验基地,研究了坡向(X1)、坡位(X2)、坡度(X3)、土层厚度(X4)、土壤容重(X5)、土粒密度(X6)、植被覆盖度(X7)、田间持水量(X8)、毛管孔隙度(X9)、土壤质地(X10)等因素与土壤含水率(y)的关系。结果表明:该地土壤含水率极低,仅为3.18%~8.61%;上述因素与土壤含水率的相关系数分别为0.745,0.612,-0.078,0.992,-0.924,-0.693,0.974,0.834,0.798,0.918;除与坡度相关不显著外,其他因素均显著或极显著相关;主成分分析筛选出坡向、坡位、土层厚度、土壤容重、植被覆盖度等5个因子对土壤含水率影响最大;直接通径系数绝对值大小排序为土层厚度(0.609)>植被覆盖度(0.224)>土壤容重(-0.185),结合间接通径系数和相关系数来看,土层厚度、植被覆盖度、土壤容重均对土壤含水率有较大影响,其中土层厚度和植被覆盖度为正效应,土壤容重为负效应。     

细菌生物学特性对其生物膜形成的影响

Biofilm-associated microorganisms play crucial roles in terrestrial and aquatic nutrient cycling and in the biodegradation of environmental pollutants.Biofilm formation was determined for a total of 18 bacterial isolates obtained from the biofilms of wastewater treatment systems and of little carpolite in soil.Among these isolates,seven showed strong biofilm-forming capacity.The phylogenetic affiliation of the isolates showing high biofilm formation capacity was determined through 16S rDNA sequencing and the isolates were grouped into 7 bacterial species including Pseudomonas sp.,Pseudomonas putida,Aeromonas caviae,Bacillus cereus,Pseudomonas plecoglossicida,Aeromonas hydrophila,and Comamonas testosteroni.The biofilm-forming capacity was closely related with flagella,exopolysaccharide,and extracel-lular protein.According to the coefficient of determination,the relative importance of the five biological characteristics to biofilm formation was,in order from greatest to least,exopolysaccharide > flagella > N-acyl-homoserine lactones (AHLs) signaling molecules > extracellular protein > swarming motility.     

大麦多数量性状相关分析

穗长、穗粒重两性对小区产量直接影响较大;每穗实粒数和每穗不实粒两性状数对小区产量直接影响很小,但通过其他性状对小区产量的间接负影响很大;每穗总粒数对小区产量直接负影响很大,株高通过其他性状对小区产量间接正影响很大。     

THE MIXED MODE FRACTURE CRITERION OF BRITTLE ROCK UNDER COMPRESSION-SHEAR STRESS STATE

In this paper the test results of mixed mode fracture of three kinds of brittle rock under two kinds of stress paths are reported. The fracture mechanism and failure patterns of brittle lock under different stress paths are discussed. Theory analysis and test results show that the Compression- Shear fracture criterion of brittle rock can be expressed:     

小麦田中天线高度对2.4GHz无线信道传播特性的影响

探索农田环境下无线信道传播特性,将为无线传感器网络部署与功率控制方面的研究打下基础。该研究在小麦田地中实地测试了不同生育期 2.4GHz 无线信号的功率衰减情况和丢包率,进而得出传输范围及路径损耗,并用MATLAB对路径损耗进行了回归分析。研究表明,小麦田中,信号衰减的速度随天线高度的变化单调递减,而传输距离随天线高度的变化单调递增,因此,天线的较优位置应略高于成熟植株（1.2 m左右）。同一天线高度下,小麦生长后期无线信号的衰减大于前期。2.4GHz 无线信号的衰减情况可用对数距离路径损耗模型来预测,理论值与测量值的相关系数在0.961～0.996之间。路径损耗指数与天线高度呈现对数衰减趋势;在同一天线高度下,路径损耗指数随着小麦的生长而增大。     

箭筈豌豆、玉米产量对间作和施氮水平的响应

研究不同施氮水平下箭筈豌豆、玉米产量对单作和间作的响应,对于优化栽培措施、提高作物产量具有重要意义.本试验于2017年在甘肃河西绿洲灌溉区进行,重点研究是不同施氮水平下箭筈豌豆、玉米在单作及间作模式中干物质累积、产量构成、产量表现.结果 表明,间作箭菩豌豆干物质累积量与单作相比在不施氮(N0)、减量施氮(N1)和常规施...