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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 相似文献
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不同坡位华北落叶松人工林生长规律研究 总被引:1,自引:0,他引:1
以河北省木兰围场国有林场管理局下属的孟滦林场的华北落叶松(Larix principis—rupprechtii Mayr.)为研究对象,采用空间代替时间的方法,借助Excel和ForStat统计分析软件,分析不同坡位华北落叶松树高、胸径以及材积变化规律,以掌握树木个体生长的基本规律。研究结果表明:华北落叶松各生长因子在生长过程中都会出现二次生长,树高和胸径的连年生长量在10年达最大值,而材积连年生长量在20年达最大值,在25年各因子同时出现二次生长。华北落叶松平均树高生长量最大为0.7m,平均胸径生长量最大为0.78cm,平均材积生长量为0.00629m^3。 相似文献
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日本落叶松种子园大龄母树去顶修枝试验初报 总被引:2,自引:1,他引:2
以长岭岗林场日本落叶松种子园大龄母树为研究对象,开展去顶及修枝试验,结果表明:去顶修枝对促进日本落叶松母树新生枝条萌发的效果显著,不同修剪强度之间萌条数量和质量差异显著,修剪强度越大新生萌条数量和质量越好;修剪后第4、5年雌雄球花数量均很少,与对照相当或少于对照,去顶修枝对促进花芽分化作用不明显。 相似文献
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开林窗与封禁对华北落叶松林下植被多样性的影响 总被引:1,自引:0,他引:1
以木兰林管局典型的华北落叶松林为研究对象,对其采取开林窗、封禁等改造措施,采用样方法进行野外调查,通过丰富度、生态优势度、多样性、均匀度指数,分析不同经营措施下的生物多样性及样地的物种组成。结果表明:开林窗面积中等及较小的样地各生物多样性指数均呈上升趋势,且高于对照,而开林窗面积较大样地的Pielou均匀度指数成降低趋势;封育区的Simpson和Shannon-Wiener多样性指数与均匀度指数均大于对照区,而封育区的Margalef丰富度指数虽然呈上升趋势,但仍小于对照区;该实验区林下植被的优势物种为乌苏里苔草。 相似文献
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By taking three forecasting methods (sample trees, sample branches and climate factors prediction) the forecasting equation
of seed were established through correlation analysis and regression analysis on seed crop of Qingshan and QinheLarix olgensis seed orchard. The research results showed that it gave more accurate prediction with less working load by taking pistillate
numbers of four sample branches at middle layer of crown to predicate seed crop. And the short-term prediction equation of
this method was established. The correlation analysis between seed crop and climate factors showed that the relative humidity
May and June, annual evaporative amount, and accumulated temperature above 10°C, possess the highest effect on bud differentiation
and seed crop, then the middle-term predication equation of climate factors was established. 相似文献
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福建柏初级种子园营建及管理技术研究 总被引:3,自引:1,他引:3
总结了福建省尤溪国有林场福建柏初级种子园的营建和管理技术措施,并对福建柏初级种子园营建效果进行了分析,结果表明种子园产种量平均为10.93 kg.a-1.hm-2,效果比较明显,最后根据福建柏树种的特性,提出了福建柏初级种子园营建和管理的要点。 相似文献
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Pollen dispersal was estimated in two test plots in a hinoki (Chamaecyparis obtusa) seed orchard using a chloroplast DNA marker, the spacer region between thetrnD andtrnY genes, and SSCP (single strand conformation polymorphism). In Plot 1, 2,020 seeds from 40 trees within 30 m of the marker
tree were analyzed using the PCR-SSCP method. In Plot 2, 1,850 seeds from 37 trees were analyzed in the same manner. The results
revealed that the maximum pollen dispersal distance in the two plots exceeded 25 m. Pollen dispersal appeared to be inversely
proportional to the distance from the marker tree. The effective pollen dispersal was suggested to be less than about 20 m
in a mature hinoki seed orchard. Adjacent trees had an excessive influence when the pollen density was increased by artificial
flower stimulation. Therefore, it was suggested that seed production better resembles ideal random mating when carried out
as naturally as possible. In conclusion, the SSCP chloroplast DNA marker was a useful tool for amassing basic information
on pollen management in seed orchards of coniferous species. 相似文献
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从华北落叶松生长量调查结果来看,华北落叶松在该地区是一个很好的适生树种,作为速生用材林具有很好的发展前途。无论是其年均生长量,还是连年生长量,都显示出不逊于原生地,甚至表现更优良的特点。但由于林分密度大,光照不足,通风透光性差,影响树冠的扩展,结实差。今后应在营林管理方面加大工作力度。 相似文献