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1.
Shoot elongation patterns in 2 and 3-year-old Pinus radiata seedlings were monitored twice a month during 2003 and once a month during 2004 in three progeny tests in northern Spain. Fifty-eight half-sib families were studied. Several annual growth parameters were measured in each seedling: initiation, termination and duration of height growth and number of new buds formed each year. Total height, internode length and frost resistance were also measured in each seedling. The variation in these traits among families and sites was studied, as well as the effects of environmental parameters (temperature and rainfall) on growth phenology patterns. The extent to which bud phenology is genetically controlled and related to growth traits was examined. Families differed significantly in total summer shoot growth and number of summer flushes (lammas growth). The number of cycles produced per year ranged from one to four. Monocyclic families grew throughout the year, whereas polycyclic families grew episodically, depending on rainfall.  相似文献   

2.
A Pinus radiata progeny trial was established in 2003 on three low fertility sites in Galicia to study the relevance of genotype×fertilization interaction. At each site, twenty seven open pollinated families derived from plus trees selected in mature plantations in Galicia (NW Spain) were planted under 9 fertilization treatments following a split-plot design. One year after planting, P and Mg fertilization significantly increased height growth whereas N did not affect or even significantly reduced height growth. Fertilization×site interaction was not significant indicating parallel responses to fertilization in the three sites. Fertilization × genotype interaction was significant in only one site, suggesting some genetic variation in the nutrient use efficiency among the studied genotypes. However, the lack of a significant interaction in the other two sites, and the lack of consistence among the genotypic stability in relation to fertilization across sites, hinder the possibility of breeding in relation to the nutrient efficiency of the genotypes. Indications for further research are given.  相似文献   

3.
4.
We evaluated seed production in a first-generation orchard of Chinese pine(Pinus tabuliformis) during the crucial transition period from first generation to advanced generations.Clones varied significantly in all traits related to seed production.Repeatability of these traits ranged from 0 to 0.96.Seed production per ramet(SPPR),seed producing index(SPI),the number of relative female strobili(RFS),the number of scales,and the number of ineffective scales had comparatively high repeatability at 0.86,0.87,0.89,0.96,and 0.91,respectively.Correlation analysis showed that SPPR was greatly influenced by RFS and by the number of full seeds per cone.Finally,we showed that SPI was the best predictor of the seed-producing ability of clones.Our findings will assist seed orchard managers in effectively predicting and improving seed production of Chinese pine seed orchards.  相似文献   

5.
马尾松无性系种子园的去劣疏伐研究   总被引:3,自引:0,他引:3  
根据无性系平均单株结实量及其种子园自由授粉子代3a生平均树高,对马尾松无性系种子园106个无性系进行了分类,在此基础上进行了去劣疏伐。疏伐后种子园平均郁闭度由068降低到041,无性系平均单株产种量增加2513%,无性系自由授粉子代3a生平均树高增加208%。  相似文献   

6.
马尾松种子园营建技术   总被引:3,自引:0,他引:3  
介绍了贵州省林科院马尾松种子园始建期和续建期的营建技术和管理手段 ,并提出今后的经营方向  相似文献   

7.
  • ? The effects of clearcutting and of different slash management procedures on N mineralization were assessed in a Eucalyptus globulus Labill. stand in Galicia (N W Spain). Treatments were no clearcutting (control), clearcutting combined with scattering, scattering + fertilization, windrowing, and two types of slash burning with two levels of severity: broadcast burning and windrow burning. Changes in mineral N were monitored in the soil during the 18 months following the treatments. Eleven years later, the treatment effects were again evaluated during a twelve month period to assess long-term effects.
  • ? During the first study period, slash burning led to a marked increase in the contents of N-NH 4 + , N-NO 3 ? and N-mineralization in topsoil layers (0–10 cm). In contrast, clearcutting followed by either scattering or windrowing of residues had no effect on mineral N in the top soil or in situ mineralization, relative to the control. Ammonium was the predominant form of mineral N. No residual effects of the treatments were detected eleven years later.
  • ? Fire severity, in relation to slash burn type, had significant negative effects on post-burn N mineralization and nitrification in the first period studied, but no long-term residual effects were observed. Some practical consequences for sustainable management of such stands are suggested.
  •   相似文献   

    8.
    马尾松第二代无性系种子园营建技术试验研究   总被引:2,自引:1,他引:2  
    介绍了福建省顺昌埔上国有林场和邵武故县国有林场马尾松第二代无性系种子园建立技术和管理技术措施。通过4 a的实施,埔上国有林场和故县国有林场分别建成了面积为7 hm2和8 hm2的马尾松第二代无性系种子园。埔上国有林场建园的103个无性系嫁接后2.5 a平均抽高达184.8 cm,平均嫁接保存率达73.03%,长势良好;故县国有林场建园的97个无性系嫁接后1 a平均抽高达60.9 cm,平均嫁接保存率达94.0%,长势良好。文中还对今后的经营管理提出了方向。  相似文献   

    9.
    华山松种子园无性系开花习性研究   总被引:2,自引:0,他引:2  
    云南楚雄华山松种子园的无性系,其雌球花着生在树冠外围枝条,而雄球花主要着生在树冠的内膛枝条。在水平方向上,雌球花多着生在树冠南部,雄球花的分布比较均衡;在垂直方向上,雄球花基本分布在树冠的中下部,雌球花则分布在树冠的中上部。大多数无性系的雄球花散粉期比雌花可授期早2~4 d;不同无性系间的雌雄花期具有一定的同步性。各无性系间雌、雄球花数量存在极显著差异,且有明显的偏雌或偏雄特性。雄球花量与无性系生长性状间存在显著正相关,雌球花量与树体生长相关性不显著。  相似文献   

    10.
    Individual and family heritabilities, as well as phenotypic and genetic correlations were estimated 2 and 3 years after plantation, in progeny tests carried out in plantations of open-pollinated Pinus radiata D.Don progeny located at three different sites in Galicia (NW Spain). The following factors were considered: survival, growth (free growth, height, diameter, volume, height/diameter ratio), form (number of branches, number of whorls, number of branches per whorl, number of branches per tree height meter, number of ramicorn branches, diameter of the thickest branch, internode length, branch angle, stem straightness, stem sinuosity, number of forks) and resistance (frost and insect resistance). Each plantation contained 50 female parents that had been selected as plus trees in genetically unimproved plantations in Galicia, as well as 6 female parents selected from the radiata pine breeding programme in the Basque Country (northern Spain) and two commercial lots of seed from Galicia, as controls. Individual heritabilities varied from low to high levels for each trait studied. Family heritabilities followed similar trends for individual heritabilities, but were of much greater magnitude. The results suggested that all traits except the number of branches per whorl and insect resistance could be expected to respond to selection based on individual performance. The less heritable traits could be improved by progeny testing. Height and diameter were strongly and positively correlated, and both traits were also correlated with the number of branches, the number of whorls and the branch diameter. The results are compared with previously published data and discussed in relation to the implications for breeding activities.  相似文献   

    11.
    水曲柳无性系种子园营建技术的研究   总被引:2,自引:0,他引:2  
    在广泛收集资料的基础上,对营建水曲柳无性系种子园的建设原则、经营方针、目标、建设程序及标准、园址选择、优树搜集和选择、田间配置、嫁接、管理等技术方面进行了探索。  相似文献   

    12.
    研究了南洋楹无性系种子园53个无性系的生长、结实和种子特征。发现不同无性系生长、结实性状的变异程度比较大,除冠幅浓密度性状以外,均存在极显著差异(P <0.001);不同性状的重复力在0.30~0.97之间;无性系生长和种实性状间无显著相关性。采用层次分析法(AHP)研究发现,生长、结实和种子特征等3类性状的子准则层间分别存在显著或极显著正相关关系;每层次判断矩阵具有满意一致性(CR <0.1),冠高比和结实量的总权重值最高。采用综合数量评价值(N)和系统聚类法将53个无性系分为3组,筛选出第Ⅰ、Ⅱ组共计15个无性系,结实量比平均值提高2.3倍,冠高比达到1.33,生长种实性状均得到综合提升,可为种子园的改良或重建提供依据。  相似文献   

    13.
    Agroforestry Systems - In Europe, sewage sludge has to be stabilised before its use as fertiliser in agricultural land. Stabilisation processes can cause differences in the concentration of heavy...  相似文献   

    14.
    Fire is a major disturbance in forests and one of the most important carbon emissions sources, which contributes to climate change. Carbon emissions are directly correlated with the degree of organic matter consumption or fire severity. Gaining knowledge about the relative strength of the various explanatory variables is essential to mitigate its environmental impact. We tested an approach that combines wind modeling, light detection and ranging (LiDAR), remotely sensed vegetation indices and topography data for assessing the occurrence of high-severity fire using the random forests ensemble learning method. Data from four wildfires that occurred in Galicia (northwestern Spain) were used to exemplify the application of this approach. The models predicted high-severity occurrence with a classification accuracy ranging from 77 to 94%. High-severity fire occurred more frequently in areas of high simulated wind speed, and more pronouncedly, for cases reported as wind-driven fires. High severity also occurred more frequently in areas of high terrain roughness, on sunny slopes and in low canopy base height stands. This approach allowed predicting spatially explicit fire severity at a mean scale level (resolution of 25 m) with accuracy rates from 80 to 95%. This approach may be helpful for fire managers when delimiting and planning fuel treatments for severity mitigation or during fire suppression, and for post hoc case studies.  相似文献   

    15.
    Abstract

    Tree vitality and height of lodgepole pine (Pinus contorta var. latifolia) originating from the six Swedish seed orchards and native Scots pine (Pinus sylvestris L.) were estimated in three 8-yr-old test plantations established in the Komi Republic (north-west Russia). A randomized row-plot design with 9–13 replicates of each entry was used. In general, the Scots pine tree vitality was better than that of lodgepole pine but these differences were significant only for seed sources of southern origins Larslund, Rumhult, and Österby. On the contrary, the lodgepole pine height growth was faster (6–21%) except for seed sources of southern origins Rumhult and Österby. In comparison with the native Scots pine, lower mean heights (4–10%) were recorded for these seed sources. Among the lodgepole pine seed sources the northern origins had better vitality, while the effect of latitude on the tree height was insignificant.  相似文献   

    16.
    马尾松种子园产量及遗传多样性研究概述   总被引:7,自引:1,他引:7  
    重点阐述和分析了影响马尾松种子园种子产量的环境因子、建园材料及其配置问题,以及种子园遗传多样性的研究进展及存在的问题,提出了促进种子园产量和保证遗传多样性的建议,旨在为我国马尾松遗传育种的进一步深入研究提供参考。  相似文献   

    17.
    我国松树种子园结实规律的研究进展   总被引:1,自引:0,他引:1  
    对松树种子园球果与种子产量变异、空间分布规律、性状变异、产量预测、败育分析、结实量与生长性状的关系等方面的研究状况作了较为系统的综述;并对今后的发展提出了展望。  相似文献   

    18.
    We analyze the type of communal forest owners' management practices through a survey in Northern Spain. In particular, we test whether the Principles of Collective Action (PCA) postulated by Ostrom (1990) are being followed in a sample of communal forests. Second, we study whether such principles derive in better forest management practices and conservation outcomes. Our results show that PCA are not perfectly fulfilled in our sample, showing a clear room for improvement. However, we have also found that in areas where their application is more predominant, forest owners have better management practices. Specifically, we have found a negative relationship between the fulfillment of PCA and the number of forest fires in our sample, while considering other socio-economic and control variables.  相似文献   

    19.
    施肥对红松无性系种子园母树结实效应研究   总被引:3,自引:0,他引:3  
    通过在红松无性系幼龄种子园进行的氮肥、磷肥和钾肥3种肥料,每种肥料设置4个水平的施肥试验,研究分析了氮肥、磷肥和钾肥3种肥料,以及每种肥料的不同施用数量,对促进红松无性系种子园幼龄母树结实的效果,提出促进红松无性系幼龄植株结实的适宜施肥数量。  相似文献   

    20.
    修剪促进红松无性系种子园母树开花效应研究   总被引:2,自引:0,他引:2  
    为增加红松无性系种子园母树雌雄花开花数量,对母树进行了树冠修剪和切根修剪试验。结果表明,适宜强度的树冠修剪和切根修剪,对增加红松母树雌雄花开花数量有显著作用。  相似文献   

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