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1.
在野外利用Piloacn对日本落叶松活立木南北向木材进行了探测,在室内测定了木芯的基本密度及早晚材的管胞长度和管胞宽度,用Pilodyn探测数据和实际密度建立了回归方程,并用该方程和其他的Pilodyn探测值预测了对应活立木的木材密度.结果表明:日本落叶松Pilodyn南向探测值Ps为15.50 mm,比北向平均值Pn高5.5%.Pn、Ps和Pa与外侧木材的平均基本密度(Dao)呈极显著负相关,相关系数比Pn,Ps和Pa与整株木材的平均基本密度(Da)的大.Pn、Ps和Pa与胸径呈极显著负相关,胸径与北向探测值(Pn)的相关系数较胸径与南向探测值(Ps)的高.木材基本密度对Pilodyn探测值的贡献率最大(40.4%).Pa与Da和Dao均存在极显著的负相关关系,显著性概率P=0.000 1.日本落叶松Pilodyn探测值(Pa)与晚材管胞长、宽存在极显著负相关关系.采用Pilodyn探测值(Pa)能够很好的预测日本落叶松活立木外侧木材基本密度(Dao)和晚材的纤维长度和纤维宽度,也能够预测整株木材的基本密度(Da). 相似文献
2.
Pilodyn和日本落叶松材性指标的关系 总被引：1，自引：0，他引：1
研究79株日本落叶松Pildoyn测定值、木材基本密度与木材纤维特性间的关系.结果表明:Pilodyn测定值、木材密度、生长量南北方向上存在显著差异.Pilodyn测定值和相同方向上的木材密度存在极显著的负相关(-0.454～-0.587),Pilodyn测定值和晚材纤维特性存在极显著的负相关(-0.329～-0.447),而与早材纤维特性的相关关系不显著(-0.015～-0.137).建立各个指标对Pilodyn测定值的通径图,并对该模型进行缩减,得到原模型85%信息的新模型.新模型中木材密度贡献率为46.71%,生长量贡献率为24.47%,晚材管胞长贡献率为28.82%.建立Pilodyn测定值和木材密度线性回归方程,南向方程决定系数(0.425 3)高于北向的决定系数(0.209),南向方程预估精度为98.05%,北向方程预估精度为97.80%,因此以上模型用来预测日本落叶松的木材基本密度是可行和可靠的. 相似文献
3.
毛白杨材性指标预测及选择 总被引：5，自引：2，他引：3
采用非破坏性测定木材材质的Pilodyn测定指标,研究毛白杨28个无性系间的材性遗传差异.室外测定毛白杨活立木胸径(DBH)和南向Pilodyn测定值(Ps),室内测定木芯木材基本密度(Ds)和木材外侧基本密度(Dso),对Pilodyn测定结果与木材密度作统计分析.研究结果表明:按照Ps、Dso及Ds分别将各个无性系的平均值进行排序,3个序列间存在极显著的相关关系(-0.749～0.651).毛白杨单株间Ps、Dso和Ds间存在极显著的相关关系(-0.506～0.706),毛白杨各个无性系Ps、Dso和Ds平均值间也存在极显著的相关关系(-0.840～0.808),使用Ps、Ds和Dso3个材质性状对毛白杨无性系进行方差分析,均得到各个无性系间存在极显著差异的结果.以这3个材性指标分别和胸径的平均值各自将28个无性系分为4类:A)高密度快生长;B)低密度快生长;C)高密度慢生长;D)低密度慢生长.经方差分析和多重比较结果证明,使用3个材性指标所分的4类各个类别间均差异显著.通过分类结果选择出11,12,346,191,337,24,384共7个生长快且木材密度高的毛白杨无性系. 相似文献
4.
通过为估计杉木Cunninghamialanceolata多代自由授粉试验林的诸多遗传参数和育种值，为开展林木多世代育种提供经验借鉴和技术支撑。以浙江省杭州市余杭区长乐林场的杉木2代种子园家系自由授粉13年生子代林为研究对象，测定杉木39个2代家系子代试验林的胸径和木材基本密度抽样数据，利用GeneXpro Tools 4.0软件，挖掘木材基本密度与胸径间的函数关系，获得全林的木材基本密度，并采用转化分析法等进行方差分析和遗传分析，估计全林的遗传参数和育种值。结果表明，13年生杉木胸径和木材基本密度在家系间的差异极显著，家系遗传力大于单株遗传力，胸径遗传变异系数为6.78%，木材基本密度的遗传变异系数为3.07%；胸径与木材基本密度呈现出极显著的负遗传相关（P<0.01），在此基础上估算出亲本和子代个体的育种值，逆向选择评选出8个胸径优良家系、9个木材基本密度突出的家系；采用独立淘汰法，前向选择评出3代育种亲本18个。上述研究研果表明，基于杉木胸径与木材基本密度间存在极显著的负遗传相关，通过预测不同世代个体育种值，可提高杉木高世代育种材料选择的准确性。 相似文献
5.
以6年生9个桉树（Eucalyptus spp．）无性系为研究对象，测定活立木胸径处的Pilodyn测定值，钻取木芯测定木材基本密度，研究木材密度与无损检测技术Pilodyn测定值之间的关系。研究结果表明：生材密度变化范围为1026-1090kg／m’，最大的是无性系DH167-2，最小的是DH33-27；木材基本密度变化范围为473～588kg／m。，最大的是无性系DH184-1，最小的是DH32-26；Pilodyn测定值变化范围为11．7～13．9Innl，最大的是无性系DH201-2，最小的是GU9。行向和株向Pilodyn测定值差异不显著。方差分析表明，生材密度、木材基本密度和Pilodyn测定值在9个无性系间存在极显著的差异。Pilodyn测定值和木材基本密度之间存在极显著的负相关关系（P〈0．01），与生材密度存在不显著的负相关关系（P〉0．05）；株向Pilodyn测定值与木材基本密度的决定系数（R^2=0．5254）大于行向决定系数（R^2=0．5833）。预估方程经精度检验，表明用该方程来预测桉树无性系木材基本密度是可行和可靠的。以胸径为横坐标，Pilodyn测定值为纵坐标，将9个无性系分为4类，根据无性系利用目的，选择合适的无性系类型。 相似文献
6.
7.
对6年生桤木种源/家系的多点试验林的材性进行了研究,结果表明木材基本密度和纤维长度的种源间差异极显著,家系间差异不显著;木材基本密度的种源×地点的交互作用并未达到显著水平,纤维长度的种源×地点的交互作用达到显著水平.3个地点木材基本密度的种源遗传力和家系遗传力分别为0.5648～0.6618、0.2857～0.6535;木材纤维长度种源遗传力和家系遗传力分别为0.2553～0.7895、0.2905～0.4528.木材密度、纤维长度和生长性状三者之间的相关关系均不显著,可以进行3个性状的独立选择.提出桤木木材密度和纤维长度随年龄变化的生长模型和早晚期相关关系,适宜的早期选择年龄为6a,从木材密度考虑培育造纸材的适宜年龄拟定为10～11a.江西点15个种源的木材密度在种源间达到了显著差异,家系间并未达到显著差异,纤维长度在种源间、家系间都达到极显著差异. 相似文献
8.
无损检测在日本落叶松材性育种中的应用前景探讨 总被引：1，自引：0，他引：1
使用 Pilodyn和微秒计对20个日本落叶松无性系进行无损检测,研究无性系间无损检测指标的表型和遗传变异,结果表明：应力波速( SWV)的表型变异系数和遗传变异系数分别为5.09%和3.57%,低于 Pilodyn南向测定值(Ps)和北向测定值(Pn);3个无损检测指标无性系重复力的分布范围为0.34～0.48,说明它们受中等强度的遗传控制。研究无损检测指标与各材质性状间的关系,结果表明： Ps和 Pn与生长轮密度、早材密度、生长轮壁腔比和早材壁腔比呈极显著负相关; SWV与生长轮微纤丝角、早材微纤丝角和晚材微纤丝角呈极显著负相关,但与生长轮弹性模量、早材弹性模量和晚材弹性模量呈极显著正相关。多元回归分析表明,对 Ps,Pn和 SWV 贡献率排名前2位的材质性状分别为生长轮密度和早材壁腔比、生长轮密度和生长轮壁腔比以及早材微纤丝角和生长轮弹性模量。建立无损检测指标与相对应材质性状的线性回归方程,发现 Ps与生长轮密度间方程的决定系数(0.340)略小于 Pn与生长轮密度的决定系数(0.360); SWV 与早材微纤丝角、生长轮弹性模量间方程的决定系数分别为0.348和0.316。 相似文献
9.
采用胸径木芯与伐倒木取样方法,对24年生长白落叶松优树子代测定林14个处理的生长性状、木芯材质性状、解析木材质性状及其制浆造纸特性进行了研究,结果表明:生长性状、木芯基本密度、木芯管胞性状均存在丰富的变异;家系间生长性状差异极显著;木芯基本密度、木芯管胞性状差异显著,家系遗传力在0.56 0.80之间;解析木基本密度、早材微纤丝角、管胞长度、早材壁腔比、木质素、阿拉伯糖含量、抗张强度、撕裂度等差异极显著,家系遗传力在0.64 0.86之间;晚材率、管胞长宽比、综纤维素含量等差异显著,家系遗传力在0.51 0.61,家系水平的材性改良潜力较大。生长性状与木芯管胞长度呈极显著正相关,与木芯基本密度、管胞长宽比相关不显著;木芯基本密度、管胞长度、管胞宽度以及管胞长宽比与解析木相应性状呈极显著正相关关系,且回归模型较为理想,可以利用胸径木芯各性状值预测其单株值,间接选择和评价纸浆材优良家系。通过生长性状、木芯基本密度和木芯管胞长宽比综合分析选出166、169为优良家系,根据解析木生长、材质以及纸张物理性状选出的优良家系与其结果一致。优良家系材积、木芯基本密度和木芯管胞长宽比的遗传增益(超过对照)分别为48.34%(38.80%)、14.01%(3.63%)和19.89%(6.42%)。 相似文献
10.
《福建林业科技》2021,(3)
为了筛选杉木第3.5代种子园建园材料,并充实第4代育种选择群体,于2011年在福建省将乐国有林场开展杉木第3代种子园自由授粉子代测定。遗传变异分析结果表明:树高、胸径、单株立木材积和木材基本密度在家系间具有明显的遗传变异。各林龄段树高、胸径、单株立木材积受到明显的非加性遗传效应影响,广义遗传力分别介于0.6386～0.7723、0.7226～0.8006、0.6627～0.7550,狭义遗传力分别介于0.1992～0.3609、0.2991～0.3481、0.2445～0.2958。9 a林龄时红心材率不受遗传控制,木材基本密度主要受到加性遗传效应影响,广义遗传力为0.4751,狭义遗传力为0.3655。遗传相关分析结果表明:5 a是杉木自由授粉子代测定林遗传选择的底限林龄。根据9 a时单株立木材积、木材基本密度的育种值排序选出优良家系5个,树高、胸径、单株立木材积、木材基本密度遗传增益分别为0.87%、1.38%、3.38%、1.24%;选出优良单株12株,树高、胸径、单株立木材积、木材基本密度遗传增益分别为5.63%、14.00%、37.77%、2.31%。以9 a时单株立木材积基因型值排序选出无性繁殖原株11株,树高、胸径、单株立木材积遗传增益分别为22.27%、34.57%、111.73%。 相似文献
11.
《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
12.
《Scandinavian Journal of Forest Research》2012,27(3):206-217
The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage. 相似文献
13.
《Scandinavian Journal of Forest Research》2012,27(1):53-61
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
14.
《Scandinavian Journal of Forest Research》2012,27(1):15-27
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions. 相似文献
15.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。 相似文献
16.
《Scandinavian Journal of Forest Research》2012,27(2):131-138
The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided. 相似文献
17.
18.
《Scandinavian Journal of Forest Research》2012,27(5):472-479
Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken. 相似文献
19.
Srisuda Thippayarugs Banyong Toomsan Patma Vityakon Viriya Limpinuntana Aran Patanothai Georg Cadisch 《Agroforestry Systems》2008,72(2):137-148
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic
or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts
(stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea
(Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content
as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest
N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized
to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea,
largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for
N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant
components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N
released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures
were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality
components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in
the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols.
Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest
age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its
components are mixed. 相似文献
20.
A. Rigueiro-Rodríguez M. R. Mosquera-Losada E. Gatica-Trabanini 《Agroforestry Systems》2000,48(3):245-256
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste
disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization,
(2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two
pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea
(Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect
on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage
sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but
affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral
systems.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献