丘陵区马尾松毛虫防治指标的研究

本研究通过室内、外饲养马尾松毛虫、松树针叶蓄积量调查以及人工模拟危害和自然状况下马尾松毛虫危害等试验获得的大量数据,利用微机进行统计和分析,结果表明:马尾松针叶损失达50％时,对树高、胸径、材积生长影响显著。由此,求算出丘陵区马尾松毛虫对5、10、15、20年生马尾松危害的防治指标是,越冬代分别为7、15、32、52(条/株),第一代分别为7、16、34、56(条/林),第二代分别为9、17、40、61(条/株)。     

马尾松毛虫危害对松树生长量影响的研究

越冬代松毛虫的严重危害 (针叶损失 70 %以上 ) ,对当年的高生长量、胸径生长量和材积生长量有极显著影响 ;一代 (7月 )的严重危害 ,对当年和后一年的胸径生长量、材积生长量有显著影响 ,对高生长影响不显著 ;二代 (9月 )的严重危害 ,对当年的生长量无影响 ,对后一年的高生长量、胸径生长量和材积生长量有极显著影响。无论哪一代危害 ,对后 2年的生长量无影响     

人工模拟摘叶对马尾松单株承受力的测定

通过人工模拟试验,找出了马尾松毛虫虫口密度、食叶量与马尾松高、径及材积生长的关糸,试验表明,失叶量超过单株针叶蓄积的50%时,就开始对马尾松的生长有显著影响,即5～10a生马尾松虫口密度达25头/株,10～20a生马尾松虫口密度达77头/株,对其树高、胸径的生长有显著影响,为控制该虫的危害提供了理论依据。     

马尾松二代无性系生长和针叶N/P化学计量特征

[目的]在土壤有效P匮乏的立地条件下,揭示针叶N、P含量及其化学计量比与马尾松生长性状的相关性。[方法]以马尾松二代育种群体内30个无性系为试验对象,野外调查11年生时马尾松二代无性系树高、胸径等生长性状与针叶N、P含量及其化学计量比的相关性。[结果]结果表明:(1)各生长性状在马尾松二代无性系间差异显著,且无性系重复力较高,均达到0.95以上。马尾松成熟针叶和当年生针叶N、P含量及N/P在二代无性系间差异均达显著水平;(2)相关分析表明,马尾松二代无性系树高、胸径与成熟针叶和当年生针叶N含量、N/P均呈显著或极显著正相关,与成熟针叶N/P的相关系数分别为0.608 6和0.542 8,与当年生针叶N/P的相关系数分别为0.515 9和0.679 2;(3)基于主要生长性状、针叶N和P含量及其化学计量比,可将30个马尾松二代无性系聚为4类:类群1无性系树高、胸径等生长表现优良,成熟针叶N/P较高,而当年生针叶N/P相对较低;类群2无性系树高、胸径等生长表现较好,成熟针叶和当年生针叶N/P值在30个无性系中居中间水平;类群3占试验无性系总数的一半,树高、胸径等生长表现一般,成熟针叶与当年生针叶N/P相差较大,大部分无性系成熟针叶N/P较低,而当年生针叶N/P相对较高;类群4树高、胸径等生长表现较差,成熟针叶和当年生针叶N/P均较低。[结论]在贫P立地下,马尾松二代亲本无性系C13(7750×1126)和C14(3201×1123)各生长指标均较高,可能是通过调整当年生针叶和成熟针叶的养分分配,增加了当年生针叶对限制其生长的P素的再利用和再吸收,促进了N素的吸收,调整了当年生针叶和成熟针叶的N/P,以形成特定的养分分配机制。     

闽西马尾松优树自由授粉子代遗传分析与选择

对14年生的闽西马尾松优树自由授粉子代测定林调查分析,结果表明:139个参试家系在树高、胸径、材积性状上存在极显著差异。树高、胸径、材积家系遗传力分别为31.04%、60.73%、55.3%。以材积遗传增益大于10%为指标,选择36个优良家系,平均材积遗传增益达16.5%。入选的优良家系可为马尾松遗传改良和种子园营建提供优质的种质资源材料。     

马尾松无性系种子园自由授粉子代测定与配合选择

对都匀马尾松无性系种子园48个半同胞家系9年生测定林的胸径、树高、材积进行了测定分析,结果表明:各家系间树高、胸径、材积差异极显著,具有较高的遗传力。从中选择出9个优良家系,其树高、胸径和材积平均为7.12 m、9.84 cm和0.037 97 m3,遗传增益分别为10.44%、7.73%和20.80%。从优良家系内选择46株优良单株,其树高、胸径、材积分别增加了53.81%,56.65%和150.18%、材积预期增益为55.05%。这些优良单株可作为贵州省营建马尾松高世代种子园的备选材料。     

马尾松毛虫危害程度与马尾松材积生长率之间关系的模拟试验

1983年3月至1985年4月在浙江省安吉县龙山林场用人工摘叶方法模拟松毛虫不同的危害程度,观察对摘叶后第一年与摘叶后第二年马尾松材积生长率的影响。试验采用树龄、土壤肥力、摘叶时间与摘叶量4个因子(每个因子各2或4个水平)的综合影响的多因子正交回归设计,所得数据用逐步回归分析方法筛选影响受害树材积生长率的主要因子,建立其间的定量关系式。结果表明,摘叶对摘叶后第一年材积生长有影响,对摘叶后第二年材积生长的影响不显著。松毛虫危害造成的影响小于树木自身生长规律所起的作用。且材积生长率的损失与针叶损失量之间不是线性关系,而是曲线回归。     

马尾松生长性状配合力和杂种优势及相关性分析

研究马尾松生长性状的配合力与杂种优势及其相关性,目的是为马尾松二代种子园进一步遗传改良及高世代种子园营建提供基础数据。以湖南省城步马尾松种子园无性系测交系交配设计的10个单亲家系、14个双亲家系为材料,对其进行每木调查及遗传分析。结果表明:马尾松种子园6年生子代测定林不同杂交组合间树高、胸径、材积的差异均达极显著或显著。2个测交设计中,只有第Ⅱ设计中父本间树高、胸径、材积、活枝轮数和母本间胸径GCA效应值的差异均达极显著或显著。第Ⅰ设计杂交组合间树高、胸径、材积的SCA效应值差异均达极显著,第Ⅱ设计杂交组合间树高的SCA效应值差异达显著。2个设计中,杂种优势在5%以上的组合与性状在第Ⅰ设计中占53.1%,在第Ⅱ设计中占29.2%,平均达41.15%。材积与树高、胸径、活枝轮数均呈极显著正相关,与下三轮活枝数呈显著负相关;树高与胸径、活枝轮数均呈极显著正相关;胸径与活枝轮数均呈极显著正相关,与下三轮活枝数呈极显著负相关;活枝轮数与下三轮活枝数呈极显著负相关。这说明在马尾松速生用材优良家系选择时,在优先选择树高、胸径速生的同时,活枝轮数多和下三轮活枝数少也是重要的选择标准,对活枝轮数、下三轮活枝数的选择是有效的。     

马尾松不同营造混交类型选择及林分生长量研究

马尾松分别与米老排等4种阔叶树及杉木采用不同混交比例、密度营造混交试验林,通过对6年生和22年生的试验林生长数据进行分析,结果表明:采用不同混交比例和方法,6年生林分树高差异达极显著水平,单株材积和单位蓄积达显著水平,而胸径无显著差异;但在22年生时胸径、树高差异均达极显著水平,单株材积达显著水平,而单位面积蓄积、冠幅无显著差异。不同混交密度的林分胸径、树高、单株材积、冠幅差异均达极显著水平,但林分单位面积蓄积无显著差异。通过分析可知,适宜营造马尾松混交林的树种有火力楠、木荷等,混交方式以马尾松阔叶树行间混交为最优,混交密度以2 m×2.5 m或2 m×1.67 m为最优。     

马尾松种源试验研究

马尾松是我国亚热带地区分布最广、资源最多的特有乡土树种.对参试的44个马尾松种源的树高、胸径、材积、枝下高和冠幅等生长指标进行了系统分析.结果表明:8年生马尾松种源试验林树高、胸径和材积生长差异显著,枝下高和冠幅生长无明显差异;树高、胸径和材积遗传力较高,分别为40.61%、39.53%和32.79%,枝下高和冠幅较低;聚类分析研究将马尾松种源分为极速生、速生和中等3种类型;综合评定的结果与聚类分析结果相符,确定了40号种源为最佳种源和33个可供采用的优良种源.     

The influence of pine twist rust (Melampsora pinitorqua) on growth and development of Scots pine (Pinus sylvestris)

The influence of pine twist must (Alelampsora pinitorqsat) on growth and development of Scots pine was studied during three consecutive years. The experimental material included three provenances from natural stands and one open pollinated seed orchrd progeny. Trees severely affected by pine twist must reached an average of 38% lower height than did not-affected trees. while mildly affected trees grew somewhat better, on the average, than did non-affected trees. Pine twist must caused tha greatest loss of height increment in the seed orchard progeny.     

Probability models for pine twisting rust (Melampsora pinitorqua) damage in Scots pine (Pinus sylvestris) stands in Finland

Factors affecting the probability that pine twisting rust (Melampsora pinitorqua) damage occur in a Scots pine (Pinus sylvestris) stand were analysed using the 7th Finnish National Forest Inventory data (NFI7) from southern Finland in 1977–1983. The inventory was based on systematic sampling. The NFI7 data was measured in clusters, each of which consisted of 21 sample plots. In addition to the stand and site characteristics measured for forest management planning purposes, the data included records of damage by pine twisting rust and occurrence of aspens (Populus tremula, the other host plant of the pathogen) in the stands. Two multilevel logit models were developed for predicting the overall probability of pine twisting rust damage and the probability of severe pine twisting rust damage. Site and stand characteristics were used as explanatory variables in the models. Residual variance in the models was studied on the inventory crew, cluster and year levels. The occurrence of aspens and site fertility were the most important factors increasing the probability that pine twisting rust damage will occur in a stand. The damage probability also decreased with increasing effective temperature sum calculated for the location. The overall damage probability was equally high on peatlands and on mineral soil if there were aspens in the stand. If, however, there were no aspens in the stand, the probability of damage was higher on mineral soils than on peatlands. In addition, the overall probability was lower in naturally regenerated stands than in planted or sown stands, and it decreased with increasing mean age of pines. In both models, the residual variance was significant on the both the inventory crew and the cluster levels.     

松树枝枯病的研究进展

文章记叙了1911年以来松枝枯病Cenangium feruginosumFr.exFr.的研究史上关于病菌的寄生性和致病性的争论，一种意见认为该菌是有寄生性的致病菌；一种意见认为完全是腐生菌。随着人工培养和在衰弱寄主上接种的成功，多数人承认它是一种弱寄生菌，其致病能力与环境胁迫所造成的树势衰弱相伴随。影响发病最高要的环境因子是气候干旱，近年研究证明，Cenangium ferruginosum是松树健康针叶中的一种占优势的内寄生菌，虽然它从未在针叶上产生症状，但有人推测，在针叶和小枝之间有相互系统蔓延的关系，文章还较详细地回顾了国内有关研究情况，并介绍了主要文献索引。     

The effects of pine mistletoe (Viscum album subsp. austriacum) on the growth of Scots pine and Crimean pine in Turkey

In this study, the effect of pine mistletoe (Viscum album subsp. austriacum) on basal area increment of Crimean pine and Scots pine was investigated. Dendrochronological data were collected from 223 (71 uninfected and 152 infected) Crimean pines and 195 (77 uninfected and 118 infected) Scots pines located in Kastamonu province of Turkey in 2014. Infected sample trees were classified as light, moderate or severe infection levels. Growth trends and basal area increment loses were compared between uninfected and infected trees for the periods of the last 10, 20 and 30 years. In addition, infection status of forest stands was investigated using temporary sample plots; 27 plots in Crimean pine stands and 26 plots in Scots pine. Results demonstrated that basal area increments were negatively affected by pine mistletoe for both species. Mean basal area increment losses of infected trees for the last decade were determined as 24% for Scots pine and 26% for Crimean pine. Basal area increment losses varied by infection levels (light, moderate and severe) as follows: 25%, 20% and 28% for Scots pines and 20%, 32% and 9% for Crimean pines. Scots pine stands were more severely infected by pine mistletoe than Crimean pine stands. There were negative correlations between number of infected trees and stand density for both species, while positive correlation was detected between the number of infected trees and mean diameter for Scots pine. The results of this study indicate that the pine mistletoe infection has negative effect on radial growth of Scots pine and Crimean pine trees. The results can be an important contribution to the forest management and protection activities in mistletoe-infected stands.     

Rectangularity of planed Scots pine (Pinus sylvestris) planks

Abstract

This study deals with how warp affects the cross-sectional shape of planed planks. A total of 20 planks with dry target cross-sectional dimensions of 50×150 mm were planed to 45×145 mm. The rectangularity of five cross sections of every plank was measured before and after planing. The cutting depths were measured in 10 positions in the cross sections, and the angles between the planks and the cutters were calculated. Also, the warp, that is, twist, bow, crook, and cup, was measured before and after planing. All the studied properties pointed in the same direction. In terms of both rectangularity and angles of cut, the problems were larger in the top and butt ends of the investigated planks than in the intermediate parts, and the main reason for deviations from the desired result after planing was twist.     

Diurnal changes in water conduction in loblolly pine (Pinus taeda) and Virginia pine (P. virginiana) during soil dehydration

We studied diurnal changes in water conduction during soil dehydration in 37-month-old seedlings of one Virginia pine (Pinus virginiana Mill.) and two loblolly pine (P. taeda L.) sources, one from North Carolina (NC) and the other from the "Lost Pines" areas of Texas (TX), in an environmentally controlled growth chamber. For seedlings of similar biomass, the TX source had higher values of transpiration, needle conductance, and plant hydraulic conductivity under well-watered conditions than the NC source. Under dry soil conditions, the TX source had lower values of water conduction than the NC source. The Virginia pine source responded similarly to the TX source under both well-watered and dry soil conditions. For all three pine sources, gradients between soil and needle water potentials were greatest when the seedlings were moderately stressed. The TX and Virginia pine sources had higher gradients and lower daytime needle water potentials under moderate stress conditions than the NC source. Predawn needle water potentials did not differ among the pine sources. We conclude that the TX and Virginia pine sources have decreased daytime needle water potentials and increased water potential gradients during the daytime under moderate stress conditions, but with no disruption of recovery at predawn. The greater rates of transpiration and water conduction by the TX source compared with the NC source under well-watered conditions suggest a means by which growth can be maximized prior to the onset of drought, thereby enhancing survival of loblolly pines in drought-prone environments.     

Induction of discolored wood in Scots pine (Pinus sylvestris)

Induction of discolored wood in Scots pine (Pinus sylvestris L.) trees by treatment with ethylene, carbon dioxide, nitrogen (hypoxia) or wounding from early April to late September was investigated. All treatments induced formation of discolored wood upward and downward from the drill hole. The amount of discolored wood formed above the drill hole depended on the treatment in the following order: ethylene > carbon dioxide = nitrogen > wounding; and below the drill hole in the order: ethylene > carbon dioxide = nitrogen = wounding. Based on chemical analyses (HPLC/UV, GS/MS, LC/MS and 1H-NMR), discolored wood induced by wounding or treatment with ethylene or carbon dioxide showed compositional similarities to natural heartwood, whereas discolored wood induced by nitrogen treatment showed fewer similarities to natural heartwood. The results suggest that ethylene is an important factor controlling heartwood formation, although wounding and internal concentrations of carbon dioxide may also play a role.     

Heat-induced colour changes of pine (Pinus pinaster) and eucalypt (Eucalyptus globulus) wood

Heat treatment of Pinus pinaster and Eucalyptus globulus wood was carried out by hot air in an oven for 2–24 h at 170–200°C and by steam in an autoclave for 2–12 h at 190–210°C. The colour parameters L*, a* and b* were determined by the CIELAB method on radial, tangential and transverse sections of untreated and treated wood, and their variation with regard to the treatment (ΔL*, Δa* and Δb*) were calculated in percent. For untreated eucalypt wood, lightness (L*) varied between 54.1 and 63.8% with a* between 7.4 and 8.5, and b* between 15.7 and 19.9. For untreated pine wood, L* varied between 67.3 and 76.1%, a* between 6.9 and 7.6 and b* between 16.3 and 24.1. Oven heat-treated wood became darker (ΔL* about 50% for 4% mass loss), and this was more for eucalypt wood under the same treatment conditions. In general, the contribution of red (a*) and yellow (b*) colour decreased with heat treatment. The transverse section of the two species darkened less for both the treatments with small differences between radial and tangential sections. Lightness decrease was related to chemical changes; with good correlations with glucose (R ² = 0.96), hemicelluloses (R ² = 0.92) and lignin (R ² = 0.86). As regards colour, the heat treatments showed an interesting potential to improve the wood quality for solid timber products from pine and eucalypt.     

Regeneration of Rocky Mountain bristlecone pine (Pinus aristata) and limber pine (Pinus flexilis) three decades after stand-replacing fires

Rocky Mountain bristlecone pine (Pinus aristata) and limber pine (Pinus flexilis) are important high-elevation pines of the southern Rockies that are forecast to decline due to the recent spread of white pine blister rust (Cronartium ribicola) into this region. Proactive management strategies to promote the evolution of rust resistance and maintain ecosystem function require an improved understanding of the role of disturbance on the population dynamics of both species and environmental conditions that favor seedling establishment. We examined patterns of bristlecone and limber pine regeneration across the perimeters of three, 29-year-old, high-severity burns in northern, central, and southern Colorado: Ouzel, Badger Mountain, and Maes Creek, respectively. Both species exhibited a very protracted regeneration response to these fires. Bristlecone pine regeneration was concentrated near burn edges and beneath surviving seed sources. This spatial pattern is consistent with limitations incurred by wind-dispersal, also borne out by the low occurrence of seedling clusters. Relative to unburned stands, the absolute abundance of bristlecone pine generally increased only on plots retaining some surviving trees. Limber pine regeneration pattern varied between sites: high in the burn interior at Ouzel, concentrated at burn edges at Badger, and mostly in unburned stands at Maes. Clark’s Nutcracker dispersal of limber pine in each study area was indicated by high seedling distance from possible seed sources and high frequencies of clustered stems. Except at Ouzel, the absolute abundance of limber pine decreased in burns. Across sites, establishment by both species was boosted by nearby nurse objects (rocks, fallen logs, and standing tree trunks), a relationship that extended out at least as far as the closest three such objects, usually found within 50 cm. Fire decreased the frequency of Pedicularis but increased Castilleja and Ribes species (alternate hosts of white pine blister rust), though only one species, R. cereum, was positively associated with either pine species. We conclude that regeneration of bristlecone and limber pine may benefit from natural disturbance or proactive management creating appropriately sized openings and microtopographic structure (e.g., abundant fallen logs); however, beneficial responses may require many decades to be achieved.