杉木多层次改良研究

本研究将试验处理分为１代种子园、优良家系、无性系、优良无性系４个改良层次。研究结果表明：改良效果依次增大。优良无性系单行小区试验，９年生材积比那坡种源增加６７．３％；块状造林，两块平均林龄８年，平均树高９．９ｍ，平均胸径１３．１ｃｍ，每６６７ｍ２林木蓄积量１７９ｍ３，比那坡种源增加９６．７％。因此，无性系选育是充分利用杉木多层次遗传变异获得最大改良效果的有效途径     

海南岛东部地区桉树树种/种源试验*

在海南岛东部进行的桉树１１个树种７９个种源试验，５年的结果表明，不同树种种源间生长差异极显著，来自印度尼西亚Ｍｔ．ｍａｎｄｉｒｉ的尾叶桉１２８９５种源是所有参试树种／种源中表现最好的，树高、胸径和每公顷材积分别为１３．８２ｍ、１２．５４ｃｍ和１２８．３４ｍ３。同一树种种源间生长差异也极显著，最佳种源的每公顷材积与最差种源相比，尾叶桉为８．４６：１，细叶桉５．８６：１，赤桉５．３２：１和巨桉３．０４：１。细叶桉、赤桉和巨桉种源树高、胸径和材积生长与原产地纬度显著负相关，尾叶桉种源与原产地海拔高极显著负相关。本文提出了适合海南岛东部地区生长的树种和种源。     

杉木多层次改良研究

本研究将试验处理分为１代种子园、优良无性系４个改良层次。研究结果表明：改良效果依次增大。优良无性系单行小区试验，９年生材积比那坡种源增加６７．３％块状造林，两块平均林８年，平均树高９．９ｍ，平均径１３．１ｃｍ，每６６７ｍ＾２林木蓄积量１７９ｍ＾３，比那坡种源增加９６．７％。因此，无性系选育是充分利用杉木多层次遗传是获得最大改良效果的有效途径。     

云杉引种及种源试验研究

经长达１４～１５ａ的云杉引种和红皮云杉种源试验研究表明：青海云杉从西北引入齐齐哈尔北部克拜地区造林是成功的，生长良好，树高、胸径、材积分别比对照大４．１％、１５．０％和１９．８％；红皮云杉美溪种源在该地区生长量高，生长稳定，为最佳种源，树高、胸径、材积分别比对照大５．０％、１１．９％和２７．１％；云杉早期选择是可行的，５～６ａ可作为早期选择的初选年龄。     

楸树造林密度及其效应的研究

楸树造林密度７年试验总结。在７种造林密度中，树高最高（平均５．１３ｍ）的密度为２１ｍ×１ｍ、３ｍ宽窄行，最低（平均４．４０ｍ）的密度为２ｍ×２ｍ，相差１６．６％；最大胸径（平均７．４ｃｍ）和最大单株立木材积（平均０．００８６６ｍ￣３）的密度为３ｍ×４ｍ，最小胸径（平均５．７ｃｍ）和最小单株立木材积（平均０．００４７１ｍ￣３）的密度为２ｍ×２ｍ，胸径相差２９．８％，材积相差８４．９％；密度居中的２ｍ×１ｍ、６ｍ宽窄行及３ｍ×３ｍ，对光照的利用较佳，冠下平均光照强度０．８０—０．９５万勒克司，冠下、株间、行间光照平均透过率分别为１２．４—１４．４％、１６．０—２１．２％、５０．８—５９．１％；２ｍ×１ｍ、６ｍ宽窄行的光台强度较２ｍ×２ｍ增加２０．１％；密度愈小，郁闭愈晚，径阶偏向大径阶分布，密度愈大，郁闭愈早，径阶偏向小径阶分布，并需较早的间伐。     

火炬松种源遗传变异研究及纸浆材优良种源评选 Ⅱ.间接选择和指数选择

经对浙江富阳点１１年生火炬松种源林生长性状和木材基本密度指标所作的早晚期相关分析表明，在中龄林阶段，以５～６年生作为火炬松种源早期选择的最低年龄是可行且较可靠的。在同一种源林中，当入选率为１０％时，采用树高或胸径来间接选择材积和干材干物质重可获得１５％以上的遗传增益；应用恰当的指数来选择纸浆材种源可使指数相对效率达到６５％以上。在４片种源林中，用多性状综合选择法共筛选出１０个速生、优质、高产的种源，入选种源的平均现实增益和遗传增益，树高分别为６．９４％和４．５９％，胸径为８．３８％和５．５５％，材积为２０．００％和１３．２４％，木材基本密度为１．６３％和１．０８％，干材干物质重为２４．７８％和１６．４０％。     

柏类引种试验研究

对柏类４个树种墨西哥柏、绿干柏、垂柏、巨柏共１２个种源的引种结果表明,不同树种和种源树高、胸径增长最大年份分别出现在造林后第４年和第５年;造林后１０ａ,各树种和不同种源树高、胸径生长差异显著,以墨西哥柏３、２、６、７号种源生长最快,树高、胸径平均值在１０．４ｍ和１５．２ｃｍ以上,其中３号种源树高最大,为１１．０９ｍ,６号种源胸径最大,为１６．９ｃｍ,分别比垂柏增加９．９％和２７．１％。各树种和种源都有倒伏现象,倒伏程度与造林树种、林龄、立地有关。     

兴凯湖松引种造林研究

１９８０年从黑龙江省东部的密山引进兴凯湖松（Ｐｉｎｕｓｕｓｓｕｒｉｅｎｓｉｓ）种子，在错海林场播种育苗，１９８２年春造林。１４年的弓１种实践证明，兴凯湖松在黑龙江省西部干旱、半干旱、土质瘠薄、岩石裸露的山地上造林表现出较强的适应性和旺盛的生长力；１０年生时开始结实；１４年生时其平均树高、胸径、单株材积和公顷蓄积量分别达到４．７７ｍ、８．０２ｃｍ、０．０１４０ｍ￣３和３２．９ｍ￣３，比同龄的子松分别大２２．９％、３３．４％、７２．８％和７４．１％；经分析，两树种各因子差异均达极显著水平；经预测，在１８年生时，兴凯湖松的公顷蓄积量将是樟子松的２倍以上；为我省西部地区增添了一个新的造林适生树种。     

火炬松的引种试验总结

青岛地区于１９７４～１９８８年，先后３次从国外引进火炬松商品种子进行引种试验，通过种子育苗、田间造林等试验研究，表明火炬松在青岛地区低丘阳坡引种是成功的，１９年生火炬松林分测定，其树高、胸径、材积的年平均生长量分别为同龄日本黑松的１７７．８％、１９６．７％和８２９．４％，火炬松干形直、材质好、松脂含量高，抗性强，未发现松干蚧危害；鉴于适宜种源种子短缺，在种源研究的基础上应恻重引入北亚热带和抗寒种源。     

大叶相思种源选择试验

对从昆士兰引进的５个大叶相思种源及１个本地种源，在琼海试点和花都试点进行试验，结果表明，引进种源在前者的生长表现均比后者好，不同种源在同一试验点比较，以１５６９７和１５４８３种源生长快，产量高，年平均生长琼海试点和花都试点分别为胸径２．０ｃｍ和１．３树高，树高２．３ｍ和１．３ｍ，生物量２５．３６ｔ／ｈｍ＾２和１３．６３ｔ／ｈｍ＾２以上，明显地优于其余各种源。花都试点５个引进种源树高，胸径生长量及生     

秘鲁的松树资源及其松脂化学组成

秘鲁具有丰富的松树资源,主要树种有展松,辐射松,粗糙枝松和粉枝五针松等。采用ＤＢ－５毛细管柱对这些树种的松脂进行分析,并用ＧＣ－ＭＳ鉴定。同时,采用ＱＦ－１毛细管柱将松脂中长叶松酸和左旋海松酸加以分离。     

Tree Planting in an Urbanizing South Africa / BOOMAANPLANTING IN VERSTEDELIKENDE SUID-AFRIKA

The title of this paper might well read “Tree planting in an urbanizing and industrializing South Africa”, because in modern South Africa industry is prominent in the urban scene. The importance of trees in the urban landscape is stressed. Purposes for which trees are used in commercial, industrial and residential areas are listed. An account is given of tree planting in boulevards and avenues, state and civic centres, car parks, bus termini, recreational parks, botanical gardens and arboreta, zoological gardens, sports enclosures and children's playgrounds. The role of trees in industrial areas is discussed and the vegetating of mine dumps described. Passing reference is made to the uses of trees on the sea front. Tree planting for economic purposes by civic authorities is briefly touched upon. The value of trees in private gardens is underlined.     

DIE INVLOED VAN RADIALE HARSGEïNFILTREERDE KERNSKEURE OP DIE GESAAGDE OPBRENGS UIT PINUS ELLIOTTII ENGELM.-SAAGBLOKKE / THE EFFECT OF RADIAL RESIN-INFILTRATED SPLITS ON THE YIELD OF SAWN TIMBER FROM PINUS ELLIOTTII ENGELM. SAWLOGS

A number of complaints, regarding the presence of resin-infiltrated splits in seasoned boards produced from Pinus elliottii sawlogs supplied from certain stands in State Forests, led to an investigation to determine the incidence of the defect and to find possible causes.

This paper deals mainly with the study of the first aspect. In the investigation two samples of stems were selected by a semi-random method from one mature stand, being clearfelled, in Entabeni State Forest (Northern Transvaal) and from three stands receiving, or due to receive, their fifth thinning. The clearfelling and thinning had produced logs containing heart shakes and this had given rise to the complaints.

During log preparation it was attempted to prepare as much as possible of the stem length into the longest sawlogs, working as closely as possible to the maximum limits for sweep and knots allowed by the departmental log specifications. This attempt resulted in the preparation of some logs containing slightly more than the permissible defects. Observations were made on stump surfaces of the orientation of shakes, and on log ends of their occurrence higher up in the stem, in an attempt to find a link between shake orientation and the known direction of strong winds, and to determine the height in the stem to which shakes extended from the stump. The orientation study produced no definite proof that wind was responsible, although there were strong indications.

This was followed by sowings up the logs mainly into structural timber, kiln seasoning and grading in two ways, viz A ignoring the resin-infiltrated checks and splits but taking all other defects pertinent to the relevant grades into consideration, and B taking all defects, including the checks and splits into consideration (Table 4). During the grading further measurements were taken on boards containing splits, to determine to what heights in the stem the shakes extended.

From the grading results, total and graded yields of sawn timber were computed, the differences in yields between the two grading procedures being a measure of the incidence and seriousness of the shake defect. Within log classes, (see footnote to Table 2) the yields obtained separately for each 2 cm top U.B. diameter class into which the logs had been segregated prior to sawing, were weighted according to the percentage size distributions of the logs yielded by the clearfelling and thinning operations in the relevant compartments, to obtain a weighted average for the log class.

The heights to which shakes were present in the stems of the two samples are shown in Table 3(a) while their incidence in logs of the various size classes are shown in Table 3(b). It is seen that shakes were more frequent and serious in the larger logs.

The presence of shake in the log samples, taken as a whole, caused only minimal yield losses (Table 4) but had the effect of somewhat reducing average board length (Table 5). However, sawn and graded yields are still excellent and the species should not be discriminated against in afforestation, because of the sporadic occurrence of the defect.

The yield figures should be of some value to sawmillers processing both normal and shake-containing logs of this species.     

Future outlook for Pinus patula in South Africa in the presence of the pitch canker fungus (Fusarium circinatum)

Approximately 50% of the area planted to softwood trees in South Africa has been established with Pinus patula, making it the most important pine species in the country. More effort has gone into developing this species for improved growth, tree form and wood properties than with any other species. This substantial investment has been threatened in the last 10 years by the pitch canker fungus, Fusarium circinatum. The fungus infects and contaminates nursery plants and, once transferred to the field, causes severe mortality of young trees in the first year after establishment. Although nurserymen have some control of the disease, it is recognised that the best long-term solution to mitigate damage because of F. circinatum infection is to identify tolerant species, clones and hybrids for deployment in plantations in the future. Research has shown that alternative species such as P. tecunumanii, P. maximinoi and P. elliottii are suitable for warm sites. Pine hybrids, particularly between P. patula and the high-elevation sources of P. tecunumanii, appear to be a suitable replacement on subtemperate and temperate sites. Although these alternative species and hybrids are more sensitive to subfreezing temperatures than P. patula, their planting range can be increased by including cold tolerance as a selection criterion. Future breeding efforts will most certainly focus on improving the tolerance of pure P. patula to F. circinatum, which can be achieved by identifying specific family crosses and tolerant clones. The commercial deployment of disease-tolerant control-pollinated P. patula and hybrid families will most likely be established as rooted cuttings, which requires more advanced propagation technology. In the long term, new seed orchards comprised of P. patula clones tolerant to F. circinatum could be used to produce seed for seedling production.     

A Procedure for Choosing Tree-Stem Volume Equations Previously Fitted in a Forest

ABSTRACT

Tree-stem volumes constitute critical measurements for forest management. We propose a general two-criterion procedure for choosing the most reliable and robust volume equation(s), among a set of them previously fitted in a forest. Also, the proposal can be used as an additional criterion when fitting new equations to a single sample. Through simulated volumes, we considered how well a model estimates the volume generated by itself (the more accurate estimation, the better) and measured a model’s variability of the mean errors when it estimates volumes rebuilt by other models (the lower variability, the better). The procedure is exemplified with volume equations of Pinus patula in the Forestry Management Unit 1302 in Hidalgo, Mexico. In the example, we found that a linearized form of the combined-variable equation results reliable and robust. This selection coincided with the one made with data of a recent 150 trees sample (validation), where the rebuilt-estimated mean volume differs 0.034 m3 from the observed mean volume; it represents around US$2.6. Therefore, it is shown that simulation becomes an effective tool to identify equations that do not reproduce the volume of trees well in the current forest and helps to choose reliable and robust equations.     

樟子松、长白松、赤松和黑松的引种研究

以樟子松7个种子源的种子和长白松，赤松和黑松的种子在北京地区做引种试验，并以油松做对照。试验结果表明，长白松生长的表现较好，优于油松。赤松和黑松表现一致，不如油松。樟子松生长表现更差。但从樟子松不同种源来看，呼伦贝尔、大兴安岭南部和小兴安岭的种源生长表现要优于大兴安岭北部的种源。     

5种松树造林的适生性研究

对樟木头林场引种的4种松树及马尾松7年生林分的生长状况进行调查。结果表明，加勒比松巴哈马变种和湿地松具有良好的冠形和干形，有一定的生长潜力；而马尾松的树高生长虽然较快，但自然整枝较差。树干不通直，且虫害较严重。抗性差；加勒比松古巴变种的抗逆性差。生长速度慢。三级木比例大，适生性较差。     

Biology of Litosermyle ocanae in Colombian Pinus patula plantations

Plantations of Pinus spp. in Colombia are severely damaged by various phasmid (Phasmatodea: Diapheromeridae) insects. Of these, Litosermyle ocanae is one of the most serious defoliators. Since 1988, several outbreaks have been recorded in Pinus patula plantations, resulting in substantial economic losses. The aim of this study was to determine the life cycle of Litosermyle ocanae in P. patula plantations in Colombia. In addition, we assessed the population levels of L. ocanae and the presence of natural enemies of L. ocanae in these plantations. The development of L. ocanae was monitored under controlled conditions, and population fluctuations and the presence of natural enemies was assessed from field-collected eggs and field observations. The results showed a total life cycle of 225 d and 235 d for males and females, respectively, and a complete fourth instar nymph cycle of 121 d and 116 d for males and females, respectively. The sex ratio was 1:1.7 female to male. Females laid an average of 112 eggs. The number of eggs peaked in November and the most dominant natural enemy observed was a parasitoid wasp Adelphe sp. (Hymenoptera: Chrysididae). The results provide important information for the management of L. ocanae in P. patula plantations.     

THE TREMA PLANTATIONS OF WESTFALIA ESTATE

Defoliation of well-stocked, 10–12-year-old P. parula, and younger E. saligna/grandis and E. cloeziana standsby the larval stages of a geometrid moth Buzura edwardsi Walker, recently indicates that this is a potentially important forest pest in the Melsetter district, one of the major areas of pine and eucalypt afforestation in Rhodesia.

Field observations of the habitsand life cycle of the pest and the damage it causes are recorded, as well as its biological control which, in normal seasons, appears to be adequate in keeping infestation at tolerable levels.

However, the necessity is stressed for immediate specialist investigation into effecting permanent control of this economically important forest pest, preferably by biological means.     

松树枯梢病潜伏侵染的研究

研究表明在火炬松、湿地松、短叶松和马尾松健康梢上整年都能分离到松枯梢病菌,其中在火炬松上的得菌率为15％—37．7％,且大多数月份高于20％;湿地松上的得菌率稍低于火炬松,为7．5％～29．1％;短叶松梢上的得菌率是13．8％—57．1％,月份之间的差异较大;马尾松得菌率最低,为9．7％—22．4％,多数分离得菌率低于20％。健康梢的不同部位得菌率有一定差异,枝和新梢较高,芽稍低,叶最低。在1年中,健康梢上得菌率有3个高峰期,即4—5月、7—8月和10—11月,是潜伏侵染的的主要时期。将健康芽和梢进行诱发培养,lOd后组织块上及周围产生松枯梢病菌的分生孢子器,得菌情况与常规分离相似。在当年孢子散发之前,对健康梢套袋隔离试验,发现套袋梢仍会发病,说明在发病的春梢中,有一部分是由于潜伏侵染的松枯梢病菌造成的。从而证明松枯梢病菌在火炬松、湿地松、短叶松和马尾松上普遍存在潜伏侵染。