白榆嫁接试验研究

在通辽市白榆种子园进行的嫁接试验表明:嫁接方法、辅助措施、砧木苗龄和嫁接时间对成活率均有显著影响。嫁接方法不同成活率相差达47%,辅助措施不同成活率相差10%,嫁接时间不同成活率相差达38%,砧木苗龄不同成活率也可相差16%。选用白榆优良种源区种子培育的2年生一级壮苗作砧木,采用袋接方法并套塑料袋,在砧木芽苞膨大但尚未放叶时进行嫁接效果最好。     

丽江油橄榄嫁接技术试验

在丽江市玉龙县大具乡营盘村开展了油橄榄嫁接试验,结果表明:嫁接砧木、接穗品种、嫁接方法3个因子对油橄榄嫁接成活率的影响顺序依次为:嫁接方法嫁接砧木嫁接品种;油橄榄嫁接成活率最高的组合为:嫁接砧木为佛奥,接穗品种为贝拉,嫁接方法采用插皮接,成活率高达96.67%;在丽江市大具乡进行油橄榄嫁接时,可采用插皮接,佛奥作为嫁接砧木的方法进行推广。     

薄壳核桃苗木嫁接培育技术探讨

在不同的时间,采用不同方法,选择不同的品种和砧木进行嫁接试验,分析其对成活率的影响。结果表明,6月中旬最适宜嫁接,各品种间嫁接和不同嫁接方法对成活率影响无显著差异,芽接砧木以长势中庸最好;砧木培育周期缩短1～2年,成功的嫁接可使1—2年生砧木嫁接成活率稳定在81％％左右,造林成活率达91．6％。薄壳核桃苗木嫁接技术的关键是合理把握嫁接时机,合理选择砧木,科学育苗。     

澳洲坚果砧木留叶数量对嫁接成活率及苗木品质的影响

以澳洲坚果品种A16枝条为接穗,使用合接法进行嫁接,探索澳洲坚果砧木叶片对嫁接成活率及苗木品质的影响。结果表明,砧木保留2片叶和保留全部叶片与砧木不留叶片之间的嫁接成活率达显著差异(P0.05),砧木保留2片叶嫁接成活率比相对保留全部叶片的要高,但差异不显著(P0.05),嫁接砧木留叶能有效提升嫁接成活率,而适当减少砧木叶片不影响嫁接成活率。砧木叶片数量的增加或减少对接穗生长表现出有促进或抑制的作用,砧木叶片减少对接穗有促进分枝的作用趋势。     

白榆嫁接试验研究

在通辽市白榆种子园进行的嫁接试验表明：嫁接方法、辅助措施、砧木苗和嫁接时间对成活率均有显著影响。嫁接方法不同成活率相关达４７％,辅助措施不同成活率要差１０％,嫁接时间不同成活率相达达３８％,砧木苗龄不同成活率也可相关１６％。选用白榆优良种源区种子的２年生一级壮苗作砧木,采用袋接方法并套塑料袋,在砧木芽苞膨大但尚未放叶时进行嫁接效果最好     

不同嫁接条件对红松嫁接成活率及生长的影响

进行了对红松(Pinus koraiensis)不同嫁接时间和不同砧木年龄嫁接的试验,研究结果表明:4月20日嫁接成活率最高,成活率为86%。砧木年龄4年生嫁接成活率最高,成活率为83%。成活率越高,接穗长势越好。     

砧木及嫁接方法和时间对张氏红山茶嫁接成活率的影响

采用L16(43)正交试验设计方法,对影响张氏红山茶嫁接成活率的砧木种类、嫁接方法和嫁接时间等因子进行研究。结果表明:砧木种类和嫁接方法是影响张氏红山茶嫁接成活率的主要因子;3个因子不同水平对嫁接成活率的影响各有差异;以油茶大砧或红露珍做为砧木,采用皮接法嫁接张氏红山茶,全年均可嫁接,且其嫁接成活率均较高。     

影响金叶珊瑚朴嫁接成活率的因素

以金叶珊瑚朴为接穗,普通珊瑚朴为砧木,进行了嫁接繁殖研究.试验结果表明:接穗粗度、砧木苗龄、嫁接时间、嫁接方法、保湿措施对嫁接成活率均有不同程度的影响.因接穗粗度不同而引起的成活率差异最大,达到100%;因砧木苗龄不同而引起的成活率达到78.7%,不同嫁接时间的成活率差达到76.2%,不同嫁接方法的成活率差达到56.2%,不同保湿措施的成活率差达到56.2%.选用健壮的两年生珊瑚朴实生苗作砧木,以金叶珊瑚朴充实的休眠枝为接穗,在早春砧木刚萌动时进行枝接并用塑料袋保湿,成活率最高,达到100%.     

不同因子对薄壳山核桃嫁接成活及生长影响

以薄壳山核桃实生苗为砧木,在8月份通过采用方块芽接法,研究砧木留存复叶数量、砧木遮阴度、砧木浇水时间、穗条不同部位芽、砧木不同粗度和气温对嫁接成活率的影响。结果表明:砧木以留存4片和2片复叶嫁接成活率较高,分别为91.11%和75.00%;砧木20%～40%和40%～70%遮阴度嫁接成活率较高,分别为73.89%和65.28%;砧木嫁接前1 d浇水和嫁接前当天浇水嫁接成活率较高,分别为78.19%和53.68%;采用穗条中部芽和底部芽嫁接成活率较高,分别为95.55%和88.89%;砧木粗度为3.0～4.9 cm和2.0～2.9 cm嫁接成活率较高,分别为74.00%和66.62%;气温为32～34℃时嫁接成活率较高为78.89%。因此,选择适宜的砧木和接穗能显著提高嫁接成活率。     

油茶高接换冠嫁接成活率影响试验

用长林系油茶4号、18号、21号、40号和55号5个优良新品种作接穗,对低产的普通油茶林进行高接换冠,开展砧木生长势、嫁接部位直径大小、嫁接高度、保留技数量和接穗新鲜程度5个因子对嫁接成活率的影响试验.结果表明,油茶砧木生长势越强嫁接成活率越高,砧木嫁接部位直径3～8cm嫁接成活率较高,接穗采集后越早嫁接成活率越高,砧木的嫁接高度、保留枝条数量对成活影响差异不显著.油茶砧木生长势强、嫁接部位直径3cm以上、接穗采集当天嫁接的成活率在90％以上.     

坚持和完善森林资源管理制度 保障和促进林业持续快速发展

概要阐述了森林资源在维护生态平衡、促进可持续发展中的重要作用,简要分析了当今全球和我国森林资源状况,全面总结了建国以来我国森林资源管理取得的成绩和经验,深入揭示了当前我国森林资源及其保护管理存在的问题和原因,系统介绍了我国森林资源管理的基本政策和制度。按照《中共中央国务院关于加快林业发展的决定》要求,对今后一个时期我国森林资源管理的思路、目标、任务提出了一些设想和建议。     

Short-term Effect of Thinning on Pinus sylvestris Damage and Sporulation Caused by Cronartium flaccidum

The short-term effect of thinning on cronartium rust on Scots pine ( Pinus sylvestris L.) was investigated in a stand of Scots pine (artificially seeded and in the pole-stage) severely infected by the stem-rust fungus Cronartium flaccidum (Alb. & Schwein) G. Winter. The disease rate (the number of old and fresh infections) was recorded before thinning, after which all trees with a resin-top as well as all individual branches with sporulating lesions were removed from the thinned plots, while the comparison plots remained non-thinned. The numbers of sporulating lesions were recorded on the plots annually for 2-5 yrs after thinning. Thinning had no significant short-term effect on the year-to-year relative number of sporulating lesions. The relative number of sporulating lesions, however, increased in both thinned and nonthinned trees, varying significantly from year to year. Thinning had no significant effect on the year of formation of the shoot bearing annual sporulating lesions, the duration of sporulation or the growth of the fungus along the infected shoot in perennial lesions during the first 5 yrs after the treatment.     

CAD与建筑设计的关系

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。     

Concentrations of Cadmium,Lead and Mercury in Different Soils in Two Swedish Forest Catchments

Accumulation of cadmium (Cd), lead (Pb) and mercury (Hg), as affected by organic matter content, pH of different soil compartments and the physicochemical properties of each metal, was studied in different soil types within two forested catchments of the Norway spruce (Picea abies - Vaccinium myrtillus) type. Independent of soil type, the highest metal concentrations were found in the organic layers of the soil, usually in the surface soil. The concentrations in the upper part of the mineral subsoil were about one-fifth to one-tenth, or less, of those in the organic surface soil. Concentration maxima in the B-horizon were more pronounced for Cd and Hg than for Pb. When comparing soil types, the highest concentrations of Cd were found in the less acidified fens in the discharge area, while for Hg and Pb the highest concentrations usually occurred in the mor layer of the well-drained Podzols. For all metals, the soil types with the largest accumulation had concentrations up to 2-3-fold higher in the organic layers than those with the smallest accumulation.     

Photosynthetic Characteristics of Ash and Larch in Mixture and Pure stands

IntroductionDuringthepasttwodecades,studieshaverevealedthatgrowingash(Fnainusmandshurica)andlarch(LarlksPP.)togetherinaproperwaycanincreasetheproduc-tivityQfthestandsI"'}'-'].Theyieldimprovementmechanismsattributetotwoaspects,i.e.,theabovegroundandundergr…     

用碘结晶法测量针叶树材的微纤丝角

采用碘溶液和氢氧化钠两种溶液的混合液处理针叶树材管胞弦壁切片，并用干燥法脱除切片胞壁水，对碘结晶法测量木材微纤丝角的方法进行改良．结果表明，切片的木素脱除干净彻底，次生壁微纤丝之间易形成空隙，有利于碘离子进入其中形成碘结晶，可清晰地观察到微纤丝的走向，有利于有效而准确地测量微纤丝角，与改良前进行比较，具有省时省力，节约经费的优点．     

Improvement of dispersing property of sodium sulfite-formal-dehydeanthraquinone pulping effluent by treatment withCoriolus versicolor

A strain of the fungusCoriolus versicolor was inoculated periodically into potato dextrose agar (PDA) slants containing the effluent to enhance the natural ability to grow in the effluent. The acclimated strain grown in the 50% effluent-containing PDA slant and the original strain were employed to treat the effluent. The acclimated strain could grow in a higher concentration of the effluent than the original unacclimated one. Both the original and acclimated strains improved the dispersing ability of the effluent, especially the acclimated strain because of its higher laccase secretion. The dispersing ability of the SFP effluent was improved to a level comparable to a commercial lignosulfonate product because it was strongly polymerized by the fungus. During the fungal treatment, more than 50% of the sugars were removed from the effluent, thereby increasing the purity of the SFP lignin product.This work was presented at the 48th annual meeting of the Japan Wood Research Society, April 3–5, 1998, Shizuoka, Japa     

森林冠层结构与功能及其时空变化研究进展*

林冠是森林与外界环境相互作用最直接和最活跃的界面层 ,同时 ,它本身又承载了森林生物多样性的主体部分。森林冠层研究的方法和技术在近些年取得了长足发展 ,从而促进了有关林冠结构与功能的研究。这些研究深化了人们对于林冠结构与光能截获以及群落干物质积累之间关系的认识 ,同时 ,对于森林冠层的物质循环和能量传输以及冠层内各营养级之间相互关系动态也有了更为深入的理解。考察森林冠层的结构与功能及其时空变化是深入理解整个森林生态系统的格局、过程及其运作机制的重要基础。     

Effect on maize growth of the interaction between increased nitrogen availability and competition with trees in alley cropping

Maize growing next toErythrina hedgerows had 44% lower biomass (p<0.01) and 35% lower N content (p<0.1) than maize growing in the middle of the alleys. Maize growing next toGliricidia hedgerows had the same biomass but 56% higher N content (p<0.1) than maize growing in the middle of the alleys. However these differences did not develop until 2 months after sowing of the maize.Spatial variability in soil nitrogen mineralization and mulch nitrogen release did not explain any of the differences in growth or N uptake of the maize with respect to distance from the trees. It is hypothesized that the slower growth of the maize next to theErythrina trees after 2 months is due to increasing light and/or nutrient competition from the trees as the trees recover from pollarding. The apparent lack of competition fromGlirigidia may be due to different rates of regrowth or different shoot and root architecture.A theoretical model is described demonstrating that if a crop is to take advantage of the higher nutrient availability under alley cropping it must complete the major part of its growth before the trees recover significantly from pollarding, and start competing strongly with the crop.     

Response of Japanese red pine to inoculation with a blue stain fungus,Ceratocystis piceae

To confirm the pathogenicity of a blue stain fungus,Ceratocystis piceae (Münch) Bakshi to the Japanese red pine (Pinus densiflora Sieb. et Zucc.), the responses of healthy young pine trees and stressed trees which were girdled by the half-circumferential girdling technique were investigated by the fungal inoculation test. Although neither of the pine trees inoculated withC. piceae in the non-girdled treatment nor the controls died, mortality of the trees girdled and inoculated withC. piceae was 28.6%. In the pine trees inoculated withC. piceae, the mean area of the necrotic lesion of the sapwood was significantly larger than that of the controls, and the mean of the water pressure potential of the xylem decreased, regardless of the girdling treatment. TheC. piceae was reisolated from the wood pieces near the inoculation points on the inoculated trees, but not from the controls. These results suggest that under strongly stressed conditions, the Japanese red pine trees might have been killed by heavy infestations ofC. piceae carried by bark beetles. A part of this paper was presented at the 103rd Annual Meeting of the Japanese Forestry Society (1992).