云杉矮槲寄生开花特性及化学防控

云杉矮槲寄生是严重危害三江源地区天然云杉林的多年生寄生性种子植物。对云杉矮槲寄生开花动态的定点监测结果表明:云杉矮槲寄生花期持续40天以上,单株花序寿命约为15天;雌花在花期结束后6～8天后开始坐果,幼果初期无果梗,浅绿色,直径约为1～1.3mm;果实成熟后期,果梗逐渐伸长至1～1.5mm,颜色转为深绿色。4种不同浓度的植物激素类药剂[40%乙烯利水剂,50%国光丁酰肼可溶性粉剂,20%国光萘乙酸粉剂(NAA)和90.8%脱落酸(ABA)]对云杉矮槲寄生花芽的药剂防治试验发现:1∶400的40%乙烯利水剂为防除效果最佳,可达100%,且未对云杉植株产生不良药害反应。     

乙烯利防治云杉矮槲寄生效果及安全性评估

为安全、高效利用乙烯利防治云杉矮槲寄生Arceuthobium sichuanense,在青海云杉Picea crassifolia树冠中部和下部喷施1:200的乙烯利水剂(AS)防治云杉矮槲寄生,并评估其对林下灌木和草本植物的安全性.结果显示:药后9 d,树冠下部的校正防效达到90％以上,树冠中部的校正防效达到80％...     

促使云杉矮槲寄生果实提前脱落药剂筛选

云杉矮槲寄生正在威胁三江源地区的部分云杉林，为阻断其传播途径，在云杉矮槲寄生刚结果初期喷施植物激素，促使其果实在种子未成熟就提前脱落。采用40％乙烯利水剂、20％国光萘乙酸粉剂、50％国光丁酰肼可溶性粉剂这3种植物激素进行促使云杉矮槲寄生的果实提前脱落的药剂筛选，结果表明在果实上喷施浓度为1：200的40％乙烯利水剂，施药后3d果实开始脱落，7d果实脱落率达到100％，其它2种药剂虽然也能促使提前落果，但效果次之。     

云杉矮槲寄生与环境因子的主成分分析

云杉矮槲寄生是多年生半寄生性种子植物,近年来已成为严重危害青海省云杉林的主要灾害之一。本研究以青海省仙米林场受矮槲寄生侵染的云杉林为对象,通过标准样地调查了云杉矮槲寄生林间发病的影响因子,采用SPSS软件进行云杉矮槲寄生害病情指数与环境因子的主成分分析,结果表明,影响云杉矮槲寄生病情指数变化前5位的因子依次是林分郁闭度、草本生物量、海拔、p H值和坡度。郁闭度与病情指数呈负相关关系,在郁闭度大于0.7以上的天然林分中云杉矮槲寄生发生较轻或没有发生,而在郁闭度0.4~0.5之间,云杉矮槲寄生发生严重。研究结果将对云杉矮槲寄生害的防治提供理论依据。     

5种云杉对云杉落针病的抗性测定

通过对５种云杉自然感病情况调查、人工诱发试验等证明，不同云杉树种对云杉落针病抗病性大小的顺序是：紫果云杉，青杵，川西云杉，青海云杉，粗枝云杉。通过病原菌在各云杉树种当年生针叶琼脂培养基上的生长速度，病原菌孢子在各树种当年生针叶浸汁中萌发情况的研究以及地各树种针叶组织结构和林木物候期的观测，找出了影响其抗病性的主要因素。     

红皮云杉短周期育苗技术

为适应林业现代化发展的需要,提高红皮云杉苗期生长速度,改变其育苗周期较长的不足,以培育优质壮苗。本文根据红球云杉生物学和生态学特性,运用塑料大棚容器育苗,系统地研究了红皮云杉育苗的系列技     

云杉梢斑螟防治指标研究

通过对云杉梢斑螟种群密度与云杉主干新梢生长损失率关系的调查研究,建立了云杉主干新梢生长损失率与云杉梢斑螟幼虫种群密度的回归方程为:Y=24.98-0.39X(Y为主干生长损失率,X为云杉梢斑螟种群密度,头∕株),相关系数R为0.981 1;在此基础上研究了不同价格与不同有效药剂防治云杉梢斑螟的防治指标。     

粗枝云杉、青海云杉叶锈病病原及转主寄主研究

对白龙江林区云杉、青海云杉叶锈病的病原形态、转主寄主与寄主病原交互隔离接种后认为,2种云杉叶锈病病原均为祁连金锈菌Chrysomyxa qilanensis Wang. Wu et L .粗枝云杉叶锈病病原转主寄主为山光杜鹃Rhododendron oreodoxa Franch,青海云杉叶锈病病原转主寄主为青海杜鹃Rh.przeowalskii Maxim.     

云杉小爪螨对云杉的危害及其防治方法

1999年春夏之交,黑龙江省西部地区出现了罕见的连续高温、无雨天气,空气异常干燥。在这种情况下,云杉的行道树、林分、苗木上均大量发生了云杉小爪螨(Ｏｌｉｇｏｎｙｃｈｕｓｐｉｃｅａ(Ｒｅｃｋ))。据在黑龙江省防护林研究所的云杉大树及苗木上的调查,10ｃｍ长的样枝上,平均就有50～60头成、幼螨,树体遍布蛛网状丝,使大量针叶发黄、脱落,树木长势衰弱,一些大树和苗木已近死亡边缘,行道树和其它林种受害的情况也与此类似,因此,应尽快采取必要的防治措施。1　云杉小爪螨的形态特征及生物学特性　　体长约0.3ｍｍ,宽0.2ｍｍ,椭圆形,褐红色,气…     

国外云杉遗传改良现状和粗枝云杉育种策略

综述国外云杉遗传改良现状和育种策略。讨论“种子园危机”缘由。介绍德国、瑞典、丹麦、挪威和芬兰等国欧洲云杉无性系林业研究方法、技术路线、生产规模、应用前景及可能障碍。世界云杉遗传改良正沿着高效益、低成本的方向快速发展。提出粗枝云杉近期改良策略。     

四川松树6种散斑壳菌记述

松落针病是四川省松林中的一类重要病害，可危害多种松树，造成严重损失。该文报道了四川松树上的6种散斑壳茵：Lophodermium conigenum(Brunaud)Hilitz．，L．pinastri(Schrad．)Chev．，L．sichuanense Qiu et Liu，L．indianum Singh et Minter，L．australe Dearn，L．sp(待定新种)，并对其主要特征作了记述。     

为传统名花绣球和粉团正名

为纠正植物学专著对传统名花“绣球”和“粉团”的错误考订,恢复它们的本来面目,进行了文献考证和实物比对。结果表明,《中国植物志》中的粉团Viburnumplicatum Thunb．实乃典籍中的绣球;而该书的绣球Hydrangeamacrophylla（Thunb．）Ser．,才是真正的粉团（该种曾称“八仙花”,更谬甚）。本文还对它们混淆的根源作了探讨。     

仁用杏良种选择研究

1997-2003年,在陕北榆林沙盖黄土区和黄土丘陵区,通过对引进的仁用杏品种设点观测,和对物候期、生长量、产量、出仁率、杏仁品质及抗病虫、抗霜冻等性能进行调查,尤其从抗冻性能上对不同仁用杏品种进行评述．提出了适于陕北地区栽培的仁用杏抗霜冻品种为“优一”。“一窝蜂”的抗冻性能优于“龙王帽”和“白玉扁”,“龙王帽”和“白玉扁”的抗冻能力较差。     

The role of extension in agroforestry development: evidence from western Kenya

The extension strategy used by the CARE International in Kenya Agroforestry Extension Project (AEP) is described. This strategy is evaluated in terms of documented changes in farmer's agroforestry practices and the importance of AEP relative to other changes in economic incentives, institutional support, and land use and tenure rules for agroforestry. The project served mainly to increase awareness of the multipurpose potential of agroforestry, expand available technical options, and strengthen local institutions. Its community-based extension approach was more suitable for local conditions than commodity-based, training-and-visit, farming systems, or media-based extension. Projects are encouraged to tailor extension design to local circumstances, use community participation to guide extension priorities, and use extensionists as catalysts and information brokers.Research undertaken while the author was a Principal Scientist at the International Council for Research in Agroforestry, Nairobi, Kenya.     

Defining competition vectors in a temperate alley cropping system in the midwestern USA: 2. Competition for water

A study was carried out in an alley cropping system in the Eastern Maize Belt of the United States with the objective of quantifying the competition for water between trees (black walnut (Juglans nigra L.) and red oak (Quercus rubra L.) and maize (Zea mays L.). Spatial and temporal variation in soil moisture, tree and maize rooting patterns, tree and maize water uptake, and maize leaf area expansion were determined in three treatments; barrier (polyethylene root barriers separating maize and tree roots), trench (trenching without a polyethylene barrier), and no barrier (control). Significant temporal variation in soil moisture was observed in both black walnut and red oak alley cropping systems. The barrier and trench treatments resulted in higher soil moisture in the maize alley and lower soil moisture in the tree row than the no barrier treatment. Uptake of water by maize was higher in the barrier than the no barrier treatment. However, tree water uptake was higher in the no barrier treatment than in the barrier treatment because tree roots utilized water from the maize alley. Maize leaf area was negatively impacted by water stress in the no barrier treatment. Quantification of rooting patterns revealed that maize and tree roots were concentrated in the top 30 cm soil layer where water fluctuations were greatest. The barrier and trench treatments successfully eliminated the belowground root competition between trees and maize and resulted in greater leaf area and higher grain yields than the no barrier treatment. Thus, competition for water rather than competition for light seems to be critical in defining the productivity and sustainability of this alley cropping system.This revised version was published online in November 2005 with corrections to the Cover Date.     

Dormancy induction in container-grown Abies seedlings: Effects of environmental cues and seedling age

Twelve-week-old container-grown seedlings of noble fir (Abies procera Rehd.) and Shasta red fir (A. magnifica A. Murr. var. shastensis Lemm.), both high-elevation species, were grown under controlled environments in a study of induction of terminal-bud dormancy. Eight treatment combinations of long (15 h) or short (11 h) photoperiods, warm (25°/20°C) or cool (18°/12°C) thermoperiods, and dry (–1.2 MPa) or wet (–0.6 MPa) moisture regimes were imposed upon seedlings for 12 weeks. Treatment factors significantly affecting the induction of dormancy in terminal buds of seedlings were identified over time. The results suggest that seedlings responded dynamically to dormancy cues. The warm/dry and cool/wet combinations induced dormancy in the first 2 weeks in noble fir and in the first week in Shasta red fir. Short-day/warm and long-day/cool combinations enhanced dormancy induction in weeks 3 to 4 in noble fir and in weeks 1 to 7 in Shasta red fir. Short days and cool thermoperiods independently hastened dormancy induction in noble fir in weeks 5 through 12.     

Changes in the physical and chemical properties of six Japanese softwoods caused by lengthy smoke-heating treatment

The effects of prolonged smoke-heating treatments on wood quality were investigated. Six Japanese softwoods were smoke-heated for 100 and 200h at a temperature of 75° ± 5°C, which was recorded inside the log. After smoke heating, wood quality, including moisture content, amounts of chemical components, relative degree of crystallinity (RDC) of cellulose, and sapwood color were examined. Moisture content decreased as a result of smoke heating, especially in sapwood, leading to a uniform distribution of moisture content within a log. Almost no difference was found in the amounts of chemical components between the control woods and the woods that were smoke-heated for 100h. However, in the wood that was smoke-heated for 200h, the amounts of holocellulose decreased, suggesting that thermal deterioration and/or degradation of hemicelluloses had occurred. We assume that the increase in RDC was caused by smoke heating with the crystallization of cellulose and/or thermal degradation of hemicelluloses. Almost no differences were found in sapwood color between the control woods and the woods that were smoke-heated for 100h. In the wood that was smoke-heated for 200h, however, L*decreased, whereas a* and b* increased. As a result, E*ab, showing the total color change, increased, resulting in a deeper color. These results suggest that thermal degradation of hemicelluloses was caused by smoke heating for over 100h. Therefore, smoke heating of softwood logs using a commercial-scale kiln should not exceed 100h.     

60Co-γ射线辐射对油茶植株生长量及果实形态的影响*

采用60Co-γ射线对岑软2号、岑软3号、岑软11号3个普通油茶（Camellia oleifera）无性系种子进行0、1000、2000、3000 rad剂量辐射处理,对连州1号普通油茶优树种子进行0、1000、2000 rad剂量辐射处理,研究辐射对成年油茶植株树高和冠幅、果产量、果实形态等指标的影响。结果表明：4种油茶经60Co-γ辐射处理后,树高、冠幅间无显著差异,且单株均能正常生长;平均单株果产量随年份呈现明显的大小年变化,岑软2号、岑软3号在2014年辐射组平均单株果产量较CK有明显提高,岑软11号的年平均单株果产量在0~3000 rad剂量范围内随辐射剂量的增加而下降;3000 r辐射使岑软11号油茶果实纵横经减小,其他辐射组岑软11号果实纵、横径生长均有不同程度的增长;岑软2号在1000 r辐射下果皮变薄,岑软11号在3000 r辐射下果皮变薄而种皮厚度变化不明显,不同辐射组间岑软3号和连州1号果皮及种皮厚度没有显著变化。