桑天牛在不同树种或品种间产卵选择性试验

选用１１个树种、２３个桑树品种、４０个毛白杨无性系、１６个苹果品种和白杨派６个树种或无性系，进行了桑天牛产卵选择性试验。结果表明：桑天牛在不同树种间产卵选择性差异极显著；在苹果品种间、桑树品种间，毛白杨无性系间，白杨派不同树种及无性系之间，产卵选择性差异均不显著，但在个别品种上产卵数量较少，有待进一步研究。     

十堰市引种栽培油橄榄品种的叶片与果实表型性状分析

以十堰市引种栽培的6个不同油橄榄品种为研究对象,测定各品种的叶片及果实表型性状，采用方差分析比较不同油橄榄品种间的性状差异，采用Person相关分析研究各表型性状间的相关性，研究结果表明：不同油橄榄品种间的叶片及果实表型性状存在显著差异，‘皮削利’、‘鄂植-8号’和‘云台’果实较大，‘豆果’、‘阿尔波萨纳’与‘奇迹’果实较小；部分表型性状间相关性显著，可根据叶片性状初步筛选果肉率高的优良品种,为油橄榄品种鉴别及良种选育提供依据。     

迷迭香的引种栽培研究

通过对引进的8个迷迭香品种在3个试验地的栽培试验研究。结果表明,迷迭香的高生长和冠幅生长在品种间存在显著差异,生长表现好的品种有SUBURY BLUE、UPRIGHT和标准迷迭香,高生长和冠幅生长在不同试验点间也存在显著差异,在乐昌市龙山林场种植的综合表现较好,文章还说明在粤北地区种植迷迭香合适的株行距离,以及修枝管理对迷迭香生长的影响。     

不同种源火炬松和湿地松木材基本密度和管胞长度的变异

对1984年种植在广西和浙江的22个种源的火炬松及在浙江的8个种源的湿地松的木材密度和管胞长度进行了测定和分析。结果表明,两个树种的木材密度和管胞长度在种源间和种源内单株间均表现出显著差异,但株间差异较种源间差异显著得多。不同地区火炬松的差异较之同一地区不同种源间的差异更为显著。种源、地区的交互作用对火炬松的木材密度和管胞长度都表现出显著影响,种源和单株的交互作用对两个树种的木材密度也有显著影响。两个树种的木材材性与年轮宽度之间没有显著的相关关系。与马尾松和早期引种的火炬松、湿地松比较表明,用新引进的材料可选育出木材材质更为优良的品种。     

不同品种大枣产量及生理特性比较研究

通过对朝阳地区6种不同枣树品种的产量和生理特性的比较研究,结果表明:金铃圆枣的产量最高,为8 491.03 kg·hm-2,大圆铃枣的产量最低,为4 925.43 kg·hm-2,大圆铃枣的产量与其余5个品种的产量差异达到极显著水平,其余枣树品种间差异都不显著;6个枣树品种光合速率和气孔导度日变化曲线均呈双峰型、蒸腾速率日变化呈单峰型,不同枣树品种的光合速率、蒸腾速率和气孔导度间的差异均未达到显著水平,枣树品种的产量受蒸腾速率的影响最大。     

猕猴桃果实畸形现象的初步研究

观察研究了中华猕猴桃和美味猕猴桃共１２个品种（系）的畸形果发生情况。结果表明，在自然状态下，不同种类品种的果实畸形果率有显著差异，品种间果实畸形率不及种间差异明显；使用大果灵（ＣＰＰＵ）会普遍提高畸形率，多毛品种提高幅度更大，而使用２，４－Ｄ和人工授粉可使畸形率显著下降；畸形部位与种子发育状况密切相关。由此推测，畸形果发生与授粉受精不完全和内源激素失衡导致的种子退化有关。     

猕猴桃果实畸形现象的初步研究

观察研究了中华猕猴桃和症状味猕猴桃共１２个品种（系）的畸形果发生情况。结果表明，在自然状态下，不同种类品种的果实畸形果率有显著品种间果帝畸形率不及种间差异明显；使用大果灵（ＣＰＰＵ）会普遍提高畸形率，多毛品种提高幅度更大，而使用２，４－Ｄ和人工授粉可使畸形率显著下降；畸形部位与种子发育状况密切相关。由此推测，形果发生与授粉受精不完全和内源激素失衡导致的种子退化有关。     

银杏幼树嫁接良种技术研究

用郯城９号、５号、１３号、１６号、３１３号、３１７号６个银杏品种进行嫁接试验，嫁接成活率均在８３．３％以上，品种间无明显差异，新梢生长量以郯城９号最大为４２．０ｃｍ，郯城９号等５个品种间无显著差异，均与３１３号（２１．２ｃｍ）有显著差异。以郯城９号为试材进行嫁接部位、接穗留芽数、接穗年龄及粗度试验，结果表明：嫁接部位在苗高５０～８０ｃｍ较好，成活率均在８５％以上，幼树生长旺盛；接穗留３芽成活率可达９０％以上，留单芽成活率仅６０％；接穗年龄对嫁接成活率影响不显著，但接后新梢生长以１～３年生较好；接穗粗度以０．４～０．９ｃｍ为好。     

辽河杨 辽宁杨 盖杨在宁夏地区的引种试验

辽宁杨、辽河杨、盖扬三个品种于1997年引入宁夏中卫地区，在同一立地类型和同等抚育措施条件下，育苗、造林均表现出良好的适应性。育苗成活率、造林成活率与当地主要杨树品种新疆杨无明显差异，但生长量显著高于新疆杨；抗寒性能与新疆杨相当；虽和新疆杨一样易感染天牛虫害，但由于其速生性使天牛不能完成生活史而不至于造成危害。作为速生树种，在中及类似条件的地区具有良好的发展前景。     

刺槐无性系造林试验研究

该文研究了在相同立地条件下 ,8个刺槐无性系品种间在地径、树高生长量方面的差异。结果表明 ,D110 与对照在地径、树高生长量上有显著差异     

云南省澳洲坚果害虫资源调查

1996～2000 年对云南澳洲坚果园害虫资源调查结果:共计有39 科,150 种害虫,按其目前的为害程度分为 5 类,Ⅰ类害虫 8 种,Ⅱ类 18 种,Ⅲ类 59 种,Ⅳ类 49 种,Ⅴ类 16 种,果园害虫种类有随树龄增长而减少和某些害虫为害增加的趋势;目前果园内害虫与对其控制的自然因子间还处于一定的平衡状态,一些重要害虫的为害尚保持在一个较低的水平。     

云南省澳洲坚果病害

通过对云南省澳洲坚果病害的3次全面调查,初步查明有19种病害(真菌病害15种,生理病害4种),并对其为害状况、分布、病原作简要描述。     

几种植物生长调节剂对澳洲坚果幼树的控梢效果比较

用植物生长调节剂多效唑、乙烯利、矮壮素、B9对澳洲坚果幼树进行控梢处理,结果表明:多效唑对澳洲坚果幼树的生长有极显著的抑制作用,其中3和2.5g/L处理的幼树营养生长受到严重抑制;乙烯利对澳洲坚果幼树新梢的抽发、梢长、节间长有显著影响,1.5和2g/L处理后幼树的新梢表现出乙烯的"三重效应"。矮壮素和B9对澳洲坚果幼树新梢抽发抑制作用极显著,矮壮素1.5、2g/L处理的幼树在喷药后2个月没有抽发新梢;B9处理的幼树新梢抽发量很少,对照的新梢数是其它处理新梢数的数十倍。     

What factors influence the collapse of trees retained on logged sites?: A case-control study

Living trees (green trees) are intentionally retained on logged sites for many purposes such as wildlife conservation, future wood potential and aesthetics. Minimizing the risk that these trees collapse in the short-term will improve the chances that green-tree retention meets its objectives. In a retrospective case-control study, we identified factors significantly associated with the collapse of living trees retained on logged and slash-burnt sites in south-eastern Australia within 8 years of harvesting. Trees with incomplete crowns or trees with at least one visible cavity were, on average, at three times greater risk of collapse relative to trees with complete crowns or no visible cavities, respectively. Trees with fire-scarring, trees retained greater than 50 m from intact forest or trees retained in isolation were, on average, around twice the risk of collapse relative to trees without fire-scarring, trees retained within 50 m of intact forest or trees retained among other trees, respectively. When considered jointly, the significant factors in a model predicting the collapse of retained trees – tree height, tree diameter, crown form – were all associated with the health of trees. Choosing the healthiest trees possible for fulfilling their function, protecting trees from damage (e.g. fire) and retaining trees near, or among, other trees are likely to reduce the risk of collapse among retained trees and thus contribute to the effectiveness of green-tree retention in logged eucalypt forests.     

磷胁迫对澳洲坚果幼苗叶片光合特性和荧光参数的影响

采用塑料管土柱法研究了磷胁迫对澳洲坚果幼苗叶片光合作用及叶绿素荧光特性的影响。结果表明:低磷CK(不施磷作为对照)、中磷MP(175 mg/kg P2O5)与高磷HP(350 mg/kg P2O5)之间有显著差异,澳洲坚果幼苗叶片的光合参数在低磷处理下净光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(C i)、气孔导度(Gs)均呈下降趋势,表明了供试的6个澳洲坚果品种(Hy、A16、863、951、695和Daddow)幼苗叶片光合能力随胁迫程度的加重均下降,叶绿素荧光参数中的最大荧光(Fm)、可变荧光(Fv)和最大荧光比(Fv/Fm)在低磷处理下也均降低,而初始荧光(F0)值升高。6个澳洲坚果品种之间有显著差异,根据测定参数对澳洲坚果各个品种幼苗的耐低磷能力进行综合评价,从强到弱依次为Daddow>951>695>A16>Hy>863。     

采伐作业对长白山阔叶红松林林下植被影响的研究(英文)

森林采伐是森林经营中的一个关键环节。采伐对树木天然更新的影响直接关系到森林的结构、组成及森林的可持续经营。本文以长白山阔叶红松林为研究对象,对择伐5 年后不同作业迹地(集材道、楞场和采伐后林窗)的幼苗更新及灌木、草本的多样性进行研究,并以没有进行采伐干扰的林地作为对照。共设计样地23 块,在各个小样地内调查幼树的种类、树木、高度;灌木和草本植物的种类、树木、高度和盖度,应用SPSS 软件进行一元方差分析。结果表明,择伐作业影响幼苗的更新,灌木和草本的多样性在作业迹地增加,尤其在林隙处的多样性最高。适当采伐能促进幼苗的更新,特别是阔叶树种的更新。集材道对幼苗密度的影响比对幼苗高度的影响大,幼苗密度在集材道上密度最高;采伐作业对针叶树种有严重的影响,在三种作业迹地上针叶树种的密度都比对照低。为了维持森林的结构和组成,在森林收获和楞场的建立时,必须采取科学措施保护针叶树种。此外,采伐林窗和楞场的面积都应该减小。为了确保采伐迹地建群树种的更新,经营中应该在保护生物多样性的前提下,适当控制过于旺盛的灌木和草本层的生长。本研究结果将为采伐后作业迹地的恢复和森林的可持续经营提供科学的依据。图1 表4 参14。     

Time course of δ1¹³C in poplar wood: genotype ranking remains stable over the life cycle in plantations despite some differences between cellulose and bulk wood

Genetic differences in δ13C (isotopic composition of dry matter carbon) have been evidenced among poplar genotypes at juvenile stages. To check whether such differences were maintained with age in trees growing in plantations, we investigated the time course of δ13C as recorded in annual tree rings from different genotypes growing at three sites in southwestern France and felled at ～15-17 years. Wood cores were cut from tree discs to record the time course of annual basal area increment (BAI). The isotopic ratio δ13C was recorded in bulk wood and in extracted cellulose from the annual rings corresponding to the period 1996-2005. Discrimination against 13C between atmosphere and tissues (Δ13C) was computed by taking into account the inter-annual time course of δ13C in the atmosphere. Annual BAI increased steadily and stabilized at about 8 years. An offset in δ13C of ～1‰ was recorded between extracted cellulose and bulk wood. It was relatively stable among genotypes within sites but varied among sites and increased slightly with age. Site effects as well as genotype differences were detected in Δ13C recorded from the cellulose fraction. Absolute values as well as the genotype ranking of Δ13C remained stable with age in the three sites. Genotype means of Δ13C were not correlated to annual BAI. We conclude that genotypic differences of Δ13C occur in older poplar trees in plantations, and that the differences as well as the genotype ranking remain stable while trees age until harvest.     

Stem sapwood permeability in relation to crown dominance and site quality in self-thinning fire-origin lodgepole pine stands

Stem sapwood hydraulic permeability, tree leaf area, sapwood basal area, earlywood to latewood ratio of annual rings, radial variation in hydraulic permeability and stem hydraulic capacity were examined in dominant (D), codominant (CD) and suppressed (SP) lodgepole pine (Pinus contorta Dougl. ex Loud.) trees growing on medium and poor sites. Hydraulic permeability on a sapwood area basis (ks) was lower in suppressed trees (0.71 x 10(-12) m2) compared to dominants (1.97 x 10(-12) m2) and codominants (1.79 x 10(-12) m2), and higher on medium than on poor sites. The leaf/sapwood area ratio (S) varied with crown dominance position (D > CD > SP) but not by site type. Leaf specific conductivity (kL) did not vary between crown classes or site types. The relationship between leaf area and stem hydraulic supply capacity (Q*) was strong, but differed among crown classes. Dominant trees and trees from the medium sites had a greater proportion of earlywood in outer rings of sapwood than suppressed trees. Sapwood permeability declined from the cambium to the sapwood-heartwood boundary in all samples, but the decline was more gradual in dominant trees compared to codominant and suppressed trees; differences in the radial variation in sapwood permeability may be related to differences in S. Sapwood permeability is positively related to crown dominance, whereas subdominant (CD and SP) trees have greater Q* in relation to leaf area, leading us to propose that this may give subdominant trees a survival advantage, slowing self-thinning.     

Dormancy of micropropagated sour cherry plantlets

Micropropagation of fruit trees results in the early onset of dormancy in the young plantlets. Prechilling of shoot cultures of sour cherry cvs Schattenmorelle and North Star at 4 degrees C for 6-8 weeks prolonged shoot extension of the plantlets but longer cold treatments adversely affected shoot growth and survival. Chilling of cultures had no affect on rhizogenesis. No significant influence of ABA, GA(3) or ABA + GA(3) was observed on root development. Gibberellic acid A(3) did not stimulate extension of the shoots, but when supplied together with ABA, it significantly decreased both shoot extension and the number of actively growing apices of plantlets of cv Schattenmorelle. The combined hormonal treatment had no effect on plantlets of the North Star cv.     

Five-year vegetation control effects on aboveground biomass and nitrogen content and allocation in Douglas-fir plantations on three contrasting sites

Despite widespread use of intensive vegetation control (VC) in forest management, the effects of VC on allocation of biomass and nutrients between young trees and competing vegetation are not well understood. On three Pacific Northwest sites differing in productivity, soil parent material, and understory vegetation community, we evaluated year-5 effects of presence/absence of 5 years of VC on allocation of aboveground biomass and nitrogen (N) between planted Douglas-fir (Pseudotsuga menziesii var. menziesii) and competing vegetation. Equations for predicting bole, branch, foliar, and total dry weights based on stem diameter at a height of 15 cm and total tree height did not differ significantly among sites or by presence or absence of VC. This contrasts with previous research, using diameter at breast height rather than at 15 cm, which found that separate equations were warranted for trees with and without competing vegetation. Estimated whole-tree biomass among the six site/VC combinations ranged from 0.8 to 7.5 Mg ha⁻¹, and increases in tree biomass associated with VC ranged from 62% to 173% among sites. Among the three sites, there were positive, linear relationships between soil total N content to a depth of 60 cm and both N content of aboveground vegetation (trees plus competing vegetation) and Douglas-fir foliar N concentration. Tree N content increased by 8.4, 8.2, and 40.0 kg N ha⁻¹ with VC at the three sites, whereas competing vegetation N content decreased with VC by 0.9, 18.8, and 32.0 kg N ha⁻¹, respectively, at the same sites. Thus, VC did not lead to a direct compensatory tradeoff between aboveground N content of trees and other vegetation. However, soil N content was linearly related to N accumulation and plant growth across the three sites. In addition to differences in N availability among sites, the effect of VC on the redistribution of resources among trees and competing vegetation also was influenced by vegetation community composition and efficacy of VC treatments.