国外松枯梢病的松色二孢菌9个菌株生物学特性的研究

对来自不同发病程度，不同地点的国外松枯梢病松色二孢菌的９个菌株的生产，产孢等生物学特性进行了研究。结果表明，各菌株生长的最适温度为２５－３０℃，ＰＨ值为６－７，相对湿度为９０％以上；９２４５、Ｈ２１二菌株对湿度在培养其中加入１‰的硼对各菌株的生长和产孢有不同程度的抑制作用，尤以抑制产孢最明显，表现出硼对国外枯病的发生，发展有一定的控制作用。     

Pseudomonas associated with Bursaphelenchus xylophilus,its insect vector and the host tree: A role in pine wilt disease?

In this study, we characterized the diversity of Pseudomonas associated with Bursaphelenchus xylophilus, its insect vector (Monochamus galloprovincialis) and its host (Pinus pinaster), by a culture‐independent approach using rpoD clone libraries. Clone libraries of Pseudomonas rpoD were obtained from B. xylophilus, M. galloprovincialis and infected P. pinaster. Most M. galloprovincialis and B. xylophilus sequences grouped together in the P. fluorescens group. Genes related to xenobiotics degradation and phenylacetate synthesis were present in the genomes of the type strains closely related to sequences retrieved from the nematode libraries. Results demonstrated that the nematode, during its life stages inside the tree, maintains a diverse Pseudomonas community that is closely related to the one associated with the insect vector. These bacteria might contribute to degradation of xenobiotics and tree weakening during the nematode tree infection.     

不同树龄福建马尾松KP法制浆性能的评价

为了合理采伐、有效利用资源，对３种不同树龄的福建戏剧性以进行性制浆性能比较。测定了它们的纤维形态和化学组成；优选出各自的最佳蒸煮工艺；测定了浆物理强度；并对漂白性能作了研究；最后用卒 标评定法全面评价它们的制浆性能。得出２０年树龄马尾松制浆性能优良，１０年次之，３０年较差的结论。     

园林树木遮荫功效研究进展

摘要：卫星遥感是现阶段测绘领域应用较为成熟的技术,然而在农林业病虫害监测预警方面使用较为迟缓,特别是针对省级管理机构缺乏监管技术和预警能力,本研究探索了利用卫星遥感技术开展异常变色林木监测的应用实践,以服务于区域松材线虫病防控的技术指导和督查。经过3年的应用表明,高空间分辨率卫星遥感技术具有客观、科学和实时的优势,能够为上级管理机构提供决策依据。     

中低强度间伐对杆材阶段马尾松林生物量的影响

对杆材阶段不同密度的马尾松林在低强度间伐后生物量的动态变化进行了分析对比，结果表明间伐后平均木的单株生物量和各器官生物量随密度增加而减少；随林分年龄的增加，单株生物量与树干、皮、根的生物量因积累而增大，但枝、叶的生物量先增加后减少，在林分年龄为20a时达到最大值，随后又接近间伐前的数值；林分生物量随年龄增加而增加，其中密度为3000株     

Nitrogen-15 Uptake by Pinus contorta Seedlings in Relation to Phenological Stage and Season

This study measured the amount of uptake of labeled nitrogen (¹⁵N) of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm) seedlings, at three different phenological stages, in a growth chamber experiment. Thirty days after ¹⁵N application, the amount of ¹⁵N recovered in seedlings as a percentage of the total ¹⁵N fertilizer applied was 4% in early spring, 43% in summer and 33% in autumn. The total ¹⁵N recovered in the plant–pot system ranged from 80 to 96%, and is higher than reported in other studies. Total ¹⁵N recovered from the pot compartment alone ranged from 48 to 95%, suggesting that substantial pools of N remain in the soil. Results suggest that low ¹⁵N uptake in the spring was associated with limited development of new root as a result of low spring soil temperatures. The lack of unsuberized roots in spring could be a key factor decreasing the effectiveness of early spring fertilization in the boreal forest.     

Timing and intensity of precommercial thinning in Pinus sylvestris stands

The effects of timing and intensity of precommercial thinning were studied in three Scots pine artificially regenerated stands on Vaccinium forest sites in southern Finland. A two-level factorial design (3×3) was used in each stand: thinning at dominant height of 3, 6 and 9 m to 1000, 1600 and 2200 stems ha^?1. The effects of the treatments were analysed after a period of 23–25 yrs when the dominant height was 14–15 m. Early thinning resulted in the highest standing volume and amount of merchantable wood, and also in slightly accelerated height development. Thinning to 1000 stems ha^?1 caused a considerable production loss, but there were no differences between the densities of 1600 and 2200 stems ha^?1. Branches became thicker after early thinning, but the differences between the treatments were negligible for crop trees. Crown ratio was lowest as the result of early or moderate thinning (2200 stems ha^?1).     

Responses of Pinus massoniana and Pinus taeda to freezing in temperate forests in central China

Abstract

Masson pine (Pinus massoniana Lamb.), a native species widely distributed in temperate forests in central China, and Loblolly pine (Pinus taeda L.), an exotic tree species introduced to China from southeastern United States, are dominant evergreen conifers that play a pivotal role in maintaining forest structure and functions for the region. We examined the effects of freezing on these species with chlorophyll fluorescence and electrolyte leakage using both field- and laboratory-based experiments in September 2009 and January 2010, respectively. We found that freezing could cause a greater impact on the Loblolly pine than the Masson pine. Although the two species showed similar values of F _v /F _m and electrolyte leakage before freezing, the Masson pine needles showed lower F _v /F _m and higher electrolyte leakage ratios than those of the Loblolly pine when treated in low temperatures (?15 to 0°C). We also found that cold-acclimation was crucial for both species to adapt to low temperatures with the F _v /F _m ratio decreased approximately by 80% in the first freezing hour for the non-acclimated needles of both species while the cold-acclimated needles showed little changes in the F _v /F _m ratio. This finding is also supported by our measurements of electrolyte leakage. These results suggest that the Loblolly pine could be more susceptible to freezing damages than the Masson pine in central China.     

松针褐斑病初步研究

松针褐斑病的病原菌为Ｉｅｃａｎｏｓｔｉｃｔａ ａｃｉｃｏｌａ，在病叶上或叶上的病了实体和病组织中的菌丝体是初侵染源。侵染期主要在５月上旬至６月中旬。病原菌通过雨水的溅散主风力而传播。在发病初期采用百菌清可湿性粉剂和托布津农药喷液及人工摘病叶的进行防治，均能收到一定效果。     

Pattern and Composition of Secondary Succession Beneath Caribbean Pine Plantations of Southwest Sri Lanka

This study examined the vegetation growing beneath Caribbean pine (Pinus caribaea) plantations established within previously abandoned tea lands adjacent to intact rain forest in southwest Sri Lanka. To examine the pattern and composition of secondary succession and factors affecting it, vegetation was sampled in different relative locations (interior and edge conditions) within plantations. Results demonstrated that more vegetation was found near the plantation edges than in the interior, and this pattern was prominent for both wind- and bird- dispersed species. The vegetation represented a mixture of species belonging to a range of successional guilds representing early (17 species, 42.4% in stem count) and late-successional species (52 species, 40.6%), although native long-lived canopy tree species were mostly absent. Bird-dispersed species dominated the flora (80 species, 86.7% in stem count). Abundance of an exotic shrub Clidemia hirta (Melastomataceae) showed a negative correlation with that of other species, indicating its impact on native flora. Underplanting of native canopy species may be effective in assisting secondary succession and control C. hirta in the plantations.