THE QUICK DETERMINATION METHOD OF RESIN CONTENT IN LARCH WOOD

The resin content in larch wood is usually determined by the traditionalBenzene-Alcohol Extract Method(BAEM).In order to meet the requirement of production prac-tice,the authors present two simple quick determination methods,IR lamp method and hydrogenperoxide solution method.Compared with the results of traditional method,the results of newmethods are nearly the same as former,therefore,both two methods can reflect the change condi-tion of resin content in wood.     

Impact of weather variables and season on sporulation of Phytophthora pluvialis and Phytophthora kernoviae

Phytophthora pluvialis and Phytophthora kernoviae are the causal agents of important needle diseases on Pinus radiata in New Zealand. Little is known about the epidemiology of the diseases, making the development of control strategies challenging. To investigate the seasonality and climatic drivers of sporulation, inoculum traps, consisting of pine fascicles floating on water in plastic containers, were exchanged fortnightly at five sites in P. radiata plantations between February 2012 and December 2014. Sections of needle baits were plated onto selective media and growth of Phytophthora pluvialis and P. kernoviae recorded. To explore the generalizability of these data, they were compared to detection data for both pathogens from the New Zealand Forest Health Database (NZFHDB). Further, equivalent analyses on infection of Rhododendron ponticum by P. kernoviae in Cornwall, UK allowed the comparison of the epidemiology of P. kernoviae across different host systems and environments. In New Zealand, inoculum of P. pluvialis and P. kernoviae was detected between January–December and March–November, respectively. Inoculum of both species peaked in abundance in late winter. The probability of detecting P. pluvialis and P. kernoviae was greater at lower temperatures, while the probability of detecting P. pluvialis also increased during periods of wet weather. Similar patterns were observed in NZFHDB data. However, the seasonal pattern of infection by P. kernoviae in the UK was the opposite of that seen for sporulation in New Zealand. Phytophthora kernoviae was likely limited by warmer and drier summers in New Zealand, but by colder winter weather in the UK. These results emphasize the importance of considering both environmental drivers and thresholds in improving our understanding of pathogen epidemiology.     

Artificial inoculation and susceptibility of Pinus armandii to Dothistroma septosporum

Dothistroma needle blight (DNB) is a serious needle disease of conifers that primarily affects pine species (Pinus spp.). Dothistroma septosporum is one of the DNB pathogens that has a diverse range of host species excluding Pinus armandii. In 15 inoculated P. armandii seedlings, D. septosporum acervuli were observed in 43 infected needles of ten seedlings with a mean disease severity of 1.11% at 25 weeks after inoculations, demonstrating the potential of D. septosporum to cause symptoms on the needles of P. armandii via artificial inoculation. The disease severity of P. armandii was similar to the positive control, Pinus nigra (median 0.75 for P. armandii to 0.70 for P. nigra), thus, P. armandii acts under artificial conditions as a susceptible host species.     

日本落叶松在旺苍县引种栽培初步研究

通过对旺苍县盐井河采育场10多年来引种栽培日本落叶松的结果与旺苍县外其它地区的引种栽培试验结果和本地华山松的生长情况进行对比分析，证明引种是成功的，进一步探讨了日本落叶松在旺苍的引种效果和生态适应性，提出了旺苍自然地理分布的引种适生区，是旺苍北部中山区主要速生造林树种之一。     

油松针叶枯黄原因调查研究

调查结果表明，承德避署山庄及其周边地区的油松针叶大量枯黄，侧枝枯死或整树枯死是由于松大蚜的严重危害所致。     

松针粉饲用价值及市场展望

松什粉是一种高效绿色饲料添加剂。松针资源在全国各地十分丰富，但这种资源没有得到合理有效地利用。从松针粉的饲用价值、生产工艺、市场前景以及研究应用现状说明松针资源和松针产品应该引起社会足够的关注。     

涨南红豆红锈病的发生与危害

海南省尖峰岭地区营造的5－6年生海南红豆行道树，严重发生了由红锈藻引起的红锈病，在500株幼树中，发病株率高达97.5%，Ⅲ-Ⅳ级病株率80％，病情指数75.5，导致部分叶片干枯或脱落，嫩枝枯死，树势衰弱，生长严重受阻。文章对该病的症状、病原、危害及发生规律进行了报道。     

Effect of soil air volume change on CH4 consumption in brown forest soil

The relationship between soil air volume and CH₄ consumption in brown forest soils was investigated. The CH₄ consumption was negatively affected when the soil air volume decreased in experiments carried out bothin situ and in the laboratory. A strong dependence of the CH₄ consumption on the soil air volume was found in the laboratory experiment. These results indicate the possibility that the soil air volume is the primary rate-limiting factor for the CH₄ consumption in forest soil. Thus our work suggests that the other factors by which CH₄ consumption might be affected should be examined under the same air volume condition in the soil. To obtain accurate data, we need to be careful not to change the air volume by trampling or disturbing during the measurement of the natural methane fluxin situ.     

北方草坪褐斑病防治技术

褐斑病为北方草坪常见病害 ,在了解其发病规律的前提下 ,选择最佳时期进行综合防治 ,控制病情蔓延 ,可使灾害降至最小