关于小蠹虫的防治策略及研究发展方向   总被引：1，自引：0，他引：1  

高长启  宋丽文  徐桂莲  刘修英  魏松艳 《吉林林业科技》2000,(4)

小蠹虫是世界性大害虫 ,特别是对松树危害极大 ,猖獗时常可造成林木成片枯死。其生活隐蔽 ,繁殖迅速 ,在造成林木枯萎前不易被人们发现。但衰弱木及某些种类的性外激素对其有很强的吸引力 ,诱集效果显著 ,可作为重要的监测手段。该虫主要发生在立地条件差、林地卫生条件不好或由其它各种原因导致树木生长衰弱的林分。因此 ,其预防措施主要是选用良种壮苗 ,进行适地适树营造混交林 ;加强监测 ,及时消灭虫源基地。其防治策略及研究发展方向应向以生态管理为基础 ,以生物防治为主导的综合治理方向发展 ,方能达到可持续控制小蠹虫对林木的危害  相似文献   

Mortality trends in the African cherry (Prunus africana) and the implications for colobus monkeys (Colobus guereza) in Kakamega Forest, Kenya     

Peter J. Fashing   《Biological conservation》2004,120(4):449-459

Prunus africana (Hook.f.) Kalkm. is a secondary forest canopy tree species that has been declining over much of its geographical range in sub-Saharan Africa during recent decades due to unsustainable harvesting of its bark for the international medicinal plant trade. One of the locations where the species is experiencing rapid mortality is Isecheno study site in the Kakamega Forest, Kenya where this study was conducted. Between 1997 and 2003, 21% of the P. africana (10 cm DBH) at Isecheno died and an additional 9% experienced 50% canopy dieback. However, scars from bark harvesting on P. africana were relatively small and scarred trees were not more likely to be dead or dying than unscarred trees, suggesting that bark exploitation is not causing P. africana mortality at Isecheno. Other possible causes that require further evaluation include disease, insect attack, nutrient deficiency, and/or climatic fluctuation. The poor regeneration of P. africana at Isecheno can likely be explained by the relative lack of recent disturbance coupled with the thick undergrowth layer at this site. P. africana mortality is of concern not only because the species is listed as Vulnerable by IUCN, but also because black and white colobus monkeys [Colobus guereza (Rüppell, 1835)] at Isecheno exploit it as their top food species and are particularly reliant on its leaves during times of ‘preferred' Moraceae fruit scarcity. The anticipated continued decline of P. africana may have adverse effects on C. guereza feeding habits, intergroup relations, and population density at Isecheno. Conservation of P. africana offers a formidable challenge since the species appears to require disturbance for regeneration, yet at sites where disturbance is occurring, P. africana is often a target of bark harvesters engaging in unsustainable levels of exploitation.  相似文献   

Factors affecting the spatio-temporal dispersion of Ips typographus (L.) in Bavarian Forest National Park: A long-term quantitative landscape-level analysis     

Angela Lausch  Lorenz FahseMarco Heurich 《Forest Ecology and Management》2011,261(2):233-245

The relationship between abiotic and biotic factors and the spread of the European spruce bark beetle, Ips typographus (L.), was investigated at a landscape level over a model period of 18 years in the Bavarian Forest National Park in Germany. Deadwood areas - where I. typographus - caused tree mortality of 100% - were photographed annually using Color-infrared aerial photography and digitally recorded in vector form. Thirty-two static and dynamic habitat variables were quantitatively determined using spatial pattern analysis and geostatistics from 1990 to 2007 at the landscape scale. The importance of the presence of deadwood areas for thirty-two habitat variables for the occurrence of the bark beetle was quantitatively recorded using an Ecological Niche Factor Analysis (ENFA).It was shown over a long model period that the intensity of the bark beetle infestation went through different phases over the 18-year study period. No mono-causal correlations could be found between individual habitat factors and the spread of the bark beetle over the entire model period. On the one hand, these findings underline the complexity of the system, on the other hand, this could be interpreted as a possible explanation for conclusions drawn by previous studies that differ from each other.The importance of individual habitat variables and the combinations of variables varied to different extents within these phases. An examination of the cumulative importance of the habitat demonstrated that the biological structural variables such as the distance from the site of the previous year's infestation, the area and the perimeter of the infested areas from the previous year are of great importance for the incidence of the bark beetle, but not across all years. Of equal significance for assessing the size of the area and the distance of the deadwood areas from the sites of the previous year's infestation are the size of the areas, the perimeter of the deadwood areas and the proximity index. An evaluation of the stages of forest succession showed that cumulatively, a short distance between the infested areas and the forest areas with conifers in the early stages of growth was an equally important habitat factor from 1990 to 2007. By quantitatively recording habitat factors that are significant for the spread of the bark beetle it may help predict areas that are at risk and thus to develop suitable management strategies to minimise or stop the spread and the effect of the bark beetle.  相似文献   

杨树树皮中化学成份与溃疡病关系的初步研究—Ⅱ．酚类与溃疡病的关系   总被引：1，自引：0，他引：1  

朱玮  景耀 《西北林学院学报》1989,4(2):45-54

本文应用统计分析方法对毛白杨、北京杨、加拿大杨、P-15A杨、箭杆杨、青杨树皮中酚类与溃疡病的关系进行了初步研究。相关分析的结果表明,杨树溃疡病菌分生孢子的萌发率和菌落生长率与总酚、其它酚类(水解单宁类、酚苷等)、咖啡酸、水杨苷成显著负相关、与缩合单宁类、水杨酸成显著正相关。主成份分析的结果表明,不同派杨树品种之间、同一派不同杨树品种之间树皮中总酚、其它酚类、缩合单宁类含量及对溃疡病抗性的差异十分明显。同时,建立两组主成份方程,为抗病品种的早期选育,提供了一种科学而实用的方法。  相似文献   

巴西橡胶树木质部和树皮比较蛋白质组学研究     

王斌  王海燕  王丹  常丽丽  王旭初  田维敏 《热带作物学报》2012,33(5):837-842

采用改进酚抽法提取巴西橡胶树木质部和树皮蛋白。结果显示,在双向电泳图谱上可分辨500多个蛋白点。木质部和树皮的蛋白表达谱存在明显差异。选取48个差异蛋白点或者高丰度蛋白进行MALDI-TOF MS质谱鉴定,成功鉴定出26个蛋白,其中,与氢氰酸合成相关的两个酶是树皮特有的,而半胱氨酸转甲基酶是木质部的高丰度蛋白。  相似文献   

刨花润楠树皮率·生材含水率及木材密度研究     

樊吉尤  韦鹏练  卓宇  符韵林 《安徽农业科学》2011,(9):5278-5280,5296

[目的]摸清刨花润楠的木材材性。[方法]从广西贺州市大桂山林场采集刨花润楠为试材,采用排水法测定生材体积,采用体积法及质量法测定树皮率,研究刨花润楠的生材密度、树皮率及含水率。[结果]刨花润楠的生材密度随树高增加而减小,平均值为0.789g/cm3;基本密度的径向变化随树龄增加而增大,纵向变化随树高增加,基本密度在枝下高以下缓慢减小,在枝下高以上缓慢增大,平均值为0.454 g/cm3;生材含水率,从髓心向外,北向减少,南向呈先增加后减少的趋势,并随树高增加,在枝下高以下逐渐增大,在枝下高以上变化不大,平均值为73.8%;树皮体积百分率及质量百分率均随树高增高而增加,平均值分别为12.2%和13.2%。[结论]该研究为保护、发展广西重点珍贵树种刨花润楠提供了科学依据。  相似文献   

Effects of bark harvest and other human activity on populations of the African cherry (Prunus africana) on Mount Oku, Cameroon     

Kristine Stewart   《Forest Ecology and Management》2009,258(7):1121-1128

Bark extracts from the African cherry, Prunus africana (Rosaceae), are a popular treatment for enlarged prostates. Harvests of the bark began in Cameroon in the 1970s. Because of concerns regarding the sustainability of the trade, the species is included on the IUCN Red List and in CITES Appendix II. This study followed five P. africana populations in the Kilum-Ijim Forest Preserve on Mount Oku, Cameroon, examining growth, mortality and reproductive parameters, as well as response to harvest and other human activities. During the first part of the study (1998–1999), the forest had limited human activity; by the second part (2007–2008), more activity was apparent, including wildfires, grazing and a forest-wide bark harvest in 2005/2006. Over the study period, population structure differed from a typical J-shaped frequency curve for long-lived species, which may reflect past harvesting. After the 2005/2006 harvest, the population structure had shifted slightly toward the smaller size classes. In addition, the number of surviving trees was reduced in all size classes. About half of the reproductive trees died during the study. Size class was not a significant predictor of death, but the location of the harvest (plot) was. All trees affected by wildfires died, suggesting that the species is not adapted to fire. Trees that were harvested without disrupting the vascular cambium survived better and had minimal loss of crown. Thus, the fate of the trees in a given plot may lie in the care taken by an individual harvester. Average growth (0.34 cm per year) was not significantly different among the size classes. Crown die-back significantly reduced fruit production, obscuring the asynchronous alternating fruiting pattern. Seedling numbers followed a similar alternating pattern, but survival was negligible due to grazing. The combined factors of mortalities of a large percentage of reproductive trees (especially the largest ones), highly reduced fruit production and poor seedling survival offer a bleak prognosis for future regeneration and long-term persistence of the species in this forest. Only after decades of harvest are existing standing crop inventories and scientifically based annual quotas now being determined. It is known that the trees are easily domesticated. Efforts have been intensified to train villagers and community forest managers in vegetative propagation techniques and nursery practices, offering some hope that the species can be successfully managed to provide for sustainable harvests and dependable rural livelihoods.  相似文献   

Structure of a Central-European mountain spruce old-growth forest with respect to historical development     

Miroslav Svoboda  Václav Pouska 《Forest Ecology and Management》2008

This study examines the structural characteristics of the tree layer, dead wood, canopy openings, and regeneration patterns of a spruce old-growth forest in the Bohemian Forest, Czech Republic. An old-growth stand with minor human influence and a stand that was presumably logged about 200 years ago were analyzed and compared, as some forest managers considered the presumable human impact as a reason for salvage logging. Even though the stands differed in tree density, height and DBH structure, it was not possible to conclude whether it was due to management history or the environmental differences. The volume of dead wood also differed between the stands. There was about 142 and 83 m³ ha⁻¹ of dead wood in the old-growth stand and presumably logged stand, respectively. The amount of dead wood found in the old-growth stand was comparable with values reported from spruce old-growth stands across Central Europe. In both stands, many canopy trees were arranged in linear patterns, which was a result of spruce regeneration on nurse logs. This suggests that the origin and development of the stands were characterized by natural processes and during the past 200 years typical old-growth structural characteristics have already evolved.  相似文献   

Bark beetles,fuels, fires and implications for forest management in the Intermountain West     

Michael J. Jenkins  Elizabeth Hebertson  Wesley Page  C. Arik Jorgensen 《Forest Ecology and Management》2008

Bark beetle-caused tree mortality in conifer forests affects the quantity and quality of forest fuels and has long been assumed to increase fire hazard and potential fire behavior. In reality, bark beetles, and their effects on fuel accumulation, and subsequent fire hazard, are poorly understood. We extensively sampled fuels in three bark beetle-affected Intermountain conifer forests and compared these data to existing research on bark beetle/fuels/fire interactions within the context of the disturbance regime. Data were collected in endemic, epidemic and post-epidemic stands of Douglas-fir, lodgepole pine and Engelmann spruce. From these data, we evaluated the influence of bark beetle-caused tree mortality on various fuels characteristics over the course of a bark beetle rotation. The data showed that changes in fuels over time create periods where the potential for high intensity and/or severe fires increases or decreases. The net result of bark beetle epidemics was a substantial change in species composition and a highly altered fuels complex. Early in epidemics there is a net increase in the amount of fine surface fuels when compared to endemic stands. In post-epidemic stands large, dead, woody fuels, and live surface fuels dominate. We then discuss potential fire behavior in bark beetle-affected conifer fuels based on actual and simulated fuels data. Results indicated that for surface fires both rates of fire spread and fireline intensities were higher in the current epidemic stands than in the endemic stands. Rates of spread and fireline intensities were higher in epidemic stands due, however, to decreased vegetative sheltering and its effect on mid-flame wind speed, rather than changes in fuels. Passive crown fires were more likely in post-epidemic stands, but active crown fires were less likely due to decreased aerial fuel continuity. We also discuss the ecological effects of extreme fire behavior. Information is presented on managing forests to reduce the impact of bark beetle outbreaks and the interplay between management, bark beetle populations, fuels and fire hazard and behavior.  相似文献   

树皮有机基质对毛竹的施肥效果初探     

杨柳青  熊芳  冯加生  龚群龙  朱天才  刘志昂 《河南林业科技》2008,28(4)

选用树皮有机基质和两种生物有机肥料对毛竹进行了施肥试验。通过连续2 a的试验观察和测量,结果表明树皮有机基质能提高土壤有机质含量,改善土壤条件,提高土壤肥力,且肥效较长,促进了行鞭育笋,减少退笋,提高了毛竹产量,每亩增加毛竹13株,增加毛竹重量216.1kg,但并没有增大毛竹胸径。与两种有机肥料相比,其增产效果相对较差。  相似文献