后山地区青扬天牛的发生与防治

一、发生与为害青杨天牛是杨树幼树的危险性害虫。以幼虫为害杨树苗木、幼树和大树枝条,先在韧皮部与木质部之间蛀食,后蛀入木质部,阻碍养分的正常运输,被害处形成纺锤形虫瘿,易造成枝条干枯和风折,幼树树干畸形、树冠秃头状,严重影响树体发育及成材,甚至整株死亡。青杨天牛分布于东北、华北和西北地区。在乌盟四子王旗该害虫发生比较严重,发生面积占杨树分布面积的10%左右,其中严重为害面积达2500余亩。成片杨树林树冠干枯及死亡,个别发生地被迫全部平茬,造成较大的经济损失。二、生活史及习性以往资料记载该虫全国各地发生均为一年一代。…     

惠农区东方田鼠对树木为害及综合防治措施的探讨

针对宁夏石嘴山市惠农区东方田鼠严重为害幼树的情况,详述了东方田鼠的为害特特,并提出了营林、化学防治等6项防治措施。     

后山地区青杨天牛的发生及防治

青杨天牛是杨树幼树的危险性害虫。以幼虫为害杨树苗木、幼树和大树枝条，先在韧皮部与木质部之间蛀食，后蛀入木质部，阻碍养分的正常运输，被害处形成纺锤形虫瘿，易造成枝条干枯和风折，幼树树干畸形、树冠秃头状，严重影响树体发育及成材，甚至整株死亡。     

南方省区6～9月幼林化学除草技术操作

幼林地除草应该在杂草萌芽前进行化学控草 ,一者操作简便 ,二者用药量少 ,可避免幼树药害 ;三者成本低 ,效果好 ,有效期长 ,幼树免受草害 ,且经济效益高 ,省工 80 %以上 ,节资 50 %以上。现在 ,幼林化学控草时间已过 ,为害杂草已经生长茂盛 ,正在严重为害幼树生长 ,为解决幼树草害 ,建议运用以下配方 (供5～ 9月期间应用 ) :1　当年定植的幼林化学除莠1.1　五节芒、白茅、茅蕨等混生为害杂草的化学除草1.1.1　配方 1:10 %草甘膦 50 0ｍｌ 10 %草灌净 2 0ｍｌ 水 10ｋｇ 洗衣粉 30ｇ 柴油 30 ｇ。配制方法 :先用少许水 (1ｋｇ)把30 ｇ洗衣…     

药剂涂抹法防治杨树透翅蛾

杨树透翅蛾是杨树的主要害虫之一。杨树幼苗和幼树生长期间,常因遭受杨树透翅蛾幼虫为害,造成小苗风折,幼树缺顶,降低苗木质量,影响杨树健康生长。两年来,我们采用涂抹法防治杨树透翅蛾,收到良好效果。这种方法简便,省工、省药,易于推广,杀虫率一般达95—100％。一、为害征状初龄幼虫多从苗木、幼树的叶腋、侧芽、侧枝的伤口入侵,间或由     

大青叶蝉生物学特性及防治方法的研究

大青叶蝉Ｃｉｃａｄｅｌａｖｉｒｉｄｉｓ（Ｌ）属同翅目、叶蝉科。主要以第二代成虫产卵于幼树或苗条上造成幼树、苗条抽干或遭冻害。近年来灌区的农田防护林、速生丰产林受害严重。为了掌握大青叶蝉发生为害规律，正确指导防治工作，从１９８８年开始我们在海流图苗圃进行定点观察，并在临河地区进行了为害情况调查。     

楊干象鼻虫的初步研究

杨干象鼻虫(Cryptorrhynchus lapathi Linne)是世界性的大害虫,严重地为害白杨、赤杨、山杨、柳树、桦树等幼树。国外对此虫研究较多,但国内尚无详细报导。1953年我们在哈尔滨东北林学院实验林场初次发现该虫为害3—4年生的中东杨幼树,1955—1957年因为害严重,曾伐去受害中东杨三万多株。由于连续为害达10年之久,一块约三公顷的中东杨林,到现在几乎只剩数株。     

黑荆树土栖白蚁的防治研究

土栖白蚁是为害黑荆树幼树的最主要害虫之一,常造成严重缺苗或成片幼树枯死,为了有效地控制土栖白蚁的为害,我们利用灭蚁灵诱饵剂、呋喃丹颗粒剂并结合营林技术措施开展系统的防治试验,总结出造林前投放灭蚁灵诱饵剂,造林后根施呋喃丹颗粒剂防治土栖白蚁等一套行之有效的方法,取得显著的防治效果。     

银白杨锈病及其防治

杨树锈病是杨树苗期及幼树的重要病害。在新疆为害杨树的锈病主要有三种、即银白杨锈病,Melampsora rostrupii Wagner,黑杨锈病Melmpsora Larici—populina Kleb,和胡杨锈病Melamprora pruinosae Tranr,这三种锈病的共同特点,都是在杨树苗期及幼树阶段为害严重,经过自然稀疏成林后或人工定植至开扩地,锈病即显著减轻而不再造成为害。     

飞超容喷防沙木机低量雾治枣虱

近年沙枣木虱(Trioza magnisetosa Log.)严重为害我区防护林带主要造林树种沙枣,为害面积占沙枣林面积的85.2％。被害幼树常成为“小老树”,重者致死。1982年我们对张掖、高台、临泽3个县9个国营     

Tree Regeneration and Sapling Damage of Pedunculate Oak Quercus robur in a Grazed Forest in Galicia, NW Spain: A Comparison of Continuous and Rotational Grazing Systems

Forest grazing has been recognised as being a useful tool in fire-risk reduction, in addition to having the potential to preserve or enhance forest biodiversity if managed correctly. Concern for natural regeneration of forest trees in Europe has also prompted interest in the effects of large herbivores on seedling and sapling growth and mortality. An investigation was carried out into sapling damage and density of natural regeneration of oak (Quercus robur) in a mature, pony-grazed, Pinus radiata forest in Galicia, NW Spain under two different grazing regimes (continuous and rotational). In all treatments significantly more oak seedlings and saplings were recorded in areas of grass sward than areas dominated by taller ground flora species. Damage to oak saplings was assessed from the form (height and canopy) relative to stem diameter. The height and average canopy diameter of similar-aged saplings were found to be significantly greater in ungrazed (control) than both continuous and rotationally grazed treatments. Height and canopy diameters of similar-aged oak were not significantly different between the two grazing treatments. Significant differences were observed in tree form, with unbrowsed saplings having the greatest height to canopy width ratio and those in the continuously browsed plots having the smallest. An obvious decrease in the goodness of fit (R²) of regression analyses were found in continuously grazed areas compared to rotational and control plots for both height and canopy data. The differences in damage observed were not significantly different enough to suggest one method of grazing over the other as being better for minimising sapling damage. Management requirements are more likely to dictate grazing regime. Overall, stock density is likely to have a more significant effect on damage than stocking system.     

Pits and rocky microsites in a subalpine forest stand facilitate regeneration of spruce saplings by suppressing dwarf bamboo growth inside a deer-proof fence

We determined patterns of microsite suppression in dwarf bamboo Sasa nipponica when grazing deer were absent. This bamboo species is able to outcompete Hondo spruce (Picea jezoensis var. hondoensis) saplings under many environmental circumstances. We set up two 10 × 100 m plots inside a deer-proof fence within a subalpine forest on Mt. Ohdaigahara, central Japan, and two similarly sized plots outside the fence. Within the plots, we surveyed microsites where spruce saplings grew. We measured height and shoot elongation of all spruce saplings, and culm height and cover ratios of dwarf bamboo growing around each spruce sapling. Spruce sapling density and average height were higher inside the deer-proof fence than outside, as were bamboo height and cover. Thus, there was a negative effect of deer browsing on vegetation parameters outside the fence and a suppression of the negative effect of bamboo on spruce sapling growth inside the fence. Spruce sapling height was higher in tree-fall pits than in other microsites inside the fence, whereas both dwarf bamboo height and cover were lower in pits and rocky sites than elsewhere. In soil and collar microsites, spruce sapling shoot growth was lower and bamboo height and cover were higher than in pits and rocky sites. Inside the fence, dwarf bamboo cover was high, but pits and rocks suppressed its growth, allowing spruce saplings to flourish. To restore heavily damaged spruce forests with advanced saplings, it will be necessary to construct deer-proof fences and create and maintain microsites with pits and rocks.     

Shrubs facilitate recruitment of <Emphasis Type="Italic">Caragana stenophylla</Emphasis> Pojark: microhabitat amelioration and protection against herbivory

Key message

Mature Caragana stenophylla shrubs facilitated intraspecific sapling establishment by two mechanisms: microhabitat amelioration and protection against herbivory. Facilitation was mediated by climate, grazing, and sapling age.

Context

Pre-existing shrubs could facilitate sapling establishment of woody plants; however, how these facilitation vary across abiotic and biotic stress gradients and the underlying mechanisms remain unclear.

Aims

The aim of this study is understanding the facilitation of shrub on sapling establishment and how the two underlying mechanisms, microhabitat amelioration and protection against herbivory, vary across climatic aridity gradients, grazing gradients, and sapling age.

Methods

We conducted field sowing experiments to examine the facilitation of mature Caragana stenophylla Pojark on intraspecific sapling establishment.

Results

Facilitation of C. stenophylla on sapling survival increased as drought stress, grazing intensity, and sapling age increased. Microhabitat amelioration increased as drought stress and sapling age increased. Similarly, protection against herbivory increased as drought stress, grazing intensity, and sapling age increased. Relative importance of microhabitat amelioration increased as drought stress increased, and relative importance of protection against herbivory increased as grazing intensity and sapling age increased.

Conclusion

Facilitation of shrub on sapling establishment involves both microhabitat amelioration and protection against herbivory. Facilitation, the two mechanisms, and relative importance between the two mechanisms would all be affected by climatic aridity, grazing intensity, and sapling age. Shrub establishment has a positive feedback effect.

     

辽东山地混牧林草系统特性及其利用研究

辽东山地林下牧草 90 %以上种类为多年生植物 ,有着比较牢固的生境生态位。生产能力、物种多样性等指标受上层体冠控制 ,并常处于一种动态变化之中。林分郁闭度在 0 5～ 0 8间是牧草产量、质量的最好光照区间。在“牛单位 3 9hm2 ”连续 3年牧压下并未引起林分蓄积增长量减少。混牧后可较大幅度提高直接经济效益产出量。牧畜的采食草量应控制在牧草生产能力的 5 0 %以下。林地坡度 30°以上应划归禁牧区     

常绿阔叶林的可持续经营

通过对常绿阔叶林研究，努力探索一条发展常绿阔叶林的途径。将阔叶林划分为3个经营类型，分别为：初期幼龄林组成抚育类型、中期幼龄林抚育间伐类型、中龄林密度管理类型。并提出小面积皆伐的采伐方式。同时对常绿阔叶林的生态功能和生产力进行初步研究。     

马尾松林改造成香樟林过程中生态系统服务功能评估

选取马尾松天然次生林和改造过程中不同阶段的香樟林为研究对象,依据《森林生态服务功能评估规范》(LY/T 1721-2008)的指标体系和计算方法,开展了观音峡林场马尾松林和不同林龄香樟林生态系统服务功能价值评估。结果表明:(1)观音峡林场马尾松林、香樟幼龄林、中龄林和近熟林2017年单位面积生态服务功能价值分别为7.65万元·hm^-2·a^-1、7.51万元·hm^-2·a^-1、8.40万元·hm^-2·a^-1和10.47万元·hm^-2·a^-1。(2)马尾松林改造为马尾松和香樟混交林过程中,改造初期由于香樟在灌木层中,乔木层密度小于马尾松纯林,因此服务功能略低于马尾松林。随着改造时间的增加,生态系统服务功能价值显著提高。(3)在马尾松林经营过程中,应营建混交林,同时增加幼龄林和中龄林的经营年限以提高森林生态系统服务功能。     

The ecology of tree regeneration in mature and old forests: combined knowledge for sustainable forest management

We focused our attention on quantifying the factor complex of forest regeneration in 423 mature and old stands with contrasting environmental conditions. We recorded the microhabitat selection of tree recruits, the frequency of tree seedlings, and evaluated the drivers of sapling abundance and diversity. The majority of forest regeneration was established on undisturbed forest floor. Dead wood was a frequent substrate in spruce-(co)dominated forests. Seedling frequency within a stand was related to the site-type specific productivity gradient of stands—pine seedlings were common in low-productivity and spruce in high-productivity boreal forests. Seedlings of temperate broad-leaved trees dominated in productive boreonemoral forests, except for oak, which showed a uniform distribution of abundance in all forest site-types. Sapling abundance was dictated by forest site-type, and facilitated by stand diversity, variability in stand closure, lying dead wood, abundant moss, and a thick organic layer. Only in boreal forests was sapling abundance suppressed by the abundant spruce and younger trees. Upon considering the relationship between sapling abundance and species richness, sapling diversity was dependent on forest site-type, suppressed by stand density and dead wood (old gap) abundance, and facilitated by stand diversity. In addition, boreonemoral stands, competition from herbs, and facilitation by mosses occurred. The observed pattern of tree recruitment points to the importance of top-down effects of the overstory, competing or facilitating interactions with forest floor vegetation, and availability of regeneration microhabitats, which in complex make their ecology comparable with forest herbs. Natural forest regeneration can be enhanced if silvicultural methods support mixed stands and enhance field layer diversity. Oak can provide the universal tree species to improve stand structure over a wide range of habitats.     

林业专用吊运车在大苗移植中的应用和效益分析

为解决大苗出圃运输人抬肩扛难题,提高树木移植机械化水平,河北农业大学教学实验林场根据生产实际需要,结合现代农机的发展成果,研发了适合苗圃林地大苗移植的“林业专用吊运车”。该吊运车在大苗出圃运输中所需人员只2名,是人工搬运的1／2,苗木完好率达到98％以上,高出人工搬运18％左右,每搬运一棵大苗所需的时间为5min,工作效率大为提高。     

须弥红豆杉幼树林农林复合经营的初步研究

为了解决须弥红豆杉幼树林无收入、抚育成本高的问题,进行了不同的间作模式试验研究,结果表明：效果较好的间作模式为“红豆杉-蚕豆-大豆”,能获得较大效益,间作植物的红豆杉幼林的树高生长高于未间作,且差异显著,依次为：红豆杉-蚕豆-大豆＞红豆杉-蚕豆-不间作＞红豆杉-不间作-大豆＞未间作;而地径则小于未间作,对当年生最长枝及发新梢树无明显差异,须弥红豆杉幼树林进行豆类（大豆、蚕豆）间作经营是一种较为理想的复合经营模式,可在适宜的区域进行推广。