国槐古树的生物危害防治及树体保护技术

国槐是中国北方地区主要古树树种之一,其木质部容易发生朽蚀,产生空洞。笔者根据工作经验,简要叙述了国槐古树刺吸类害虫、食叶类害虫、蛀干类害虫的发生规律和防治措施,并针对蚁类和鸟类危害提出了防治方法。最后,从复壮保护、修补树洞、保护天敌、支撑和围箍等方面阐述了国槐古树的树体保护技术。     

国槐木虱的发生与防治实验

国槐木虱是兰州市近10年来上升为园林树木的主要害虫。该虫发生普遍,为害严重,污染环境甚至干扰市民正常活动。总结报道了该虫的发生危害情况及形态学、生物学特性,并进行了新农药对该虫的药效试验研究,为科学有效控制该害虫的发生提出了可行的方法。     

北京永定门公园国槐枝干害虫的综合治理

通过对国槐主要枝干害虫发生情况的调查,掌握枝干有害生物的发生规律,危害特点和程度,探索预防和综合治理的措施。国槐虫害的发生率从2007年的47.85%降低到2011年春季的8.4%,国槐的死亡数量从49株降到4株,枝干害虫的治理取得了有效成果。     

国槐尺蠖在昌平发生情况及其防治措施

国槐尺蠖在昌平发生情况及其防治措施国槐尺蠖是国槐的大害虫之一。对国槐的危害轻则把树叶吃的残缺不全，重则把树叶全部吃光，造成树冠大量枝条枯死，对绿色景观影响极大。最近几年，在昌平县随着国槐栽植范围的扩大，国槐尺蠖的危害亦随之扩散蔓延，京张路、昌南路、昌...     

保定市行道树国槐主要虫害发生演变特点及防治策略

该文总结分析了从1998～2010年间保定市街道绿化树种国槐的害虫发生种类、为害程度及其演变特点,提出园林虫害持续控制理念。加强街道树种的合理配置,保护物种多样性,加强对树木的栽培管理,进行生物调控是国槐害虫防治的基本策略和措施。     

国槐衰退病因的研究

对合肥市国槐衰退和枯死原因的调查研究表明，造成国槐衰退、枯死的原因是多方面因素共同作用的结果，是一种树木衰退病。该病发生的主要原因是：1诱发因素——土壤板结或透气性差、土壤污染(轻微)、根系裸露或深埋、树龄较大、枝梢害虫危害等；2激化因素——食叶害虫、土壤污染(中度)、机械损伤、干旱和积水等；3促进因素——腐烂和溃疡病菌、腐朽菌、蛀干害虫危害等。该研究结果为国槐衰退病的防治提供了理论依据，也为城市其他树木衰退或枯死原因的研究和防治提供参考。     

国槐主要害虫可持续防治技术

国槐是天津市主要绿化树种 ,受国槐尺蛾、槐蚜、桑白盾蚧、国槐红蜘蛛和国槐小卷蛾等害虫危害严重。无公害药剂防治技术、国槐小卷蛾性引诱剂的引进和应用等规范化防治技术的研究和实施 ,可持续控制这几种害虫的危害 ,减少喷药次数和喷药量 ,保护环境 ,节约防治费用     

槐小卷蛾发生初报

槐小卷蛾Cydia trasias(Meyrick)以幼虫钻蛀国槐、龙爪槐1～2a生枝条危害,该害虫在张家口市1a发生1代。树木被害后造成满树卷叶,后期枯黄脱落,影响树木生长和园林绿化景观效果。     

国槐尺蛾的防治

国槐尺蛾为鳞翅目尺蛾科的一种食叶害虫 ,又名槐尺蠖、吊死鬼。主要危害国槐。我们自 1995年以来 ,连续对国槐尺蛾进行了观察及防治研究 ,基本掌握了其生活习性及防治措施 ,使中华公园内病虫害得到了有效的控制 ,树木长势良好。1　生活习性国槐尺蛾在华北地区每年发生 3代 ,以蛹在土壤中越冬 ,越冬蛹于 4月下旬至 5月中旬羽化。一般 6月上旬出现第 1代幼虫 ,7月下旬出现第 2代幼虫 ,9月上旬出现第 3代幼虫 ,该虫为夜出性害虫。交尾、产卵均在夜间进行 ,多在黄昏后进食 ,趋光性不明显。卵产于枯梢、叶片、叶柄、小枝等处 ,以树冠南面分布最多…     

树干基部注射药液防治国槐尺蠖试验

国槐尺蠖是为害城市优良行道树种国槐的食叶性害虫,1997年以来,对行道树的国槐进行了干基注射药液防治试验,害虫死亡率达95%以上,这种方法简便易行,且降低城市的环境污染。     

槐豆木虱发生与主要环境因子关系调查研究

槐豆木虱的发生主要与温度、风、寄主、害虫、天敌以及生产活动关系尤为密切,在国槐上调查发现,槐豆木虱的捕食性天敌昆虫有5目8科17种及多种蜘蛛,其中异色瓢虫种群数量占其他瓢虫种群数量的80％以上,在自然状态下完全能够控制槐豆木虱的种群数量。     

国槐木虱生物学及第一代若虫种群数量消长动态研究

国槐木虱(Cyamophila willieti Wu)在关中中部地区发生危害,造成国槐生长不良,严重影响其观赏价值。该虫主要危害当年生嫩叶、嫩枝,4月底至5月下旬为第一代若虫危害高峰期;种群数量大,树冠南方位数量最高;世代重叠。在若虫盛发初期喷洒40%氧化乐果乳油或50%久效磷乳油1000～1500倍液等,或保护利用瓢虫、草蛉等天敌措施,控制其危害。     

槐豆木虱预测预报及综合防治技术

槐豆木虱,是近年来临夏地区在国槐上严重发生的害虫之一。运用越冬成虫发生预测、历期法、物候法、有效基数预测法,预测预报下一虫态的发生期和虫口数量,提出了加强树体管理、调整树种结构、生物药剂防治、物理防治及保护和利用国槐上捕食性天敌的自然控制作用相结合的多种防治措施,为更好地开展槐豆木虱防治工作提供了重要依据。     

色木槭、拧劲槭生长分析及生长阶段划分初探

以色木槭、拧劲槭天然林解析木为对象,用Logistic模型对树高、胸径、材积生长进行拟合,研究其生长规律。结果表明：树高、材积生长拟合效果良好。色木槭树高生长9 a前为生长前期,9～31 a为速生期,20 a为生长高峰年,31 a后为生长后期;材积生长25 a前为生长前期,25～38 a为速生期,32 a为生长高峰年,38 a后为生长后期。拧劲槭树高生长9 a前为生长前期,9～40 a为速生期,12 a为生长高峰年,40 a后为生长后期;材积生长28 a前为生长前期,28～43 a为速生期,36 a为生长高峰年,43 a后为生长后期。色木槭、拧劲槭树高、胸径生长在15 a前比较接近,15 a后色木槭明显高于拧劲槭;色木槭、拧劲槭材积生长在18 a前比较接近,18 a后色木槭明显高于拧劲槭。     

不同林龄云南松针叶养分回流及利用效率的季节变化

以云南玉溪森林生态系统定位研究站内不同林龄(15、30和45 a)云南松为对象,通过1 a的定位观测,对不同林龄云南松的养分回流及利用效率特征进行了分析,以期为深入揭示云南松养分自我保持机制及云南松林地的养分管理提供科学依据。结果表明:(1)云南松针叶中养分元素含量夏秋季相对较高,而冬季相对较低,N元素含量随林龄增加而减少,其它元素则以45 a含量相对较高,30 a含量相对较低,总体上,各林龄养分元素平均含量从高到低为Ca、N、K、Mg、P。(2)各林龄云南松针叶中N、P、K在不同季节中均有明显的回流,回流率随林龄及季节的变化而差异明显,大多在冬季的回流率相对较高;Ca元素则在各林龄各季中出现富集,富集率随林龄增加而增大;Mg元素除45 a在春秋冬季中有少量回流外,其它林龄及季节则均出现富集。(3)各林龄N、P、K的利用效率在冬季较高,而Ca、Mg的利用效率则在秋季较高,利用效率随林龄及季节的变化而变化明显。结果显示,各林龄对养分元素的平均回流率从大到小为K、P、N、Mg、Ca,平均利用效率从高到低为P、K、Mg、N、Ca,养分元素的回流率及利用效率与养分元素含量呈显著负相关关系。云南松针叶对N、P、K保持较高的回流率和利用效率,表明云南松对贫瘠低磷环境具有较强的适应能力,是贫瘠低磷环境下造林的优良树种。     

Forest vegetation of Xishuangbanna, south China

1 Introduction The tropical area of southern China is climatically and biogeographically located at the northern edge of tropical Asia, including southeastern Xizang (Tibet, lower valleys of the southern Himalayas), southern Yunnan, southwestern Guangxi, southern Taiwan and Hainan Island. The largest tropical area still covered by forests is in southern Yunnan. Tropical forests of southern Yunnan were little known until the late 1950s because of poor access except for some brief descrip-…     

火炬松人工林林木营养特性的研究

通过试验控制，定位观测和养分元素分析测定，定量地研究了莎下蜀林场１５年生火炬松人工林林木矿质营养特征。     

Structural characterization and radioprotection of bone marrow hematopoiesis of two novel polysaccharides from the root of Angelica sinensis (Oliv.) Diels

Two novel homogeneous polysaccharides, APS-1a and APS-3a were successfully isolated from the root of Angelica sinensis. APS-1a was composed of galactose, arabinose and glucose in a relatively molar percentage of 57.34%, 27.67% and 14.98%, and had a molecular weight of 49.0 kDa, whereas APS-3a was composed of galactose, arabinose and glucose in a relatively molar percentage of 84.54%, 6.50%, and 8.96%, and had a molecular weight of 65.4 kDa. APS-1a and APS-3a mainly consisted of 1,4-linked galactose, 1,3,6-linked galactose, T-galactose and T-arabinose, and the molar ratio of each linkage was different between APS-1a and APS-3a. The bioactivity analysis showed that APS-1a and APS-3a increased the thymus and spleen index, the number of red blood cell (RBC) and white blood cell (WBC) in peripheral blood and the cellularity of bone marrow cell numbers in irradiated mice, protected mice against radiation-induced micronucleus formation in bone marrow, suggesting that polysaccharides could be used as radioprotective agents, especially for promoting bone marrow hematopoiesis.     

树木、林内、林冠上与森林区风速廓线研究

One of the most important and frequently studied variable in forests and the most basic element in governing transport processes of airflow is wind speed. The study of wind profile, defined as the change of wind velocity with height, and wind velocity are important because of tree physiological and developmental responses. Generally, wind profiles above the ground or at a canopy surface follow classical logarithm law, but wind profiles in a single tree and in a forest stand are not logarithmic. This paper summarizes the results of wind profile studies within a single tree, in a forest stand, above the forest canopy and in a forest area from recent research in a coastal pine forest. The results demonstrate that: 1) wind profiles with in a single conifer tree crown showed an exponential function with height, 2) wind profiles in forest stands were able to be expressed by attenuation coefficient of wind, 3) wind profiles over a forest canopy could be determined using profile parameters (friction velocity, roughness length and displacement), and 4) for a forest area, the extreme wind speed could be predicted reasonably using the methods developed for the design of buildings. More research will be required to demonstrate: 1) relationships between wind profiles and tree or stand characteristics, 2) the simple methods for predicting wind profile parameters, and 3) the applications of wind profile in studies of tree physiology, forest ecology and management, and the detail ecological effects of wind on tree growth.     

Adoption of improved fallow technology for soil fertility management in Zambia: Empirical studies and emerging issues

In the subsistence-agricultural region of eastern Zambia, less than 10% of the households have adequate supply of maize (Zea mays L.), the staple food, throughout the year. A major constraint to increasing crop production in the region is poor fertility status of the soil. In order to address this problem, improved fallow has been introduced as a technology for improving soil fertility within a short span of two to three years. Farmers have been testing the technology and a number of empirical studies have been undertaken over the years to identify the factors influencing farmers' decision to adopt the technology. This paper presents a synthesis of the results of adoption studies and highlights generic issues on the adoption of improved fallows in Zambia. The synthesis indicates that farmers' decision on technology adoption does not have a simple directed relationship of some technological characteristics only, but constitutes a matrix of factors including household characteristics, community level factors, socioeconomic constraints and incentives that farmers face, access to information, local institutional arrangements and macro policies on agriculture. The adoption of improved fallows is not strictly speaking a binary choice problem but a continuous process in which farmers occupy a position along a continuum in the adoption path. Further, adoption of improved fallows may not take place in a policy vacuum but needs to be facilitated by appropriate and conducive policy and institutional incentives. Several questions and issues that require further study emerge from the synthesis. These include determination of the relative importance of the factors in the adoption matrix, identification of the conditions under which farmers use a combination of inputs and their profitability under changing price scenarios, exact definition to delineate between `non-adopters', `testers' and `adopters' of agroforestry technologies, and understanding the impact of cash crop farming in farmers' adoption decisions of improved fallows (where off farm opportunities exist). Further, there is a need to determine the inter-relationship between household poverty, labor availability and the adoption of improved fallows and, to evaluate a combination of policy interventions at both national and local level to promote the adoption of agroforestry-based soil fertility management. This revised version was published online in June 2006 with corrections to the Cover Date.