三清山高海拔栎林云斑白条天牛危害调查

对三清山高海拔栎林中云斑白条天牛Batocera lineolata Chevrolat补充营养、产卵刻槽、排粪孔、羽化孔等危害情况进行调查。结果表明,云斑白条天牛成虫与幼虫的主要寄主均为小叶青冈和多脉青冈。成虫啃食1～2 a生的枝皮补充营养。同一受害植株,树干阳面受害重。受害树木胸径集中在14～31 cm范围内。虫害部位主要分布在树干4 m以下区域。统计分析表明小叶青冈受害株产卵刻槽数与胸径呈负线性相关,羽化孔、产卵刻槽高度与胸径呈正线性相关;幼虫活动区间(羽化孔与产卵刻槽的高度差)与胸径相关不显著。     

云斑天牛产卵刻槽在杨树树干上的分布规律

通过标准地及样树调查，查明云斑天牛产卵刻槽在杨树树干上的垂直分布规律．其垂直分布位置随树龄增大而逐年上移．在2～5a生幼树上，主要分布在离地1m以下．树皮厚度是影响产卵刻相垂直分布变化及产生空槽的主要因子．     

贵州山地杨树云斑白条天牛危害特性

对云斑白条天牛Batocera lineolata Chevrolat在贵州山地条件下杨树人工林中的产卵危害部位及不同因素对其发生危害的影响进行调查。结果表明:云斑白条天牛主要在树干2 m以下产卵危害,占调查总数91.79%;杨树品种、树龄、树高、胸径、林分类型,成虫食物源等因素一定程度影响其发生危害。三倍体毛白杨、响叶杨是抗云斑白条天牛品种;杨树有虫株率随树龄增加呈先升后降趋势,5~15 a生杨树受害比较严重;杨树受害率随树高增加也呈先升后降趋势,在树高8~14 m时达到高点;杨树受害率在胸径5~11 cm时达到高点后,随着胸径增大逐渐下降;混交林较纯林受害轻;成虫食物源丰富度越高,杨树受害越重。     

云斑天牛对永善县核桃危害程度分析

为了掌握云斑天牛对永善县核桃的危害程度,采用随机抽样的方法,按不同方位(东、南、西、北)、不同树龄及不同垂直高度等因子对云斑天牛产卵刻槽数量进行调查。结果表明,核桃林云斑天牛有虫株率50. 00%,每株平均产量17. 16粒,最高达74粒/株。1-6年生核桃幼树上无云斑天牛产卵刻槽,云斑天牛主要危害10-30年生核桃,82. 5%产卵量集中在距地面0-2. 0m的范围内,但云斑天牛在树干上产卵没有方向的偏爱。根据其产卵习性,可采用树干基部涂白,人工敲击产卵痕的方法进行防治。     

杨树云斑白条天牛的危害特点及空间分布

以危害杨树的云斑白条天牛种群为调查对象,对其危害特点与空间分布进行调查研究。结果表明,云斑白条天牛的危害程度与杨树的树龄、胸径均呈抛物线式相关,危害程度随树龄、胸径的增大先上升后下降,4~8年生树龄、12.0~21.9cm胸径的杨树受害最严重;不同林地环境下的杨树受害程度也不一样,渠道林受害最重,村庄林和道路林次之,片林较轻。通过频次比较法分析表明,危害杨树的云斑白条天牛幼虫的空间分布型符合负二项分布,为聚集分布。     

光肩星天牛卵及初孵幼虫垂直分布格局的研究

采用聚集度指标法测得光肩星天牛在10年生大关杨主干上产卵刻槽及初孵幼虫为害的垂直分布格局为聚集分布型,其严重为害部位为4.68±2.58m。     

桑天牛雌成虫产卵器解剖和刻槽及产卵习性研究

桑天牛刻槽产卵行为主要包括刻槽位置选择、咬槽、产卵、封槽4个阶段.制作刻槽时头部向下,先咬"川"字形浅槽,再于浅槽下方咬椭圆形深槽,然后产卵器伸入深槽底部翘起的木缝并产卵于木质部中,封好的刻槽呈"U"字形,且中部突起.产卵器长14.28±1.91 mm,其上分布多数毛状感器.刻槽长13.78±1.75 mm,宽6.94±0.99 mm.在2年生枝条上,刻槽宽与枝条直径、木质部厚度相关极显著;刻槽深度与木质部厚度相关极显著.空槽与有效刻槽在长度与宽度方面均无显著差异,但空槽深槽较浅,难以形成木缝.     

危害白蜡树的云斑白条天牛种群空间格局及抽样技术

云斑白条天牛在黄河三角洲地区严重危害白蜡树,本研究应用聚集指标法、Taylor幂法则、Iwao m*-m回归分析法,对危害白蜡云斑白条天牛种群卵、幼虫、成虫的空间分布型和抽样技术进行了研究。结果表明:危害白蜡云斑白条天牛种群的卵、幼虫、成虫均呈聚集分布,其聚集性随密度的增加而增大。运用Iwao m*-m回归中的两个参数α和β值,建立了在不同精度下以刻槽、排粪孔和羽化孔为防治指标时的理论抽样数公式及序贯抽样数公式,计算出了抽样调查时的理论抽样数据表及序贯抽样数据表,在生产实践中可根据实际需要查询表中数据确定调查样本数。     

松褐天牛在马尾松树干上的分布规律

作为松材线虫病(Bursaphelenchus xylophilus)的最重要传播媒介,松褐天牛已成为控制松材线虫病的重点。明确松褐天牛各虫态在不同地区寄主树干上的分布,对因地适宜地释放天敌昆虫有着重要意义。为此,本研究通过解剖受害马尾松,结合林间调查,系统地研究了松褐天牛产卵刻槽、幼虫和蛹在马尾松树干上的分布规律。结果表明:松褐天牛产卵刻槽主要分布在树干的2.5 6.5 m范围内,刻槽数量与树干高度和胸径显著相关;松褐天牛幼虫数量与树干胸径关系不显著;多数蛹室位于侵入孔正上方,少数蛹室位于侵入孔下方,两种蛹室数量差异显著;两种蛹室与侵入孔中心的平均距离分别为3.93 cm和4.39 cm,两者之间差异不显著;并建立了松褐天牛幼虫在马尾松树干上的垂直分布模式图。本研究表明了松褐天牛种群密度与寄主树木大小的关系,为释放天敌进行生物防治提供了基础。     

松褐天牛产卵繁殖研究

通过对松褐天牛在健康木和伐倒木刻槽、产卵及卵成活率的研究发现:松褐天牛虽然在健康木上能刻槽,但刻槽数较少,且几乎不产卵,偶有产卵也不能正常孵化成活;在伐倒木上则刻槽较多,产卵量大,且成活率高。接种在伐倒木上的松褐天牛卵孵化率高,幼虫生长发育正常,而接种在健康木上的松褐天牛卵孵化率低,幼虫生长发育情况较差。     

美国山核桃在云南的引种适应性报告

1974～2000年美国山核桃在云南省漾濞、永平、昌宁等地进行引种试验和扩大引种试验表明，该树种生长量以第7年最大，金华和绍兴品种结果多，产量高；山站2号和兴林13号各项丰产指标均低，株产量少；结实大小年明显，金华品种为2年一周期，绍兴为3年；与原产地浙江相比，品质较好；在中亚热带生长和开花结实表现很好。美国山核桃与国内外在良好管理条件下的产量和质量基本相同，适宜于云南省栽培。从而为云南省增添了一个新的经济林木树种，填补了核桃分布下限没有好的油料干果树种可供发展的空白。     

金华、绍兴两个薄壳山核桃种在红河地区的表现

通过对金华、绍兴2个薄壳山核桃种10多年引种调查认为：薄壳山核桃2年生苗移栽后,4~7 a进入结实期,10 a后进入大量结实期,其中：金华13年生最高株产16 kg;果形大,种实单粒重6.5~9.4 g,种壳厚0.9~1.1 mm,出仁率51%~56.9%,粗脂肪76.9%~78.5%,蛋白质8.5%~9.7%,可作为主栽品种发展。绍兴13年生最高株产14.6 kg,平均7 kg;单果较小,核果重5.5~6.3 g,核壳厚1.1~1.2 mm,出仁率52%~53.8%,种仁饱满,粗脂肪74.1%~74.4%,蛋白质7.5%~8.3%,可为供种或授粉树适当发展。上述2个品种适宜红河州海拔800~1 600 m的地方推广栽培。     

不同年龄构树皮的纤维、化学特性与制浆性能研究

对金沙江干热河谷不同年龄构树皮的化学、纤维特性与制浆性能进行研究.结果表明,构皮纤维长、木素含量低,纤维素含量高,纤维形态好,易于成浆.随着年龄的增大,低龄构皮化学组分稍有增大,但至6-7 a,灰分和木素含量增大,纤维素和硝酸-乙醇纤维素含量明显下降,不利于成浆;1%Na0H抽提物一直呈缓慢上升趋势,第6-7年达到最高;构皮纤维长度、长宽比及长纤维比例都随年龄的增长而增加,3-5 a增至最大,第6年后呈快速下降趋势.2-4年生构皮手抄片有较高的结合强度和耐折度,5-7 a后趋于稳定.因此,优质构皮纤维原料最佳收获期为2-5 a,综合经济效益考虑,纤维原料人工林培育最佳周期为2-3 a.     

Growth strain in coconut palm trees

Until recently, growth stress studies have been made only on coniferous and dicotyledonous trees. Growth stress of trees is thought to be initiated in newly formed secondary xylem cells. This stress can accumulate for years and is distributed inside the trunk. Major characteristics of the trunk of monocotyledonous trees include numerous vascular bundles scattered inside the ground tissue and the lack of secondary growth for enlarging the diameter of the trunk. We used the strain gauge method to measure the released growth strain of the monocotyledonous woody palm, coconut (Cocos nucifera L.), and to investigate the surface growth strain of the trunk and central cylinder at different trunk heights. The internal strains of both vertical and leaning trunks were measured and compared with those of coniferous and dicotyledonous trees. We found that tensile stress existed longitudinally on the surface of vertically growing trunks, whereas compression stress was found at the bending position of leaning trunks. Compression stress was found in the outer part of the central cylinder, whereas tensile stress is generally found in the outer part of the trunk in coniferous and dicotyledonous trees. The distribution of strain in the palm trunk is similar to that of compression wood of the leaning trunk of a conifer. Specific gravity was greater in the outer part of the trunk than in the inner part of the trunk. This difference may be related to the distribution of growth stress.     

贵州省古银杏资源的分布及生长特征研究

2011年8月通过访谈、查阅文献资料与实地调查,对贵州省古银杏资源的分布及生长特征进行分析。结果表明,贵州省100～4000年生古银杏共有1969株,主要分布于遵义市和六盘水市;垂直分布海拔为300～1700m,集中分布800—1100m。其中75．96％为雌株,24．04％为雄株,雌雄比为3．16：1;树高最高为50．0m,最矮为2．0m;树龄最大为4000年,最小为100年;胸径最大为479cm,最小为26cm;其平均冠幅最大为40．0m,最小为1．0m。垂乳银杏有88株,复干银杏有35株,雌雄同株仅1株。     

配方施肥对美国山核桃树体生长的影响

以云南新平县4年生美国山核桃为研究对象,采用了3个因素3个水平的iF交试验设计,分析施肥对地径、树高、冠幅的影响.结果表明,地径增粗的最佳施肥比例为N100P100K200,增粗最快的处理为最慢的1.77倍;树高增长的最佳施肥比例为N200P100K200,增长最快的处理为最慢的2.32倍;冠幅增大的最佳施肥比例为N400P200K200,增量最快的为最慢的1.83倍.     

云南木蠹象蛹室在云南松树内的分布

云南木蠹象是我国西南地区新发现的云南松的一种重要蛀干害虫。云南木蠹象蛹室在被害云南松树木上的分布规律,反映了该虫幼虫和蛹在树木上的危害与分布。研究表明,云南木蠹象蛹室主要分布在云南松树木主干的中上部,其蛹室数量占主干蛹室量的76．99％;同时,云南木蠹象蛹室集中于树木主干,主干上的蛹室数占全树蛹室数的70．26％。云南木蠹象蛹室在轮枝上的分布多集中在中上部轮枝,即第1～3轮轮枝。在这些轮枝上的蛹室数目是所有轮枝蛹室数目的87．69％。从生长年龄而言,蛹室主要分布在1～2年生的主干和侧枝上。     

Development of tree hollows in pedunculate oak (Quercus robur)

Many invertebrates, birds and mammals are dependent on hollow trees. For landscape planning that aims at persistence of species inhabiting hollow trees it is crucial to understand the development of such trees. In this study we constructed an individual-based simulation model to predict diameter distribution and formation of hollows in oak tree populations. Based on tree ring data from individual trees, we estimated the ages when hollow formation commences for pedunculate oak (Quercus robur) in southeast Sweden. At ages of about 200–300 years, 50% of the trees had hollows. Among trees <100 years old, less than 1% had hollows, while all >400-year-old trees had hollows. Hollows formed at earlier ages in fast-growing trees than in slow-growing trees, which may be because hollows are formed when big branches shed, and branches are thicker on fast-growing trees in comparison to slow-growing trees of the same age. The simulation model was evaluated by predicting the frequency of presence of hollows in relation to tree size in seven oak stands in the study area. The evaluation suggested that future studies should focus on tree mortality at different conditions. Tree ring methods on individual trees are useful in studies on development of hollow trees as they allow analysis of the variability in time for hollow formation among trees.     

Variability with xylem depth in sap flow in trunks and branches of mature olive trees

Knowledge of sap flow variability in tree trunks is important for up-scaling transpiration from the measuring point to the whole-tree and stand levels. Natural variability in sap flow, both radial and circumferential, was studied in the trunks and branches of mature olive trees (Olea europea L., cv Coratina) by the heat field deformation method using multi-point sensors. Sapwood depth ranged from 22 to 55 mm with greater variability in trunks than in branches. Two asymmetric types of sap flow radial patterns were observed: Type 1, rising to a maximum near the mid-point of the sapwood; and Type 2, falling continuously from a maximum just below cambium to zero at the inner boundary of the sapwood. The Type 1 pattern was recorded more often in branches and smaller trees. Both types of sap flow radial patterns were observed in trunks of the sample trees. Sap flow radial patterns were rather stable during the day, but varied with soil water changes. A decrease in sap flow in the outermost xylem was related to water depletion in the topsoil. We hypothesized that the variations in sap flow radial pattern in a tree trunk reflects a vertical distribution of water uptake that varies with water availability in different soil layers.