种植密度及施肥量对广西地区桉树幼苗生长的影响研究

种植密度和施肥量是影响桉树植株生长的主要因素,为确定广西地区桉树幼苗对不同种植密度和施肥量的响应机制,该研究以广西国有钦廉林场为研究区域,通过正交试验探讨了种植密度和施肥量对桉树幼苗苗高、胸径和单株材积的影响。研究结果显示,不同种植密度条件下的桉树幼苗苗高之间不存在显著差异(P﹥0.05),不同施肥量条件下的桉树幼苗苗高之间存在显著差异(P﹤0.05),不同种植密度、施肥量条件下桉树幼苗胸径之间均存在显著差异(P﹤0.05),不同种植密度、施肥量条件下桉树幼苗单株材积之间均存在显著差异(P﹤0.05),种植密度83株/亩和施肥量65 kg/亩条件下桉树幼苗的各项生长指标均较高。综上所述,推荐在实际生产中采用种植密度83株/亩和施肥量65 kg/亩的标准进行桉树种植。

3种桉树幼苗叶片养分变化及其转移特性

Nutrient dynamic and transfer characteristics of trees reflect the preservation and utilization of nutrients,and the adaptability to the infertile soil and environment.The change of nutrient content and the transfer ratio of element N,P,K,Ca,Mg in living and fallen leaves of three Eucalyptus varieties of 184-1,201-2,guanglin-9 were measured and analyzed.The results indicated that the content of N,P,K,Ca,Mg in leaves was significantly different monthly within a year.In general,the nutrient content and the transfer rate of the leaf were relatively higher in the growing season（6-10 months）than that in other seasons.The nutrient content in the living leaves was significantly higher than that of the fallen ones,and the nutrient content in the living leaves was positively correlated（r=0.94,P<0.01）with that in the fallen ones.The nutrient content and the transfer ratio were different among the three varieties of eucalyptus.Contents of N and Ca were the highest in 184-1,and contents of P,K,Mg were the highest in 201-2,while contents of the other four elements except N were the lowest in Guanglin-9.In terms of the nutrient transfer rate,Ca had no change,and the rate of the other four elements was P>N>K>Mg and the difference was significantly different（F=192.19,P<0.01）.The nutrient content of the leaf was significantly(t=2.97> t 0.025 6=2.446 9),however the nutrient transfer rate was not remarkably affected by fertilization.There was no significant difference in the nutrient transfer rate among the three Eucalyptus varieties.The results showed that the changes of leaf nutrient content and the transfer rate were related with many factors,such as growth characteristics and biological characteristics of species and external conditions.

NaCl胁迫对桉树幼苗膜脂过氧化与膜保护酶系统的影响

以4个桉树品种组培苗叶片为材料,研究了NaCl胁迫对其膜脂过氧化和膜保护酶活性的影响。结果表明:随着NaCl浓度的增加,质膜相对透性、丙二醛(MDA)含量呈上升趋势,超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性先升后降;SOD的活性在不同桉树品种之间差异不显著,而CAT和POD在不同品种之间则存在极显著或显著差异。

桉树幼苗缺素症状的研究

通过砂培法对桉树U6幼苗氮、磷、钾缺乏时表现症状进行了研究,旨在为生产中直观判断养分的丰缺提供理论依据。结果表明:形态和生长状况方面,缺K处理前期表现生长良好,但后期最先表现出缺素焦枯症状,其次是缺N、缺P处理,说明桉树苗木前期需钾肥相对较少;生理指标、叶绿素含量、光合速率、根系活力以及干重中均是缺N的表现最低,其次是缺K,缺P的表现相对较高,这说明N、P、K三种元素缺乏都能对桉树幼苗造成伤害,N元素表现尤其明显。

桉树内生菌对尾巨桉幼苗抗寒生理指标的影响

20世纪50年代我国开始大规模种植桉树（Eucalyptus spp.）,现在栽植已经遍布我国17个省、自治区的600多个县,栽植面积达到150多万hm^2（祁述雄,2002）。然而,随着桉树大面积的种植,影响其种植的主要限制因子低温伤害也逐渐呈现。目前对桉树抗寒性的研究主要有抗寒锻炼、良种选育与引种、抗寒分子水平的研究等方面（庄国庆等,2010;赵娟娟,2006;郭祥泉,2003;黄德先等,

叶面喷施生物醋液对桉树苗期营养及生长的影响

[目的]研究生物醋液对桉树幼苗生长和养分吸收的影响。[方法]通过设置不同浓度生物醋液,采用叶面喷施的方式,同时以0.5%尿素+0.3%磷酸二氢钠溶液和清水CK作为对照,分析喷施生物醋液后对桉树幼苗生长和养分吸收的影响,探索并研究生物醋液作为叶面肥在桉树苗木施肥中的应用效果。[结果]施用不同浓度生物醋液对桉树苗木生长和叶片养分吸收有显著影响,其中生物醋液喷施浓度在100～200 ml/L时,对苗木的生长具有良好的促进效果;低浓度的生物醋液喷施桉树幼苗能够增加叶片叶绿素含量,当浓度高于400 ml/L时,由于浓度过高,叶片造成"烧"伤,叶绿素含量降低;养分分析结果表明,生物醋液浓度在50～400 ml/L范围时,均能提高叶片N、P、K、Cu、Zn、B、Fe和Mg元素的含量,但对Ca和Mn元素影响不大。[结论]生物醋液作为叶面肥在桉树中应用时的最佳浓度范围为100～200 ml/L。

桉树主要病虫害种类及科学防治技术要点

中国林木主要虫害种类已经增加至上百种,严重影响桉树等阔叶类林木的生长,本文通过对桉树主要病虫害种类进行分析,针对性提出防治方案,以期促进桉树生长。1桉树主要病害种类及防治药剂1.1桉树溃疡病桉树溃疡病是桉茎点霉侵染桉树幼苗或黄绿色侧枝引发的真菌性病害,春季开始发病,夏季发病严重,主要病症表现为:初期形成灰褐色圆形病斑,随着病情蔓延,病斑扩大为中央凹陷、边缘树皮皲裂的不规则型病斑。