9种桉树幼林营养元素累积特性研究

为了研究在相同立地和养分供给条件下,不同桉树的生物量和营养元素(N、P、K)累积量及其分配特征,以1年生9种桉树(尾叶桉、窿缘桉、细叶桉、大叶桉、赤桉、巨桉、粗皮桉、托里桉、大花序桉)为材料,通过测定树根、树干、树皮、叶片、树枝5个器官的生物量以及氮、磷、钾含量,了解养分吸收和分配情况,揭示生物量构成特点。结果表明:9种桉树总生物量最大的是赤桉,为711.20 g·株-1,其次是托里桉、粗皮桉、巨桉、大叶桉、细叶桉、尾叶桉和大花序桉,窿缘桉的生物量最小,为69.20 g·株-1。不同器官生物量分配规律为树干或叶片最大,树根、树枝、树皮次之。不同器官营养元素含量为叶片最高,树干最低。9树种营养元素累积总量由高到低排序为赤桉(29)托里桉(29)巨桉(29)大叶桉(29)粗皮桉(29)细叶桉(29)尾叶桉(29)大花序桉(29)窿缘桉,各树种对3种元素累积量均为N最多,其次是K,P最少;9树种对N、P和K的吸收效率范围为分别为0.80%~7.69%,0.11%~1.32%和0.61%~10.38%;吸收效率最高的为赤桉,最低的为大花序桉,而其他桉树对各元素的吸收效率规律各不相同。     

黛袋蛾发生与环境因子的关系

黛袋蛾是我国桉树的一种重要食叶害虫。结合室内试验和林间调查等方法，对黛袋蛾的发生与环境的关系进行了研究。结果表明：黛袋蛾4龄幼虫在27℃时取食量最大，随着温度的升高，取食量下降，当温度达到40℃时，幼虫基本不取食；幼虫在黑暗条件下的取食量较在光照下多；1年生幼林受害轻，4年生中龄林受害较重；害虫在阳坡虫口密度显著高于阴坡；桂南地区害虫发生比桂北地区严重。     

黛袋蛾生物学特性研究

黛袋蛾 Dappula tertia Templeton是桉树的一种灾害性食叶害虫.采用室内饲养和室外观察的方法,对黛袋蛾形态特征、生物学特性进行了初步研究.结果表明,黛袋蛾在广西1 a发生1代,以蛹和老熟幼虫越冬;幼虫一般在上午8-11时,下午17-19时活动较为频繁.     

尾叶桉生长调查小结

调查结果表明:1.尾叶桉在雷州地区的生长显著比其他的一些引种桉树速生:(1)尾叶桉和13个树种(种源)(以窿缘桉作对照)的引种生长比较,1年生、2年9个月生和3年2个月生,尾叶桉的树高、胸径、材积均高于13个树种(种源)和对照;(2)尾叶桉与雷林1号桉(50号)、刚果12号桉、窿缘桉(对照)等进行造林对比试验,3年半生,尾叶桉的树高、胸径和材积生长均居几个树种之首,分别为对照的164.2％、161.3％和435.3％。2.尾叶按的抗风力较强。3～5年生的3片尾叶桉林,1984年和1985年受到两次阵风10～11级的强台风袭击,风害率为10.1％～19.6％,而同龄的窿缘桉、小帽桉、葡萄桉等风害率高达26.1％～55.3％。     

桉树抗青枯病树种和无性系的鉴定

通过林间调查、人工接种试验和自然抗病性测定发现:桉树树种和无性系之间抗青枯病特性差异显著.赤桉、窿缘桉、柠檬桉、刚果桉、窿缘桉83002、雷林1号、雷林33号、刚果12号桉A2、、刚果12号桉A5、刚果12号桉W4、尾叶桉1号、巴勒斯桉等属于抗病类型.这些树种和无性系适应性强,速生,有些在生产中已被应用,其效益显著.     

桉树天然杂交及杂种优势的利用

桉树是以异花授粉为主的树种。许多不同树种之间具有很强的杂交亲和力。随着桉树树种和种源的不断引进,为自然杂交和人工控制杂交提供了更多的机会和广泛的基因基础。一、天然杂交我国已发现和利用的天然杂交桉树种有:蓝大桉,雷林一号桉,柳窿桉等。最近在东门发现了尾叶桉(E.urophylla)×窿缘桉(E.exserta),巨桉(E.grandis)×窿缘桉,巨桉×褐桉     

短轮伐期薪炭用材桉树的选择

在海南贫瘠的海滨阶地对尾叶桉、斑叶桉等８种桉树进行了造林试验。用座标综合评定方法选出适生性强、生长快、产量高、抗性强的尾叶桉、巨桉、斑叶桉和粗皮桉为优良短轮伐期薪炭、用材树种；窿缘桉、赤桉和细叶桉为较好的树种；野桉生长差，保存率低。     

短轮伐期薪炭用材桉树的选择

在海南贫瘠的海滨阶地对尾叶桉、斑叶桉等８种桉树进行了造林试验。用座标综合主定方法选出适出性强、生长快、产量高、抗性强的尾叶桉、巨桉、斑叶桉和粗皮桉为优良短轮伐期薪炭、用材树种；窿缘桉、赤桉和细叶桉为较好的树种；野桉生长差，保存率低。     

桉树枝瘿姬小蜂成虫羽化量的研究

桉树枝瘿姬小蜂(Leptocybe invasa Fishher & La Salle)能够在巨圆桉(Eucalyptus grandis×E tereticornis)、窿缘桉(E excserta)、尾叶桉(E urophylla)等多种桉树上危害,对不同寄主的危害程度、产生的虫瘿数量和羽化成虫数量有明显差异.观察...     

无瓣海桑主要害虫绿黄枯叶蛾的取食行为研究

绿黄枯叶蛾Trabala vishnou Lefebure是红树林植物无瓣海桑Sonneratia apetala Buch-Ham的重要害虫,为制定科学的防治指标和防治策略,对该虫的取食行为和取食量进行了初步的研究。结果表明:绿黄枯叶蛾幼虫喜食无瓣海桑、尾巨桉,拒食秋茄、桐花树;幼虫5龄,1～3龄幼虫具有聚集性,4龄幼虫开始分散取食;1～2龄幼虫取食量少,3～5龄取食量占整个幼虫期取食量的98.12%,其中5龄幼虫的取食量占整个幼虫期取食量的74.52%;幼虫期平均取食无辨海桑叶片178.94 cm2/头,确定防治指标为9.8头/千叶。     

福建省引种的13种桉树叶片解剖分析

本文对1986年所引种的13种桉树的叶片结构进行解剖研究,结果表明:属两面叶的有9种,等面叶的有4种;根据角质膜与表皮、栅状层与海绵层厚度比值、主脉中柱与主脉横切面积比值以及3项比值的平均值为指标,结合各自结构特点,把13种桉树对光、水变化的协调适应程度分为3个层次:(1)柠檬桉、白桉、赤桉和窿缘桉其叶片各组织对旱、寒、风和强光照的协调适应较强;(2)巨桉、昆士兰桉的角质膜与表皮比值、尾叶桉栅状层与海绵层比值均较高,适于一定水肥条件生长;(3)粗皮桉、小果灰桉3项比值最低,抗逆性较差,最差为托里桉和斑叶桉。     

Retranslocation of foliar nutrients in evergreen tree species planted in a Mediterranean environment

Internal nutrient recycling through retranslocation (resorption) is important for meeting the nutrient demands of new tissue production in trees. We conducted a comparative study of nutrient retranslocation from leaves of five tree species from three genera grown in plantation forests for commercial or environmental purposes in southern Australia--Acacia mearnsii De Wild., Eucalyptus globulus Labill., E. fraxinoides H. Deane & Maiden, E. grandis W. Hill ex Maiden and Pinus radiata D. Don. Significant amounts of nitrogen, phosphorus and potassium were retranslocated during three phases of leaf life. In the first phase, retranslocation occurred from young leaves beginning 6 months after leaf initiation, even when leaves were physiologically most active. In the second phase, retranslocation occurred from mature green leaves during their second year, and in the third phase, retranslocation occurred during senescence before leaf fall. Nutrient retranslocation occurred mainly in response to new shoot production. The pattern of retranslocation was remarkably similar in the leaves of all study species (and in the phyllodes of Casuarina glauca Sieber ex Spreng.), despite their diverse genetics, leaf forms and growth rates. There was no net retranslocation of calcium in any of the species. The amounts of nutrients at the start of each pre-retranslocation phase had a strong positive relationship with the amounts subsequently retranslocated, and all species fitted a common relationship. The percentage reduction in concentration or content (retranslocation efficiency) at a particular growth phase is subject to many variables, even within a species, and is therefore not a meaningful measure of interspecific variation. It is proposed that the pattern of retranslocation and its governing factors are similar among species in the absence of interspecies competition for growth and crown structure which occurs in mixed species stands.     

Influences of the Populus deltoids seedlings treated with exogenous methyl jasmonate on the growth and development of Lymantria dispar larvae

Introduction The interplant signal transduction has been hypothesized for many years (Baldwin and Schultz 1983; Rhoades 1983). It has been found that the resistance to insects is induced not only in damaged plants but also in the neighboring undamaged ind…     

柠檬桉叶化学成分研究(四报)——单宁组分研究

从柠檬桉叶醇提取物中分离和鉴定了倍酸,鞣花酸和栗木鞣花素等化合物。研究表明柠檬桉叶单宁为鞣花单宁类化合物,并有较多的C-甙类鞣花单宁,这类单宁系首次从桉树属植物发现。     

Effects of herbicides on consumption,growth and food utilization by cotton leafwormSpodoptera littoralis (Boisd.) larvae

The deterrent effects of nine herbicides on feeding and growth of cotton leafworm,Spodoptera littoralis (Boisd.), larvae were investigated. Fourth-instar larvae were fed on castor-bean leaves treated with recommended field rates of selected herbicides. Nutritional indices were measured regularly throughout the feeding tests until pupation. The food consumed by larvae in most herbicide-treatments was below that of control. Fluazifop [500 active ingredient (AI)], bentazon (250 AI), ametryne (800, 1600 AI), flamprop (130 AI), and isoxynil (187.5 AI) treatments seemed to be the best feeding deterrents. Relative growth rates of larvae fed on leaves treated with bentazon (250 AI), ametryne (1600 AI), gluphosate (1440 AI), glufosinate (800 AI), and bromoxynil (120 AI) were significantly reduced compared to that in control. Likewise, both the efficiency of conversion of ingested food to body substance (ECI) and the efficiency of conversion of digested food to body substance (ECD) were reduced with herbicide treatments below that in control. Approximate digestibility (AD), however, was significantly increased with most herbicide treatments. Moreover, feeding on herbicide-treated leaves resulted in a significant reduction in both pupation and adult emergence compared to that in control.     

自然低温胁迫下3种桉树的叶绿素荧光特性研究

对临安市3种桉树幼苗叶片叶绿素荧光特性进行研究,结果表明,自然低温下,各桉树表现出不同的适应性,总的来说,邓桉>柳桉>巨桉;自然低温(日最低气温-3.6℃)对柳桉和巨桉造成较大损害,而邓桉可通过维持相对较高的光化学效率,以及利用不断增加的qN来进行耗散,具有较强的抵抗低温胁迫伤害的能力。     

Water stress and seedling growth of two eucalypt species from contrasting habitats

Seedlings of Eucalyptus maculata Hook (mesic environment) and E. brockwayi C.A. Gardn. (arid environment) were supplied 100, 70 or 40% of their water requirements estimated from leaf area and the water used by well-watered seedlings. Restricting water supply caused large differences in growth rates, which were related to large differences in total leaf area. There was a fivefold range of variation in number of leaves per plant, and a reduction of up to 20% in average leaf size as a consequence of restricting water supply. Eucalyptus maculata seedlings produced more dry matter than E. brockwayi seedlings, but net assimilation rate was higher in E. brockwayi seedlings. Transpiration rates were also higher in E. brockwayi than in E. maculata. Leaf expansion was analyzed as a function of water stress integral (S(Psi)), which is the cumulative integral over time of predawn water potential below a datum. The leaf area achieved at any stress level was not uniquely dependent on total S(Psi), there was a secondary effect associated with reduced leaf growth caused by previous stress. At any value of S(Psi), reductions in leaf growth of water-stressed seedlings relative to leaf growth of well-watered control seedlings were greater in E. maculata seedlings than in E. brockwayi. Treatment differences in both species showed that, within the levels of stress applied, a moderate water stress over a long period of time was more detrimental to dry matter production than a severe stress for a short time.     

应用电导法评价5个桉树抗寒性

文章从材料和条件控制上探讨电导法评价桉树抗寒性的应用,具体评价了4个桉树无性系和邓恩桉实生种的抗寒性.结果表明:EG-6无性系抗寒性较强,叶片半致死温度为-9.76～-8.95℃,井冈1号和广9次之,叶片半致死温度为-9.26～-8.22℃,邓恩桉和DH201-2较弱,叶片半致死温度为-8.80 ～-7.77℃.不同叶...     

Genetic and Environmental Variations in Leaf Oils of Six Eucalypt Species

Chemical analyses were conducted with leave oils of Eucalyptus smithii, E. bakeri, E. polybractea, E. dives, E. radiata and E. macarthurii vvhich were introduced to southwestern China from Australia. It was found that the leaf oils of E. smithii, E. bakeri and E. polybractea contained 81-90% of 1 ,8-cineole, and E. dives and E. radiata contained higher a-phelandrene and piperitone. There vvere significant inter- and intraspeciflc variations in leaf oil yield, it also varied with seasons in vvhich leaves vvere harvested. The results suggested that more research should be undertaken to identify genotypes with high-yield of leaf oils. These species could be applied to develop community forestry.