热带桉树种、种源选择及生长

我国引种桉树已有百年历史，早期引种的桉树大部分作为庭园观赏树木，５０年代初试种桉树人工林，现在南方１６个省区栽培，栽培面积约为１５５万公顷，主要桉树栽培区集中在广东、广西、海南，即华南地区，其次为西南（云南、四川等地）。桉树作为速生纸浆材、用材及薪材树种受到世界广泛重视，桉树和杨树、松树一起被誉为世界三大速生树种。它适应性广，不同桉树种对气候及立地条件要求也有所不同。此次重点调查热带桉树，以尾叶桉、刚果桉、细叶桉、赤桉为主，旨在了解８０年代在广东、海南等不同气候区引种桉树及不同种源的生长及适应（如抗风等），为在本地区发展桉树的“适地、适树、适种源”提供科学依据。     

薪炭林营造技术的研究

1982—1991年,在陆良、普洱、永胜等三个地区,海拔1500—1990米的范围内,先后开展了包括桉树、荆树、合欢、车桑子等9个树种在内的引种、选种及营造技术的百亩薪炭林裁培试验。结果:(1)筛选出蓝桉、银荆、黑荆、直干桉、赤桉、大叶桉为当地主要薪材树种;(2)桉树与银荆,黑荆或蒙自合欢混交,具有功能互补和较好的生态效益与经济效益;(3)以每亩333—666株为合理的定植密度。当年或次年追施N+P混合肥或有机肥,4—6年即可轮伐,年均亩产干柴800kg以上。比一般薪炭林产柴量高2—3倍。     

我国耐寒桉树的种质资源及其遗传改良

本文概述了中澳合作“耐寒桉树”研究项目在良种筛选与遗传改良方面的主要工作。通过对我国耐寒桉树目标推广区气候特点的认识,及对20年来这些区域桉树引种试验的重新评估,项目筛选出一批耐寒能力在-5℃至-10℃的优良桉树,并它们把分为2类,一类为适生于高海拔地区树种,主要有:蓝桉、直干桉、史密斯桉和亮果桉;一类为适生于低海拔地区树种,包括:邓恩桉、赤桉、巨桉、柳桉。在耐寒桉树的遗传改良方面,该项目通过改建、新建等方式,在全国各地建立以上树种的种子园19个,并制定了各树种的详细改良计划。为获得更多优良耐寒树种,我国近年已建立了一大批耐寒桉树筛选试验,可望在耐寒能力的提高上取得突破。     

四川桉树基因收集及培育技术

经过近100年的引种历史,四川共收集了130余种桉树,目前仍保留有近40种桉树。这些树种在四川省的林业建设中发挥了重要作用。在四川具有发展前途的桉树有：巨桉、直干兰桉、柳桉、史密斯桉、邓恩桉、迪恩桉、亮果桉、赤桉、大花序桉、尤曼桉等。根据桉树生物学特性以及四川多年来桉树栽培情况,将四川桉树栽培地区划分为盆地、攀西河谷阶地和干热河谷等三个栽培区。针对不同的栽培区,提出相应的适宜桉树种,并对巨桉、直干蓝桉、赤桉树种不同培育目标的栽培技术进行了总结。     

云南造纸用桉树树种选择的研究

报道了云南桉树的引种、资源及桉树在造纸工业中的利用状况。结合云南的实际和国内外有关的文献资料,筛选出适于造纸的优良树种——蓝桉,和较好树种——直杆桉、柳桉。论述了影响桉树制浆造纸的主要因素——容重及抽提物。)     

桉树耐寒性的观察与研究

本文对引种桉树及其赤桉、细叶桉、巨桉、柳桉等主要桉树种的93个种源的耐寒性进行观察,在对1981、1984、1987、1991年4次特大寒流袭击的调查结果表明;树种间和种源间耐寒性差异十分显著。在调查观察基础上,对桉树抗寒性进行综合分析,并筛选出耐寒性较强的桉树种和种源。     

亮果桉等七个树种的引种试验

七种桉树的引种试验在保山市羊邑镇进行,以我省原引种成功的直于桉作对照。经对幼林阶段生长量,年生长节律,生物量,抗性等的观测和方差分析,并采用多指标综合评定法对各引种树种的树高、胸径生长,生物量及抗性进行综合评定。结果表明:亮果桉、巨桉、双肋桉其各项指标接近或优于对照。亮果桉、巨桉高生长比对照大25～40％,胸径生长比对照大11～22％,双肋桉生长量与时照近似。因此,上述桉树可在相应的地区引种发展。树木引种栽培是树木改良工作的重要途径之一。本次引种试验是以引进纤维用材和提取桉油树种为目的,通过气侯条件以及与蓝桉亲缘关系密切的树种生态、生物学特性的研究,我们选定王桉(Eucalyptus regnans)、巨桉(E·grandis)、山桉(E.dalrympleana)、亮果桉(E·nitens)、双肋桉(E·bicostata)、直干桉(澳,E·maidenii)、毛皮桉(E·maearthuri)等七种桉树进行引种栽培试验。     

云南桉树引种历史、发展现状及展望

全面论述了云南桉树引种历史、发展情况及在科学试验中取得的成绩,并对今后云南桉树发展提出了建议。云南约1896年首次引种蓝桉于昆明,至2005年云南引种保存桉树100种左右,面积达23.6万hm2。目前,在生产中种植较多的有直干桉、蓝桉、史密斯桉、双肋桉、巨桉、尾叶桉等10多种,选出优树348株,优良种源28个,家系176个,无性系21个,提出了工业原料林集成培育技术,对桉材、桉油的利用进行了大量的基础性研究。据不完全统计,至2005年,发表论文109篇,获得部省级以上研究成果奖14项,对云南桉树发展起到了较好的作用。     

闽西北适栽桉树树种选择研究

自上个世纪90年代以来，闽西北进行了多批桉树树种引种或种源家系试验，结果表明：适宜闽西北地区推广种植的桉树有巨桉、邓恩桉、柳桉和赤桉，其中赤桉、邓恩桉最为耐寒。可以推广到闽西北大部份地区，巨桉、柳桉适宜闽西北较低海拔、绝对最低温度在-5℃以上的地区，但需要选择适宜的种源。树种内种源和家系间的生长性状、抗寒性存在显或极显差异，单株间的生长差异比家系间的生长差异大，而家系间又比种源间大。此外，桉树树种原产地的雨量分布情况对决定引种桉树极为重要。在高温潮湿的福建地区不适宜引进冬雨型桉树树种。     

桉树基因组研究进展

桉属的一些树种在全世界的热带和亚热带地区广为种植。该属树种生长快,工业性能好,适应范围广,引起了许多国家的种植兴趣。据估计,1985年全球桉树种植面积约6百万hm~2。现在,全世界引种的绝大多数硬材林树种是桉树,桉树已成为一个主要的生物资源树     

不同栽植密度下欧美杨叶片耐荫性与生物累积量的关系

为阐明不同栽植密度下欧美杨无性系树冠叶片耐荫性与生物累积量的关系,选择高密度(2 m×3 m)和低密度(2 m×5 m)栽植的不同亲本的5个欧美杨无性系为研究对象,测量了生物量、树冠结构、叶面积指数及光合参数。结果表明:(1)不同无性系对栽植密度有不同的反应;(2)具有较高生物量的欧美杨无性系树冠叶片在高、低栽植密度下均表现出较强的耐荫性特征;(3)树冠耐荫性在不同密度中表现出差异性,在低密度栽植中,树冠上层耐荫性与生物量和叶面积指数关系密切;在高密度栽植中,树冠上、下层叶片耐荫性与生物量和叶面积指数关系密切;(4)树冠耐荫性特征受亲本和环境的共同影响,由低密度到高密度,具有较高生物量的03-04-97、03-04-111、03-04-171树冠中下层叶片光补偿点和暗呼吸速率大幅度降低。该研究结果可为选择适合高密度栽植的欧美杨无性系提供数据和理论支持。     

试论世界桉树栽培现状和我国桉树人工林发展策略

桉树是世界上热带、亚热带地区最重要的人工林树种之一,其面积已超过600万ha。文中着重介绍了巴西发展按树的经验,并提出了我国应采取的对策。     

An evaluation of the conical approximation as a generic model for estimating stem volume, biomass and nutrient content in young Eucalyptus plantations

Accurately and non-destructively quantifying the volume, mass or nutrient content of tree components is fundamental for assessing the impact of site, treatment, and climate on biomass, carbon sequestration, and nutrient uptake of a growing plantation. Typically, this has involved the application of allometric equations utilising diameter and height, but for accurate results, these equations are often specific to species, site, and silvicultural treatment. In this study, we assessed the value of incorporating a third piece of information: the height of diameter measurement. We derived a more general volume equation, based on the conical approximation, using a diameter projected to the base of the tree. Common equations were developed which allowed an accurate estimate of stem volume, dry weight and nutrient content across two key plantation grown eucalypt species, Eucalyptus grandis W. Hill ex Maiden and Eucalyptus globulus (Labill.). The conical model was developed with plantation-grown E. grandis trees ranging from 0.28 to 15.85 m in height (1.05 g to 80.3 kg stem wood dry weight), and E. globulus trees ranging from 0.10 to 34.4 m in height (stem wood dry weight from 0.48 g to 652 kg), grown under a range of contrasting cultural treatments, including spacing (E. grandis), site (E. globulus) and fertilization (nitrogen and phosphorus) for both species. With log transformed data the conical function (V_con) was closely related to stem sectional volume over bark and stem weight (R² = 0.996 and 0.990, respectively) for both E. grandis and E. globulus, and the same regressions can be applied to both species. Back transformed data compared with the original data yielded modelling efficiencies of 0.99 and 0.97, respectively. Relationships between V_con and bark dry weight differed for the two species, reflecting differing bark characteristics. Young trees with juvenile foliage had a different form of relationship to older trees with intermediate or adult foliage, the change of slope corresponding to heights about 1.5 m for E. grandis and age 1 year for E. globulus. The V_con model proved to be robust, and unlike conventional models, does not need additional parameters for estimating biomass under different cultural treatments. More than 99% of the statistical variance of the logarithm of biomass was accounted for in the model. V_con captures most of the change in stem taper associated with cultural treatments and some of the change in stem form that occurs after the crown base has lifted appreciably. Fertilization increased N and P concentrations in stem wood and bark, and regressions to estimate N and P contents (the products of biomass and concentration) were dependent on treatment. For instance, there was a large growth response to N fertilization in E. globulus corresponding with a change (P < 0.05) in the intercept of the regression to estimate N content.     

米老排造林密度试验初报

米老排(Mytilaria laosensis)属金缕梅科半落叶乔木,是中国南亚热带优良速生用材树种,材质优良,经济效益高。60年代在广西大青山试种成功后,已成为主要的造林树种之一。广西已发展到1300ha,幼林普遍生长良好,但某些林分因密度过大而出现生势衰退现象。如何提高经营水平,合理确定其造林密度,是有待解决的问题。为此,1980年我们做了米老排造林密度试验,取得了初步成效。现将试验结果初报如下。     

Chloride content and biomass partitioning in Eucalyptus hybrids grown on saline sites

Eucalyptus camaldulensis × globulus and E. camaldulensis × grandis hybrids have been developed to combine the salt–waterlogging tolerance and high-quality wood fibre of their respective parents. The aim is to develop trees that will grow in relatively dry and/or saline environments and provide commercial wood products. Previous studies indicate that the hybrids exhibit faster growth than either of their pure species parents, and that there are significant differences in growth rates between them. We undertook a comparative study of the partitioning of above-ground biomass (AGB) to examine biomass and chloride (Cl) allocation of trees growing on two saline-irrigated sites in south-eastern Australia. Eucalyptus camaldulensis × globulus had a higher proportion of AGB in leaves (20–29% cf. 15–16%), and lower proportion in live branches (3–10% cf. 6–14%) than E. camaldulensis × grandis. The concentration of Cl was highest in the stembark (4.2–9.6 g kg⁻¹) and lowest in the stemwood (0.6–2.0 g kg⁻¹), suggesting that trees can export Cl through bark shedding. Total Cl content was strongly related to volume under bark (R² = 0.99), and differences in partitioning of Cl into tree components differed between the hybrids in the same way as AGB. Preferential partitioning of Cl to live branches rather than foliage in E. camaldulensis × grandis suggests that this hybrid may be compartmentalising Cl to reduce the risk of Cl toxicity in the leaves.     

Relationship between species diversity and biomass of eucalyptus plantation in Guangxi, south China

To reveal the relationship between species diversity and biomass in a eucalyptus (Eucalyptus urophylla × E. grandis) plantation located in the Dongmen State Forestry Farm of Guangxi, south China, 18 sample plots were established and the total biomass, arbor layer biomass and undergrowth biomass of communities were subsequently harvested. The results were as follows: 1) Species richness in eucalypt plantation had remarkable positive correlation with biomass of arbor layer, undergrowth and community (α = 0.001), its correlation coefficients were 0.6935, 0.7028 and 0.7106 respectively. 2) Leaf area index (LAI) had remarkable positive correlation with species richness and undergrowth biomass (α = 0.001). Its correlation coefficients were 0.7310 and 0.6856, respectively. 3) Arbor layer biomass had remarkable correlation with soil organic matter and hydrolysable N, its correlation coefficients was 0.6416 and 0.6203 respectively. Species richness had remarkable correlation with soil organic matter and correlation coefficient was 0.6359. Among them, the correlation was significant at the 0.1 level. Undergrowth biomass had little correlation with nine soil nutrients and correlation coefficients were under 0.4. To sum up, species diversity was advantageous to the promotion of the biomass of the eucalyptus plantation, and the variation of LAI and soil nutrient in small-scales could result in the difference of species diversity and biomass in different sample plots. Translater from Scientia Silvae Sinicae, 2008, 44(4): 14–19 [译自: 林业科学]     

桉树薪炭林混交试验-Ⅰ.不同密度不同比例混交试验初报

桉树在华南地区广泛分布,是多种用途的速生用材和薪材树种。但纯林连续多代经营易引起林地土壤物理性质恶化,地力衰退,木材产量下降,因而期望通过树种混交来保持和培肥地力。我们从1982年开始在琼海县阳江镇林场和上埇乡林场选择根瘤发达,枯枝落叶量大,具有固氮改土能力,且幼树阶段耐一定程度庇荫的大叶相思和黑荆进行混交试验。现将3年观测结果初报如下。     

Nondestructive sampling of Eucalyptus globulus and E. nitens for wood properties. I. Basic density

A non-destructive sampling strategy for basic density, based on removing 12 mm bark-to-bark cores, was developed in E. globulus and E. nitens. Fifty trees of each species, aged 5 to 9 years, were sampled across a range of sites. Core samples were removed on both a north-south and an east-west axis from 6 fixed heights in the base of the tree (0.5 m, 0.7 m, …, 1.5 m). Whole-tree values were calculated from disc samples removed at eight percentage heights (0, 10, 20, …, 70%) and correlations between the cores and whole-tree values were used to determine the optimal sampling height. Core samples were found to be reliable predictors of whole-tree density, explaining between 84% and 89% of the variation between trees. Core sampling of E. globulus and E. nitens to estimate basic density of whole-trees and stands is feasible; cores from trees at all E. globulus sites gave high correlations with whole-tree values. For E. nitens, site differences were apparent, and it is recommended that a small destructive sampling program should be undertaken prior to commencing a major sampling program. Recommended optimal sampling heights are 1.1 m for E. globulus and 0.7 m for E. nitens. Core orientation was not important and density was not related to tree size. Six whole-tree samples or eight core samples are required for estimating the mean density of a stand at a specific site to an accuracy of ±20 kg m⁻³ with a 95% confidence interval. Received 17 September 1998     

Study onSonneratia apetala productivity in restored forests in Leizhou Peninsula, China

The exoticSonneratia apetala in Leizhou Peninsula, has shown outstanding fast-growing ability in restored mangrove forests, at the middle and high tide intertidal zone, with year-round fresh water input from drainage. By setting plot and selecting standard tree, investigation and measurement on height growth, diameter growth, biomass, productivity, and so on, were made in aS. apetala plantation at age of six at Lanbel, Fucheng, Leizhou Peninsula in May 2001. The investigating results showed that the mean annual height growth of plantation was 2.03 m and mean annual growth of diameter at breast height (DBH) was 2.35 cm. There exists a significant correlation between the diameter at ground surface (DGS) and DBH. The average biomass of a single standard tree in dry weight was 95.647 kg/m². A ratio of above-ground biomass to under-ground biomass was 1.60. The stand biomass of unit area was 22.955 kg/m², singletree wood volume was 88.23 dm³, and the annual wood volume productivity (P _A) of the same year was 0.407. The forest energy accumulation was 424.851 MJ/m², with annual solar energy fixing rate of 40.68×10⁻⁷%. It is concluded thatS. apetala species had characteristics of outstanding high biomass accumulation and could be used as coastal planting tree species in southern China. Foundetion item: The paper was supported by the project of integrated mangrove management and coastal protection (IMMCP) in Leizhou Peninsula, Guangdong Province. Biography: Han Wei-dong (1963-), male, associate professor, in Zhanjiang Ocean University, Zhanjiang 524088, Guangdong; and presently as postdoctoral researcher in Life Science College, Xiamen University, Xiamen 361005, Fujian, P.R. China Responsible editor: Zhu Hong.     

Nondestructive sampling of Eucalyptus globulus and E. nitens for wood properties; II. Fibre length and coarseness

Within-tree variation in fibre length and coarseness was studied in fifty trees of E. globulus and E. nitens to develop a non-destructive sampling strategy. Trees, aged 5 to 9 years, were sampled across a range of sites in southern Australia. Simulated core samples were removed at six fixed heights easily accessible from the ground (0.5, 0.7, ... 1.5 m) and at eight percentage heights (0, 10, 20, ... 70%). Whole-tree values, calculated from percentage height data, were correlated with the core data to determine the optimal sampling height. Core samples were found to be reliable predictors of whole-tree fibre length, but results were variable for fibre coarseness. Simulated cores taken from the recommended sampling heights explained 87% and 71% of variation in whole-tree fibre length for E. globulus and E. nitens respectively and 54% and 45% of the variation in whole-tree fibre coarseness. Fibre length at all fixed heights showed good correlations with whole-tree values at all sites for E. globulus. For E. nitens the correlations were slightly lower and variable across sites. Results for fibre coarseness varied across sampling heights and sites for both species. The recommended sampling height for fibre length is 1.5 m for both species, whilst for fibre coarseness, the recommended sampling heights are 0.9 and 1.1 m for E. globulus, and 0.9 and 1.3 m for E. nitens. Radial orientation of cores was not important and neither fibre length nor coarseness were related to tree size or basic density. To estimate stand mean fibre length to an accuracy of ±5% would require sampling 9 whole trees or taking cores from 13 trees for E. globulus and 4 whole trees or cores from 8 trees for E. nitens. For estimating stand mean fibre coarseness, 10 whole trees of E. globulus and 7 whole trees are needed for E. nitens. Core sampling for stand mean coarseness would require more trees: 13 to 21 for E. globulus and 11 to 16 trees for E. nitens. Received 17 September 1998