【作者】 周家维；

【导师】 徐大平；

【作者基本信息】 中国林业科学研究院 ， 森林培育， 2011， 博士

【摘要】 本文围绕贵州桉树人工林培育工作中出现的问题,开展桉树树种、种源、家系和无性系的引种栽培试验研究,通过大田试验观测,依据生长性状进行综合评价,筛选出速生、适应性强的种质材料供生产上应用推广;同时,针对贵州土壤普遍缺硼制约桉树生长的状况,开展硼不同施用量的梯度试验,根据生长性状和叶片养分分析,找出促进桉树生长的合理施硼量;此外,还进行了不同季节施肥对桉树生长影响的研究。通过系列研究,选出适合贵州发展的优良树种和优质材料,扩大生产群体,降低种植风险;同时为桉树的速生丰产提供技术支持,促进贵州桉树的稳步发展,提高林分产量。经多年观测和分析初步结论如下:（1）贵州桉树引种距今已有70余年的历史,在黔中、黔南、黔东南和黔西南展开引种与保存的实地调查,60年代前后引种的桉树,保存至今的仅有大叶桉、柠檬桉和窿缘桉3个种,三个树种的耐寒性较差,均分布在贵州南部热量充足的都柳江、南盘江和红水河流域,并且以四旁树为主零星保存;90年代以种植油材两用的直杆蓝桉为主,耐寒性和速生性较好,分布范围也较广但经营不善,短期高强度采收后放弃经营,保存者林相很差。（2）树种/种源筛选试验中,对参试的23个树种/种源中保存率大于50%的19个树种/种源的单点和2个试验点13个树种/种源的各年度方差分析结果表明,所有生长性状和形质性状在树种/种源间均存在显著或极显著差异。39个月生时,采用综合指数法评选出优良树种/种源8个,分别是邓恩桉、柳桉、巨桉13023、直杆蓝桉、柠檬桉和尾叶桉3个种源;通过2点稳定性评价分析,柳桉最不稳定,在高水肥条件下可获得理想的生长量,其次是邓恩桉、尾叶桉10144、巨桉13023在良好环境条件下生长表现好;稳定性较高的是尾叶桉17841号种源,适合广泛栽培,但该种源耐寒性较差,推广应用时要注意立地选择;巨桉20758号种源耐瘠薄能力较强,在较差立地上生长表现可能较好。（3）贵州中部引种的邓恩桉种源/家系试验林中,第二年的树高生长节律观测、分析表明,15个种源的树高生长曲线均呈双峰曲线,即邓恩桉树高生长5月开始进入速生期,7月上旬达到峰值,在当地气温最高而降水相对较少的7月下旬～8月上旬高生长出现减缓的现象,曲线下降,8月上旬降雨量增加,高生长加快,形成第二个生长高峰,之后生长随着温度的降低和雨量的减少而减缓直到停止生长。说明水热平衡和同步是维持邓恩桉速生的基础。15个种源78个家系各年生长性状方差分析结果显示:树高、胸径和单株材积在种源、家系间均达极显著差异水平。试验的家系遗传力为0.0322～0.3535,呈低到中度遗传,表明性状受遗传控制的影响较小,而受环境的影响更大;而且所有性状家系遗传力均大于单株遗传力,说明通过在家系层次上的选择比基于单株的选择更能获取较大的遗传增益。按标准差法对参试种源和家系进行评价,选出优良种源3个,种源遗传增益为3.543～11.983%;优良家系9个,入选率11.53%,遗传增益在0.446～9.913%之间,说明通过种源和家系选择各性状均可获得较大的增益。（4）无性系试验中,试验Ⅰ174个无性系各年度方差分析结果表明,无性系间各生长性状差异达极显著水平。4.5年生时,筛选出单株材积大于广泛栽培无性系DH32-29（对照）的优良无性系有11个;试验Ⅱ在4.5年时,从经过前期选择的5个无性系和4个已推广无性系中选出了平均单株材积高于总体均值的4个无性系,其中有2个是尚未推广的无性系,为当地桉树营造林提供了更多的候选材料。（5）无性系试验Ⅲ直接引进华南地区表现优良的11个无性系在2个海拔高度进行对比试验,高海拔试验林的生长优于低海拔试验林,平均树高、胸径、单株材积和蓄积量比低海拔的分别高12.51%、34.47%、109.04%和89.13%,生长最好的无性系Eg5的年蓄积量为45.66 m3/hm2,比其余无性系高11.7%～87.5%。稳定性分析表明,生长量大于总体均值的Eg5、DH32-29、GL-9、DH32-22和Eg6等5个优良无性系的回归系数bi>1,说明好的无性系基因型为立地条件越好,生长越有利类型。（6）对上述无性系选择试验Ⅰ～Ⅲ的早期与晚期年度生长性状相关分析结果表明,2.5年生各生长性状与后期的生长性状的相关关系紧密,说明2.5年生生长性状对后期具有较好的预测性,为桉树无性系的早期选择提供了依据。（7）不同硼肥施用量对桉树生长影响试验结果表明,从0.5 a开始,有B处理的树高和胸径均显著大于对照,说明基肥施硼有利于促进尾巨桉的早期生长;有B处理间,不同B水平对尾巨桉胸径生长影响较小,有B处理的胸径显著高于对照,但各施B处理间胸径差异不显著;施B对树高生长的影响较大,处理间树高生长差异显著,2.5 a生以前,高B处理的树高生长大于低B处理,以L5值最大;4.5 a生时,与对照相比,林分蓄积量增幅最大的是L₁₀,其次是l₅,即每株施5～10 g硼砂林分蓄积量可增加44.72～64.56%,而且还可获得较优的干形和分枝。（8）对无性系DH32-29进行不同施肥季节与施用量试验结果表明:冬季施肥能够促使桉树迅速进入速生期,延长生长时间,提高桉树的生长量,在相同甚至低肥量的情况下,无性系的生长明显优于夏季施肥的处理。这与夏季雨量大,养分地表流失和向下淋溶都会明显高于冬季相关。无性系的单株材积生长在年施肥量300g（F2）时达到峰值,并未随着施肥量的增加而增加,2.5年生时,高肥处理F5（450g）的单株材积是各施肥处理中最小的,仅比对照略高,说明施肥量过大并不一定能促进桉树速生快长,因此施肥要适当,过量则有抑制生长的危险。更多还原

【Abstract】 This paper focuses on the selection of introduced Eucalyptus species, provenances, families and clones for plantation management in Guizhou Province, China. Germplasm materials with characteristics of fast-growing, cold-resistance and strong adaptability were selected through overall evaluation of the field experiments for extended planting and promotion; Meanwhile, taking into account the general lack of boron in soils of Guizhou, one of the main factors restricting eucalyptus growth, a test of application of boron at different concentrations was carried out to find out the appropriate rate of application of boron by analizing the growth traits and nutrient contents of the leaves of Eucalyptus tree species. In addition, the effects of fertilization at different seasons were studied to find out the proper fertilizatiing seasons for eucalyptus plantations. All these studies provided Guizhou with good planting materials, appropriate rate of fertilizer applications and low risk of planting for the development of Eucalyptus plantations. The results of the studies are summarized below:(1) Eucalypts were first intrduced into Guizhou more than 70 years ago. Among the species introduced in 1960s, only three species, Eucalyptus robusta, E. citriodora and E. exserta, are survived in river basins of Liujiang, Nanpanjiang and Hongshuihe rivers in Southern Guizhou with comparitive rich in heat resources as they are not cold-resistant. E. globulus, a species introduced in 1990s, can survived in Southern and Central Guizhou as it is more cold-resistant.(2) The results of analysis of variance (ANOVA) of yearly grwoth traits and form quality traits conducted for 19 species/provenances with more than 50% survival rate in a species/provenance trial and 13 species/provenances in two species/provenance trials showed that the grwoth traits and form quality traits were significantly different. At the age of 39 months, 8 species/provenances, Eucalyptus dunnii, E. saligna Smith, E. grandis Seedlot No.13023, E. globulus, E. citriodora and three provenance of E. urophylla, were selected through eveluation by using synthetic index method. Analysis of statability of growth performance of trials plantations at two sites reaveled E. saligna was the most unstable,which performed well in fertile soil with high water content, followed by Eucalyptus dunnii, provenance 10144 of E. uroppylla and provenance 13023 of E. grandis which performed well under good environmental conditions. Provenance 17841 of E. urophylla, the provenance most suitable for extensive growing, is less cold-resistant and careful selection of planting sites is needed for extended planting. Provenance 20758 of E. grandis performed well in infertile soils.(3) E. dunnii provenance/family trials was established in Central Guizhou, the survey of tree high growth rhythms showed that the growth curves of 15 provenances tend to be bimodal. E. dunnii started to grow fast in May and reach the peak in early July, while slowdown from late July to early August when the temperature is high and rainfall is low in the trial area; the second peak period of growth occurs in August with increasing rainfall, and then growth becomes slowly due to the decreasing rainfall amd low temperature. Water and heat balance seems to be the basis of maintaining the fast-growing E. dunnii Maiden.The ANOVA of growth traits of 78 families of 15 provenances showed that tree height, DBH and individual volume among provenances and families were significantly different. The heritability of the tested familis is 0.0322-0.3535, a low to medium heritability indicating that the traits are less affected by genetic control but by environmental influence. The heritability of the traits is bigger in famililies than in individuals, this means that larger genetic gain can be obtained while selection is conducted at familiy level. Three provenances are selected according to the standard deviation method, the genetic gains are 3.543-11.983%;9 families or 11.53%, are selected with genetic gainsof 0.446-9.913%.(4) The ANOVA of yearly growth traits of 174 clones in the clonal test I indicated that all the growth traits among clones were significantly different. At the age of 4.5 years, 11 fine clones having the individual volume more than the widely cultivated clone DH32-29 were selected. In clonal test II, 4 clones were selected from the 5 ever-selected clones and 4 ever extensively planted clones with individual volimes heigher than the average of the tested clones, of which 2 have not been widespread, thus providing the local people with more lanting materail.(5) Eleven fine clones directly introduced from south China were planted at two sites at two altitudes. Experimental results showed that superior to that at low altitude. The average tree height, DBH, individual volume and stand volume of trees at high altitude is are 12.51%, 34.47%, 109.04% and 89.13% higher than tose at low altitude, respectively. The best clone is Eg5 clone with an annual syand volume of 45.66 m3 / hm2, which is 11.7% - 87.5 % higher than the other clones. Analysis of statibility reaveled that the regression coefficient (bi) of 5 clones, Eg5, DH32-29, GL-9, DH32-22 and Eg6,which recorded higher stand volumes than the average, is more than 1, showing that better clone genotype and site conditions are resulted in better tree growth performance.(6) Correlation analysis of yearly growth traits of clones in the above three clonal tests at early stage and later stage showed that better growth prediction can be made with use of growth traits at the age of 2.5 years.(7) Results from a study on the effects of application rates of boron on the growth performance of Eucalyptus urophylla x E. grandis showed that the height and DBH of six-month-old young trees in plots applied with boron were significantly higher than those in the control, indicting that applicantion of boron benefits the early growth of Eucalyptus urophylla x E. grandis. The differences in DBH of young trees among plots applied with different rates of boron were not significant, while those in tree height were significant. At the age of 2.5 years, tree height in plots applied with higher rates of boron was higher than that in plots applied with lower rates of boron; and the greatest height growth was recorded in the treatment of L5. Low applicaion rate of boron resulted in high mortility of young tress, and thus provided the survived trees with more growth spaces which may lead to greater rates of growth of DBH and height of individual trees during the late stage of growth. At the age of 4.5 years, the greatest standing volume was recorded in the boron application treatment of L10, follwed by L5. Application of boron at 5-10 g per trees resulted in increasing standing volume by 44.72-64.56% and better stem forms and branching.(8) Fertilization trials of clone DH32-29 at different rates and in different seasons indicated that fertilization in Winter can lead an early fast growing stage, a longer growing period and higher productivity of Eucalyptus trees than fertilization in Summer, even the fertilization rate is low. This may be due to the loss of fertilizers resulted from soil errosion caused by heavy summer rains. The annual individual volume of clones reached the peak when fertilization rate is 300g (F2) without increament with increasing fertilization rate. At the age of 2.5 year, the individual volume of high fertilization treatment F5 (450g) is the least, only slightly higher than the control, indicating that too high rates.of fertilizer application do not promote eucalyptus growth, or contrary inhibit growth potential.更多还原