Long‐term effects of liming on the fine‐root standing crop of Picea abies and Pinus sylvestris in relation to chemical changes in the soil

The long‐term effects of lime application on fine roots of Norway spruce, Picea abies (L.) Karst, and Scots pine, Pinus sylvestris (L.), have been studied in five experimental forest stands subjected to different lime applications 5 to 18 years before the present study was undertaken. The effects of liming does not seem to significantly influence fine‐root development in forest stands in the long term. The only response to liming in measured root variables was a tendency to increased specific root length (SRL = fine‐root length/fine‐root dry weight, m/g). A correlation between increased SRL, decreased root biomass and increased stem volume growth was indicated. Changes in water extractable amounts of mineral elements—P, K, Ca, Mg, Mn, S, Al and Fe‐in bulk soil and rhizosphere soil from the mineral soil layers were studied in a control area and an area treated with 3830 kg CaCO₃ ha^‐1. Few significant differences were found between treatments, and then mainly in the case of Ca.     

Modelling incidence of root rot in picea abies plantations in Southern Sweden

An empirical model is presented to forecast the incidence of root rot at stand level. In addition, the impact of different thinning programmes on the incidence of root rot is evaluated. The model is based on data from 152 permanent forest research plots of pure Picea abies in southern Sweden, within which the incidence of root rot at stump height in thinned trees has been recorded after each thinning since 1950. In total, about 20 000 stumps have been studied. According to simulations with the model, areas previously used as fields or for grazing are particularly susceptible to root rot, while old hardwood sites are less susceptible. Furthermore, simulations with the model imply that the earlier, the harder or more often a stand is thinned, the faster will be the development of root rot.     

日本落叶松容器苗不同控释肥生长效应

以落叶松网袋容器播种苗为对象,施用不同配方控释肥,进行落叶松苗期生长量、生物量、根冠比、叶绿素含量的测定,采用模糊数学隶属值计算方法选出适合日本落叶松育苗的专用配方控释肥。结果表明:按播种后天数,日本落叶松苗期生长阶段为:出苗期(7 39 d),生长初期(40 54 d),速生期(55 114 d)及生长后期(115 135d);不同配方控释肥对落叶松苗高、地径、单株生物量、地上生物量、地下生物量及叶绿素含量的影响差异极显著,而不同配方控释肥间根冠比差异不显著。控释肥配方2综合效果优于其他配方控释肥及从美国进口控释肥爱贝施,可以作为日本落叶松育苗专用肥。     

Root growth capacity and field performance of Pinus sylvestris and Picea abies seedlings

Correlations between root growth capacity (RGC), at the time of planting, and field performance were studied for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings. Before planting a gradient in seedling viability was generated through exposure to low root temperatures and different winter storage regimes. The hypothesis that high RGC values would improve field performance was to some extent verified for pine seedlings while no correlations could be registered for spruce. Reasons for these results are discussed.     

Lobarin from the Sumatran lichen, Stereocaulon halei

The diphenyl ether, lobarin (1) (syn. lobariol carboxylic acid) related to lobaric acid was isolated for the first time as a natural product along with five known compounds from Stereocaulon halei, a fruticose lichen collected in Indonesia. The structure of lobarin was elucidated by spectroscopic data analysis and its most stable conformers were determined by molecular mechanic dynamic calculations. A marked superoxide anion scavenging was found for compound 1 while no cytotoxicity on the B16 murine melanoma and HaCaT human keratinocyte cell lines was observed.     

盐胁迫对‘南林895’杨组培再生芽生根及抗氧化能力的影响

以‘南林895’杨经组培获得的2 cm长再生芽为试验材料,研究不同浓度NaCl处理下再生芽不定根发生能力及其耐盐能力。结果表明:‘南林895’杨再生芽在75 mmol/L以下能够正常产生不定根,100 mmol/L完全抑制不定根的形成。25～50 mmol/L盐处理能够促进‘南林895’杨再生芽不定根的伸长,增加根数,提高叶绿素a及总叶绿素的含量。25 mmol/L处理的SOD、CAT、POD、GR 4种保护酶与对照之间没有显著性差异,MDA含量和电导率也低于对照;而在高浓度盐处理下(75～100 mmol/L),SOD、CAT、GR保护酶活性下降,导致膜透性加大,MDA含量增加,POD和AsA-POD酶活性的提高有助于缓解盐胁迫对‘南林895’杨造成的氧化损伤。     

文冠果根系分布特征及生长适应性

通过对文冠果根系分布及生长调查分析表明:文冠果根深、根系发达、根幅大,5个月的幼苗主根深度可达50 cm,根幅可达28 cm,主根明显垂直向下深入土壤下层,能够吸收土壤深层水分,在极端干旱条件下能够生长.文冠果根系保水力强,抗干旱贫瘠,但不耐水涝,低温土壤中生长缓慢.在积水土壤中栽植时,应创造良好的排水条件.     

广宁红花油茶根尖压片制作技术

广宁红花油茶在广东、广西等原生地种植容易获得高产,具有良好的遗传改良潜力。文章以广宁红花油茶为对象,探索了适用于荧光原位杂交技术中的染色体制片技术,并与传统的染色体压片制作技术进行比较,总结了一套节省时间、技术要求较低和效果较好的染色体根尖压片制作技术,可用于广宁红花油茶的细胞学研究,为开展分子染色体工程育种以及基因组分析奠定技术基础。     

嫁接在杨树远缘杂交育种上的应用研究

为了在吉林省西部地区选育出耐盐碱性强,又能无性扦插育苗进行快速繁殖的杨树新品种,选用了白杨派的银新杨作母本与青杨派的小叶杨为父本进行远缘杂交育种,但两派之间杂交不亲和。为解决这一问题,进行了先嫁接再杂交的育种方法。试验表明,此方法在一定程度上提高了远缘杂交的结实率,而且杂种苗具有明显的父母本双亲的性状,为杨树新品种培育开辟了新的途径。     

如何在园林绿化机关单位中执行ISO9000标准确保工程质量——以在施工中对监理单位的监督管理为例

城市绿化建设管理的机关单位,在工程建设的过程中作为甲方如何站在更权威更专业的高度去管理工程质量,如何对监理单位进行更有效的监督管理至关重要。本文以ISO9000质量管理体系标准作为操作管理平台,探讨建设单位如何对监理单位提供的服务过程进行监督管理,从而提高园林绿化机关单位工程项目建设的管理水平。