梵净山冷杉和珙桐的碳氮磷分布特征

为科学有效地保护梵净山珙桐和冷杉,保障梵净山旅游业的持续发展,稳定梵净山生物多样性提供理论依据,以梵净山典型珍稀植物梵净山冷杉和珙桐为研究对象,采用野外调查与室内分析相结合的方法,对2种植株不同部位的碳氮磷含量分布特征及其与土壤碳、氮、磷含量的相关性进行研究。结果表明:梵净山2种珍稀植物C和P含量的分布规律为冷杉叶冷杉茎珙桐茎珙桐叶,N含量的分布特征为珙桐叶冷杉叶珙桐茎冷杉茎;C∶N分布规律为珙桐茎冷杉叶冷杉茎珙桐叶,C∶P和N∶P的分布特征为珙桐叶珙桐茎冷杉茎冷杉叶。根据2种珍稀植物的化学计量数比判断,该地区植物更多受氮限制(N∶P14),但有充足的磷。珙桐土壤的N含量与茎的N含量呈正相关性但差异不显著,与叶的N含量呈正相关且差异显著;冷杉土壤的N含量与冷杉茎和叶的N含量均呈正相关且差异显著。珙桐土壤的P含量与珙桐茎的P含量呈正相关且显著,与叶的P含量呈正相关且极显著;冷杉土壤的P含量与茎的呈正相关且极显著,与叶的P含量呈正相关且显著。     

太白山巴山冷杉林初步研究

在定性分析巴山冷杉林种类组成及生活型港基础上,根据法瑞（Ｂｒａｕｎ—Ｂｌａｎｑｕｅｔ）学派概念,以林下植物种类组成作为依据,用定量分类方法将巴山冷杉划分为：杜鹃──巴山冷杉林;藓类──巴山冷杉林;草类──巴山冷杉林;茶　子──巴山冷杉林;忍冬──巴山冷杉林５个类型,分别简述了各类型特点,并对巴山冷杉林更新状况及大小结构进行了分析研究,认为巴山冷杉林为稳定的异龄林。     

秦岭太白山巴山冷杉天然林群落物种多样性

研究秦岭太白山区域巴山冷杉天然林群落的物种组成、多样性及其对海拔的响应,可为天然林的保护与合理开发利用提供科学依据。采用典型样方调查法,分析巴山冷杉天然林群落各层次的物种组成,计算其重要值、物种多样性指数,并针对天然林物种多样性与其所在海拔因子的关系进行耦合。结果表明,巴山冷杉天然林群落共有123种植物,巴山冷杉为该群落的建群种,重要值高达64.95%,乔木物种构成比较单一;灌木层共有41个物种,其中秦岭箭竹重要值高达32.39%,为灌木层主要优势种;草本层的物种多达77种,呈随机分布,单个物种的优势度不高。群落中各层次物种丰富度为草本层>灌木层>乔木层,均匀度指数、优势度指数和多样性指数均为草本层高于木本层。随着海拔的升高,灌木层的多样性指数变动幅度较大,而草本层多呈平缓上升趋势。物种丰富度在海拔2 500 m处有最大值,均匀度指数、优势度指数、多样性指数均在海拔2 886 m处达到最大值。秦岭太白山巴山冷杉天然林群落的自我更新演替能力较差,呈衰退状态。海拔对林下各层次物种多样性有一定影响,且对灌木层的影响大于草本层。     

极度濒危植物百山祖冷杉水培繁殖

[目的]研究植物外源激素（ABT和IAA）和营养液对百山祖冷杉水培生根的作用。[方法]设清水不加任何激素（CK）、清水＋10mg/L ABT、清水＋10mg／L IAA、10mg/L ABT＋霍格兰营养液、10mg/L IAA＋霍格兰营养液5个处理进行水培百山祖冷杉,观察插条生根情况,统计愈伤形成率、生根率、生根数、根长等。[结果]ABT和IAA对百山祖冷杉水培愈伤诱导和生根率、生根数有明显促进作用,两者都适合在百山祖冷杉水培繁殖中应用;外源激素处理对最长根长和平均根长无规律性影响;有无营养液处理对百山祖冷杉水培繁殖前期各项均无影响,但在出根后会影响根的生长。[结论]研究为百山祖冷衫繁育提供了新思路,有望使其迅速脱离濒危现状。     

干旱胁迫下罗浮槭苗期的生理和形态变化

以罗浮槭1年生幼苗为材料,测定其在不同干旱处理下的生理和形态变化,以及利用扫描电镜观察不同处理下的叶片生理指标和气孔变化,结果表明:随着处理时间的延长,株高降低;幼苗的MDA含量、可溶性蛋白含量、SOD活性和POD活性均高于对照,前三者均在干旱处理10 d时达到最高值,POD活性在干旱处理20 d时最高,而Pro含量低于对照。MDA含量和POD活性呈先增加后减少的趋势,处理组的Pro含量和可溶性蛋白含量变化不大。此外,在干旱处理下罗浮槭的叶片蜡质增多,总气孔密度减少,气孔器的长、宽和开张度变化不明显。     

日本冷杉播种育苗技术探讨

日本冷杉是园林应用范围广泛的常绿乔木。从种子采摘与处理、圃地选择、播种、苗期管理及换床移栽等方面对日本冷杉的播种育苗技术进行了探讨。     

Growth of Mixed Birch-Coniferous Stands in Relation to Pure Coniferous Stands at Similar Sites in South-eastern Norway

Mean age, mean and top heights and yield were studied in 20 mixed stands of birch ( Betula pubescens Ehrh. and B. pendula Roth) and Picea abies (L.) Karst. and nine mixed stands of birch and Pinus sylvestris L. in south-eastern Norway. Each mixed stand and the adjacent pure coniferous stand (control) were growing under the same site conditions and had not been commercially thinned. There were no significant differences in mean age at breast height or in top heights between birch and conifers in the mixed stands, while mean height was significantly higher for birch than for spruce. A growth index was calculated based on total volume and age at breast height. For the spruce sites the growth in young mixed stands (birch < 17 m) was superior to that of pure spruce, while the difference was insignificant in older stands. The growth index correlated positively with the ratio between generatively and vegetatively regenerated birch trees, and negatively with the age of the oldest species in the mixture and with site quality. For the pine sites there was no significant difference in the growth index between mixed birch-pine and pure pine stands. A mixture effect of birch on the volume yield of spruce or pine could not be demonstrated.     

巴山冷杉种群结构及空间分布格局的研究

在太白山自然保护区设置 2 0 m× 2 0 m样地 8块 ,应用相邻格子法进行每木调查 ,并对巴山冷杉(Abies fargesii)种群结构和分布格局进行了动态分析。结果表明 ,种群大小结构为进展型 ,幼苗、幼树的后备资源储备量大 ,约 95 4株 / hm2 ;种群在 ～ 发育阶段死亡率较高 ,达 82 .3% ,随后死亡率趋于稳定 ;存活曲线属于Pearl 或 Deevey C型 ;种群的空间分布格局总体为聚集分布 ,负二项分布参数 (K) 1.6 0 0 ,扩散型指数 (Iδ) 1.6 2 9,丛生指标 (I) 7.6 77,Cassie指标 (CA) 0 .6 2 5 ,扩散系数 (C) 8.6 77,聚块性指标 (m* / m) 1.6 2 5。离散拟合符合负二项分布模型 ;但随着植株年龄的增长及发育阶段的不同 ,分布格局由初期的聚集分布逐渐扩散为随机分布 ,离散拟合由负二项 (Negative Binomial)分布转变为泊松 (Poisson)分布     

Environmental factors related to damage by Heterobasidion abietinum in Abies alba forests in Southern Italy

A study was carried out in southern Italy to determine the role of some factors in favouring Heterobasidion annosum s. l. spread and damage in eight Silver-fir (Abies alba Mill.) forests. All the studied stands were colonised by H. abietinum. The presence of the fungus (as carpophores on colonised wood) was detected by means of transects and varied from 7.0 to 56.0% of trees. Stand history, precipitation and forest origin, analysed by the χ²-test, had a significant effect on rot severity. Damage was more severe in stands more xerophytic where the woods were planted on pasturelands.     

极度濒危植物百山祖冷杉水培繁殖

1材料与方法1．1材料试材为百山祖保护区利用日本冷杉作砧木剪接繁殖的木质化枝条,粗0．2-0．5cm,生长健壮,无病虫害,每段枝条8-12cm,留部分叶片,每枝均含顶芽。剪好的枝条放在0．5％KMnO4溶液中,消毒30min,然后用清水冲洗3遍,备用。1．2方法试验因子：培养液,清水和霍格兰营养液;植物激素,10mg／L吲哚乙酸（IAA）和10mg／I。生根粉（ABT）。