湖北樟属植物资源

樟属（Cinnamomum）植物是一类十分重要的经济林林,是我国亚热带常绿阔叶林的主要建群种或优势种。湖北是我国樟属植物资源丰富的省区之一,经我们多年的野外采集调查、引种栽培和分类研究,现已鉴定共有13种3变种,占全国种类总数的28．8％。笔者对这些种类进行了系统整理,订正了若干历史遗留的分类学问题,同时报道了各分类群的地理分布。对于湖北樟属植物资源的现有状况,按种分别作出了具体的描述,而且还从总体上进行了分析和评价。     

Studies on Mei Pian Tree (Cinnamomum burmannii Physiological Type) as a New Resource of Natural d-Borneol

The leaves of Mei Pian tree (Cinnamomum burmannii physiological type) liave an essence of borneol. The semi-solid sample extracted by steam distillation contains 70.81% d-borneol and other 34 different chemical constituents.     

年龄效应对香樟古树程序性衰老的影响

以福建省三明市6个树龄阶段(0~49、50~149、150~349、350~549、550~749和750~900 a)香樟为研究对象,通过分析其生长发育规律、形态学和生理特征的变化,结合曲线拟合与遗传算法筛选表征衰老的相关指标,评价树龄与衰老的相关性,探讨香樟古树衰老机制,为香樟年龄预测、古树复壮和保护提供理论依据。结果表明:(1)年龄极显著地影响着古香樟的植株形态、叶片解剖结构及生理机能等生长发育指标,并以生理指标的年龄效应最大,其次为植株形态指标,最小的是解剖结构指标。(2)香樟呈现出程序性衰老的特征为:叶片细胞在130 a、叶片解剖结构和生理代谢在400 a、树皮厚度和新梢粗度在450 a先后进入衰老阶段,但香樟树体的离心生长(梢长、冠幅和胸径)在0~900 a内仍一直处于旺盛生长,还未进入衰老阶段。(3)冠幅和新叶超氧化物歧化酶(SOD)活性可作为单指标来评价香樟独立木的衰老程度,树皮厚度、冠幅、新叶SOD活性、多酚氧化酶(PPO)活性和栅栏组织与海绵组织比为参数构成的模型可作为古香樟年龄预测模型。研究认为,古香樟的保护和复壮,应先从叶片细胞着手,提高其生理功能,特别是提高其抗氧化能力,保护叶细胞结构完整,以保障叶片处在持续高效的光合状态。     

施氮对亚热带樟树林土壤呼吸的影响

人类活动引起全球范围内大气氮沉降量的升高,增加了陆地生态系统氮输入,从而影响土壤CO2排放.为揭示生态系统氮输入升高对土壤呼吸的影响,2010年6月至2012年1月,对亚热带樟树林(Cinnamomum camphora)进行模拟氮添加试验,每月上、下旬采用红外分析法测定4种氮输入水平(CK,0 gm-2a-1;低氮LN,5gm-2a-1;中氮MN,15 g m-2 a-1;高氮HN,30gm-2a-1)下的土壤呼吸速率.结果表明:(1)樟树林土壤呼吸存在明显的季节动态,最高值出现在6月,最小值出现在1月.氮添加处理显著抑制了樟树林的土壤呼吸,LN、MN、HN处理土壤呼吸年累积量分别较对照CK下降37.66％、30.62％、38.95％,各施氮处理间无显著差异,施氮对土壤呼吸的抑制作用随时间推移而减弱;(2)氮添加不影响土壤呼吸昼夜波动特征,但显著抑制土壤呼吸速率;(3)土壤呼吸与土壤温度间存在极显著的指数关系,与土壤湿度相关性不显著,CK、LN处理Q10相近,MN处理最小:(4)氮添加处理促进了土壤中氮的淋失,且随施氮水平的升高而增大.     

香樟凋落叶分解物对辣椒生长发育的影响

采用盆栽试验,研究了香樟(Cinnamomum camphora)凋落叶(0、25、50、75、100g凋落叶分别与10kg土壤混合)分解过程中对辣椒(Capsicum annuum)及其子代生长发育的影响,并采用气质联用(GC-MS)技术对凋落叶分解前后的萜类物质进行了检测和对比。结果显示:(1)香樟凋落叶分解物显著地抑制了辣椒的叶片数量、整株叶面积以及株高和基径生长,抑制效应随凋落叶剂量的增大而增强,而分解过的凋落叶和塑料片替代凋落叶原样的试验并不抑制辣椒的生长。(2)观察期内(处理45~76d),辣椒的现蕾数、开花数和结实数在各凋落叶处理下均明显低于同期对照;采用指数方程拟合的现蕾、开花和结实动态显示,25g凋落叶处理使辣椒的始蕾期、始花期和始果期分别推迟了0.81、0.17和1.35d,50g处理使这3项参数分别推迟了4.69、5.78和6.27d,而75g和100g处理均使这3项参数推迟10d以上。(3)辣椒的单株果实产量在凋落叶处理下降低29.44%~61.29%,而单果重受到的影响相对较小。(4)辣椒产出的种子千粒重和子代的生长状况并未受到凋落叶分解物的影响。(5)凋落叶的正己烷提取物中萜类占78.05%,而分解后其相对总量下降至40.76%,峰面积下降至原样的约1%。研究认为:香樟凋落叶添加处理对辣椒营养生长和生殖生长产生的明显抑制作用,不是由凋落叶添加对土壤通气透水性或对受体生长造成机械阻隔引起的,其在分解过程中释放樟脑(Camphor)、1,8-桉叶油醇(1,8-cineole)等萜类物质引起化感作用可能才是关键原因。     

不同化学型樟树叶挥发性成分组成的多变量分析

为明确不同化学型樟树(Cinnamomum camphora)叶挥发性成分的异同,以5种不同樟树叶的25个样本为实验材料,采用静态顶空-气相色谱-质谱联用法(SHS-GC-MS)研究了其挥发性成分组成,并运用主成分分析(PCA)、聚类分析(CA)和判别分析(DA)等对不同化学型樟树叶挥发性成分组成进行了多变量分析。研究结果表明,不同化学型樟树叶的挥发性成分共有8种:β-芳樟醇、莰烯、β-愈创木烯、γ-松油烯、α-侧柏烯、2-乙基呋喃、α-石竹烯和大牛儿烯;不同化学型樟树叶的挥发性化合物种类和含量存在显著差异。检测出的平均化合物数量分别为52(异樟)、40(脑樟)、37(油樟)、34(芳樟)和33(龙脑樟)。主成分分析提取了3个主成分因子,累计贡献率达到86.40%。聚类分析和判别分析结果表明,其中的12种挥发性成分能够对5种化学型樟树进行较好的区分,准确率分别为96%和100%。实验结果说明,这12种挥发性成分可以较好地用于樟树化学型分类。     

桂林岩溶石山阴香种群结构的研究

探讨了桂林岩溶石山阴香种群的高度、胸径和冠幅结构以及三者间的相互关系,并采用分异指数量化了种群个体间高度、胸围和冠幅结构的差异程度。结果表明:阴香种群个体高度集中分布在2-8m;胸径集中分布在2-6cm;冠幅多集中分布在1-4m,少数分布在5-7m之间;阴香种群个体的高度、胸围和冠幅多数为中等分异;阴香种群以幼树和小树个体占多数,自然更新能力较好,处于稳定的增长状态,这将有利于增加种群结构的复杂性和稳定性。     

Research on characteristics of biomass distribution in urban forests of Shanghai metropolis based on remote sensing and spatial analysis

Aims
Monitoring and quantifying the biomass and its distribution in urban trees and forests are crucial to understanding the role of vegetation in an urban environment. In this paper, an estimation method for biomass of urban forests was developed for the Shanghai metropolis, China, based on spatial analysis and a wide variety of data from field inventory and remote sensing.
Methods
An optimal regression model between forest biomass and auxiliary variables was established by stepwise regression analysis. The residual value of regression model was computed for each of the sites sampled and interpolated by Inverse-distance weighting (IDW) to predict residual errors of other sites not subjected to sampling. Forest biomass in the study area was estimated by combining the regression model based on remote sensing image data and residual errors of spatial distribution map. According to the distribution of plantations and management practices, a total of 93 sample plots were established between June 2011 and June 2012 in the Shanghai metropolis. To determine a suitable model, several spectral vegetation indices relating to forest biomass and structure such as normalized difference vegetation index (NDVI), ratio vegetation index (RVI), difference vegetation index (DVI), soil-adjusted vegetation index (SAVI), and modified soil-adjusted vegetation index (MSAVI), and new images synthesized through band combinations such as the sum of TM2, TM3 and TM4 (denoted Band 234), and the sum of TM3, TM4 and TM5 (denoted Band 345) were used as alternative auxiliary parameters .
Important findings
The biomass density in urban forests of the Shanghai metropolis varied from 15 to 120 t·hm^-2. The higher densities of forest biomass concentrated mostly in the urban areas, e.g. in districts of Jing’an and Huangpu, mostly ranging from 35 to 70 t·hm^-2. Suburban localities such as the districts of Jiading and Qingpu had lower biomass densities at around 15 to 50 t·hm^-2. The biomass density of Cinnamomum camphora trees across the Shanghai metropolis varied between 20 and 110 t·hm^-2. The spatial biomass distribution of urban forests displayed a tendency of higher densities in northeastern areas and lower densities in southwestern areas. The total biomass was 3.57 million tons (Tg) for urban forests and 1.33 Tg for C. camphora trees. The overall forest biomass was also found to be distributed mostly in the suburban areas with a fraction of 93.9%, whereas the urban areas shared a fraction of only 6.1%. In terms of the areas, the suburban and urban forests accounted for 95.44% and 4.56%, respectively, of the total areas in the Shanghai metropolis. Among all the administrative districts, the Chongming county and the new district of Pudong had the highest and the second highest biomass, accounting for 20.1% and 19.18% of the total forest biomass, respectively. In contrast, the Jing’an district accounted for only 0.11% of the total forest biomass. The root-mean-square error (RMSE), mean absolute error (MAE) and mean relative error (MRE) of the model for estimating urban forest biomass in this study were 8.39, 6.86 and 24.22%, respectively, decreasing by 57.69%, 55.43% and 64.00% compared to the original simple regression model and by 62.21%, 58.50%, 65.40% compared to the spatial analysis method. Our results indicated that a more efficient way to estimate urban forest biomass in the Shanghai metropolis might be achieved by combining spatial analysis with regression analysis. In fact, the estimated results based on the proposed model are also more comparable to the up-scaled forest inventory data at a city scale than the results obtained using regression analysis or spatial analysis alone.     

樟根生产法培育的苗与常规苗的丛枝菌根真菌多样性

以湖南省林业科学院龙伏实验基地的3年生樟根生产（root production method,RPM）苗和同龄常规技术培育的苗木（以下简称常规苗）为研究对象,采集两种苗木的根系和根际土,观察根系上菌根形态,并对其苗木样品进行高通量测序研究,探索二者根系菌根特征及根系、根际土丛枝菌根真菌（arbuscular mycorrhizal fungi,AMF）群落结构及土壤微生境差异,旨在为进行接种有效性菌根苗木来改善常规苗木的土壤微生境,进而培育高质量苗木提供理论依据。结果显示：2种樟苗木根系均显示AM菌根特征,未见外生菌根结构。测序得到属于AMF群落的有效序列共25 738条,隶属1门,2纲,3目,5科,5属,按有效序列占比从高到低依次为Acaulospora、Glomus、Diversispora、Rhizophagus和Paraglomus。根生产法（RPM）苗和常规苗的优势属均为Acaulospora和Glomus,只是RPM苗中Glomus占比高（在根、根际土内占比分别为28.04%、57.36%）而常规苗中Acaulospora占比高（在根、根际土内占比分别为99.58%、42.2%）。2种苗木均是根际土内的丰富度指数（Ace和Chao）远高于根系,并且RPM苗根际土的丰富度指数高于常规苗,但二者根系内的丰富度指数无显著差异（P<0.05）。冗余分析结果显示,土壤pH和有效磷是决定AMF群落结构的主要影响因子。不同理化因子对AMF群落的菌属影响程度也不同。     

四川淫羊藿属一新种

四川淫羊藿属一新种严克俭（广西中医药研究所,南宁５３００２２）关键词少花淫羊藿ＡＮＥＷＳＰＥＣＩＥＳＯＦＥＰＩＭＥＤＩＵＭＦＲＯＭＳＩＣＨＵＡＮ￥ＹｅｎＫｅｃｈｉｅｎ（ＧｕａｎｇｘｉＩｎｓｔｉｔｕｔｅｏｆＴｒａｄｉｔｉｏｎａｌＭｅｄｉｃａｌ＆Ｐｈａｒ...