四种云杉的核型分析

首次报道了中国珍稀濒危保护植物长叶云杉 ( P. smithiana ( Wall.) Boiss.)和康定云杉 ( P. likian-gensis( Franch.) Pritz.var.montigena( Mast.) Cheng ex Chen)及我国特产的青海云杉 ( P.crassif oliaKom.)和林芝云杉 ( P.likiangensis( Franch.) Pritz.var.linzhiensis Cheng et L.K.Fu)的核型。它们的核型公式都是 K( 2 n) =2 4 =2 2 m+2 sm (林芝云杉有 1条 B染色体 ) ,染色体相对长度组成分别为 2 n=1 4 M2 +8M1 +2 S,2 L+1 2 M2 +6M1 +4S,2 L +1 0 M2 +1 0 M1 +2 S,和 2 L+1 2 M2 +6M1 +4S.均为 2 A (除青海云杉 1 A外 )核型类型。     

林芝云杉群落特征的研究

析了林芝云杉( Picea likiangensis var. linzhiensis )群落的种类组成、区系特征、群落外貌、垂直结构和水平结构等特性。结果表明：调查样地共有维管植物144种,隶属于53科116属,其中只含1种的属占81.03%。林芝云杉群落的区系组成、植物生活型谱、叶片性质等特征反映了群落的温带性质。群落垂直结构明显,可分为乔木层、灌木层、草本层及层间植物,乔木层郁闭度为0.4~0.8,林芝云杉大多为乔木层的单一优势种,有时与急尖长苞冷杉(Abies georgei var. smithii)、华山松(Pinus armandii)等混生,而群落植物的水平分布不均匀。优势种种群的年龄结构分析表明,该种群处于稳定状态;群落的物种丰富度为32.6364,其Shannon-Wiener指数为3.0926,Simpson指数为0.9366,均匀度指数为0.8942,且均为草本层>灌木层>乔木层。     

西藏原始林芝云杉林雨季林冠降水分配特征

利用2006-2007年对西藏米林县南伊沟原始林芝云杉(Picea likiangensis var.linzhiensis)林林外降水、穿透水和树干茎流定位观测数据,对林芝云杉林的林冠降水再分配特征进行研究。结果表明:西藏南伊沟的年降水量为716.4mm,主要集中在4-9月份,占全年降雨量的86.95%。在林芝云杉的生长季节(4-10月份),林冠截留量为338.6mm,占同期林外降水量的51.60%;林内穿透水量为316.3mm,占同期林外降水量的48.21%;树干茎流量仅为1mm,仅占0.19%。林内穿透水(Tp)、树干茎流(Sf)、林冠截留量(Ip)及林冠截留率(PIp)与林外降水量(p)之间的关系分别为:Tp=0.8622p-3.5229,r=0.9964;Sf=0.0004p1.4586,r=0.9458;Ip=1.2222p0.6341,r=0.874;PIp=253.6p-0.7008,r=0.9732。林芝云杉林雨季林冠降水的分配规律与该森林结构复杂、林分年龄高、胸高断面积大密切相关,说明该森林在涵养水源和保持水土等方面发挥着重要的作用。     

Relationship between volatile compounds of Picea likiangensis var. linzhiensis cone and host selection of Dioryctria abietella

This study aimed to determine the relationship between volatile compounds of Picea likiangensis var. linzhiensis cone and host selection of Dioryctria abietella. During the infestation of P. likiangensis var. linzhiensis by D. abietella, their cones and branches emitted volatile compounds, which were extracted using CH₂Cl₂ extraction and XAD₂ adsorption methods, and were analyzed using gas chromatography–mass spectrometry. Before and after overwintering, D. abietella larva preferred annually infested cones and their extracts, and adult D. abietella preferred to lay eggs on annually infested cones and healthy cones of the year, and the oviposition rate of adult D. abietella was 72% on branches with healthy cones of the year, and no egg was laid on branches with annually healthy cones or branches without cones. The volatile compounds after infestation, α- and β-pinene, were significantly higher in cones than those in other tissues; however, myrcene in cones was significantly lower than those in other tissues. The annually infested cones produced β-caryophyllene and (1S)-(-)-β-pinene, while the annually healthy cones and branches produced myrcene and 3-carene. The annually infested cones and their extracts attracted D. abietella larvae, while that of healthy cones and annually infested cones attracted the adults, indicating that the terpene compounds: α-pinene, β-pinene, (1S)-(-)-β-pinene, limonene, and β-caryophyllene are attractive to D. abietella, and the terpene compounds—myrcene and 3-carene—from the branch tissues may be repulsive to D. abietella.