绵阳官司河流域防护林物种多样性特征

用对数正态分布模型分析绵阳司官司河流域防护林乔木层的种多度关系，用多种公式计算防护林各层次的物种多样性，并与我国暖温带落叶阔叶林的物种多样性相比较，得出以下结论：（１）该流域防护林乔木层的种多度关系符合对数正态分布模型，说明个体数量最多的乔木仅限于当数几种树木，（２）主要群落内乔木层，灌木层和草本层的丰富度，均匀度和总多样性指数都比较低，甚至低于我国暖温带落叶阔叶林相对应的指数，这说明防护林尚属于     

喜玛拉雅白皮松种子组分的分析

本文对喜玛拉雅白皮松种子的主要成分进行了分析,结果表明胚乳和胚中脂肪含量高达57.57％和31.84％,且均可检测出6种脂肪酸;两种组织中蛋白质含量分别为14.15％和23.09％,其水解物均可检测出20种氨基酸;胚中含有较多的可溶性糖,而淀粉较少。     

云南石屏县牛达林区天然云南松中幼年林林木生物量的研究

本文在划分群落类型的基础上,分析了石屏县牛达林区天然云南松中幼年林林木生物量和蓄积量与林木结构、林木密度、单纯林和阔叶树混交林以及与生境因子(海拔、土壤水分、坡向和坡度等因子)之间的关系;分析了云南松林的生产力指标。试图探索云南松林木高生物量的林分特征及其生境条件,为云南松营林造林提供一些科学依据。     

河南省石人山自然保护区针阔叶混交林群落生态特征(Ⅱ)(续完)

采用法瑞学派植被生态学的研究方法,在确定群落最小面积的基础上设置典型样地研究了石人山自然保护区油松 锐齿栎混交林、油松 短柄枹混交林等针阔叶混交林的生境特征和群落的基本生态学特征,为自然保护区管理和植物群落生物多样性的保护提供了科学理论依据.     

Pollen records of Holocene vegetation and climate changes in the Longzhong Basin of the Chinese Loess Plateau

Pollen records with an average time resolution of 20—200 years from Holocene loess sections at Dingxi, Qin'An, and other localities of Gansu Province reveal a detailed history of vegetation and climate changes in the western Loess Plateau. For most time of the Holocene, the landscape was dominated by grasslands or forest steppes. However, during the middle Holocene (7.5—5.8 ka BP), relatively dense forests developed, and the endemic vegetation flourished, suggesting a much warmer and more humid climate condition than the present. Superimposed upon this general pattern are several dry intervals marked by the episodic expansion of grasslands or forest steppe. Xeric vegetation expanded after 3.8 ka BP, indicating a trend towards dry conditions.     

马尾松愈伤组织诱导条件的研究

采用马尾松(Pinus massoniana Lamb.)成熟合子胚为起始材料,经过0.1%升汞溶液7~9min消毒后,接种于WPM培养基上,在温度26℃,光照强度2 000~3 000 lx,光照时间16 h/d的条件下培养得到无菌苗.采用无菌苗的各器官作为外植体在光照条件下进行愈伤组织的诱导条件的研究,结果显示,以幼茎为外植体,在含GD 6-BA 4.0 mg.L-1 NAA 0.10 mg.L-1 0.3%~0.4%活性碳(CA) 500 mg.L-1水解酪蛋白的培养基上,愈伤组织诱导率可达到93%.     

Arthropods associated with nests of Cacicus sp. and Psarocolius sp. (Passerida: Icteridae) in varzea forest near the meeting of the rivers Negro and Solimões (Central Amazonia,Brazil) at high water

We analysed the arthropod fauna from nine nests of Cacicus sp. and nine nests of Psarocolius sp. (Passerida: Icteridae), in the varzea forest of Central Amazonia, Brazil, during high water, establishing these nests as one of the probable refuges for several arthropods performing vertical migration during periods of flooding and high water, besides discussing the role of these arthropods in the nests. We also evaluate the effectiveness of the extraction of arthropods from nests using an apparatus based on the Berlese–Tullgren funnel. We obtained 15,128 arthropods from three subphyla, five classes and 16 orders. The nests were shown as complex ecosystems sheltering groups from different functional and trophic categories and revealed striking differences from those of terra firma, remarkably in Blattaria, Arachnida and Pseudoscorpiones. The increasing volume of the funnel and time of heat exposure was shown to be appropriate for extraction of the arthropods from the bulky nests of these birds.     

Identification of sex pheromones of four economically important species in genusDendrolimus

The female-produced sex pheromone of Dendrolimus superans was identified by gas chromatography (GC), coupled GC-mass spectrometry (GC-MS), electroantennographic (EAG) studies and field tests as a blend of (Z,E)-5,7-dodecadienal (Z5,E7-12:Ald) and (Z,E)-5,7-dodeca- dien-1-ol (Z5,E7-12:OH). In D. kikuchii, (Z,E)-5,7-dodeca- dien-1-yl acetate (Z5,E7-12:OAc) and Z5,E7-12:OH were found by GC and GC-MS analyses. However, in EAG studies male antennae were more sensitive to Z5,E7-12:OAc and (Z,E)-5,7-dodecadien-1-yl propionate (Z5,E7-12:OPr) than Z5,E7-12:OH. For D. spectabilis, Z5,E7-12:OH had been previously reported as the sex pheromone. However, in our studies, traps baited with Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr in a ratio of 1:1:1 caught three times more males than those baited with Z5,E7-12:OH alone. Relatively strong EAG responses were elicited from male antennae by Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr, but in addition to Z5,E7-12:OH, only very small amounts of Z5,E7- 12:OAc was found in the pheromone gland. These facts suggest that Z5,E7-12:OAc is a pheromone minor components and Z5,E7-12:OPr is a sex attractant in D. spectabilis. For D. tabulaeformis, Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12: OPr were found in extracts of pheromone glands of female moths, and the three compounds elicited strong EAG responses from antennae of male moths. These three compounds have been reported as a sex attractant of D. tabulaeformis, and our data confirm their roles as components of the sex pheromone of this species. The role of blend components in antagonizing cross attraction between congeners is discussed.     

Host tree unsuitability recognized by pine shoot beetles in flight

Summary In spring, the landing rate of flying European pine shoot beetles,Tomicus piniperda L., on injured Scots pine diminishes as colonization continues. This is due to olfactory cues that indicate progressive host degradation. Verbenone was shown to play a role in the beetle's recognition of this unsuitability of a formerly suitable host, since the compound was increasingly released from colonized tree sections as they aged, but not from uninfested sections. Also, the release of verbenone at natural rates in the forest inhibited the attraction of beetles to host monoterpenes.     

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Summary

Five early ontogenic stages of Scomberomorus lineolatus (C. &; V.) ranging in standard length from 18·4 mm to 99·5 mm are described.

Direct comparison of these early stages with those of S. commerson (Lac.) showed differences in the number of gill rakers, the length of preopercular spines and the position of the anal fin in relation to the second dorsal fin. In the case of S. guttatus (Bl. &; Schn.) the gill rakers are of the same number as in S. lineolatus but the preopercular spines decrease in size from above with the upper two subequal in size and none projects beyond the operculum.

In the earlier stages, S. lineolatus could be easily distinguished from S. guttatus by the absence of the bluish green coloration characteristic of S. guttatus. In later stages when the coloration has developed in both the species the only marked difference between the two is in the nature of the bent portion of the lateral line which is wavy in S. lineolatus and straight in S. guttatus.

The number of vertebrae is 46 in S. lineolatus; 42–45 with 43·9 as mean in S. commerson and 47–52 with 49·7 as mean in S. guttatus.