期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
林业部分引智项目简介
1
作者 熊晓姣 《湖北林业科技》 2001年第1期44-46,共3页
关键词 中国 林业 引智项目 用材林 经济林 花草类 推广 品种更新
下载PDF
Relative pollen productivities of typical steppe species in northern China and their potential in past vegetation reconstruction 被引量:13
2
作者 XU QingHai CAO XianYong +6 位作者 TIAN Fang ZHANG ShengRui LI YueCong LI ManYue LI Jie LIU YaoLiang LIANG Jian 《Science China Earth Sciences》 SCIE EI CAS 2014年第6期1254-1266,共13页
The Relative Pollen Productivities(RPPs)of common steppe species are estimated using Extended R-value(ERV)model based on pollen analysis and vegetation survey of 30 surface soil samples from typical steppe area of nor... The Relative Pollen Productivities(RPPs)of common steppe species are estimated using Extended R-value(ERV)model based on pollen analysis and vegetation survey of 30 surface soil samples from typical steppe area of northern China.Artemisia,Chenopodiaceae,Poaceae,Cyperaceae,and Asteraceae are the dominant pollen types in pollen assemblages,reflecting the typical steppe communities well.The five dominant pollen types and six common types(Thalictrum,Iridaceae,Potentilla,Ephedra,Brassicaceae,and Ulmus)have strong wind transport abilities;the estimated Relevant Source Area of Pollen(RSAP)is ca.1000 m when the sediment basin radius is set at 0.5 m.Ulmus,Artemisia,Brassicaceae,Chenopodiaceae,and Thalictrum have relative high RPPs;Poaceae,Cyperaceae,Potentilla,and Ephedra pollen have moderate RPPs;Asteraceae and Iridaceae have low RPPs.The reliability test of RPPs revealed that most of the RPPs are reliable in past vegetation reconstruction.However,the RPPs of Asteraceae and Iridaceae are obviously underestimated,and those of Poaceae,Chenopodiaceae,and Ephedra are either slightly underestimated or slightly overestimated,suggesting that those RPPs should be considered with caution.These RPPs were applied to estimating plant abundances for two fossil pollen spectra(from the Lake Bayanchagan and Lake Haoluku)covering the Holocene in typical steppe area,using the"Regional Estimates of Vegetation Abundance from Large Sites"(REVEALS)model.The RPPs-based vegetation reconstruction revealed that meadow-steppe dominated by Poaceae,Cyperaceae,and Artemisia plants flourished in this area before 6500–5600 cal yr BP,and then was replaced by present typical steppe. 展开更多
关键词 typical steppe modern surface pollen relative pollen productivity relevant pollen source area PALEOVEGETATION
原文传递
Towards a coherent nomenclature of plant viruses
3
作者 Muhammad Ali 《Virologica Sinica》 SCIE CAS CSCD 2016年第3期197-198,共2页
The International Committee on Taxonomy of Viruses(ICTV)has the decree to set the rules for the classification and naming of viruses.The species is the lowest level considered in the taxonomic hierarchy.In general,v... The International Committee on Taxonomy of Viruses(ICTV)has the decree to set the rules for the classification and naming of viruses.The species is the lowest level considered in the taxonomic hierarchy.In general,virus species are named according to the structure"and the word‘virus’".A typical example is Tobacco mosaic virus[Genus: 展开更多
关键词 Genus coherent isolation taxonomic mosaic instance letter names abbreviated mottle
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部