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A. A. Gontcharov 《Hydrobiologia》1996,336(1-3):93-97
A survey of the freshwater algal flora of the Primorsky Region, Russian Far East, is presented. During more than 70 years
of investigations 1659 species (including varieties and forms 2276 taxa) belonging to 346 genera of different groups of algae
have been recorded from this territory. The Primorsky Region is rich in habitats attractive to algae-rivers, lakes, reservoirs,
and ponds. The details of the distribution of algae in different types of waterbodies have been examined. The algal flora
of the region is comparable to the areas, and its taxonomical structure is typical for Eurasia. From this territory some new
species and varieties have been described — Achnanthes chankensis, Cymbella ventricosa var. hankensis, Surirella alisoviana, and others. The flora includes some rare species — Fragilaria magocsyi, Perone dimorpha, and Heterothrix monochloron, and some endemics of Asia — Navicula scutelloides var. baicalensis, N. globulifera var. nipponica, Gomphonema sphaerophorum, and Surirella tientsinensis. 相似文献
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N. H. Russel A. E. Hunter A. Haynes E. M. Bessell 《BMJ (Clinical research ed.)》1994,308(6945):1715-1716
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One of the major problems faced by conservation biologists is the allocation of scarce resources to an overwhelmingly large number of species in need of preservation efforts. Both demographic and genetic information have been brought to bear on this problem; however, the role of information obtained from genetic markers has largely been limited to the characterization of gene frequencies and patterns of diversity. While the genetic consequences of rarity may be a contributing factor to endangerment, it is widely recognized that demographic factors often may be more important. Because patterns of genetic marker variation are influenced by the same demographic factors of interest to the conservation biologist, it is possible to extract useful demographic information from genetic marker data. Such an approach may be productive for determining plant mating systems, inbreeding depression, effective population size, and metapopulation structure. In many cases, however, data consisting only of marker frequencies are inadequate for these purposes. Development of genealogical based analytical methods coupled with studies of DNA sequence variation within and among populations is likely to yield the most information on demographic processes from genetic marker data. Indeed, in some cases it may be the only means of obtaining information on the long-term demographic properties that may be most useful for determining the future prospects of a species of interest. 相似文献