The Preliminary Study Of Flora And Ecology On Bacillariophyta Pennatae-araphidiales, Raphidinales, Monoraphidinales From Heilongjiang Province

Heilongjiang province locates in Northeastern of China, and there are especial positon and peculiar climate characterisyic. There are very abundance algae esources in this place, but few research of algae flora taxonomy had been done. Diatoms, as a major group of autotrophic and eukaryotic algae, are one of the most common types of phytoplankton found in almost every aquatic habitat. The character of diatom communities are a popular tool commonly used in monitoring environmental conditions and water quality.From 1981 to 2009, Samples were collected from some places in Heilongjiang province. 128 specimens had been collected from April to September. The surface water temperature varied from -1℃to 27℃. The pH level fluctuated between 5.5 and 8.4 . Araphidiales, Raphidionales, Monoraphidinales were observed and identified by Light microscope and SEM, 90 taxa have been reported, including 61 species, 22 varieties, 2 forms, 5 subspecies, which belong to 11 genera, 3 families, 3 orders. Each taxon was described and illustrated with one digital photograph.In Araphidiales, 7 genera (Tetracyclus, Tebellaria, Diatoma, Meridion, Asterionella, Syndra, Fragilaria) and 47 taxa had been identified , including 33 species, 13 varieties, 1 forms.In Raphidionales, 1 genus (Eunotia) 23 taxa had been identified , including 17 species, 5 varieties, 1 forms.In Monoraphidinales, 3 genera (Cocconeis, Achnanthes, Rhoicosphenia) and 20 taxa had been identified , including 11 species, 4 varieties, 5 subspecies. In present stuied, Syndra,Fragilaria,Eunotia and Achnanthes were accounted for 81.1% of total taxa.The character of species composition and distribution in Heilongjiang province were discussed preliminarily. It as follows:1.The most taxa of Araphidiales, Raphidionales and Monoraphidinales are epiphytic and a few taxa are typical planktonic. Of the three order, there are plenty of taxa belonged to low and low-to-moderate electrolytic species.Compared with the others two order, some species of Raphidionales prefer low electrolytic waters. The taxa of Araphidiales prefer circumneutral waters, the taxa of Raphidionales prefer acid waters and the taxa of Monoraphidinales prefer circumneutral and alkalescent waters; The cold-water species always found in Heilongjiang Province and the warm-water species were accidental. The taxa of Araphidiales were in different nutrition waters, the most taxa of Raphidionales and Monoraphidinales prefer oligotrophic waters.2. In Da Higgnan Mountains, there were many oligotrophic species, meso-oligotrophic species, acidophil species and alpine cold-water species found. In Xiao Higgnan Mountains, there were some low electrolytic species, acidophil species, oligotrophic species and cold-water species reported. Most taxa of Araphidiales, Raphidionales and Monoraphidinales from Zhangguangcai Mountain and Laoye Mountain belonged to low electrolytic species, neutral species, oligotrophic species and cold-water species. In Song-Nen Plain, accounted for 64% of Araphidiales taxa idenfied in this stuided area, some meso-eutrophic species were found increasedly, and some acidophil species, alkalescent species were found also. Compared with Song-Nen Plain, there are fewer taxa of Araphidiales in Sanjiang Plain, but oligotrophic species were reported increasedly.In this paper, the preliminary study on Araphidiales, Raphidionales and Monoraphidinales from Heilongjiang Province would provide an important data for the algae resource investigation in China.