Taxonomic Study On Diatoms From Qinling Mountains

Qinling Mountains,which traverses the Eastern China,is the important geographical North-South line.Its north and south have significant differences in the temperature,climate and topography.This area probablely holds a lot of algae resources in store because of its complex terrain and water environment.Horever,there are few studies on diatom reported in Qinling Mountains.In this study,we systematically collected 252 diatoms samples for 3 times totally,which are during the July to September,2012,August,2013 and August,2015 for survey of Qinling Mountains.The collected samples were observed,photographed by optical microscope and scanning electron microscope and then identified.Finally,175 taxa of diatom species were found,including 36 species,2 varieties and 3 forms,belonging to 2 classes,6 orders,10 families,31 genera.Centricae is less,only 3genera are found.Horever,the pennatae covered all the other genera.Among the identified species,there are 5 taxa are newly recorded in China.Morover,in order to research the species distribution and seasonal variation of diatom in different seasons,we take the Stone River National Wetland Park for example,36 diatoms samples were collected in March 2014,July 2014,October 2014 and January 2015 Respectively.45 taxa were identified,in which there are 3 common taxa in four seasons,they are Navicula radiosa?Diatoma hiemale,Synedra ulna and Synedra ulna var.oxyrhynchus.The dominant genera in the four seasons are Navicula,and the density of this genus is in the dominant position.In the four seasons,the number of diatom species and the diatom density were both the largest,and both were the least in autumn.The diatom species in summer was more than that in winter,but the cell density was less than that in winter.