Flora of Silica-Scaled Chrysophytes (Chrysophyceae: Synurales, Paraphysomonadales) of the Mekong Delta
- PDF / 1,891,113 Bytes
- 9 Pages / 612 x 792 pts (letter) Page_size
- 73 Downloads / 156 Views
TIC FLORA AND FAUNA
Flora of Silica-Scaled Chrysophytes (Chrysophyceae: Synurales, Paraphysomonadales) of the Mekong Delta E. S. Guseva, c, *, V. A. Gusakovb, c, E. E. Gusevaa, M. S. Kulikovskiya, A. I. Tsvetkovb, c, and Cù Nguyên Địnhc aTimiryazev
Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Nekouzskii district, Yaroslavl oblast, Russia cVietnam–Russia Tropical Center, Hanoi, Vietnam *e-mail: [email protected]
b
Received August 2, 2019; revised October 10, 2019; accepted November 23, 2019
Abstract—This paper presents the first data on the flora of silica-scaled chrysophytes (orders Synurales and Paraphysomonadales) in the delta of the Mekong River (Vietnam). A total of 15 taxa have been identified: nine from the genus Mallomonas, one from Synura, and five from Paraphysomonas. Six taxa are reported for the first time from Vietnam. At most sites, 1–2 species per station are recorded. The maximum diversity (12 taxa) is revealed at the station with salinity >1 g/L. Based on previous floristic studies of silica-scaled chrysophytes in Vietnam, the number of taxa known from the country has been increased to 66. Our studies have expanded the list of species which have tolerance to salinity of about 1 g/L. Keywords: South Vietnam, Mallomonas, Synura, Paraphysomonas, diversity, salinity gradient DOI: 10.1134/S1995082920020224
INTRODUCTION The Mekong River is the main artery in Southeast Asia and one of the largest rivers in the world. At present, approximately 70 million people across six countries: China, Myanmar, Thailand, Laos, Combodia, and Vietnam live near the banks of the Mekong River and its tributaries. The Mekong River Delta, almost entirely located in the territory of Vietnam, is one of the most densely populated regions of the country, with a population of >17 million people and average population density of >400 persons per square kilometer. At present, the natural and social systems in the Mekong Delta face numerous problems of increasing environmental degradation. They are rapid urbanization and hydro construction in the basin and increasing pollution and depletion of biological resources as consequence of agricultural, industrial, and other human activities in the catchment area and in the river. Global climate change, namely, warming, poses new threats which can lead to a rise in sea level. This may cause flooding of large territories in the delta mouth and the salinization of soils and water (Cosslett T. and Cosslett P., 2014; Kuenzer and Renaud, 2012; Räsänen, 2014). In this regard, the assessment of the modern environmental state of the delta basin and the river and prediction of further changes in view of the existing threats is very important. In the framework of these tasks, integrated studies of the internal and con-
tour communities of hydrobionts in different branches of the Mekong River in the territory of Vietnam and the main factors determining their structural and functional or
Data Loading...
