Littoral vegetation of estuarine rivers of the southern part of Vaygach Island and the Yugorsky Peninsula

The saline tidal estuaries of two small rivers of Vaygach Island, the Krasnaya and the Varkulyakha, and one in the area adjacent to the Yugorsky Peninsula, the Nikolskaya River, contribute to the occurrence of salt marshes that are home to halophytic vegetation. In terms of marine exposure, the studied area comprises three types of habitats – low marshes, middle marshes and high marshes, each with a specific composition and structure of the vegetation cover. Along with salt marshes, the study has identified more habitats of smaller area and with specific vegetation, among them lowland wetlands in marsh-tundra ecotones, pebble-sand beaches, rubble beaches, salt lakes, and microdepressions. The marshes of Vaygach Island are classified Vaygachas Arctic type, as evidenced by the presence of halophytic communities dominated by Arctic and hypoarctic species, represented by three associations: Caricetum subspathaceae herbosum, Caricetum glareosae potentillosum egedae and Caricetum glareosae arctantemosum polarae. In our study, the estuarine vegetation has been discovered to comprise a fourth association, Plantaginetum schrenkii. Using the metric scaling method, we provided evidence that the studied estuaries support different vegetation types. While the communities of Vaygach Krasnaya and Varkulyakha estuaries tend to be similar in species composition and structure, the vegetation of the Nikolskaya River estuary appears to be markedly different. The differences relate mostly to the geomorphology of the three estuaries, consisting mainly in the fact that the Vaygach estuarine marshes occupy much larger areas compared to the tidal flats available to halophytic vegetation in the Nikolskaya estuary. The paper proposes a classification of the estuarine vegetation based on ecological and phytocenotic descriptions. Abandoned mines located at the mouth of the Krasnaya River, where polymetallic ores were previously mined, are unlikely to influence the composition and structure of halophytic vegetation. A variety of phytocenoses have formed in this area, as in the mouth of the Varkul'yakha River, where no mining activity has occured.