Latitudinal variations in the composition and structure of vegetation in the northwestern Tatar Strait

The pattern of the latitudinal distribution of the floristic composition and structure of the submerged vegetation cover in the western Tatar Strait (within Khabarovsk Krai) is studied using the published data and original materials. Irregularities of the floristic composition have been found within limited areas of bays in this region, where they do not form any distinct borders or gradients. In the vegetation cover, vice versa, borders and gradients have been shown to form various combinations. The specific biomasses of most of the dominant species are significantly increasing, whereas the width and depth of the vegetation belt decreases from the south to the north. Their regression lines intersect at the latitude of 50° N (Cape Syurkum). Discrete coenotic variations are manifested most clearly as well at this point, where the dominance of Saccharina japonica, observed south of the cape, changes for S. cichorioides north of it. This allows establishing the phytocoenotic border here. The revealed features correspond to the direction of the temperature gradient, as well as to the variations in topical conditions and the level of hydrodynamic load along the coast.