In Primorye, bog and meadow vegetation occupies considerably lesser areas
than forests, and is widspread chiefly on the Hanka-Ussuri plain, over
expanded flat interfluves in the lower parts of basins of right-hand tributaries
of River Ussuri, and on weakly drained sites of intermontane depressions.
On the Japan Sea coast, meadow-bog vegetation occupies very restricted
areas on low marine terraces. Small sites of forest bogs occur on depressions
in the central parts of mountain plateaus of the Sikhote Alin main watershed.
The lowest plain levels adjoining Lake Hanka are occupied by floats, reed (Phragmites communis, Typha orientalis) and tall-grass bots (Sagittaria trifolia, Zizania, etc.). Aqueous plants, such as the water nut (Trapa spp.), the Nymphaea tetragona), and the Potamogetum spp., grow among them in direct proximity to these bogs on open lake water sites and oxbows. Lotus (Nelumbium komarivii) and Euryale ferox thickets were recently not infrequent here, but are now being actively destroyed.
Constantly overhumidified and to some extent bogged and humid meadows connected by gradual transitions with grass bogs form at slightly higher levels of the lake plain and over wide flat river terraces and interfluves. Their grass cover is based on Carex spp., Calamagrostis spp. and moisture-loving herbage. A large part of these meadows is “hummocked” (covered with hummocks) and needs improvement.
In less humidified habitats, where water stands only occasionally on the soil surface, herbage-reed grass meadows develop, and at still higher levels of ancient lake and river terraces remains of dry valley meadows with participation of less moisture-loving species and even those considered more typical of steppes (Arundinella anomala, Koeleria gracilis, Tanacetum boreala and even Stipa baicalensis still grow in some places.
Bogs are commonly classified into basic types depending on their water supply. Lowland (eutrophic) bogs receive their “water supply” chiefly from ground and floodwater. The role of precipitation in this is insignificant. The above mentioned reed grass bogs are their typical representatives, and the extreme link of starting bog-formation is lake floats. These bogs may exist indefinitely long as an independent vegetation formation, but with bogging of relatively small water reservoirs they become the initial bogging stage. They occupy relatively small areas on the Hanka Lowland and on flat and hollow terrain in interfluves near Ussuri River.
Transitional (mesotrophic) bogs form when the substrate of bog vegetation rises with peat accumulation and when the role of ground and atmospheric water supply becomes approximately equal. Herbaceous vegetation gradually leaves room for mosses from the genera Plytrychum and Sphagnum. They also exist as the second stage of water reservoir bogging, and on more or less significant flat plain sites for a long time and independently.
Low rare larchwood trees, occasionally with participation of flat-leaf birch, often occur on lowland and transitional bogs. In everyday usage, and now also in botany, they are called “mari”.
Raised (oligotrophic) bogs receive their water supply chiefly from precipitation. In fact, ground water supply may be entirely absent. In Primorye, such bogs occur on relatively small areas in the central parts of the basalt plateaus of the main Sikhote Alin watershed to represent a botanical-geographic rarity of Primorye, reproducing as they do the landscape of the larchwood “mari”, typical of more northerly regions. Mosses from the genus Sphagnum, and Vaccinium uliginosum, Ledum spp. dominate their cover, and shrub representatives of the genus Betula commonly grow in the rare shrub tier.
Irises, charm of PrimopyeV. ROSENBERG, Cand. Sci. (Biology), Leading Researcher, Institute of Biology and Soil Science, F. E. Branch, Russian Academy of Sciences.
E. SHATKOVSKAYA, Leading Engineer, Institute of Biology and Soil Science, F. E. Branch, Russian Academy of Sciences.
I. LANDINA, Senior Lab. Researcher, Institute of Biology and Soil Science, F. E. Branch, Russian Academy of Sciences.
S. KRASNOPEEV, S. M., Cand. Sci. (Physics and Maths), Senior Research Fellow, Pacific Institute of Geography, F. E. Branch, Russian Academy of Sciences
T. KRASNOPEEVA, 1st Category Programmer, Pacific Institute of Geography, F. E. Branch, Russian Academy of Sciences
S. TOURCHANOV, 1st Category Programmer, Pacific Institute of Geography, F. E. Branch, Russian Academy of Sciences
E. SHESHIKOVA, 1st Category Programmer, Pacific Institute of Geography, F. E. Branch, Russian Academy of Sciences
T. SHASHURA, 1st Category Engineer, Pacific
Institute of Geography, F. E. Branch, Russian Academy of Sciences