and elm forests, normally with participation of poplars (P. suaveolens
in northern Primorye) and P. maximoviczii and P. coreana in the central
and southern parts of the area, respectively, are typical for transitional,
seldom flooded or partially submerged terraces and valleys of medium and
large rivers. They also occur on declined sites of wide (never flooded)
terraces situated above the flood plain. The correlation of the basic forest
formers, viz. ash and elm, fluctuates from absolute prevalence of one of
them to codominance in the tree stock. Shrub-tall grass types of forests
with tree stocks ranging from quality grade I to II prevail. In the north
of Primorye, the altitude of elm-ash forests varies from 350 to 400 m,
and in the south from 500 to 550 m. Nearer to those marks, the tree stocks
are found to have increased admixture of Populus and Salix, and higher
up ash-elm forests are replaced by poplar-willow forests.
Juglans mandshurica, Phelodendron amurense, Malus mandshurica, Maackia amurensis and other species take part in the tree stocks of most elm-ash forests. Alike Chosenia, Salix and Populus forests, all these forests perform water-regulating, shore-protecting, fish protecting and many other ecology-protective functions. Most of them have been included in protective belts along rivers.
At the same time, timber reserves of nationally significant hard larchwood species (chiefly Fraxinus mandshurica) are still (strangely enough!) concentrated in those forests. Unfortunately, industrial logging of ash in recent years had sharply increased to acquire exhaustive nature. Hence, there is need for stricter and more effective regulation of their commercial exploitation.
Continually overhumidified and to some extent bogged and wet meadows, connected by gradual transitions with grass bogs, form on somewhat higher levels of the lake plain and on wide flat river terraces and interfluves. Their grass cover is essentially based on Carex spp., Calamagrostis spp. and moisture-loving herbage. A large part of these meadows is covered with hummocks and requires improvement.