Today forests with prevalence of Q. mongolica occupy significant areas
on the eastern and western slopes of Sikhote Alin in the south and central
Primorye, on the western and southwestern foothills of Sikhote Alin, on
the spurs of Chornye Gory, which penetrate to the southwest of Primorye
from Manchuria, and on the ridges surrounding the Hanka-Ussuri plain. Thirty
five-forty years ago, forests with prevalence of Q. mongolica occupied
15-16% of Primorye’s forest area. Today their area has increased because
Pinus koraiensis, Fraxinus mandshurica and other species in high demand
on the timber market were felled from mixed forests with considerable share
of Q. mongolica to make the latter prevalent among tree stocks.
Several basic groups of forest types
would form depending on afforestation conditions.
Thin oak groves, grade V-Va, with
prevalence of Rhododendron mucronulatum in the underbrush grow on rocky
peaks and very steep, preferentially southern slopes. They occupy about
10-12% of the total oak forest area of Primorye, but have very high ecoprotective
significance. The tree stocks are commonly found to have an admixture of
Larix sp. in the north, and Fraxinus rhynohophylla, Juniperus rigida, and
Pinus funebris (P. densiflora?) in the south.
Oak groves with prevalence of Lespedeza
bicolor in the underbrush and with participation of Corylus heterophylla
develop over less steep and less rocky, also preferentially southerly slopes,
and Weigela praecox in the south, where Vitis amurensis is also commonly
present. The rare grass cover consists of xeromesophyte-like species. The
tree stock grade is IV, occasionally III. Their composition also includes
Larix sp., Picea koraiensis and Pinus koraiensis in the north of Primorye,
and Betula schmidtii, Fraxinus rhynchophylla and Abies holophylla in the
south. These forests occupy about 40% of Q. mongolica forests in Primorye.
Q. mongolica forests with prevalence
in the underbrush of Corylus heterophylla and C. mandshurica, and involving
Eleutherococcus senticosus, Eunonimus spp., Deutzia amurensis, etc. occupy
approximately the same areas in Primorye. Liana species include Actinidia
kolomicta, A. polygama (in the south) and Vitis amurensis. They occupy
gently sloping and not-very-steep slopes of various, but more often southerly
directions. Tree stock quality is commonly grade III, seldom IV. The underbrush
is dense and consists of representatives of the genera Lonicera, Euonimus,
Corylus, Eleutherococcus, etc. Liana species are present in quite large
numbers. The grass cover is dense, with prevalence therein of representatives
of the fam. Polypodiacea, among which the genera Pteridium, Dryopteris
and Athyrium are most numerous. Cacalia spp., Aconitum spp., Valeriana
spp., Angelica, etc. participate significantly in the grass cover.
The main species of these forests,
Quercus mongolica, is characterized by wide ecological amplitude and can
therefore occupy such different habitats. Besides, it is considerably more
stable than all other tree species against forest fires and felling, retaining
its viability after multiple fires and its growth ability after felling
and fires for decades. Ultimately, oak forests degrade, albeit slowly.
Their extreme degradation degree shows in so-called “undergrowth tree-shrub
thickets”, in which Q. mongolica, Lespedeza bicolor and other shrubs form
a single 0.5-2-2.5 m-tall canopy. In Primorye, such thickets occupy over
one million hectares on ridges of the Hanka-Ussuri plain and the surrounding
In addition to Q. mongolica,
Q. dentata grows in the very south of Primorye to form shrub-herbage rare
forests on the southwestern coast of Peter the Great Bay. These tree stocks
are rare not because of the biological properties of Q. dentata itself,
but due to many centuries of man-made influence, chiefly forest fires.