The results of an investigation of mixed broadleaved forest in the basin of the Bolshaya Ussurka River (territory of National Park «The Udege Legend») with the following relict vascular plant species: Taxus cuspidata, Picea jezoensis, Coniogramme intermedia, Osmundastrum asiaticum, Osmorhiza aristata in the basin of the Bolshaya Ussurka River (territory of National Park «The Udege Legend») are presented. Taxus cuspidata is a dominant in this forest. High biological diversity is typical for this forest type. 89 species of vascular plants, belonging to various ecobiomorfological groups, are recorded on the studied plot.
Prickly castor-oil tree (Kalopanax septemlobus) is a valuable medicinal, edible and ornamental tree. It is included in the «Red Book of the Russian Federation» as a rare species. The mean density on 1 ha of Kalopanax stems and understory individuals on the Russian Island were respectively 5.8 and 20.5. The density of potentially mature trees was3.4 stems/ha. These unique species habitats on the Russian Island are destroyed or degraded due to large-scale construction, fires and high recreational load. The stands with Kalopanax participation should be protected; it is necessary to take measures to its natural and artificial regeneration.
Fir-spruce forest condition in the Central Sikhote-alin is considered in the article. It is determined that natural dark coniferous forests in the Bikin river upper courses are in the unstable condition. Secondary ripening even-aged fir-spruce forests which did not suffer from large drying out in 1980th now got the structure, which is characteristic to the normal forest stands.
Rare plant communities of the "Ussuriisk" nature reserve are considered in the article. Rarity categories, protection reasons, laws of their distribution, habitat conditions and the basic destabilizing factors are given for each community.
The article gives the results of the research of soil ranging in broad-leave cedar forests of the Ussurisk national park according to the natural fertility character and productive moisture reserves. The character of the definite soil types (subtypes) relevant to the types of forests is shown.
Long monitoring (1926–2003) on the permanent test plot laid by B. A. Ivashkevich in the overmature virgin hornbeam-Korean pine forest with spruce shows that the Korean pine is subject to dying-off and has lost its prevailing role in the tree stand. At the same time the tree species dominating the lower layer of tree stand that have completed their life cycle fall off. The dead trees of these species are quickly replaced by young growth, whereas the young generation of Korean pine able to shape a new tree stand has not formed. All this indicates that the cyclicity of the alternation of the Korean pine generations is disturbed. The phase of dominance of deciduous species begins.
