In Primorye, the notion”spruce-fur forests” is commonly applied to typical
bidominant forests formed by P. ajanensis and A. nephrolepsis. P. ajanensis
chiefly forms them as a predominant species in most stages of age development,
while A. nephrolepsis becomes predominant in periods of natural necrosis
of older generations of P. ajanensis, or as a result of its commercial
chopping. Besides these representatives of the Picea and Abies genera,
Picea koraiensis and Abies holophylla also grow in Primorye. P. koraiensis
takes part in the composition of certain types of larchwood-coniferous
forests and, less often, spruce-fur forests till an altitude of 650-700
m in the south of Primorye, and till 550-600 m in Samarga River basin.
A. holophylla grows to come up as a forest-forming species only in the
In Primorye, spruce-fur forests comprised of P. ajanensis and A. nephrolepis form a well-pronounced mountain belt of forest vegetation extended along both sides of the main watershed of Sikhote Alin and its southern extremity. This belt is a direct continuation of the latitudinal zone of dark coniferous forests of Priamurye, and precisely this caused B.P Kolesnikov to assign them the “zone-belt” status. Nowhere else in Eurasia do forests typical of the northern temperate zone move so far southward. In the central continental regions of Eurasia, deserts occupy this latitude.
At their upper distribution boundary, P. ajanensis and A. nephrolepis forests link with Betula lanata forests and, occasionally, directly with thickets of shrubs and creeping plants. These forests are usually called sub-bare peak or alpine forests. The tree stands normally include B. lanata, and Acer ucurunduense in the south. Despite their low productivity (quality V-Vb), they have outstanding ecoprotective significance. Yet, those forests have no commercial significance, though Bergenia pacifica, Echinopanax elatum and other valuable medicinal plants grow under their normally thinned-out canopy. As a rule, forest fires in these places lead to irreversible replacement by rock birches, shrub thickets and even by rocky talus. Alpine spruce-fur forests occupy less than 10 percent of the area of this forest formation in Primorye.
Spruce-fur forests with productivity ranging from quality II to IV occupy most of the mountain slopes and plateaus. In fact, they occupy up to 85-90% of the area of this forest formation in Primorye.
Thickly greenleaved spruce-fur forests, preferentially quality III, less often IV and II, are widespread in the northern part of Primorye. They form highly compact stocks with thick moss (Hypnum spp) carpet developed under their canopy; grass and shrubs do not form distinctly pronunced tiers, and not infrequently occur only as scattered single specimens. Participation in tree stocks of concomitant species (Betula lanata, B. costata, Tilia take, etc.) is insignificant, and they are often absent altogether.
Fern types of spruce-fur forests occupy the largest areas in central and southern Primorye. Their productivity corresponds to quality class III, and not infrequently to class II. Admixtures of Pinus koraiensis, Betula costata, Tilia take, T. amurensis, etc. normally characterize the tree stocks). Representatives of the genera Acer, Eunonymus, Ribes, Rosa and Lonicera form the underbrush. Actinidia kolomikta is common among lianas. The grass cover is developed well, with Plypodiophyta prevailing. Mosses occur only in soil surface microdepressions and on brushwood.
Shrub spruce-fur forests occupy quite considerable areas in southern Sikhote Alin to occur less often to the north on small areas.
The arboreal tier of these forests is composed best in specific composition, age structure and structure of the entire phytocoenosis. Concomitant species also include Acer mono, Ulmus lacciniata, Tilia mandshurica, etc. Concomitant species amount to 30-50% of the wood reserve. The abundant underbrush is composed of two alpine canopies with overall compactness of up to 0.8. The grass cover is developed well to form two-three canopies with herbage and ferns prevailing. Tree stock productivity corresponds to class II, less often to quality class III. The abundance of representatives of broad-leaf forests in all phytocoenotic tiers, and the fact that in periodic decomposition of coniferous trees broad-leaf species begin to prevail temporarily in the tree stock, allows believing this group of spruce-fur forests to represent a transitional link to broad-leaf coniferous forests.
In mountain river valleys and gently sloping drags, spruce-fur forests occupy approximately 5-6 percent of the area of this formation in Primorye. The most widespread are tall-grass--shrub types, which occupy narrow strips along stream and small riverbeds. The tree stocks are complex in composition and structure, class II-III. In the upper parts of rivers and in the northern area of Primorye, these forests are chiefly composed of P. ajanensis and A. nephrolepis, and in the south and on lower levels their role diminishes to 50-60% to give rise to admixtures of Populus spp, Padus maakii, Ulmus japonica, Fraxinus mandshurica, etc. The underbrush is diversified and two-tier, with representatives of the genera Acer, Euonimus, Eleutherococcus, Ribes, Lonicera, etc. prevailing. Actinidia kolomikta and Vitis amurensis are commonly occurring species. The grass cover is dense with moisture-loving tall grass species (Cacalia spp, Aconitum spp, Angelica spp, etc.) prevailing; Calamagrostis spp, Carex spp, Equsetum spp, etc. also take part. These forests are almost fully included in protective belts established along the banks of all rivers and streams and their sources.
Grassy-moss forests with absolute prevalence of P. ajanensis and A. nephrolepis represent a rare, albeit unique group. They occupy habitats with excess, at times stagnant soil moisture. In some places, they also include a small admixture of
Betula platiphylla, with Fraxinus mandshurica in the south and Larix spp in the north. Class V commonly characterizes tree stock productivity, less often by class IV or Va. The underbrush is developed weakly and is poor in composition. Common in the relatively rare grass cover are Smillacina dahurica, Carex spp, Calamagrostis spp, and individual specimens of Osmunda cinnamomea. Mosses from the genera Sphagnum and Polytrichum form a continuous soil and old brushwood cover. Mosses from the genus Hypnum and others also occasionally occur. These forests are observed on poorly drained sites of broad terraces, on lower flat sites of gently sloping drags, and in central depressed mountain plateau sites. They are common in the zone of ecological and topological contact of P. ajanensis and A. nephrolepis with Larix spp forests. Mixed P. ajanensis and Larix spp forests, representing an independent forest subformation form the next ecological link.