Included here is Manchuria in northern China and Russia. It includes the southeastern part of the Khabarovski Krai including the middle and lower reaches of the Amur River, the Primorski Krai. In Russia it extends to include the Sihote-Akin Mountains on the east and Lake Khanka to the west of these mountains. The border then extends south to the Amur Gulf, the northern part of the Korean Peninsula and includes the basin of the middle and lower reaches of the Yalu River. In the north it includes the southeastern part of the Onon-Argun steppes in the Transbaikalia area together with the basins of the Uldza and Onon rivers and the foothills of the Khingan Mountains in northeastern Mongolia. In China the western boundary extends from the west of the Great Khingan Mountains east to Shenyank and then cuts across the Yalu River. In addition to boreal forest the area also supports a rich diversity of broad-leaved forests.
Manchurian Oak Forest
This zoneincludes a rich diversity of oak forest types each dominated by a different species of oak. Quercus mongolica forest is widespread with trees reaching 18 m in the more temperate areas. The shrub layer varies from place to place but includes several endemic species such as Rhododendron schlippenbachii (Ericaceae) and Spiraea pubescens (Rosaceae). The herb layer can be up to 80 cm tall and may include Artemisia keiskeana, Dendranthema naktongense, Silene jenisseenis and the endemic or near endemic Diarrhena manshurica (Poaceae). Vines such as the endemic or near endemic Clematis manschurica (Ranunculaceae) may also be present. Quercus dentata forest extends from southeastern Heilongjiang south to Liaoning. Pure stands are confined to steep south facing slopes and rarely reach more than about 4 m tall. The sparse shrub layer typically includes Indigofera kirilowii, Lespedeza davurica, Prunus humilis and Securinege suffruticosa. Likewise the herb layer is pretty sparse and usually dominated by Carex callitrichos, but may also include the endemic Polygonatum stenophyllum (Liliaceae) and Rubia cordifolia (Rubiaceae). Forests dominated by the endemic Quercus liaotungensis (Fagaceae) are confined to central and western Liaoning. They have a well-developed shrub layer that varies from place to place but may include the endemic Exochordia serratifolia (Rosaceae). The herb layer is usually dominated by Carex calitrichos, but also includes Asparagus oligoclones, Iris ruthenica, Melampyrum roseum and Saposhnikovia divaricata. Forests dominated by Quercus aliena occupy small areas mainly on the Liaodong Peninsula. Associated trees include the endemic or near endemic Juglans mandshurica (Juglandaceae). Alangium platanifolium, Corylus heterphylla, Euonymus alata and Symplocos paniculata are among the dominants of the species-rich shrub layer. Carex again dominates the herb layer mainly C. ciliato-marginata and C. siderosticta, but these are usually joined by other species such as the endemic Geranium koreanum (Geraniaceae). Also found on the Liaodong Peninsula as well as on adjacent islands is forest dominated by Quercus acutissima. The shrub layer of these forests includes Rhus javanica, Weigela praecox and Zanthoxylum schinifolium. Important herbs include Carex calitrichos and C. humida but these may be joined by Cleistogenes polyphylla, Leontopodium leontopodioides and Potentilla discolor. Finally small stands of forest dominated by Quercus variabilis can also be found on the Liaodong Peninsula, but confined to southern areas. The shrub layer tends to be dominated by Indigofera kirilowii and the herb layer is again dominated by Carex callitrichos. But many other herbaceous species may be encountered including Codonopsis lanceolata, Cynanchum atratum, Duchesnea indica and Syneilesis aconitifolia.
Manchurian Birch Forest
Birch forest in this zone maybe dominated by one of four species - Betula davurica, B. ermanii, B. platyphylla or the endemic B. costata (Betulaceae). Betula platyphylla forest is the most widely spread forest type in northeast China covering about 20% of the total forested area, despite being a secondary forest type. Betula davurica forest is far less common being confined to areas south of Daxingan-ling and Xiaoxingan-ling. It occurs in small patches on south-facing slopes between about 300 -700 m. Betula costata forest is another secondary forest type occurring mainly at high elevations and pure stands are rarely encountered. Betula ermanii forests are also confined to high elevations mostly near the tree line in the eastern parts of the BioProvince. Other associated trees vary from forest to forest but may include several endemic or near endemic species such as Fraxinus mandshurica (Oleaceae), Juglans mandshurica (Juglandaceae), Phellodendron amurense (Rutaceae) and Tilia mandshurica (Tiliaceae). The shrub layer also varies but endemic species such as Acer pseudosieboldianum (Aceraceae) and Ribes komarovii (Grossulariaceae) may be present. Endemic species possibly encountered in the herb layer include Jeffersonia dubia (Berberidaceae), Ligusticum tenuissimum (Apiaceae) Trollius macropetalus (Ranunculaceae) and Veratrum dahuricum (Liliaceae).
Manchurian Aspen-Poplar Forest
These forests can be be broady divided into three mainly secondary forest types - Populus koreana forest, P. maximowiczii forest, P. suaveolens forest and P. tremula var. davidiana forest. The most widespread of these is P. tremula forest which occurs mainly on leeward slopes between 800 – 1000 m. Populus koreana and P. maximowiczii forests are far less common being mainly confined to eastern areas, while P. suaveolens forest occurs primarily on Daxingan-ling. Their canopies vary in height from about 23 m in P. tremula forest to about 30 m in P. maximowiczii forest. Associated tree vary from forest to forest but include many endemic or near endemic species such as Fraxinus mandshurica (Oleaceae), Juglans mandshurica (Juglandaceae) and Tilia amurensis (Tilaceae). The shrub and herb layers also vary but several endemic species may be encountered such as the shrubs Atraphaxis manshurica (Polygonaceae) and Lonicera maximowiczii (Caprifoliaceae), and the herbs Fritillaria maximowiczii (Liliaceae) and Plectranthus excisus (Lamiaceae).
Manchurian Elm Forest
One or two of three elm species dominate these forests - Ulmus japonica, U. macrocarpa and U. pumila - depending on location. Natural forests of U. macrocarpa and U. pumila are confined to the temperate steppe region of Northeast China and in places both species occur together. Canopy height varies from 7-10 m. Typical shrub layers include Caragana microphylla, Sambucus williamsii and Spiraea fritschiana, while the varied herb layer often comprises the endemic or near endemic Erysimum amurense (Brassicaceae). Ulmus japonica forest is usually confined to alluvial soils and rivers banks in eastern areas where it often forms monodominate canopies. Typical shrub layers include Salix gracilistyla and Sorbaria sorbifolia, while the well-developed herb layer comprises species such as Aconitum kusnezoffii, Angelia dahurica, Equisetum sylvaticum, Galium maximowiczii and Urtica angustifolium.
Manchurian Lime Forest
Forest dominated by the endemic or near endemic Tilia amurensis (Tiliaceae) occur widely in eastern areas as well as in western Liaoning Province. The canopy can be very dense with a cover of up to 90% formed by a diverse mixture of broad-leaved trees. Other characteristic species include Acer mono, Aralia elata, Carpinus cordata, Fraxinus rhynchophylla and several endemic taxa. The shrub layer is often high, up to 2 m and very rich in species including Myripnois dioica, Ostryopsis davidiana, Philadelphus pekinensis and a great variety of endemic taxa. Vines are also prolific with species like the endemic or near endemic Aristolochia manchuriensis (Aristolochiaceae) and Vitis amurensis (Vitaceae). Endemic or near endemic taxa are also well represented in the rich herb layer with species such as Asarum heterotropoides var. mandshuricum (Aristolochiaceae) and several spring-ephemerals like Adonis amurensis (Ranunculaceae) and Gagea hiensis (Liliaceae).
Manchurian Ash Forest
These forests are either dominated by Frazinus mandshurica or F. rhynchophylla. The former occurs in eastern areas mainly along rivers or on gentle slopes, while the latter is confined to slopes in Liaoning Province. They share a similar assemblage of associated trees including several endemic or near endemic species like Maackia amurensis (Fabaceae) and Syringa reticulata var. mandschurica (Oleaceae). The shrub and herb layers also have several species in common including the endemic shrub Rhamnus diamantiaca (Rhamnaceae) and the endemic herb Plectranthus excisa (Lamiaceae).
Manchurian Alder Forest
These forests, dominated by Alnus hirsuta, are mainly confined to mountainous areas in the east and north of the BioProvince. The canopy can reach 10-12 m and may include Malus buccata, Prunus padus and Pyrus ussuriensis. Shrub layer species can reach 2 m in height and typically include Ribes procumbens, Rosa davurica and Rubus matsumuranus. The herb layer is usually well developed with species such as Comarum palustre, Geranium eriostemon, Maiathemum dahuricum and Pedicularis resupinata.
Manchurian Chosenia arbutifolia Forest
These forests usually form narrow strips along rivers and streams on well-drained soils in northern and eastern areas. They are strongly dominated by Chosenia arbutifolia, but may also include Populus maximowiczii and the endemic or near endemic Fraxinus mandshurica (Oleaceae). The shrub layer usually includes Cornus alba, Salix udense, Sambucus buergeriana and the endemic or near endemic Syringa reticulata var. mandschurica (Oleaceae). With herb layer cover of up to 70 %, it includes a large variety of species such as Anemone dichotoma, Girardinia cuspidata, Lysimachia davurica, Parasenecio hastata, Picris davurica, Saussurea parviflora and Veronicastrum sibiricum.
Manchurian Kalopanax septemlobus Forest
These forests are confined to the middle and lower slopes of Changbaishan. Associated trees include several endemic species such as Abies holophylla (Pinaceae). Shrub layer species comprise Rubus crataegifolius, Viburnum burejaeticum and stunted specimens of Acer ukurunduense. Typical herb layer species are Lilium distichum, Syneilesis aconitifolia and the endemic or near endemic Adonis amurensis (Ranunculaceae).
Manchurian Celtis bungeana Forest
These forests are confined to the western parts of Liaoning Province where they usually occupy dry, south-facing slopes between altitudes of 500 to 600 m. Other trees may include Acer truncatum, Tilia mongolica and Ziziphus spinosa. Major shrub layer taxa include Ampelopsis humulifolia, Rhamnus arguta and the endemic Spiraea pubescens (Rosaceae). Dominant in the herb layer are Carex humida, C. lanceolata, Cleistogenes nakai and C. caespitosa.
Manchurian Carpinus turczaninovii Forest
These forests are confined to south-facing slopes on the Liaodong Peninsula and in western Liaoning Province. Carpinus turczaninovii strongly dominates the canopy but there may also be Fraxinus rhychophylla and Quercus mongolica. Shrub layer species include Celastrus flagellaris, Clerodendron trichotomum and Symplocos paniculata. The herb layer is quite sparse with a cover no more than about 10%. The main species are Calamagrostis arundinacea var. brachytricha, Carex lanceolata, Polygonatum odoratum and Spodiopogon sibiricus.
References
Kolbek, J., Srutek, M. & Box, E. O. 2003. Forest Vegetation in Northeast Asia. Kluwer Academic Publishers.
Richardson, S. D. 1977. Forestry in communist China. The John Hopkins Press.
Wang, Chi-Wu. 1961. The forests of China with a survey of grassland and desert vegetation. Maria Moors Cabot Foundation. Publication No. 5.
Yang, X. & Xu, M. 2003. Biodiversity conservation in Changbai Mountain Biosphere Reserve, northeastern China: status, problems, and strategy. Biodiversity and Conservation, 12: 883-903.