Autumn is in full swing in the birch forest

Autumn is in full swing in the birch forest

Autumn is in full swing in the birch forest

Birch forests are woodlands composed mainly of birch trees. The birch belongs to the genus Betula of the family Betulaceae. It is native to the Greater Khingan Mountains, Lesser Khingan Mountains, Changbai Mountains in Northeast China, as well as high-altitude areas in North China. Its vertical distribution reaches below 1,000m in the Northeast and 1,300–2,700m in North China. It is also found in Eastern Siberia of Russia, the Korean Peninsula, and Northern Japan.

The birch is a deciduous tree that can grow up to 25m tall with a trunk diameter of 50cm. It has an ovoid crown and white, papery bark that peels off in layers, with yellow lenticels. The twigs are slender, reddish-brown, hairless, and covered with a white waxy layer. The leaves are triangular-ovate or rhombic-ovate, with acuminate tips, broadly cuneate bases, and irregularly double-serrate margins. They have 5–8 pairs of lateral veins, scattered oil glands on the underside, and are either hairless or have hairs in the vein axils. The fruiting catkins are solitary, pendulous, and cylindrical. The nuts are small and flattened, with broad wings on both sides. Flowering occurs from May to June, and the fruits ripen from August to October. The flowers are unisexual but monoecious, arranged in catkins. The fruiting catkins are cylindrical, with bracts 3–7mm long. The middle lobe of the bract is triangular, while the lateral lobes are spreading or pendulous. The small nuts are oval-shaped, with membranous wings as wide as or slightly wider than the nut itself.

It prefers full sunlight and does not tolerate shade. It is highly cold-resistant. The birch adapts well to various soil types, preferring acidic soils, and can grow in swamps, dry sunny slopes, and moist shady slopes. It has a deep root system, is tolerant of poor soils, and often grows in mixed stands with Korean pine, larch, mountain poplar, and Mongolian oak, or forms pure forests. It has good natural regeneration, grows relatively quickly, sprouts vigorously, but has a shorter lifespan.

Address: Raohe County, Shuangyashan City, Heilongjiang Province