Autumn is in full swing in the birch forest

　　The birch forest refers to a woodland composed of birch trees. The birch belongs to the genus Betula of the family Betulaceae. It is found in the Greater Khingan Mountains, Lesser Khingan Mountains, Changbai Mountains, and high-altitude regions of North China; its vertical distribution reaches below 1,000m in Northeast China and 1,300–2,700m in North China. It is also distributed in Eastern Siberia (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 bark that peels off in paper-like 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, tapering to a point at the apex, broadly wedge-shaped at the base, with irregular double serrated edges. They have 5–8 pairs of lateral veins, scattered oil glands on the underside, and are 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; fruit ripens from August to October. The flowers are unisexual but on the same plant, arranged in catkins. The fruiting catkins are cylindrical, with bracts 3–7mm long, a triangular central lobe, lateral lobes that are either spreading or pendulous, and small oval nuts with membranous wings as wide as or slightly wider than the nut.

　　It prefers full sunlight and does not tolerate shade. It is highly cold-resistant. The birch adapts well to various soils, preferring acidic ones, 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 mixed 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