1. Distribution area

Coniferous forest: mainly distributed in the cold temperate zone between 45° and 70° north latitude and in the sub-alpine areas of mid- and low-latitudes. In the cold temperate zone of the northern hemisphere, it is distributed almost from the east coast of the continent to the west coast, across Eurasia and the northern part of North America. The East Siberian region extends eastward from Norway, passing through Sweden, Finland, Russia and Siberia, and crossing Beringia. Strait reaches Alaska and Canada. The area of ??North American coniferous forests is second only to that of Eurasia. It is distributed from the Atlantic coast to the Pacific coast, spanning the entire North American continent.

Evergreen broad-leaved forest: Evergreen broad-leaved forest is a forest under subtropical maritime climate conditions, roughly distributed between 22° and 34° (40°) in south and north latitudes. Mainly found in the southern Yangtze River Basin of China, the southern part of Korea and the Japanese archipelago, the southeastern coast and northwest of Africa, the Canary Islands in the Atlantic Ocean, the eastern tip of North America and Mexico, and Chile, Argentina, Bolivia and Brazil in South America. Some areas, eastern Oceania and New Zealand. Among them, the evergreen broad-leaved forest in the southern Yangtze River Basin of China is the most typical and has the largest area.

Deciduous broad-leaved forest: widely distributed in temperate areas between 30° and 50° north latitude. The typical deciduous coniferous broad forest in Western Europe can be distributed to the European part of the former Soviet Union. In eastern North America, approximately south of the 45° north latitude line. South America is found in the Patagonian Plateau. Due to the influence of the Gulf Stream, Europe can be distributed in the northwest to 58° north latitude. Eastern Asia is distributed in China, the eastern coastal areas of the former Soviet Union, Kamchatka, Sakhalin, North Korea and the northern islands of Japan. China's deciduous broad-leaved forests are mainly distributed in Northeast China and North China.

2. Morphological characteristics

Coniferous forest: Coniferous forest is a general term for all types of forests composed of coniferous trees. Including evergreen and deciduous, cold-tolerant, drought-tolerant and warm-humidity-loving coniferous pure forests and mixed forests. It is mainly composed of some cold-resistant tree species such as spruce, fir, larch and pine. Commonly called boreal forest, also known as taiga. Among them, those composed of larch are called bright coniferous forests, while those composed of spruce and fir are called dark coniferous forests.

Evergreen broad-leaved forest: It has the characteristics of Lauraceae laurel leaves, which are evergreen, leathery, and slightly hard. The surface of the leaves is glossy and hairless, and the leaves are arranged perpendicular to the sun's rays. The appearance is evergreen all year round, generally dark green with slightly flashing reflections. The forest appearance is neat, and vegetative growth occurs all year round, and is more vigorous in summer. It can be divided into tree layer, shrub layer and herb layer.

Deciduous broad-leaved forest: widely distributed, refers to broad-leaved tree species that lose their leaves in winter. The seasonal phases of winter and summer are very different. Even in summer, there are different seasons due to the diversity of species. The structure is simple and can be clearly divided into tree layer, shrub layer and herb layer. Most of the seeds and fruits of trees in deciduous broad-leaved forests are winged, often mature in autumn, and spread by wind. Understory herbs and shrubs rely on animals to pollinate and disperse their fruits and seeds. The lianas and epiphytes in the forest are underdeveloped.

Extended information:

Common tree species:

Coniferous forest: North China larch forest; white cypress, green cypress forest; tabulaeformis pine forest; whitebark pine, Platycladus orientalis; Fir, spruce, etc.

Evergreen broadleaf forest: Canary laurel (Laurus canariensis), Apollonias barbujana (Apollonias barbujana), Ocotea foetens; Virginia oak (Quercus virginiana), black oak (Q .nigra), Camphor; Magnolia grandif-lora, Persea americana, Liquidambar styraciflua, Fagus americana; Nothofagus dombeyia, Hinoki cypress , Podocarpus (Podocarpus), Araucaria (Araucaria);

Eucalyptus, Acacia, Podocarpus, Lujun pine, Kauri (Agathis), Yew (Taxus), Libocedrus (Libocedrus); Quercus (Quercus), Castanopsis; Machilus thunbergii, Castanopsis cuspidata, Cyclobala-nopsis gilva, C.glauca, Cinnamomum japonicum, Distylium racemosum, Symplocos prunifolia, etc.

Deciduous broad-leaved forest: oak forest (Quercus petraea and Q. pubecens, etc.), water green forest (Fagus sylvatica and Tauri water) F. taurica, etc.), Fagus americana, Acer saccharum, Quercus mongolica, Fraxinus madshurica, Tilia mandschurica, Carpinus cordata), Catalpa walnut, Phellodendron amurense, Populus euphratica, Choseniamacrolepis, etc.

Reference materials: Baidu Encyclopedia - Coniferous Forest; Baidu Encyclopedia - Evergreen Broad-leaf Forest ;Baidu Encyclopedia-Deciduous Broad-leaf Forest