寒帶、熱帶、温帶森林有什麼樹林

Forests can be classified in different ways and to different degrees of specificity. One such way is in terms of the "biome" in which they exist combined with leaf longevity of the dominant species (whether they are evergreen or deciduous). Another distinction is whether the forests composed predominantly of broadleaf trees, coniferous (needle-leaved) trees, or mixed.

Boreal forests occupy the subarctic zone and are generally evergreen and coniferous.
Temperate zones support both broadleaf deciduous forests (e.g., temperate deciduous forest) and evergreen coniferous forests (e.g., Temperate coniferous forests and Temperate rainforests). Warm temperate zones support broadleaf evergreen forests, including laurel forests.

Tropical and subtropical forests include tropical and subtropical moist forests, tropical and subtropical dry forests, and tropical and subtropical coniferous forests.

Physiognomy classifies forests based on their overall physical structure or developmental stage (e.g. old growth vs. second growth).

Forests can also be classified more specifically based on the climate and the dominant tree species present, resulting in numerous different forest types (e.g., ponderosa pine/Douglas-fir forest).
http://en.wikipedia.org/wiki/Forest
Also Chinese version:
森林是一个高密度树木的区域(或许在历史上, 一个树木繁茂的区域为狩猎留出) 。这些植物群落覆盖着全球大面积并且对二氧化碳下降、动物群落、水文湍流调节和巩固土壤起着重要作用，构成地球生物圈当中的一个最重要方面。
森林在任何樹木可以生長的地方出現，不管屬哪一緯度。森林的樹木通常为不同的樹種，並有不同的高度。用生物学术语, 森林也许从林地被区分:A forest has a more or less closed canopy, in which the branches and foliage of trees meet or interlock. A woodland has an open canopy, which allows some sunlight to penetrate between the trees (see also: savanna).


圖片參考：http://upload.wikimedia.org/wikipedia/commons/thumb/c/c9/Forest1.jpg/250px-Forest1.jpg



圖片參考：http://zh.wikipedia.org/skins-1.5/common/images/magnify-clip.png
A decidous beech forest in Slovenia.
很多种森林的存在，在生态学中的类型是：

雨林 (热带和温带)
针叶林
温带阔叶林
热带干旱森林
熱帶森林資源
森林通常被根据它们存在的生物群系来分类，并按照主要种类的树叶寿命(它们是否常青的或落叶的) 。Boreal forests occupy the subarctic zone and are generally evergreen and needle-leaved. Temperate zones support both deciduous forests (e.g., temperate deciduous forest) and evergreen forests (e.g., temperate rainforest, chaparral). Tropical and subtropical forests include tropical rainforest, tropical moist forest and tropical dry forest.
http://zh.wikipedia.org/wiki/%E6%A3%AE%E6%9E%97

See Green Fact web-site on forest:

http://www.greenfacts.org/en/forests/index.htm