Complex ecosystem in which trees are the dominant life-form. Tree-dominated forests can occur wherever the temperatures rise above 50 °F (10 °C) in the warmest months and the annual precipitation is more than 8 in. (200 mm). They can develop under various conditions within these limits, and the kind of soil, plant, and animal life differs according to the extremes of environmental influences. In cool, high-latitude subpolar regions, taiga (boreal) forests are dominated by hardy conifers. In more temperate high-latitude climates, mixed forests of both conifers and broad-leaved deciduous trees predominate. Broad-leaved deciduous forests develop in midlatitude climates. In humid equatorial climates, tropical rainforests develop. There heavy rainfall supports evergreens that have broad leaves instead of the needle leaves of cooler evergreen forests. Having extensive vertical layering, forests are among the most complex ecosystems.

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Tundra ~

An area supporting some vegetation beyond the northern limit of trees, between the upper limit of trees and the lower limit of perennial snow on mountains, and on the fringes of the Antarctic continent and its neighboring islands. The term is of Lapp or Russian origin, signifying treeless plains of northern regions. Biologists, and particularly plant ecologists, sometimes use the term tundra in the sense of the vegetation of the tundra landscape. Tundra has distinctive characteristics as a kind of landscape and as a biotic community, but these are expressed with great differences according to the geographic region.

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Jungle ~

The term may still be used in a technical context to describe the forest biome rainforest, a forest characterised by extensive biodiversity and densely tangled plants such as trees, vines, grasses, and also various roses. As a forest biome, “jungles” are present in both equatorial and tropical climatic zones, and are associated with preclimax stages of the rainforest. For this reason, jungle is to be distinguished from tropical rainforest in that the former is a profuse thicket of tropical shrubs, vines, and small trees growing in areas outside the light-blocking canopy of a tropical rainforest. Hence, jungle may be found at the edges of such forests.

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Tundras are ICE.

A jungle is generally warm and humid, in a more tropical area.