Tundra (Biomes of the Earth) (repost)

From the Preface
..One of the most exciting things about the Earth is the rich
pattern of plant and animal communities that exists over its
surface. The hot, wet conditions of the equatorial regions
support dense rain forests with tall canopies occupied by a
wealth of animals, some of which may never touch the
ground. The cold, bleak conditions of the polar regions, on
the other hand, sustain a much lower variety of species of
plants and animals, but those that do survive under such
harsh conditions have remarkable adaptations to their test-
ing environment. Between these two extremes lie many
other types of complex communities, each well suited to the
particular conditions of climate prevailing in its region. Sci-
entists call these communities biomes…
This set of books aims to outline the main features of each
of the Earth’s major biomes. The biomes covered include the
tundra habitats of polar regions and high mountains, the
taiga (boreal forest) and temperate forests of somewhat
warmer lands, the grasslands of the prairies and the tropical
savanna, the deserts of the world’s most arid locations, and
the tropical forests of the equatorial regions. The wetlands of
the world, together with river and lake habitats, do not lie
neatly in climatic zones over the surface of the Earth but are
scattered over the land. And the oceans are an exception to
every rule. Massive in their extent, they form an intercon-
necting body of water extending down into unexplored
depths, gently moved by global currents.
Humans have had an immense impact on the environ-
ment of the Earth over the past 10,000 years since the last Ice
Age. There is no biome that remains unaffected by the pres-
ence of the human species. Indeed, we have created our own
biome in the form of agricultural and urban lands, where
people dwell in greatest densities. The farms and cities of the
Earth have their own distinctive climates and natural history,
so they can be regarded as a kind of artificial biome that peo-
ple have created, and they are considered as a separate biome
in this set.
Each biome is the subject of a separate volume. Each richly
illustrated book describes the global distribution, the climate,
the rocks and soils, the plants and animals, the history, and
the environmental problems found within each biome.
Together, the set provides students with a sound basis for
understanding the wealth of the Earth’s biodiversity, the fac-
tors that influence it, and the future dangers that face the
planet and our species…