A habitat is the immediate environment in which a living organism (an
animal or plant), exists. A habitat can exist in any size and can even
be as small as a rock pool or a log that is decaying on the forest
floor. The word habitat however, generally refers to the grouping of
animals and plants, together with their surroundings. Habitats contain
both living organisms and non-living objects and can contain anywhere
from just a few species to thousands of them, all coexisting in a very
small space.
Habitats are constantly changing due to bursting rivers,
fires, storms and changes in climate. Animal species are often capable
of adapting to their altered surroundings although some species of
animal require very specific conditions in order to survive. Ice ages
come and go, taking life with them and forcing animals into areas which
they previously would not of inhabited. In the modern world, natural
climate change is accelerated by the levels of pollution that are
produced from the burning of fossil fuels by people, which is speeding
up the naturally occurring climatic changes.
For
years now, the incredible variety of species (and the variety within
species) has fascinated scientists all around the world. It has been
noted that the greatest levels of species richness are in the regions
surrounding the Equator, and the lowest levels of biodiversity are found
at the poles. No-one is really sure as to the reason why the Earth is
filled with such an incredible number of animal species, but more and
more people are slowly becoming concerned about the effects that climate
change, pollution and deforestation will have on habitats that are rich
in species such as coral reefs and tropical rainforests.Habitats are
spread across enormous areas of the world such as the South American
Amazon Rainforest which covers 5,500,000 km2, while the African Sahara
Desert covers 8,600,000 km2 both of which are enormous regions of the
planet. Animals however, are not spread out across the earth so evenly
as many are still inhabiting the same regions where they first evolved
millions of years ago. The colder parts of the world, such as the polar
regions have little in the way of species variation as animals
inhabiting these areas must be specially adapted to the cold.
However,
what the polar regions lack in biodiversity they make up for in
population numbers as the Antarctic Ocean is home to millions and
millions of crab-eater seals, which are the most numerous large mammals
on the planet. Some animals are also distributed around the world in
accordance with the plants that grow there, as certain species of animal
must eat certain species of plant (like a giant panda needing to
inhabit areas where bamboo grows).
