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As what geographers have estimated, about twenty percent of the earth's
surface is occupied by deserts. A majority of us view deserts as one unique
kind of landscape -- areas with little or no rainfalls. In actual fact,
there are differences between the deserts, though in varying degrees. While
it is common for laymen like us to see deserts as rocky or covered with
gravel or pebbles, there are some where
large sand dunes inhabit. Despite the fact that rainfall is minimal,
temperatures do change in deserts, ranging from seasonal ones to daily
changes where extreme hotness and coldness are experienced in the day and
night.
Unfavorable conditions in the deserts, especially the lack of water,
have discouraged many living things from inhabiting these landscapes.
Nevertheless, there are exceptionally surviving ones which through their
superb tactics, have managed to live through and are still going strong. One
such kind is the specialist annual plants which overcome seasonal
temperature changes with their extremely short, active life cycles. In
events of sudden rain, the plant seeds pullulate
and grow very quickly to make full use of the rain water. Their flowers
bloom and set seeds that ripen quickly in the hot sun too. Once the water
runs dry, the mother plant dies, leaving behind the drought-resistant seeds,
waiting patiently for the next rainy season to arrive.
The Cacti, a native in American deserts, adapts to the dry surroundings
by having unique body structures. The plant has swollen stems to help store
water that carries it through months. By having sharp pines instead of
leaves, water loss through respiration is minimized. Besides, these pointed
pines also help the plant ward off grazing animals, thus enhancing its
survival period.
Besides plants, there are also animals with distinct surviving tactics in
deserts too. For instance, Skinks ( desert lizards ) metabolize stored fats
in their bulbous tails, producing water
to supplement their needs, just like what camels do with the stored food in
their humps during long journeys through deserts. Antelopes like the addax,
have very low water needs and hence are able to tolerate the conditions in
deserts, extracting moisture from the food they eat.
Finally, there are the sandgrouses ( desert birds ) which do not have
special features to overcome the drought-like nature in deserts. Hence, to
survive in these hot, dry deserts, they need to spend a large part of their
time flying in search of waterholes. |
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Despite the dry conditions in the deserts, some plants and
animals still manage to survive there. One of them is the specialist annual
plants. Their short life cycles allow them to germinate, grow and produce
seeds during short rainy seasons. These seeds are drought-resistant and are
able to wait for the next rainy season before starting their life cycles
again. The Cacti adapts to the dry weather by having swollen stems for water
storage and pine-like leaves to minimize water loss through respiration.
Skinks generate water from stored fats in their tails and antelopes which
requires very little water, survives in deserts by extracting water from
food they eat. Finally, sandgrouse with no adaptive features turn to
waterholes constantly for help.
( 119 words ) |
