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.
Summary: 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.
No comments:
Post a Comment