Deserts are hot, barren, arid regions, where the topsoil has been whisked away
by the wind.
They have low rainfall, hot desiccating high speed winds, very high evaporation
rates, and high temperatures.
Typically most plants and animals are absent from deserts, due to the
inhospitable conditions that previal there.
Desert reclamation involves establishing plants in the affected area.
This typically involves the construction of shelterbelts,
windbreaks and woodlots - to provide protection against the wind
for other plants - and irrigation and fertilization projects.
Shelterbelts are composed of rows of trees, typically arranged
perpendicular to the prevailing winds. Woodlots are more extensive
areas of woodland.
Plants which extract nitrogen from the air and fix it in the soil (e.g. legumes)
can be useful to help restore fertility to deserted regions.
Water availability is a key factor when battling desertification. Irrigation can be
done by diverting freshwater sources, or by pumping in sea water. Cloud seeding is
another possible source of water. If salt water is used, desalination or
salt-tolerant plants are needed. Also some means of keeping the water on
or near to the surface is often desirable.
Ground treatments with bacteria and clays can transform sandy regions into something
more closely resembling concrete. A crust on the dunes makes the sand less likely to
be blown about - and helps control dust storms. It also makes the sand retain moisture
better by decreasing evaporation surfaces.