Introduction - Afforestation, Reforestation and Forest Restoration in Arid and Semi-arid Tropics - page 4

Fig. 1.1 Commons lying as a wasteland: a result of depletion of vegetation because of continued
overgrazing
dune stabilisation plantations. Forests and savannah vegetation improve terrestrial
environment in many ways, which includes supporting the supply of clean water,
protection against erosion and accumulation of carbonates, and preservation of the
landscape.
The marginal and degraded lands in the tropics have been surveyed and mapped
in many parts of the world, but the exact potential for such work is probably vast,
and definitely much more than what is recorded. It would be, perhaps, impossible
to afforest all such lands in the immediate future for lack of financial resources and
institutional capacity. It is, therefore, necessary to prioritise such lands on the basis
of their productivity and the risk of further degradation. The dilemma of choosing
better lands for higher productivity and lower afforestation costs versus choosing the
poorest lands—albeit at a greater cost per hectare—lest these cross the threshold of
recovery, is a characteristic issue that should be resolved consciously and carefully.
The fact that decisions in this regard should be based on the needs of the local
communities and other considerations such as availability of labour and finance,
further makes deeper thought in this regard necessary (Fig. 1.1 ).
Conservation afforestation often concerns with promoting regeneration of natural
forests as against planting of artificially raised seedlings of multipurpose tree species.
An advantage of regeneration of natural forests, apart from reduced cost per unit area,
is that the ecological balance is established at an earlier stage and the local biodiver-
sity of the area is conserved at the same time. Sustained-use management of such
regenerated forests can yield valuable products and services to the local communities.
The use of multipurpose fast-growing tree species in afforestation is imperative
from the point of view of better returns but it must be done with a cautious consid-
eration. Conservation forestry should not only aim at the protection of soil but also
ensure that ecological balance is restored in the area. Introduction of exotics is likely
to have unpredictable effects in this regard. In no case should the existing woodlots
of native species be cleared to make way for the exotics.