forestry, the management of forest lands for
wood, water, wildlife, forage, and recreation.
Because the major economic importance of the
forest lies in wood and wood products, forestry
has been chiefly concerned with timber management,
especially reforestation, maintenance of the
extant forest stands at prime condition, and
fire control. Silviculture is the name usually
given to this manipulation of the forest for
human purposes.It is the chief goal of forestry
to devise methods for felling trees that provide
for the growth of a new forest crop and to ensure
that adequate seed of desirable species is shed
onto the ground and that conditions are optimal
for seed germination and the survival of saplings.
The basic rule of timber management is sustained
yield; that is, to cut each year a volume of
timber no greater than the volume of wood that
grew during that year on standing trees.
Desirable timber species are usually those
of the native climax vegetation (see ecology)
that can perpetuate themselves by natural succession,
although at times (intentionally or unintentionally)
a forest may not represent the climax vegetation—such
as the pine of the SE United States, which grows
faster than, and has replaced, the hardwoods
destroyed by fire and logging. The Douglas fir
of Western forests is encouraged because it
is more valuable than the climax vegetation
of mixed conifers that tends to establish itself
in the absence of human intervention. Planting
trees of different sizes (either because of
species or of age) prevents crowding and insures
maximal growth for the given area. Extermination
of diseases and insect pests is standard forestry
practice.
The management of woodland to provide timber for
sale. New areas are ploughed and planted while
cut-over forests may be replanted. The trees are
given fertilizer and are protected from pests,
diseases, and major fires. They are felled when
the trees are mature, when there is overcrowding,
or when the trees die. Most forests in Britain
are planted with fast-growing, softwood conifers
although hardwoods may be planted at the periphery
to soften the environmental impact.
