wood
, the principal strengthening and nutrient-conducting
tissue
of
trees
and other plants and one of the most
abundant
and versatile natural materials. Produced by many botanical species, including both
gymnosperms
and
angiosperms
, wood is available in various colours and grain patterns. It is strong in relation to its weight, is insulating to
heat
and
electricity
, and has desirable
acoustic
properties. Furthermore, it imparts a feeling of “warmth” not possessed by competing materials such as metals or stone, and it is relatively easily worked. As a material, wood has been in service since humans appeared on Earth. Today, in spite of technological advancement and competition from
metals
,
plastics
,
cement
, and other materials, wood maintains a place in most of its traditional roles, and its serviceability is expanding through new uses. In addition to well-known products such as
lumber
, furniture, and
plywood
, wood is the raw material for wood-based panels,
pulp
and
paper
, and many chemical products. Finally, wood is still an important fuel in much of the world.
Production and consumption of wood
In
botanical
terms, wood is part of the system that conveys
water
and dissolved minerals from the roots to the rest of the
plant
, stores
food
created by
photosynthesis
, and furnishes mechanical support. It is produced by an estimated 25,000 to 30,000 species of plants, including herbaceous ones, though only 3,000 to 4,000 species produce wood that is suitable for use as a material. Wood-producing
forest
trees and other woody plants are of two categories:
gymnosperms
and
angiosperms
. Gymnosperms, or cone-bearing trees, produce
softwoods
, such as
pine
and
spruce
, and angiosperms produce temperate and tropical
hardwoods
, such as
oak
,
beech
,
teak
, and
balsa
. It should be noted that the distinction implied by
hardwood
and
softwood
is not true in all cases. Some hardwoods?e.g., balsa?are softer than some softwoods?e.g.,
yew
.
Wood is a material of great economic importance. It is found throughout the world and can be sustainably managed as a renewable resource?in contrast to
coal
, ores, and
petroleum
, which are gradually exhausted. By means of its harvesting in
forests
, its transportation, its processing in workshops and industries, and its trade and use, wood provides jobs and supports economic development and, in some countries, basic subsistence. Indicative of this importance is the continued high demand for wood and wood products.
On a weight basis, the
consumption
of wood exceeds by far that of other materials. More than half of roundwood (log) production is consumed as fuel, mainly in less-developed countries. Production of paper and paperboard has shown the most rapid increase among wood products; this trend is expected to continue as consumption per person in the less-developed countries approaches that in the developed nations. Rising world population is the driving force of increasing consumption of wood and consequent
deforestation
. The depletion of many forests, especially in the tropics, makes uncertain the provision of an adequate wood supply to satisfy the anticipated need. Efforts to stop the reduction of Earth’s forest cover and increase the productivity of existing forests, establishment of
extensive
reforestation programs and plantations of fast-growing
tree
species,
recycling
of paper, and improved utilization of wood through research could ease the problem of wood supply and help to lessen the environmental toll of the lumber
industry
.
Britannica Quiz
Building Blocks of Everyday Objects