LITTER PRODUCTION I N FORESTS O F THE WORLD
103
The harvesting of present edible fungal growth is still inefficient and
haphazard. Smith (1958) notes that conifer forests and plantations of
Michigan, U.S.A., each year “burst with great quantities of relatively
few species of Boletus”. He suggests that lumber companies could
harvest the fungus crop as a means of paying taxes and other costs
while the trees are growing to commercial size.
Glesinger (1949), in a popular account entitled “The Coming Age of
Wood”, points out that the cellulose in wood wastes is capable of being
used not only as natural fibre, but as reconstituted cellulose in rayon
and plastics, and as raw material for hydrolysis to sugar. The sugar can
then be used to produce alcohol, high-protein yeast fodder, and a
variety of other useful products. Presumably the cellulose in litter
materials could also be so employed, though not as economically. It
seems likely that the lignin in wood waste and litter, like the cellulose,
can eventually become the raw material for a wide range of chemical
conversions, whose industrial importance will increase greatly as
reserves of coal and oil dwindle and demands for industrial raw materials
grow. Brauns and Brauns (1960, pp. 742-9), in their book on lignin
chemistry, point out that this substance is already used (though not
on a large scale, in proportion to its availability) in the production of
vanillin, plastics, ion-exchange resins, soil stabilizers, fertilizers, rubber
reinforcing agents, tanning agents, stabilizers for asphalt emulsions,
dispersants in oil-well drilling and other processes, and in ceramic
processing. New and large-scale industrial uses will undoubtedly appear
as the chemistry of lignin is further investigated. Other litter components beside cellulose and lignin may have industrial potential, the
oils and resins in Gymnosperm litter being perhaps the most probable
example.
If litter is to be utilized commercially, harvest methods will need to
be developed. Mechanized raking might serve in well-spaced plantations
with closed canopy and little ground flora. In other types of forest some
form of vacuum collection might be devised, since the litter material is
loose and unattached. Should litter utilization become economic, it
will inevitably involve replacement of the nutrient elements present in
the organic debris harvested. Nitrogen is probably the most important
of these, but phosphorus, potassium and calcium will also be significant
(Tamm, 1958). In time, nitrogenous fertilizers may be synthesized from
atmospheric nitrogen a t low cost, through the use of small nuclear
reactors which could provide local sources of power in forested areas.
The increasing use of human excretory wastes as fertilizers through
sewage processing may also enable a low cost return of nitrogen,
phosphorus, potassium and other nutrients to forested areas, especially since the costly sterilization needed for the agricultural use of
103
The harvesting of present edible fungal growth is still inefficient and
haphazard. Smith (1958) notes that conifer forests and plantations of
Michigan, U.S.A., each year “burst with great quantities of relatively
few species of Boletus”. He suggests that lumber companies could
harvest the fungus crop as a means of paying taxes and other costs
while the trees are growing to commercial size.
Glesinger (1949), in a popular account entitled “The Coming Age of
Wood”, points out that the cellulose in wood wastes is capable of being
used not only as natural fibre, but as reconstituted cellulose in rayon
and plastics, and as raw material for hydrolysis to sugar. The sugar can
then be used to produce alcohol, high-protein yeast fodder, and a
variety of other useful products. Presumably the cellulose in litter
materials could also be so employed, though not as economically. It
seems likely that the lignin in wood waste and litter, like the cellulose,
can eventually become the raw material for a wide range of chemical
conversions, whose industrial importance will increase greatly as
reserves of coal and oil dwindle and demands for industrial raw materials
grow. Brauns and Brauns (1960, pp. 742-9), in their book on lignin
chemistry, point out that this substance is already used (though not
on a large scale, in proportion to its availability) in the production of
vanillin, plastics, ion-exchange resins, soil stabilizers, fertilizers, rubber
reinforcing agents, tanning agents, stabilizers for asphalt emulsions,
dispersants in oil-well drilling and other processes, and in ceramic
processing. New and large-scale industrial uses will undoubtedly appear
as the chemistry of lignin is further investigated. Other litter components beside cellulose and lignin may have industrial potential, the
oils and resins in Gymnosperm litter being perhaps the most probable
example.
If litter is to be utilized commercially, harvest methods will need to
be developed. Mechanized raking might serve in well-spaced plantations
with closed canopy and little ground flora. In other types of forest some
form of vacuum collection might be devised, since the litter material is
loose and unattached. Should litter utilization become economic, it
will inevitably involve replacement of the nutrient elements present in
the organic debris harvested. Nitrogen is probably the most important
of these, but phosphorus, potassium and calcium will also be significant
(Tamm, 1958). In time, nitrogenous fertilizers may be synthesized from
atmospheric nitrogen a t low cost, through the use of small nuclear
reactors which could provide local sources of power in forested areas.
The increasing use of human excretory wastes as fertilizers through
sewage processing may also enable a low cost return of nitrogen,
phosphorus, potassium and other nutrients to forested areas, especially since the costly sterilization needed for the agricultural use of