LITTER PRODUCTION IN FORESTS OF THE WORLD
149
derived which is applicable within species or taxonomic groups. It is
likely that amount of foliage will be more easily correlated with current
growth than with mean growth over the lifetime of a tree or forest.
Table XX lists strdies from which leaf production can be compared
to non-lea€ and total net production. If below-ground production figures
were lacking, a conversion factor of 0.2 times above-ground production
was employed to estimate them (Bray, 1963). A value of 12.9 t/ha for
stem plus below-ground production in Picea abies (Moller, 1945) was
separated into 10.4 and 2.5.t/ha respectively by using the average ratio
of stem to below-ground production in six Cool Temperate stands for
which observed values were available. (The stand of Betula verrucosa
on deep peat, sampled by Ovington and Madgwick (1959), was excluded
because it fielded a widely aberrant ratio.) It is clear from Table XX
that stem production (4.3 to 19-2 t/ha/yr) exceeds leaf production
(1.5 to 9.5 t/ha/yr), which in turn exceeds root production (1.2 to
2.9 t/ha/yr). Total annual production ranges from 7.8 t/ha in a Japanese
stand of Populm davidiana to 31.5 t/ha in a Congo forest.
A summary of relative litter production by climatic zones together
with various indexes of net total production is shown in Table XXI,
with Arctic-Alpine values being taken as unity in the f i s t three columns,
and Cold Temperate values in the last three columns. Bole production
was estimated from data in Paterson (1956) by determining the range
of C W (climate-vegetation-productivity) indexes for the climatic areas
of the stands summarized in Table IV from Tables 16, 17, 18, 19, 20
and 21 of Paterson as follows: Arctic-Alpine,, CVP: 25-100; Cold
Temperate, CVP: 100-500; Warm Temperate, CVP: 500-ca 3 000;
Equatorial, CVP: 3 000-20 000. Mean bole production in m3/ha calculated from Table XXII of Paterson was 2.0 for Arctic-Alpine, 5.5 for
Cold Temperate, 10-3 for Warm Temperate and 14.0 for Equatorial
forest areas. Relative bole production for the four climatic areas was
1 to 2.7 to 5-1 to 7.0, which was similar to the ratios for leaf litter of 1 to
3.6 to 5.1 to 9.7, although the relative range for bole production from
Arctic-Alpine to Equatorial forest was less than the range for leaf
litter production. The other relative production values summarized
in Table XXI are for Cold Temperate and Equatorial forest only, and
show a range of from 2.3 to 3.0 (mean 2.6) for Equatorial forest over
Cold Temperate values. Litter production of Equatorial forest varies
from 2.7 (leaf litter) to 3.1 (total litter) times Cold Temperate litter production, which indicated that the use of litter data t o predict total production would slightly overestimate the difference in production between
Cold Temperate and Equatorial forest. The ratios in Tables XX and XXI
indicate that Equatorial forest is around two to three times as productive
as Cold Temperate forest ; that Warm Temperate forest productivity
F
C.E.R.
149
derived which is applicable within species or taxonomic groups. It is
likely that amount of foliage will be more easily correlated with current
growth than with mean growth over the lifetime of a tree or forest.
Table XX lists strdies from which leaf production can be compared
to non-lea€ and total net production. If below-ground production figures
were lacking, a conversion factor of 0.2 times above-ground production
was employed to estimate them (Bray, 1963). A value of 12.9 t/ha for
stem plus below-ground production in Picea abies (Moller, 1945) was
separated into 10.4 and 2.5.t/ha respectively by using the average ratio
of stem to below-ground production in six Cool Temperate stands for
which observed values were available. (The stand of Betula verrucosa
on deep peat, sampled by Ovington and Madgwick (1959), was excluded
because it fielded a widely aberrant ratio.) It is clear from Table XX
that stem production (4.3 to 19-2 t/ha/yr) exceeds leaf production
(1.5 to 9.5 t/ha/yr), which in turn exceeds root production (1.2 to
2.9 t/ha/yr). Total annual production ranges from 7.8 t/ha in a Japanese
stand of Populm davidiana to 31.5 t/ha in a Congo forest.
A summary of relative litter production by climatic zones together
with various indexes of net total production is shown in Table XXI,
with Arctic-Alpine values being taken as unity in the f i s t three columns,
and Cold Temperate values in the last three columns. Bole production
was estimated from data in Paterson (1956) by determining the range
of C W (climate-vegetation-productivity) indexes for the climatic areas
of the stands summarized in Table IV from Tables 16, 17, 18, 19, 20
and 21 of Paterson as follows: Arctic-Alpine,, CVP: 25-100; Cold
Temperate, CVP: 100-500; Warm Temperate, CVP: 500-ca 3 000;
Equatorial, CVP: 3 000-20 000. Mean bole production in m3/ha calculated from Table XXII of Paterson was 2.0 for Arctic-Alpine, 5.5 for
Cold Temperate, 10-3 for Warm Temperate and 14.0 for Equatorial
forest areas. Relative bole production for the four climatic areas was
1 to 2.7 to 5-1 to 7.0, which was similar to the ratios for leaf litter of 1 to
3.6 to 5.1 to 9.7, although the relative range for bole production from
Arctic-Alpine to Equatorial forest was less than the range for leaf
litter production. The other relative production values summarized
in Table XXI are for Cold Temperate and Equatorial forest only, and
show a range of from 2.3 to 3.0 (mean 2.6) for Equatorial forest over
Cold Temperate values. Litter production of Equatorial forest varies
from 2.7 (leaf litter) to 3.1 (total litter) times Cold Temperate litter production, which indicated that the use of litter data t o predict total production would slightly overestimate the difference in production between
Cold Temperate and Equatorial forest. The ratios in Tables XX and XXI
indicate that Equatorial forest is around two to three times as productive
as Cold Temperate forest ; that Warm Temperate forest productivity
F
C.E.R.