LITTER PRODUCTION IN FORESTS O F THE WORLD
137
Missouri it is reported (Anon., 1960) that 60% of litter-fall occurs in
the 3 months from September to November.
In Cool Temperate forests seasonal patterns of litter-fall are often
striking (Fig. 4), with autumnal cooling leading to more or less complete
leaf-fall in deciduous species, as shown by the graphs for Dutch Quercus
and mixed Angiosperms, and for Finnish. Betula. I n New Hampshire
(Anon., 1932) it is reported that four-fifths of the mixed Angiosperm
litter-fall over the seven months June to December occurs in October.
Among Gymnosperms the pattern of deposition ranges from distinctly
seasonal, as in the various stands of Pinus silvestris represented in
Fig. 4, to irregular throughout the year, as is the case with Picea abies
in the stands shown. Chandler (1944) has noted however that Picea
abies planted in the north-eastern U.S.A. shows distinctly lower needlefall in spring and summer than at other times of year. In contrast
irregular collections by Lindberg and Norming (1943) in Sweden showed
high rates of needle-fall during late spring and early summer. Picea
sitchensis in Wales showed a rather irregular pattern of needle-fall
whether the total for the year was high (1946-47, with a very cold winter)
or low (1947-48). There was however a slight tendency for spring and
autumn maxima. Such a bimodal spring and autumn pattern of needlefall was more strongly exhibited by Japanese stands of Cryptmeria
japonica, Chumaecyparis obtusa and Pinus densijora.
TABLE XVII
Speci,fic Differences in Leaf Fall within an Upland Oak Porest in
Tennessee, U.S.A.
Leaf fall as per cent of total for
each species
Late
MidEarly
August
October December
Overstory
Quercw velutina
Quercus coccinea
Understory
Cornus sp.
Oxydendrum arboreum
Nyssa sylvatica
Quercw montana
Quercus falcata
Quercw stellata
Aeer rubrum
Carya sp.
Pinw echinata
Miscellaneous
Quercw alba
0
1
3
1
63
0
0
0
0
0
0
0
3
12
72
99
37
16
4
43
71
32
52
20
97
87
25
0
0
7 4*
96
57
29
68
48
80
~
~
~~~~
* Balance of 10% overwinters, 5 % falling by February and the remainder by April.
137
Missouri it is reported (Anon., 1960) that 60% of litter-fall occurs in
the 3 months from September to November.
In Cool Temperate forests seasonal patterns of litter-fall are often
striking (Fig. 4), with autumnal cooling leading to more or less complete
leaf-fall in deciduous species, as shown by the graphs for Dutch Quercus
and mixed Angiosperms, and for Finnish. Betula. I n New Hampshire
(Anon., 1932) it is reported that four-fifths of the mixed Angiosperm
litter-fall over the seven months June to December occurs in October.
Among Gymnosperms the pattern of deposition ranges from distinctly
seasonal, as in the various stands of Pinus silvestris represented in
Fig. 4, to irregular throughout the year, as is the case with Picea abies
in the stands shown. Chandler (1944) has noted however that Picea
abies planted in the north-eastern U.S.A. shows distinctly lower needlefall in spring and summer than at other times of year. In contrast
irregular collections by Lindberg and Norming (1943) in Sweden showed
high rates of needle-fall during late spring and early summer. Picea
sitchensis in Wales showed a rather irregular pattern of needle-fall
whether the total for the year was high (1946-47, with a very cold winter)
or low (1947-48). There was however a slight tendency for spring and
autumn maxima. Such a bimodal spring and autumn pattern of needlefall was more strongly exhibited by Japanese stands of Cryptmeria
japonica, Chumaecyparis obtusa and Pinus densijora.
TABLE XVII
Speci,fic Differences in Leaf Fall within an Upland Oak Porest in
Tennessee, U.S.A.
Leaf fall as per cent of total for
each species
Late
MidEarly
August
October December
Overstory
Quercw velutina
Quercus coccinea
Understory
Cornus sp.
Oxydendrum arboreum
Nyssa sylvatica
Quercw montana
Quercus falcata
Quercw stellata
Aeer rubrum
Carya sp.
Pinw echinata
Miscellaneous
Quercw alba
0
1
3
1
63
0
0
0
0
0
0
0
3
12
72
99
37
16
4
43
71
32
52
20
97
87
25
0
0
7 4*
96
57
29
68
48
80
~
~
~~~~
* Balance of 10% overwinters, 5 % falling by February and the remainder by April.