ECOLOGY OF FIRE IN GRASSLANDS
243
in Iceland (Fridriksaon, 1963), Kansas (Gay and Dwyer, 1966), and
California (Sarnpmn, 1944). According to Blaisdell (1953) this waa also
true of the burns he studied in eastern Idttho, but Pochanec el d. (1954)
state that the grass in this region cures earlier on burned areas, In
Louisiana too it has been observed that graas dries first on burned
areas (Campbell, 1945).
In tropic climates where dormancy is correlated with a &y rather
than a cold season, g r m may appear with surprising promptness after
a fire. The new foliage of Arietida stricta in Florida may appear within
3 days (Lewis, 1964), Andropogon schirenais and dltmocybium cerisiiforme sprout within 6-10 days in Nigeria (Hopkins, 1963), and Trachypogon app. appear in 9 days in Venezuela (Blydenstein, 1963).
Alterations of phenology , with new shoots commonly developing
earlier or later on burned are=, and then sometimes remaining green
longer, complicate sampling where contiguous burned and unburned
areas are being compared from the standpoint of chemical composition
or moisture contents. Meaningful comparisons would seem possible only
by constructing curves to show seasonal progressions in burned and
unburned tracts.
E. VIGOR (SIZE)
Fire has varied effects on the subsequent size of the vegetative organs
of herbs. In California grasslands annual species of Avena, Brmw,
E~odium and Fe&ca have been reported as noticeably smaller in the
first post-burn season (Hart et d., 1932: Hervey, 1949). Among annuals
such a response must be attributed to changed environment, whereas
among perennials it may be due in part at least to hsat injury.
In New Zealand a severe burn resulted in a drastic shortening of the
leavea of Chionochlac rig&, with approximately three years being required for a return to normal length (O’Connor and Powell, 1963). But
this fire also greatly increased the number of tillers and production wm
but slightly reduced. Mark (1965~) reports different effects of fire on
the same species. Presumably in consequence of lower burning temperatures, foliage was 36% longer than normal in the first post-burn
season, and still slightly longer than normal in the second. Five years
later a similar burn had almost as much stimulative effect, but a re-burn
only three years later resulted in little stimulation. In another New
Zealand grass, Danthoniafluvescens, fire reduced its coverage by a third
(Barker, 1953). Still elsewhere in New Zealand the leaves of Festuca
novae-zelandiae that appeared after a fire were only half normal size
(Sewell, 1948).
In eastern Idaho the shoots of perennial grasses were dwarfed in the
first (only) post-burn season, but this was more than compensated by
243
in Iceland (Fridriksaon, 1963), Kansas (Gay and Dwyer, 1966), and
California (Sarnpmn, 1944). According to Blaisdell (1953) this waa also
true of the burns he studied in eastern Idttho, but Pochanec el d. (1954)
state that the grass in this region cures earlier on burned areas, In
Louisiana too it has been observed that graas dries first on burned
areas (Campbell, 1945).
In tropic climates where dormancy is correlated with a &y rather
than a cold season, g r m may appear with surprising promptness after
a fire. The new foliage of Arietida stricta in Florida may appear within
3 days (Lewis, 1964), Andropogon schirenais and dltmocybium cerisiiforme sprout within 6-10 days in Nigeria (Hopkins, 1963), and Trachypogon app. appear in 9 days in Venezuela (Blydenstein, 1963).
Alterations of phenology , with new shoots commonly developing
earlier or later on burned are=, and then sometimes remaining green
longer, complicate sampling where contiguous burned and unburned
areas are being compared from the standpoint of chemical composition
or moisture contents. Meaningful comparisons would seem possible only
by constructing curves to show seasonal progressions in burned and
unburned tracts.
E. VIGOR (SIZE)
Fire has varied effects on the subsequent size of the vegetative organs
of herbs. In California grasslands annual species of Avena, Brmw,
E~odium and Fe&ca have been reported as noticeably smaller in the
first post-burn season (Hart et d., 1932: Hervey, 1949). Among annuals
such a response must be attributed to changed environment, whereas
among perennials it may be due in part at least to hsat injury.
In New Zealand a severe burn resulted in a drastic shortening of the
leavea of Chionochlac rig&, with approximately three years being required for a return to normal length (O’Connor and Powell, 1963). But
this fire also greatly increased the number of tillers and production wm
but slightly reduced. Mark (1965~) reports different effects of fire on
the same species. Presumably in consequence of lower burning temperatures, foliage was 36% longer than normal in the first post-burn
season, and still slightly longer than normal in the second. Five years
later a similar burn had almost as much stimulative effect, but a re-burn
only three years later resulted in little stimulation. In another New
Zealand grass, Danthoniafluvescens, fire reduced its coverage by a third
(Barker, 1953). Still elsewhere in New Zealand the leaves of Festuca
novae-zelandiae that appeared after a fire were only half normal size
(Sewell, 1948).
In eastern Idaho the shoots of perennial grasses were dwarfed in the
first (only) post-burn season, but this was more than compensated by