ECOMWY OF IIlFCE LN OFCASSLANDS
237
killed Uanthonia flavmcens in a habitat where it had been dominant
(Barker, 1953).
Owing perhaps to ecotypic differences, t'he response of a species t n
fire may be different in different geographic areas. For example, Poa
secunda was injured temporarily after a fire in eastern Idaho, but then
quickly recovered and showed stimulation lasting over 15 yoars (Blaisdell, 1953). The same species in northeastern California declined progressively after a fire and had disappeared completely by the fifth
post-burn season (Countryman and Cornelius, 1957).
Indirectly fire may result in damage to herbs by hastening their
development in spring so that they are for a time more susceptible to
drought than are the retarded shoots of unburned plants (Campbell,
1945; Cook, 1939; Scott, 1951; West, 1965).
B. CHEMICAL COMPOSITION
The attractiveness to grazing animals of new grass appearing after a
fire, together with the superior gains made by livestock on such forage
(Greene, 1929; Southwell and Hughes, 1965; Hilmon and Hughes, 1965)
direct interest to possible changes in the nutritive quality of the plant
shoots. One report from Louisiancr (Campbell, 1946) and two from
Missouri (Koelling and Kucera, 1065; Kucera and Ehrenreich, 1962)
state that burning had no significant effect on the quality of the new
foliage as judged from chemical analyses, but most published data
(Table 11) reveal little to much improvement. Indigestible material is
usually reduced, with foods and minerals usually increased.
Interpretation of the plant analyses in Table I1 must. be tempered
by two factors that might easily escape attention. First, increases or
decreases may be determined by the season of burning. For example,
late spdng burning of Andropyon swpar&a grassland in Kansas increased protein content, whereas burning at other seaaons decreased it
(Aldous, 1934). Second, where fire alters dry-matter production per
unit land surface (or per plant), the gains or losses expressed aa a per
cent of dry matter may be reversed when expressed on a land-area
(or plant) basis. Thus, the percentage protein in the shoots of certain
Australian grassea was higher after a fire, but the stand of grass was
thinned RO much that there was lee8 total protein on a land-area basis
(Smith, 1 SBO), and in Missouri the reduced mh content of shoots appears
to be a ronuequence of greater dry-matter production by the plants
rather than reduced mineral uptake per unit of land area (Koelling and
Kucera, 1965).
It would be an easy assumption that inoreased uptake of nutrients
or increased vigor of plants after a fire was a direct result of a sudden
increase in available nutrients derived from ash of the fire. Supporting
237
killed Uanthonia flavmcens in a habitat where it had been dominant
(Barker, 1953).
Owing perhaps to ecotypic differences, t'he response of a species t n
fire may be different in different geographic areas. For example, Poa
secunda was injured temporarily after a fire in eastern Idaho, but then
quickly recovered and showed stimulation lasting over 15 yoars (Blaisdell, 1953). The same species in northeastern California declined progressively after a fire and had disappeared completely by the fifth
post-burn season (Countryman and Cornelius, 1957).
Indirectly fire may result in damage to herbs by hastening their
development in spring so that they are for a time more susceptible to
drought than are the retarded shoots of unburned plants (Campbell,
1945; Cook, 1939; Scott, 1951; West, 1965).
B. CHEMICAL COMPOSITION
The attractiveness to grazing animals of new grass appearing after a
fire, together with the superior gains made by livestock on such forage
(Greene, 1929; Southwell and Hughes, 1965; Hilmon and Hughes, 1965)
direct interest to possible changes in the nutritive quality of the plant
shoots. One report from Louisiancr (Campbell, 1946) and two from
Missouri (Koelling and Kucera, 1065; Kucera and Ehrenreich, 1962)
state that burning had no significant effect on the quality of the new
foliage as judged from chemical analyses, but most published data
(Table 11) reveal little to much improvement. Indigestible material is
usually reduced, with foods and minerals usually increased.
Interpretation of the plant analyses in Table I1 must. be tempered
by two factors that might easily escape attention. First, increases or
decreases may be determined by the season of burning. For example,
late spdng burning of Andropyon swpar&a grassland in Kansas increased protein content, whereas burning at other seaaons decreased it
(Aldous, 1934). Second, where fire alters dry-matter production per
unit land surface (or per plant), the gains or losses expressed aa a per
cent of dry matter may be reversed when expressed on a land-area
(or plant) basis. Thus, the percentage protein in the shoots of certain
Australian grassea was higher after a fire, but the stand of grass was
thinned RO much that there was lee8 total protein on a land-area basis
(Smith, 1 SBO), and in Missouri the reduced mh content of shoots appears
to be a ronuequence of greater dry-matter production by the plants
rather than reduced mineral uptake per unit of land area (Koelling and
Kucera, 1965).
It would be an easy assumption that inoreased uptake of nutrients
or increased vigor of plants after a fire was a direct result of a sudden
increase in available nutrients derived from ash of the fire. Supporting