ECOLOGY OF FIRE IN GRASSLANDS
267
in forest, hiimirrp;. The nutrient content of the soil is measurably incraancd only where hurnit~g inweawn tho proportion of legumes in the
community and ao raiNeR the N content indirectly. Soil pH is chwacteristically raised slightly, but it remains in the slightly acid range and
likewise seems unimportant to vegetation. Post-burn microclimate may
favor frost damage to seedlings, especially since it often hastens spring
germination.
Although the majority of perennial herbs readily send up new shoota
following fire, the composition of both plant and animal communities
can be materially altered. If perennial plants have already started
growth at the time of the fire, or if the perennating buds are at or near
the soil surface, the plants may be injured if not killed by burning. The
density of annuals can be drastically but only temporarily reduced by
a fire coming just before seed cast. Whereas some perennials are killed,
and others are essentially unaffected by fire, a great many are conspicuously stimulated. Among the last group, flowering activity is enhanced, with inflorescences much taller although vegetative shoots are
commonly reduced, these effects persist for 2-12 or more years. The
stimulation may be most pronounced during the first post-burn season
or suppressed until the second. The cause of the stimulation is as yet
quite obscure, but seems associated with the removal of litter by the
fire. The production of herbaceous vegetation may be increased or
reduced in consequence of burning, the latter result often being msociated with an inopportune timing of the fire in relation to phenology,
or with a very dry climate. Protein and mineral contents of post-burn
grass shoots are higher EO the herbage is much more nutritious for
animals. Seedlings often appear in abnormal numbers after a grassland fire.
REFERENOES
Acocka, J. P. H. (1966). Karoo vegetation relation to the development of deuerta.
In “Ecological Studiea in Southern Africa”, 100-112 (D. H. Davis, ed.).
W. Junk, Netherlands.
Adams, F., Ewing, P. A. and Huberty, M. R. (1947). Hydrologic aepeots of
burning brush and woodland-grw rangea i n Cdifornia. pp. 84. Cel. Div.
Forestry, Sacramento.
Ahlgren. I. F. and Ahlgren. C. E. (1960). Bot. Rev. 26.483-636. Ecological effecta
of forest firm.
Aikman, J. M. (1965). lowr A d . SCa. Pvoc. 63, 63-62. Burning in the management of prairie in Iowa.
Albrecht, W. A. (1946). Sci. Monthly 60, 347-362. Discrimination i n food selection
by animals.
on Kenees blueatem paetures.
Aldom, A. E. (1984). Kana. A p k . Exp. I%. Tech. BUU. 88,66. Effect of burning
267
in forest, hiimirrp;. The nutrient content of the soil is measurably incraancd only where hurnit~g inweawn tho proportion of legumes in the
community and ao raiNeR the N content indirectly. Soil pH is chwacteristically raised slightly, but it remains in the slightly acid range and
likewise seems unimportant to vegetation. Post-burn microclimate may
favor frost damage to seedlings, especially since it often hastens spring
germination.
Although the majority of perennial herbs readily send up new shoota
following fire, the composition of both plant and animal communities
can be materially altered. If perennial plants have already started
growth at the time of the fire, or if the perennating buds are at or near
the soil surface, the plants may be injured if not killed by burning. The
density of annuals can be drastically but only temporarily reduced by
a fire coming just before seed cast. Whereas some perennials are killed,
and others are essentially unaffected by fire, a great many are conspicuously stimulated. Among the last group, flowering activity is enhanced, with inflorescences much taller although vegetative shoots are
commonly reduced, these effects persist for 2-12 or more years. The
stimulation may be most pronounced during the first post-burn season
or suppressed until the second. The cause of the stimulation is as yet
quite obscure, but seems associated with the removal of litter by the
fire. The production of herbaceous vegetation may be increased or
reduced in consequence of burning, the latter result often being msociated with an inopportune timing of the fire in relation to phenology,
or with a very dry climate. Protein and mineral contents of post-burn
grass shoots are higher EO the herbage is much more nutritious for
animals. Seedlings often appear in abnormal numbers after a grassland fire.
REFERENOES
Acocka, J. P. H. (1966). Karoo vegetation relation to the development of deuerta.
In “Ecological Studiea in Southern Africa”, 100-112 (D. H. Davis, ed.).
W. Junk, Netherlands.
Adams, F., Ewing, P. A. and Huberty, M. R. (1947). Hydrologic aepeots of
burning brush and woodland-grw rangea i n Cdifornia. pp. 84. Cel. Div.
Forestry, Sacramento.
Ahlgren. I. F. and Ahlgren. C. E. (1960). Bot. Rev. 26.483-636. Ecological effecta
of forest firm.
Aikman, J. M. (1965). lowr A d . SCa. Pvoc. 63, 63-62. Burning in the management of prairie in Iowa.
Albrecht, W. A. (1946). Sci. Monthly 60, 347-362. Discrimination i n food selection
by animals.
on Kenees blueatem paetures.
Aldom, A. E. (1984). Kana. A p k . Exp. I%. Tech. BUU. 88,66. Effect of burning