Grasslands of the World.pdf - Disasters and Conflicts - UNEP

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Grasslands of the world
Plate 6.19
Prescribed burn to control aspen growth on the mixed -grass of the Wolverine
Prairie Farm Rehabilitation Area, Saskatchewan, Canada.
Rangeland burning
Fire is another useful tool in managing Great Plains grassland (Wright, 1974,
1978; Wright and Bailey, 1982). Vallentine (1989) lists 18 separate objectives in
rangeland burning but suggests that there are three main reasons to burn: 1. To
kill or suppress undesirable brush plants (Plate 6.19). 2. To prevent invasion of
inferior species in the understorey. 3. To increase forage production and thus
grazing capacity .
Especially in tall-grass prairie , prescribed burning is often used to reduce
old growth and stimulate new, more palatable growth (Anderson, Smith and
Owensby, 1970; McMurphy and Anderson, 1965; Smith and Owensby, 1972).
Wright (1978) suggested that burning in tall-grass vegetation increased palatability,
suppressed encroachment of trees and shrubs and reduced competition
from cool-season plants. However, timing of the burning is very important.
Cool-season grasses are detrimentally affected by spring burning (Hensel, 1923;
Wright, 1978). Spring burning tends to increase summer gains of cattle , but
gains may not hold up into the autumn (Anderson, Smith and Owensby, 1970;
Vallentine, 1989). Late winter burning may initiate spring growth two to three
weeks earlier than in the absence of burning (Ehrenreich and Aikman, 1963).
Development of grasslands
Grasslands are very dynamic, both spatially and temporally (Dix, 1964; Sims,
1988). Consequently, different authors have considered different factors as
MAE ELSINGER