Bison selectivity and grazing response of little bluestem in tallgrass prairie
Issue Date
1995-01-01Keywords
bisonburning
Schizachyrium scoparium
Kansas
grazing experiments
regrowth
plant density
prairies
feeding preferences
Metadata
Show full item recordCitation
Pfeiffer, K. E., & Hartnett, D. C. (1995). Bison selectivity and grazing response of little bluestem in tallgrass prairie. Journal of Range Management, 48(1), 26-31.Publisher
Society for Range ManagementJournal
Journal of Range ManagementDOI
10.2307/4002500Additional Links
https://rangelands.org/Abstract
The perennial bunchgrass little bluestem (Schizachyrium scoparium [Michx.] Nash) was examined in a 5-yr study on tallgrass prairie to determine how fire influences its use by bison and its responses to grazing. On unburned prairie, bison grazed only 5% of the available little bluestem, selecting it only 30% as frequently as big bluestem, the dominant co-occurring species. On burned prairie, grazing frequency of little bluestem was over 3-fold greater and equal to that of its dominant neighbor. Grazing frequency of little bluestem was affected by plant size (basal area). On burned sites, plants of intermediate size classes were least abundant (< 10% of total) but were grazed most frequently (> 50%). Small plants were most abundant but were grazed least frequently. Density, tiller numbers, and basal area of little bluestem were significantly greater in annually burned compared to infrequently burned sites but were decreased by > 50% in grazed compared to ungrazed sites. Grazing shifted the population size distribution toward higher frequencies of smaller individuals (< 5 0 cm2 basal area), whereas burning increased the frequency of large (> 200 cm2 basal area) individuals. In unburned prairie, little bluestem accumulates a persistent clump of standing dead tillers that appear to serve as a physical deterrent to grazing. Although burning enhances its growth, it also removes its canopy of dead tillers exposing the plant to grazers. The shift in population structure toward a high frequency of smaller (and perhaps less drought- or grazing-tolerant) individuals may contribute to the decline of little bluestem populations under persistent grazing. Thus, plant growth form, population size structure, and fire interact to influence bison grazing patterns and responses of little bluestem to grazing on tallgrass prairie.Type
textArticle
Language
enISSN
0022-409Xae974a485f413a2113503eed53cd6c53
10.2307/4002500