SPATIAL VARIABILITY IN SEED PRODUCTION OF THE PERENNIAL BUNCHGRASS BOUTELOUA-GRACILIS (GRAMINEAE)

Citation
Dp. Coffin et Wk. Lauenroth, SPATIAL VARIABILITY IN SEED PRODUCTION OF THE PERENNIAL BUNCHGRASS BOUTELOUA-GRACILIS (GRAMINEAE), American journal of botany, 79(3), 1992, pp. 347-353
Citations number
42
Language
INGLESE
art.tipo
Article
Journal title
ISSN journal
0002-9122
Volume
79
Issue
3
Year of publication
1992
Pages
347 - 353
Database
ISI
SICI code
0002-9122(1992)79:3<347:SVISPO>2.0.ZU;2-C
Abstract
The effects of soil texture and grazing by cattle on the production of seeds of Bouteloua gracilis were evaluated for a semiarid grassland i n northeastern Colorado. Ten locations were chosen to represent the ra nge in soil textures and grazing intensities found at the Central Plai ns Experimental Range research site. Number of flowering culms, inflor escences and seeds, length of each flowering culm, total biomass of re productive structures (culms, inflorescences, and seeds), and basal ar ea were assessed for 96 B. gracilis plants at each location. Community -level estimates of density of flowering culms and density of viable s eeds were made for each location. Both soil texture and grazing by cat tle were important to spatial variability in seed production and other indicators of reproductive effort by B. gracilis. Grazing was importa nt in mediating effects of soil texture. On locations protected from g razing, soil texture had significant effects on seed production; the l argest number of seeds was produced on the coarsest-textured soil and the fewest number on the finest-textured soil. Relationships between s eed production and clay content and between seed production and other indicators of reproductive effort by B. gracilis were different for gr azed and ungrazed locations. Spatial variability in seed production of B. gracilis as a result of spatial variability in soil texture and gr azing may be important to the continued dominance of this species in t he presence of disturbances that vary in time and space.