Tussock regrowth after grazing: Intercalary meristem and axillary bud activity of tillers of Agropyron desertorum
-
-
Authors: B. E. Olson, and J. H. Richards
Date: 1988
Journal: Oikos
Volume: 51
Number: 3
Pages: 374-382
Summary of Methods: Olson and Richards examined the regrowth of a tussock grass, Agropyron desertorum, after grazing by cattle in the cold-desert shrub steppe of Utah. On tussocks grazed before internode (culm) elongation, tiller relative regrowth rates were usually greater than on ungrazed tussocks for up to three weeks. Grazing during culm elongation usually reduced tiller relative growth rates, but stimulated the growth of axillary tillers. Grazing after the completion of internode elongation decreased tiller relative growth rates and did not stimulate axillary tiller production. Spring tillering may ameliorate some of the long-term effects of grazing during or after culm elongation when regrowth of grazed tillers is limited by the lack of intercalary meristem activity.
Article Summary / Main Points: None
Vegetation Types:
MLRA Ecoregions:
Agrovoc Control Words: Riparian zones Rangelands Wildlife
Article Review Type: Refereed
Article Type: Experimental Research
Keywords: tussock grass, agropyron desertorum, grazing, regrowth, tillers, culm elongation, intercalary meristem activity
Annotation: The native woody vegetation of the study area, in 1951, was mechanically removed. Agropyron desertorum was drill-seeded and remains the dominant species. Sheep grazed the site until the mid-1960s; cattle have been the domestic herbivore since then. The authors used an intensive grazing system with ten 8.5 ha paddocks. The system provided control of the time of grazing within 1-2 days. Cattle were rotated through the system for two 30 day cycles. Exclosures were used to control whether tussocks were grazed during the first cycle or the second cycle of the grazing system. Thus, the authors were able to monitor sets of tussocks grazed once at the pre-, early-, late-, and post-internode elongation developmental stage of tillers. With uniform grazing, all tillers were grazed to a similar height; with partial grazing, about 50% of the canopy was grazed. Heavy grazing left a 5-6 cm stubble height whereas moderate grazing left a 10-12 cm stubble height. Adjacent to grazed tussocks were ungrazed control tussocks that were located within a fenced exclosure.
-
Get article
Cite article with DOI
-