Rangeland Ecology & Management

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EVALUATING THE EFFICACY OF INTENSIVE EARLY STOCKING IN MAINTENANCE OF THE FIRE-GRAZER INTERACTION
Author
Raynor, Edward J.
Hillhouse, Heidi
Schacht, Walt
Debinski, Diane
Miller, James R.
Publisher
Society for Range Management
Publication Year
2018
Body

The maintenance of a historic grassland disturbance, the fire-grazer interaction, through patch-burn grazing is a tool for maintaining heterogeneity in mesic grasslands. However, the efficacy of different grazing strategies for preserving or enhancing the utility of patch-burn grazing (PBG) management remains mostly untested. Season-long stocking (SLS) is the primary grazing strategy employed in PBG yet how a modified grazing regime such as intensive early stocking (IES) affects PBG is unknown. Stocking at twice the normal season-long rate for the first half of the season with no grazing during the last half, IES takes advantage of early summer high-quality forage and provides an ecosystem service in the form of invasive species control. If IES can reduce cover of invasive plants that inhibit fire spread to a higher degree than SLS, IES could be an excellent tool for conservation. To determine the efficacy of IES within PBG pastures to both 1) control an invasive plant and 2) maintain or enhance the utility of PBG, we evaluated tall fescue (Schedonorus phoenix) cover in IES pastures relative to SLS pastures and compared pasture heterogeneity (i.e., variance in vegetation structure) between IES and SLS pastures. Because tall fescue growing season overlaps with timing of prescribed spring burns, this grass creates a discontinuous fuel load and reduces fire spread in tallgrass prairie, thus inhibiting the fire-grazer interaction and PBG-driven pasture heterogeneity. We report on the usefulness of this grazing strategy in maintaining pasture heterogeneity in the Grand River Grasslands of southern Iowa and northern Missouri, where IES began in 2014. July vegetation structure and tall fescue cover collected among IES and SLS pastures revealed patch contrast (heterogeneity) of IES pastures reached SLS levels by 2016, whereas tall fescue cover in IES pastures was 18% lower than SLS by the end of the three-year PBG cycle.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Reno, NV