GRASSLAND FIRE EFFECTS ON BARBED-WIRE

Fire and its effects on rangeland plants, animals, soils, habitats, an d watersheds has been studied extensively. Few studies have been devot ed to fire effects on rangeland developments and no studies to our kno wledge have been done on the effects of fire on barbed wire, From fire records and a known fence age at the Cross Timbers Experimental Range near Stillwater, Okla., we were able to determine the effect of varyi ng fire frequencies on the breaking strength and zinc coating of tradi tional 2-point, double-stranded barbed wire. Samples from 4 burning fr equency treatments, 8 locations each, of either 4 or 5-wire fencing we re collected and stripped of their zinc coating for mass determination . Weight of zinc coating remaining on the wire was determined after be ing subjected to 0X, 1X, 2X, or 6X burn treatments over a 14-year peri od. A subset of 4 wires from 1X, 2X, and 6X burn treatments was tested for breaking strength. Photomicrographs and coating thickness measure ments were also taken on samples from 1X, 2X, and 6X burn treatments. All tests were compared with unused wire of the same lot that had been in storage since fence installation. For the 6X burn treatment, break ing strength of 5,160 Newtons (N) and zinc coating thickness of 18.5 m u m were equivalent to unused wire breaking strength and zinc coating (5,160 N, 16.6 mu m respectively). It appeared that repeated fires did not adversely affect the corrosion resistance or breaking strength, a nd therefore service life of relatively new barbed wire fence.