Vegetation response to late growing-season wildfire on Nebraska Sandhills rangeland.

Abstract

This study examined the effects of late growing-season (September) wildfire on the subsequent production and species composition of upland Nebraska Sandhills prairie vegetation. Three paired-plots (burn and control), 0.5 ha in size were established in 1995 on sands range sites on each of 3 replications in west-central Nebraska. Soil temperature data were collected the following growing season and herbage standing crop and species composition data were collected for 3 growing seasons following the burn. During March through May of the 1996 growing season, soil temperature in the burn treatment was an average of 1.6 degrees C higher at both 15 and 30 cm depths compared to the control (P < 0.05). This small increase in spring soil temperature under the burn treatment did not appear to result in earlier growth or to increase herbage standing crop in May. Total herbage standing crop in August averaged 143, 142, and 185 g m-2 in 1996, 1997, and 1998, respectively, and did not differ between the burn treatment and control (P > 0.05). Little bluestem [Schizchyrium scoparium (Michx.) Nash] was the species most adversely affected by burning. Percentage composition by weight of little bluestem in August 1996 averaged 8% under the burn treatment compared to 47% in the control. Other species and species groups, however, were more abundant in burned plots, thus offsetting the lesser amounts of little bluestem. Little bluestem exhibited a marked recovery during the second and third growing seasons after the burn. During the third growing season, percent composition of little bluestem averaged 46% and was not different between treatments (P > 0.05). Forbs were more abundant under the burn treatment compared to the control only during the first growing season following the burn (P < 0.05).

DOI:10.2458/azu_jrm_v53i4_volesky