Viewpoint: The response of central North American prairies to seasonal fire

Abstract

Natural fires on the native grasslands of Oklahoma and Kansas were important for maintaining ecosystem structure and function. Today, land managers largely conduct prescribed fires in the late dormant season or they do not burn at all. When wildfires occur in other seasons, conventional wisdom assumes that desirable forage species for cattle are compromised. This assumption is based on a few fire studies limited in breadth and scope. To address this, we revisited numerous data sets to quantify the influence of season of fire on plant production and species composition. Research demonstrates that tallgrass prairie burned in the late spring starts growth earlier, grows more rapidly early in the growing season, and produces more tall grasses than unburned prairie. We contrast this response with the literature reporting the results of fire occurring in other seasons. Fire effects vary with fire frequency, fire-return interval, grazing history, herbicide use, successional stage, weather pattern, edaphic features, and topography. Our review of research suggests that a variety of responses to fire season are possible and rules-of-thumb that generalize responses are misleading. Most of the research on fire also does not report the interaction of fire and herbivory. Thus it is difficult to judge the influence of fire within the context of herbivory. Results from ongoing research suggest that the prairie is far more resilient under the interaction of fire and herbivory than earlier believed.Key Words: native grasslands, prescribed fire, fire frequency, fire interactions, fire return interval, wildfire Fire on the native grasslands of Oklahoma and Kansas, as in other portions of the Great Plains, provided a portion of the energy required for the development and maintenance of these grasslands (Bragg 1995). Natural fire was possible from late in the growing season before the first killing freeze in autumn, through the dormant season (i.e., after the first freeze in autumn and before the last freeze in spring), and up to several weeks after the last freeze in spring (Bragg 1982, Higgins 1986. The timing of fires with respect to season or within a season potentially influences plant species composition and productivity, and therefore influences rangeland management in the modern landscape. In this paper we demonstrate that a variety of plant species composition and production responses to season of fire are possible, and that prairie is far more resilient to burning in any season than is accepted commonly by conventional wisdom.Prescribed fire for livestock management in the grasslands of Oklahoma and Kansas is usually intended to enhance forage quality for cattle. Fires conducted early in the freeze-free period of the spring, traditionally referred to as late spring, coincide with resumption of active growth of warm-season grasses following winter dormancy. Late spring burning has been recommended for optimum cattle production (Launchbaugh and Owensby 1978). Fires conducted in winter or early spring are intended to e...

Replacing Hay-mowing with Prescribed Fire Restores Species Diversity and Conservation Value in a Tallgrass Prairie Sampled Thrice: A 59-Year Study

“…In the Willamette Valley, fire application is often pushed to the latter portion of the seasonal burn window to allow for full maturation and senescence of many high fidelity prairie and savanna herbaceous species that are still setting seed in September and October, such as Perideridia montana (common yampah), Symphiotrichum hallii (Hall's aster), Sericocarpus rigidus (Columbian white-top aster) and Pyrrocoma racemosa (clustered goldenweed). Land managers and researchers in the central U.S. tallgrass prairie have found that burning at different times can select for vastly different vegetation communities (Engle 2000, Engle andBidwell 2001). In (Bidwell et al 1990, Bidwell andEngle 1992), fire frequency (Blair 1997, Emery andGross 2004) and topography (Abrams et al 1986).…”

“…Many native grassland species have been found to benefit from fire, but only when it is applied during a particular season and paired with other restoration treatments (herbicide, mowing, native seeding) (Engle and Bidwell 2001, Suding and Gross 2006, Brudvig et al 2007, Simmons et al 2007, Stanley et al 2011). Because fire alone can also benefit several non-native invasive species, the current restoration challenge in many fire-adapted systems involves creating habitat for native prairie species while excluding or prohibiting invasion by non-natives.…”

Population and clonal level responses of a perennial grass following fire in the northern Chihuahuan Desert

“…Resprouting dynamics of perennial grasses are inXuenced by variation in Wre regime characteristics, including intensity (Engle and Bidwell 2001). In turn, Wre intensity is determined by fuel characteristics (Byram 1959;Alexander 1982), such as perennial grass abundance (Rossiter et al 2003) and the depth and dryness of soil organic matter or litter which inXuences heat penetration into soil and, thus, the amount of damage to bud banks.…”

Fire and grazing in a mesic tallgrass prairie: impacts on plant species and functional traits

“…While species composition differs in burned and grazed grasslands, these disturbances may be selecting for similar traits that are distributed among different species. However, the effects of grazing and fire on the abundance of plant functional traits may differ depending on both the frequency and the intensity of burns and grazing (Engle and Bidwell 2001, Briggs et al 2002, Heisler et al 2003. Changes in the fire regime can have strong effects on the species and trait composition of plant communities (Pausas 1999, Franklin et al 2001, Kahmen and Poschlod 2008.…”