The effects of fire regime on legume reproduction in longleaf pine savannas: is a season selective?

Abstract

The biodiversity of fire-dependent ecosystems is increasingly threatened by habitat fragmentation and fire suppression. Reducing species loss requires that salient features of natural fire regimes be incorporated into managed regimes. Lightning-season burns have been emphasized as the critical component of disturbance regimes that maintain native biodiversity within endangered longleaf pine savannas, the most diverse plant community in North America. Over evolutionary time, lightning-season fire is thought to have exerted strong selection pressure on plant pollinator interaction, flower production, and seedling establishment. In this study, season of burn had no effect on pollination activity of native legumes. Contrary to the conventional paradigm, we found a wide range of reproductive responses among dominant legumes in response to the season of burn treatments, suggesting that a variable fire season, rather than a single season of burn, is appropriate to maintain a greater variety of native species. We propose that varying the components of fire regimes, rather than selecting a particular fire regime, is likely to be important to conserve biodiversity in this and other fire-dependent communities.

Range of Variability in Southern Coastal Plain Forests: Its Historical, Contemporary, and Future Role in Sustaining Biodiversity

“…First and foremost, biodiversity of the coastal plain is inextricably linked to the presence of frequent fire on the landscape. Maintaining frequent fire, varied in season based on changing management objectives for fire through time, is the most important management tool for sustaining biodiversity (Hiers et al 2000). Development and implementation of silvicultural approaches that sustain fuels necessary for frequent fire, but also maintain heterogeneity in stocking, size and age classes, and vigor including dead and dying trees, and that view forests with respect to maintaining legacies that provide continuity across harvests and throughout the landscape are critical for sustaining biodiversity (Lindenmayer et al 2006).…”

Ecological effects of prescribed fire season: a literature review and synthesis for managers

“…The variable response of understory species to fire season suggests that a heterogeneous fire regime (including variation in the seasonal timing of fire) may help conserve biodiversity (Hiers et al 2000). Rideout et al (2003) was attributed mainly to climatic differences.…”

The effects of fire and fragmentation on occurrence and flowering of a rare perennial plant

“…Yates and Ladd (2005) also observed increased reproduction and germination on roadsides and disturbed areas with little plant cover. Other studies have shown that fire stimulates flowering in pine rockland plants (Snyder et al 1990;Spier and Snyder 1998;Liu et al 2005b;Cardel and Koptur 2010), but for some species in other firedependent ecosystems, reproduction is not strictly fire-dependent (Wrobleski and Kauffman 2003;Hiers et al 2000;Borchert and Tyler 2009), and reproduction in years without fire plays an important role in The percent of these plots that were in an open area was estimated by plots that produced flowers that were in an open area over the total number of plots that produced flowers per site Plant Ecol (2011) 212:1057-1067 1065 maintenance of the species in the ecosystem (Hiers et al 2000). The effects of fire can also be overridden by local environmental heterogeneity, herbivory, or other factors (Harrod and Halpern 2009).…”

“…Some plant species produce more flowers and fruit after fire (Koptur 2006;Liu et al 2005a; Moreno and Oechel 1991). Although increased reproduction may result from greater light, soil moisture, and nutrient availability after fire (Whelan 1995;Wrobleski and Kauffman 2003), some plants produce flowers in years without fires; this reproduction is also of great importance to plant population viability (Hiers et al 2000;Wrobleski and Kauffman 2003;Borchert and Tyler 2009).…”