Fire history and vegetation data reveal ecological benefits of recent mixed-severity fires in the Cumberland Mountains, West Virginia, USA

Abstract

Background Without periodic fire, fire-adapted plant communities across the Central Hardwood Forest Region (CHF) in the USA have undergone significant changes in forest structure and species composition, most notably a decrease in oak regeneration and herbaceous diversity and an increase in shade-tolerant, fire-sensitive tree species. In this study, we conducted a comparative analysis of two mixed pine-oak (Pinus-Quercus) forests with different land management histories in the Cumberland Mountains of southern West Virginia where fire ecology and fire effects are understudied. We reconstructed the fire history of both sites from fire-scarred shortleaf pine (Pinus echinata Mill.) and pitch pine (Pinus rigida Mill.) trees to describe variation in the fire regimes over time. We also made plant community measurements that spatially coincided with fire-scarred pines to assess present-day plant community structure in relation to recent fire history. Results Before 1970, fires at Hite Fork and Wall Fork occurred frequently and almost exclusively in the dormant season, every 7–8 years on average. The fire regimes diverged in the Post-Industrial era (1970–2020), during which there was a single fire at Wall Fork, while six major fires, scarring more than 40% of sampled trees, occurred between 1985 and 2017 at Hite Fork. Four of these dormant-season fires correspond to late fall incendiary fires in the observational record. These differences in recent fire history had large effects on plant community structure. Recent mixed-severity fires at Hite Fork likely caused mortality of pole-sized trees and opened the canopy, creating conditions favorable for pine recruitment and resulted in significantly higher species richness in the herbaceous layer compared to Wall Fork, which exhibited the effects of mesophication. Conclusions Our results suggest that frequent mixed-severity fire in pine-oak forests of the Cumberland Mountains can meet management objectives by reducing mesophytic tree abundance, increasing herbaceous diversity and pine recruitment, and generally promoting forest heterogeneity.

Perspectiva sobre los incendios forestales en el semidesierto queretano hidalguense, México

“…El fuego es un proceso biofísico que interviene en la distribución de especies y ecosistemas terrestres. Evolutivamente, las interacciones entre el clima, la vegetación y el uso antropogénico de la tierra han determinado las características -como frecuencia, intensidad, patrones de consumo del combustible, extensión espacial y el momento estacional-y los mecanismos de adaptación a los regímenes de incendios (Jardel Peláez et al, 2014;Keeley et al, 2011;Saladyga et al, 2022).…”

Higher severity fire increases the long-term competitiveness of pyrophytes in an upland oak-pine forest, Kentucky, USA

“…Such a transformation has extensive ecological implications, as oaks play a keystone role in biotic and abiotic ecosystem processes (Fralish 2004) With the aim of curtailing these forest changes, land managers have reintroduced re primarily through prescribed burning, or burning combined with thinning treatments (P. Brose et al 2001). However, there is a growing recognition of the ecological bene ts of incorporating attributes of wild re into management plans (Ryan et al 2013), particularly for restoring re-dependent species and alleviating oak-pine recruitment issues (Black et al 2018;Saladyga et al 2022). Wild re events often create a heterogeneous mosaic of burn severity (Hutchinson et al 2008) that prompts a greater range of ecological responses than prescribed res, which are typically lower in severity and more spatially homogenous (P. Brose et al 2001).…”

“…Patches with increased burn severity are more likely to experience decreased density and basal area in the midstory and overstory initially following a re, which increases understory light availability (Reilly et al 2006). These changes to forest structure are essential for promoting the establishment and growth of understory pyrophytic species (Kuddes-Fischer and Arthur 2002), and have been shown to directly increase the recruitment of oak (Black et al 2018) and pine (Black et al 2018;Saladyga et al 2022) saplings. At our research site in the Cumberland Plateau, Black et al (2018) found that increased burn severity bolstered the competitive status of oaks and pines in the understory at six years post-re.…”

“…Arthur et al 2021;Saladyga et al 2022). Thus, pyrophytes are species that have physiological tolerances to re, have evolved characteristics to promote re events, and are known to be more successful in frequent re regimes(Varner et al.…”