Ponderosa Pine Regeneration, Wildland Fuels Management, and Habitat Conservation: Identifying Trade-Offs Following Wildfire

Victoria Donovan,David Wedin,Dirac Twidwell,Carissa Wonkka,Caleb Roberts

doi:10.3390/f10030286

Abstract

Increasing wildfires in western North American conifer forests have led to debates surrounding the application of post-fire management practices. There is a lack of consensus on whether (and to what extent) post-fire management assists or hinders managers in achieving goals, particularly in under-studied regions like eastern ponderosa pine forests. This makes it difficult for forest managers to balance among competing interests. We contrast structural and community characteristics across unburned ponderosa pine forest, severely burned ponderosa pine forest, and severely burned ponderosa pine forest treated with post-fire management with respect to three management objectives: ponderosa pine regeneration, wildland fuels control, and habitat conservation. Ponderosa pine saplings were more abundant in treated burned sites than untreated burned sites, suggesting increases in tree regeneration following tree planting; however, natural regeneration was evident in both unburned and untreated burned sites. Wildland fuels management greatly reduced snags and coarse woody debris in treated burned sites. Understory cover measurements revealed bare ground and fine woody debris were more strongly associated with untreated burned sites, and greater levels of forbs and grass were more strongly associated with treated burned sites. Wildlife habitat was greatly reduced following post-fire treatments. There were no tree cavities in treated burned sites, whereas untreated burned sites had an average of 27 ± 7.68 cavities per hectare. Correspondingly, we found almost double the avian species richness in untreated burned sites compared to treated burned sites (22 species versus 12 species). Unburned forests and untreated burned areas had the same species richness, but hosted unique avian communities. Our results indicate conflicting outcomes with respect to management objectives, most evident in the clear costs to habitat conservation following post-fire management application.

Highlights

Increasing wildfires in western North American conifer forests have led to increasingly heated debates surrounding the application of post-fire management [1,2]
The potential benefits of attempting to hasten forest regeneration and decrease wildland fuels in eastern ponderosa pine comes at the cost of post-fire habitats, which we demonstrate host unique community compositions that are as species rich as unburned forests
Our results are consistent with a number of other studies that highlight the detrimental ecological impacts of post-fire management that need to be reconciled with other management objectives [1,7]

Summary

Introduction

Increasing wildfires in western North American conifer forests have led to increasingly heated debates surrounding the application of post-fire management [1,2]. Forest management objectives commonly incorporate yield-based paradigms with societal interests, such as biodiversity and conservation, social and cultural values, and system resilience [3,4]. Forest managers must often balance competing interests when planning post-fire management. Forests 2019, 10, 286 implemented post-fire management to recuperate economic loss from fire, reduce subsequent fire risk, and boost post-fire forest regeneration [5,6]. The alteration of post-fire habitats by management can have negative ecological consequences, making it difficult to balance competing objectives [1,7]. Surging wildfire activity threatens timber resources, posing large economic losses to the forestry sector [9]. Post-salvage logging is a common practice used to recuperate timber loss following fire by harvesting damaged timber from burned sites [10,11]

Methods

Results

Discussion

Conclusion