Do post-fire mulching treatments affect regeneration in serotinous lodgepole pine?

Abstract

Broadcast mulching is a widely implemented post-fire erosion control method, although it remains uncertain how it affects post-fire regeneration in serotinous conifers. We used field data and unbiased conditional inference trees with random effects to test if mulching affects lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm. ex S. Watson) regeneration following a wildfire in northern Colorado, USA. Our results suggest that post-fire application of straw mulch may have modest beneficial effects for regenerating lodgepole pine. However, these effects were minor compared to other spatial predictors of seedling density, including whether or not tree crowns were consumed in the fire and the presence of post-fire needle cast. These results suggest that post-fire mulching treatments in lodgepole pine ecosystems will have minimal effect on tree regeneration, and that managers need not be concerned about hindering regeneration when considering whether to use straw mulch for post-fire erosion mitigation in this forest type.