Experiments to enhance post-fire aspen seedling survival and growth
Aspen forests offer ecological and fire‑mitigation benefits, yet optimal conditions for seedling establishment in the western United States remain understudied. This research tested how shading structures (logs) and biochar influence survival and growth of 960 outplanted seedlings across three post‑fire exclosures, and whether placing logs near 120 naturally occurring seedlings improved outcomes. Despite hot, dry conditions, planted seedlings showed high survival (66%). Logs and biochar had minimal positive effects, and in one exclosure, logs reduced survival by sheltering small herbivores. Naturally occurring seedlings showed slightly higher survival when logs were placed on the south side, though growth effects were weak. Overall, where aspen regeneration is already robust, microsite modifications may not be needed, informing more efficient post‑fire restoration strategies.
Subject Tags
- Forest
- Biodiversity
- Fire management
Abstract
Aspen forests provide wildlife, watershed and aesthetic value and the potential for reduced fire occurrence, behavior and severity. There is interest in planting aspen to achieve various management objectives. However, few studies have investigated the optimal conditions for aspen seedlings in the western U.S. We conducted two experiments to address this knowledge gap. First, we tested the effects of shading structures (i.e., logs) and biochar on the survival and growth of 960 outplanted aspen seedlings in three exclosures in a recent fire footprint. Second, we tested whether experimentally placing logs near 120 naturally occurring post-fire aspen seedlings affected survival or growth. Survival of outplanted seedlings was high (66%) despite hot and dry conditions in the years of the study. Logs and biochar had minimal effects on planted seedling survival and growth, but in one exclosure, survival of planted seedlings was lower in log and log + biochar treatments, likely due to the protection logs provided to small mammalian herbivores. Survival was higher for naturally-occurring seedlings with logs placed on the south side compared to control seedlings in one site, and growth was higher for naturally occurring seedlings with a nearby log, but not significantly so. In sites where aspen seedling survival and growth are relatively robust, management actions to modify the microsite may not be necessary.
Citation
Yocom, L. L., Kreider, M. R., Burney, O. T., Parsons, T., Choi, R. T., Liese, E. K., & Mock, K. E. (2025). Experiments to enhance post-fire aspen seedling survival and growth. New Forests, 56(4), 41. https://doi.org/10.1007/s11056-025-10097-7
TNC Authors
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Mark R. Kreider
The Nature Conservancy