Interactions between landscape and local factors inform spatial action planning in post-fire forest environments

• Published in: Landscape ecology Vol. 36; no. 12; pp. 3523 - 3537
• Main Authors: Peeler, Jamie L., Smithwick, Erica A. H.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.12.2021; Springer Nature B.V
• Subjects: Abies lasiocarpa; Biomedical and Life Sciences; Context; Density; Ecology; Environmental Management; Forest management; Forests; Landscape Ecology; Landscape/Regional and Urban Planning; Life Sciences; Nature Conservation; Nitrogen; Nutrients; Patches (structures); Pine trees; Plant species; Regeneration; Research Article; Seeds; Soil nutrients; Stocking; Sustainable Development; Thresholds; Trees; Vegetation; Regeneration; Pattern; Seed dispersal; Stand-replacing fire; Conifer forest; Resilience
• ISSN: 0921-2973; 1572-9761
• DOI: 10.1007/s10980-021-01325-4

Context Landscape and local factors govern tree regeneration across heterogeneous post-fire forest environments. But their relative influence is unclear—limiting the degree that managers can consider landscape context when delegating resources to help stand-replacing patches restock successfully. Objectives We investigated how landscape and local factors shape tree regeneration across heterogeneous post-fire forest environments. Our research questions were: What is the relative influence of landscape and local factors on tree species presence (RQ1) and stocking density (RQ2) at stand-replacing patches? Do thresholds occur when landscape factors are influential (RQ3)? Methods We sampled landscape and local variables at 71 plots near Jackson, Wyoming, United States. We used Random Forests to investigate how local and landscape variables affect post-fire tree recovery. Relative influence was determined using mean decrease in accuracy. Partial dependence plots were used to visualize whether thresholds occurred for variables with mean decrease in accuracy > 15%. Results Landscape factors like seed source area were associated with subalpine fir presence and stocking density. But different thresholds occurred. Specifically, subalpine fir presence required 10% seed source area, while stocking density required 40%. Northeast aspects surrounded by > 10% seed source area were most likely to support subalpine fir presence. Conversely, local factors like soil nutrients were associated with lodgepole pine presence, highlighting effects of different regeneration strategies. Conclusions Landscape factors bolster spatial resilience and help stand-replacing patches restock naturally. But landscape factors do not support tree regeneration equally across heterogeneous post-fire forest environments. Consequently, considering stand-replacing patches in their landscape context will be critical for future spatial action planning.