Spatial and temporal drivers of post-fire tree establishment and height growth in a managed forest landscape

Fire Ecology

Original Research

Penelope Morgan¹  Madeline C. Franz²  Arjan J. H. Meddens²  Robert A. Andrus²  Leigh B. Lentile³  Andrew T. Hudak⁴  Sarah A. Lewis⁴  Peter R. Robichaud⁴  Christine A. Droske⁵ 

[1] Department of Forest, Rangeland, and Fire Sciences, University of Idaho, 875 Perimeter Drive, 83844, Moscow, ID, USA;School of the Environment, Washington State University, PO Box 642812, 99164, Pullman, WA, USA;Spatial Informatics Group - Natural Assets Laboratory (SIG-NAL), 2529 Yolanda Court, 94566, Pleasanton, CA, USA;US Department of Agriculture Forest Service, Rocky Mountain Research Station, 1221 South Main, 83843, Moscow, ID, USA;US Department of Agriculture Forest Service, Salmon-Challis National Forest, 1206 N. US Hwy. 93, 83467, Salmon, ID, USA;

关键词: Conifer forest;    Wildfire;    Burn severity;    Post-fire tree regeneration;    Post-fire treatments;    Salvage logging;    Grass seeding;    Remeasurement;   

DOI  :  10.1186/s42408-022-00153-4

 received in 2022-03-01, accepted in 2022-10-26,  发布年份 2022

来源: Springer

【 摘 要 】

BackgroundIn seed-obligate conifer forests of the western US, land managers need a better understanding of the spatiotemporal variability in post-fire recovery to develop adaptation strategies. Successful establishment of post-fire seedlings requires the arrival of seeds and favorable environmental conditions for germination, survival, and growth. We investigated the spatiotemporal limitations to post-fire seedling establishment and height growth in dry to moist mixed conifer forests with and without post-fire forest management treatments (salvage logging, grass seeding) in areas burned from low to high severity. In 2011, we measured post-fire seedling establishment year, juvenile density (seedlings and saplings), and height growth (annual and total) in 50 plots with six conifer species in the School Fire (2005), Blue Mountains, WA, USA. In 2021, we remeasured the plots for post-fire juvenile density and height growth.ResultsPost-fire juvenile tree densities appeared sufficient for self-replacement of forest (> 60 stems ha−1) in 96% of plots in 2021 (median 3130 stems ha−1), but densities were highly variable (range 33–100,501 stems ha−1). Annual seedling establishment was positively correlated with cooler, wetter climate conditions during the summer of germination (July–September) and the growing season of the subsequent year (April–September) for multiple tree species. We found lower juvenile densities at greater distances to seed sources and with higher grass cover, while salvage logging had no effect. Annual height growth was shorter on warmer, drier topographic positions for three species, whereas annual height growth was associated with climate variability for one species. Shifts in height class structure from 2011 to 2021 were, in part, explained by differences among species in annual height growth.ConclusionsAbundant and widespread tree seedling establishment for multiple conifer species after fire was strong evidence that most burned sites in the present study are currently on a trajectory to return to forest. However, post-fire establishment may be constrained to brief periods of cooler, wetter climate conditions following future fires. Long-term monitoring of post-fire recovery dynamics is needed to inform management activities designed to adapt forests to climate change and future disturbances, which will collectively shape future forest structure and composition.

【 授权许可】

CC BY   
© The Author(s) 2022

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