Wildfire severity and postfire salvage harvest effects on long‐term forest regeneration
Abstract Following a wildfire, regeneration to forest can take decades to centuries and is no longer assured in many western U.S. environments given escalating wildfire severity and warming trends. After large fire years, managers prioritize where to allocate scarce planting resources, often with li...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2020-08-01
|
| Series: | Ecosphere |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ecs2.3199 |
| _version_ | 1818415679337922560 |
|---|---|
| author | Nicholas A. Povak Derek J. Churchill C. Alina Cansler Paul F. Hessburg Van R. Kane Jonathan T. Kane James A. Lutz Andrew J. Larson |
| author_facet | Nicholas A. Povak Derek J. Churchill C. Alina Cansler Paul F. Hessburg Van R. Kane Jonathan T. Kane James A. Lutz Andrew J. Larson |
| author_sort | Nicholas A. Povak |
| collection | DOAJ |
| description | Abstract Following a wildfire, regeneration to forest can take decades to centuries and is no longer assured in many western U.S. environments given escalating wildfire severity and warming trends. After large fire years, managers prioritize where to allocate scarce planting resources, often with limited information on the factors that drive successful forest establishment. Where occurring, long‐term effects of postfire salvage operations can increase uncertainty of establishment. Here, we collected field data on postfire regeneration patterns within 13‐ to 28‐yr‐old burned patches in eastern Washington State. Across 248 plots, we sampled tree stems <4 m height using a factorial design that considered (1) fire severity, moderate vs. high severity; (2) salvage harvesting, salvaged vs. no management; and (3) potential vegetation type (PVT), sample resides in a dry, moist, or cold mixed‐conifer forest environment. We found that regeneration was abundant throughout the study region, with a median of 4414 (IQR 19,618) stems/ha across all plots. Only 15% of plots fell below minimum timber production stocking standards (350 trees/ha), and <2% of plots were unstocked. Densities were generally highest in high‐severity patches and following salvage harvesting, although high variability among plots and across sites led to variable significance for these factors. Post hoc analyses suggested that mild postfire weather conditions may have reduced water stress on tree establishment and early growth, contributing to overall high stem densities. Douglas fir was the most abundant species, particularly in moderate‐severity patches, followed by ponderosa pine, lodgepole pine, western larch, and Engelmann spruce. Generalized additive models (GAMs) revealed species‐level climatic tolerances and seed dispersal limits that portend future challenges to regeneration with expected future climate warming and increased fire activity. Postfire regeneration will occur on sites with adequate seed sources within their climatic tolerances. |
| first_indexed | 2024-12-14T11:38:49Z |
| format | Article |
| id | doaj.art-a92dc978c1304a8ba97e337c0b8e25f2 |
| institution | Directory Open Access Journal |
| issn | 2150-8925 |
| language | English |
| last_indexed | 2024-12-14T11:38:49Z |
| publishDate | 2020-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecosphere |
| spelling | doaj.art-a92dc978c1304a8ba97e337c0b8e25f22022-12-21T23:02:54ZengWileyEcosphere2150-89252020-08-01118n/an/a10.1002/ecs2.3199Wildfire severity and postfire salvage harvest effects on long‐term forest regenerationNicholas A. Povak0Derek J. Churchill1C. Alina Cansler2Paul F. Hessburg3Van R. Kane4Jonathan T. Kane5James A. Lutz6Andrew J. Larson7USDA‐Forest Service Pacific Northwest Research Station 1133 N Western Avenue Wenatchee Washington98801‐1229USAWashington State Department of Natural Resources Forest Health and Resiliency Division Olympia Washington98504USASchool of Environmental and Forest Sciences University of Washington Box 352100 Seattle Washington98195USAUSDA‐Forest Service Pacific Northwest Research Station 1133 N Western Avenue Wenatchee Washington98801‐1229USASchool of Environmental and Forest Sciences University of Washington Box 352100 Seattle Washington98195USASchool of Environmental and Forest Sciences University of Washington Box 352100 Seattle Washington98195USAQuinney College of Natural Resources & Ecology Center Utah State University Logan Utah84322USAW.A. Franke College of Forestry & Conservation University of Montana Missoula Montana59812USAAbstract Following a wildfire, regeneration to forest can take decades to centuries and is no longer assured in many western U.S. environments given escalating wildfire severity and warming trends. After large fire years, managers prioritize where to allocate scarce planting resources, often with limited information on the factors that drive successful forest establishment. Where occurring, long‐term effects of postfire salvage operations can increase uncertainty of establishment. Here, we collected field data on postfire regeneration patterns within 13‐ to 28‐yr‐old burned patches in eastern Washington State. Across 248 plots, we sampled tree stems <4 m height using a factorial design that considered (1) fire severity, moderate vs. high severity; (2) salvage harvesting, salvaged vs. no management; and (3) potential vegetation type (PVT), sample resides in a dry, moist, or cold mixed‐conifer forest environment. We found that regeneration was abundant throughout the study region, with a median of 4414 (IQR 19,618) stems/ha across all plots. Only 15% of plots fell below minimum timber production stocking standards (350 trees/ha), and <2% of plots were unstocked. Densities were generally highest in high‐severity patches and following salvage harvesting, although high variability among plots and across sites led to variable significance for these factors. Post hoc analyses suggested that mild postfire weather conditions may have reduced water stress on tree establishment and early growth, contributing to overall high stem densities. Douglas fir was the most abundant species, particularly in moderate‐severity patches, followed by ponderosa pine, lodgepole pine, western larch, and Engelmann spruce. Generalized additive models (GAMs) revealed species‐level climatic tolerances and seed dispersal limits that portend future challenges to regeneration with expected future climate warming and increased fire activity. Postfire regeneration will occur on sites with adequate seed sources within their climatic tolerances.https://doi.org/10.1002/ecs2.3199climatic toleranceDouglas firdry foresthigh severitylodgepole pineponderosa pine |
| spellingShingle | Nicholas A. Povak Derek J. Churchill C. Alina Cansler Paul F. Hessburg Van R. Kane Jonathan T. Kane James A. Lutz Andrew J. Larson Wildfire severity and postfire salvage harvest effects on long‐term forest regeneration Ecosphere climatic tolerance Douglas fir dry forest high severity lodgepole pine ponderosa pine |
| title | Wildfire severity and postfire salvage harvest effects on long‐term forest regeneration |
| title_full | Wildfire severity and postfire salvage harvest effects on long‐term forest regeneration |
| title_fullStr | Wildfire severity and postfire salvage harvest effects on long‐term forest regeneration |
| title_full_unstemmed | Wildfire severity and postfire salvage harvest effects on long‐term forest regeneration |
| title_short | Wildfire severity and postfire salvage harvest effects on long‐term forest regeneration |
| title_sort | wildfire severity and postfire salvage harvest effects on long term forest regeneration |
| topic | climatic tolerance Douglas fir dry forest high severity lodgepole pine ponderosa pine |
| url | https://doi.org/10.1002/ecs2.3199 |
| work_keys_str_mv | AT nicholasapovak wildfireseverityandpostfiresalvageharvesteffectsonlongtermforestregeneration AT derekjchurchill wildfireseverityandpostfiresalvageharvesteffectsonlongtermforestregeneration AT calinacansler wildfireseverityandpostfiresalvageharvesteffectsonlongtermforestregeneration AT paulfhessburg wildfireseverityandpostfiresalvageharvesteffectsonlongtermforestregeneration AT vanrkane wildfireseverityandpostfiresalvageharvesteffectsonlongtermforestregeneration AT jonathantkane wildfireseverityandpostfiresalvageharvesteffectsonlongtermforestregeneration AT jamesalutz wildfireseverityandpostfiresalvageharvesteffectsonlongtermforestregeneration AT andrewjlarson wildfireseverityandpostfiresalvageharvesteffectsonlongtermforestregeneration |