@article{e87fc538cf6040f681ffcc37bc9165b6,
title = "Material Legacies and Environmental Constraints Underlie Fire Resilience of a Dominant Boreal Forest Type",
abstract = "Resilience of plant communities to disturbance is supported by multiple mechanisms, including ecological legacies affecting propagule availability, species{\textquoteright} environmental tolerances, and biotic interactions. Understanding the relative importance of these mechanisms for plant community resilience supports predictions of where and how resilience will be altered with disturbance. We tested mechanisms underlying resilience of forests dominated by black spruce (Picea mariana) to fire disturbance across a heterogeneous forest landscape in the Northwest Territories, Canada. We combined surveys of naturally regenerating seedlings at 219 burned plots with experimental manipulations of ecological legacies via seed addition of four tree species and vertebrate exclosures to limit granivory and herbivory at 30 plots varying in moisture and fire severity. Black spruce recovery was greatest where it dominated pre-fire, at wet sites with deep residual soil organic layers, and fire conditions of low soil or canopy combustion and longer return intervals. Experimental addition of seed indicated all species were seed-limited, emphasizing the importance of propagule legacies. Black spruce and birch (Betula papyrifera) recruitment were enhanced with vertebrate exclusion. Our combination of observational and experimental studies demonstrates black spruce is vulnerable to effects of increased fire activity that erode ecological legacies. Moreover, black spruce relies on wet areas with deep soil organic layers where other species are less competitive. However, other species can colonize these areas if enough seed is available or soil moisture is altered by climate change. Testing mechanisms underlying species{\textquoteright} resilience to disturbance aids predictions of where vegetation will transform with effects of climate change.",
keywords = "Boreal forest, Drought, Pinus banksiana, Populus tremuloides, Seed limitation, Seedbed, Taiga plains, Taiga shield, Vegetation change, Wildfire",
author = "Day, {Nicola J.} and Johnstone, {Jill F.} and Reid, {Kirsten A.} and Cumming, {Steven G.} and Mack, {Michelle C.} and Turetsky, {Merritt R.} and Walker, {Xanthe J.} and Baltzer, {Jennifer L.}",
note = "Funding Information: This article is part of Project 170 of the Government of the Northwest Territories (GNWT) Department of Environment and Natural Resources Cumulative Impacts Monitoring Program (awarded to JLB, JFJ, and SGC). Additional funding was provided by Natural Science and Engineering Research Council (NSERC: Changing Cold Regions Network), Northern Scientific Training Program, NSERC Discovery to MRT and JFJ, a National Science Foundation DEB RAPID (Grant #1542150), and NASA Arctic Boreal and Vulnerability Experiment (ABoVE) Legacy Carbon grant (Grant #Mack-01) to MCM. NJD was supported by an NSERC Postdoctoral Fellowship and Rutherford Postdoctoral Fellowship from the Royal Society of New Zealand Te Apārangi. In kind support was provided by the Bonanza Creek LTER program. We thank the GNWT Aurora Research Institute (Research License 15879), the Ka{\textquoteright}a{\textquoteright}gee Tu First Nation, the Tlicho Government, and the Wek{\textquoteright}{\'e}ezh{\`i}i Renewable Resources Board for their support of this research. The Wilfrid Laurier University—GNWT Partnership Agreement was instrumental in providing logistical support and laboratory space. We thank J. Paul for making the map and numerous students and technicians for field assistance. Seed extractions and viability tests were aided by the Ontario Tree Seed Plant (jack pine, black spruce, and aspen) and the Alberta Tree Improvement and Seed Centre (birch). Tree images in Figure 1 are from Natural Resources Canada, Canadian Forest Service: https://tidcf.nrcan.gc.ca/en/trees. We thank four anonymous referees for helpful comments on earlier versions of the manuscript. Funding Information: This article is part of Project 170 of the Government of the Northwest Territories (GNWT) Department of Environment and Natural Resources Cumulative Impacts Monitoring Program (awarded to JLB, JFJ, and SGC). Additional funding was provided by Natural Science and Engineering Research Council (NSERC: Changing Cold Regions Network), Northern Scientific Training Program, NSERC Discovery to MRT and JFJ, a National Science Foundation DEB RAPID (Grant #1542150), and NASA Arctic Boreal and Vulnerability Experiment (ABoVE) Legacy Carbon grant (Grant #Mack-01) to MCM. NJD was supported by an NSERC Postdoctoral Fellowship and Rutherford Postdoctoral Fellowship from the Royal Society of New Zealand Te Apārangi. In kind support was provided by the Bonanza Creek LTER program. We thank the GNWT Aurora Research Institute (Research License 15879), the Ka{\textquoteright}a{\textquoteright}gee Tu First Nation, the Tlicho Government, and the Wek{\textquoteright}{\'e}ezh{\`i}i Renewable Resources Board for their support of this research. The Wilfrid Laurier University—GNWT Partnership Agreement was instrumental in providing logistical support and laboratory space. We thank J. Paul for making the map and numerous students and technicians for field assistance. Seed extractions and viability tests were aided by the Ontario Tree Seed Plant (jack pine, black spruce, and aspen) and the Alberta Tree Improvement and Seed Centre (birch). Tree images in Figure are from Natural Resources Canada, Canadian Forest Service: https://tidcf.nrcan.gc.ca/en/trees . We thank four anonymous referees for helpful comments on earlier versions of the manuscript. Funding Information: Open Access funding enabled and organized by CAUL and its Member Institutions. Natural Sciences and Engineering Research Council of Canada, NASA Arctic Boreal and Vulnerability Experiment (ABoVE), Mack-01, Royal Society Te Apārangi, Northern Scientific Training Program, Government of the Northwest Territories Cumulative Impacts Monitoring Program, Project 170, National Science Foundation DEB RAPID, 1542150. Publisher Copyright: {\textcopyright} 2022, The Author(s).",
year = "2023",
month = apr,
doi = "10.1007/s10021-022-00772-7",
language = "English (US)",
volume = "26",
pages = "473--490",
journal = "Ecosystems",
issn = "1432-9840",
publisher = "Springer New York",
number = "3",
}