Stand and environmental conditions drive functional shifts associated with mesophication in eastern US forests

There is a growing body of evidence that mesic tree species are increasing in importance across much of the eastern US. This increase is often observed in tandem with a decrease in the abundance and importance of species considered to be better adapted to disturbance and drier conditions (e.g., Quer...

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Main Authors: Margaret Woodbridge, Tara Keyser, Christopher Oswalt
Format: Article
Language:English
Published: Frontiers Media S.A. 2022-10-01
Series:Frontiers in Forests and Global Change
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/ffgc.2022.991934/full
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author Margaret Woodbridge
Tara Keyser
Christopher Oswalt
author_facet Margaret Woodbridge
Tara Keyser
Christopher Oswalt
author_sort Margaret Woodbridge
collection DOAJ
description There is a growing body of evidence that mesic tree species are increasing in importance across much of the eastern US. This increase is often observed in tandem with a decrease in the abundance and importance of species considered to be better adapted to disturbance and drier conditions (e.g., Quercus species). Concern over this transition is related to several factors, including the potential that this transition is self-reinforcing (termed “mesophication”), will result in decreased resiliency of forests to a variety of disturbances, and may negatively impact ecosystem functioning, timber value, and wildlife habitat. Evidence for shifts in composition provide broad-scale support for mesophication, but we lack information on the fine-scale factors that drive the associated functional changes. Understanding this variability is particularly important as managers work to develop site-and condition-specific management practices to target stands or portions of the landscape where this transition is occurring or is likely to occur in the future. To address this knowledge gap and identify forests that are most susceptible to mesophication (which we evaluate as a functional shift to less drought or fire tolerant, or more shade tolerant, forests), we used data from the USDA Forest Service Forest Inventory and Analysis program to determine what fine-scale factors impact the rate (change through time) and degree (difference between the overstory and midstory) of change in eastern US forests. We found that mesophication varies along stand and environmental gradients, but this relationship depended on the functional trait examined. For example, shade and drought tolerance suggest mesophication is greatest at sites with more acidic soils, while fire tolerance suggests mesophication increases with soil pH. Mesophication was also generally more pronounced in older stands, stands with more variable diameters, and in wetter sites, but plots categorized as “hydric” were often highly variable. Our results provide evidence that stand-scale conditions impact current and potential future changes in trait conditions and composition across eastern US forests. We provide a starting point for managers looking to prioritize portions of the landscape most at risk and developing treatments to address the compositional and functional changes associated with mesophication.
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spelling doaj.art-129889039ff3471c8d2f46f2bcd1f92e2022-12-22T02:24:49ZengFrontiers Media S.A.Frontiers in Forests and Global Change2624-893X2022-10-01510.3389/ffgc.2022.991934991934Stand and environmental conditions drive functional shifts associated with mesophication in eastern US forestsMargaret Woodbridge0Tara Keyser1Christopher Oswalt2US Department of Agriculture, Forest Service Southern Research Station, Asheville, NC, United StatesUS Department of Agriculture, Forest Service Southern Research Station, Asheville, NC, United StatesUS Department of Agriculture, Forest Service Southern Research Station, Knoxville, TN, United StatesThere is a growing body of evidence that mesic tree species are increasing in importance across much of the eastern US. This increase is often observed in tandem with a decrease in the abundance and importance of species considered to be better adapted to disturbance and drier conditions (e.g., Quercus species). Concern over this transition is related to several factors, including the potential that this transition is self-reinforcing (termed “mesophication”), will result in decreased resiliency of forests to a variety of disturbances, and may negatively impact ecosystem functioning, timber value, and wildlife habitat. Evidence for shifts in composition provide broad-scale support for mesophication, but we lack information on the fine-scale factors that drive the associated functional changes. Understanding this variability is particularly important as managers work to develop site-and condition-specific management practices to target stands or portions of the landscape where this transition is occurring or is likely to occur in the future. To address this knowledge gap and identify forests that are most susceptible to mesophication (which we evaluate as a functional shift to less drought or fire tolerant, or more shade tolerant, forests), we used data from the USDA Forest Service Forest Inventory and Analysis program to determine what fine-scale factors impact the rate (change through time) and degree (difference between the overstory and midstory) of change in eastern US forests. We found that mesophication varies along stand and environmental gradients, but this relationship depended on the functional trait examined. For example, shade and drought tolerance suggest mesophication is greatest at sites with more acidic soils, while fire tolerance suggests mesophication increases with soil pH. Mesophication was also generally more pronounced in older stands, stands with more variable diameters, and in wetter sites, but plots categorized as “hydric” were often highly variable. Our results provide evidence that stand-scale conditions impact current and potential future changes in trait conditions and composition across eastern US forests. We provide a starting point for managers looking to prioritize portions of the landscape most at risk and developing treatments to address the compositional and functional changes associated with mesophication.https://www.frontiersin.org/articles/10.3389/ffgc.2022.991934/fullmesophicationFIAQuercus-Carya forestsfunctional traitsforest dynamicsrestoration
spellingShingle Margaret Woodbridge
Tara Keyser
Christopher Oswalt
Stand and environmental conditions drive functional shifts associated with mesophication in eastern US forests
Frontiers in Forests and Global Change
mesophication
FIA
Quercus-Carya forests
functional traits
forest dynamics
restoration
title Stand and environmental conditions drive functional shifts associated with mesophication in eastern US forests
title_full Stand and environmental conditions drive functional shifts associated with mesophication in eastern US forests
title_fullStr Stand and environmental conditions drive functional shifts associated with mesophication in eastern US forests
title_full_unstemmed Stand and environmental conditions drive functional shifts associated with mesophication in eastern US forests
title_short Stand and environmental conditions drive functional shifts associated with mesophication in eastern US forests
title_sort stand and environmental conditions drive functional shifts associated with mesophication in eastern us forests
topic mesophication
FIA
Quercus-Carya forests
functional traits
forest dynamics
restoration
url https://www.frontiersin.org/articles/10.3389/ffgc.2022.991934/full
work_keys_str_mv AT margaretwoodbridge standandenvironmentalconditionsdrivefunctionalshiftsassociatedwithmesophicationineasternusforests
AT tarakeyser standandenvironmentalconditionsdrivefunctionalshiftsassociatedwithmesophicationineasternusforests
AT christopheroswalt standandenvironmentalconditionsdrivefunctionalshiftsassociatedwithmesophicationineasternusforests