Arctic shrub growth trajectories differ across soil moisture levels

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The circumpolar expansion of woody deciduous shrubs in arctic tundra alters key ecosystem properties including carbon balance and hydrology. However, landscape-scale patterns and drivers of shrub expansion remain poorly understood, inhibiting accurate incorporation of shrub effects into climate models. Here, we use dendroecology to elucidate the role of soil moisture in modifying the relationship between climate and growth for a dominant deciduous shrub, Salix pulchra, on the North Slope of Alaska, USA. We improve upon previous modeling approaches by using ecological theory to guide model selection for the relationship between climate and shrub growth. Finally, we present novel dendroecology-based estimates of shrub biomass change under a future climate regime, made possible by recently developed shrub allometry models. We find that S. pulchra growth has responded positively to mean June temperature over the past 2.5 decades at both a dry upland tundra site and an adjacent mesic riparian site. For the upland site, including a negative second-order term in the climate–growth model significantly improved explanatory power, matching theoretical predictions of diminishing growth returns to increasing temperature. A first-order linear model fit best at the riparian site, indicating consistent growth increases in response to sustained warming, possibly due to lack of temperature-induced moisture limitation in mesic habitats. These contrasting results indicate that S. pulchra in mesic habitats may respond positively to a wider range of temperature increase than S. pulchra in dry habitats. Lastly, we estimate that a 2°C increase in current mean June temperature will yield a 19% increase in aboveground S. pulchra biomass at the upland site and a 36% increase at the riparian site. Our method of biomass estimation provides an important link toward incorporating dendroecology data into coupled vegetation and climate models.

Original languageEnglish (US)
Pages (from-to)4294-4302
Number of pages9
JournalGlobal change biology
Volume23
Issue number10
DOIs
StatePublished - Oct 1 2017

Fingerprint

Soil moisture
shrub
soil moisture
trajectory
Trajectories
dendroecology
Climate models
Biomass
Temperature
tundra
Salix
temperature
climate modeling
biomass
climate
habitat
Hydrology
Ecosystems
ecological theory
allometry

Keywords

  • arctic
  • biomass
  • climate change
  • dendroecology
  • shrub expansion
  • tundra

Cite this

Arctic shrub growth trajectories differ across soil moisture levels. / Ackerman, Daniel; Griffin, Daniel; Hobbie, Sarah E; Finlay, Jacques C.

In: Global change biology, Vol. 23, No. 10, 01.10.2017, p. 4294-4302.

Research output: Contribution to journalArticle

@article{e5741b8b13ab4dfc9b92861417975bec,
title = "Arctic shrub growth trajectories differ across soil moisture levels",
abstract = "The circumpolar expansion of woody deciduous shrubs in arctic tundra alters key ecosystem properties including carbon balance and hydrology. However, landscape-scale patterns and drivers of shrub expansion remain poorly understood, inhibiting accurate incorporation of shrub effects into climate models. Here, we use dendroecology to elucidate the role of soil moisture in modifying the relationship between climate and growth for a dominant deciduous shrub, Salix pulchra, on the North Slope of Alaska, USA. We improve upon previous modeling approaches by using ecological theory to guide model selection for the relationship between climate and shrub growth. Finally, we present novel dendroecology-based estimates of shrub biomass change under a future climate regime, made possible by recently developed shrub allometry models. We find that S. pulchra growth has responded positively to mean June temperature over the past 2.5 decades at both a dry upland tundra site and an adjacent mesic riparian site. For the upland site, including a negative second-order term in the climate–growth model significantly improved explanatory power, matching theoretical predictions of diminishing growth returns to increasing temperature. A first-order linear model fit best at the riparian site, indicating consistent growth increases in response to sustained warming, possibly due to lack of temperature-induced moisture limitation in mesic habitats. These contrasting results indicate that S. pulchra in mesic habitats may respond positively to a wider range of temperature increase than S. pulchra in dry habitats. Lastly, we estimate that a 2°C increase in current mean June temperature will yield a 19{\%} increase in aboveground S. pulchra biomass at the upland site and a 36{\%} increase at the riparian site. Our method of biomass estimation provides an important link toward incorporating dendroecology data into coupled vegetation and climate models.",
keywords = "arctic, biomass, climate change, dendroecology, shrub expansion, tundra",
author = "Daniel Ackerman and Daniel Griffin and Hobbie, {Sarah E} and Finlay, {Jacques C}",
year = "2017",
month = "10",
day = "1",
doi = "10.1111/gcb.13677",
language = "English (US)",
volume = "23",
pages = "4294--4302",
journal = "Global Change Biology",
issn = "1354-1013",
publisher = "Wiley-Blackwell",
number = "10",

}

TY - JOUR

T1 - Arctic shrub growth trajectories differ across soil moisture levels

AU - Ackerman, Daniel

AU - Griffin, Daniel

AU - Hobbie, Sarah E

AU - Finlay, Jacques C

PY - 2017/10/1

Y1 - 2017/10/1

N2 - The circumpolar expansion of woody deciduous shrubs in arctic tundra alters key ecosystem properties including carbon balance and hydrology. However, landscape-scale patterns and drivers of shrub expansion remain poorly understood, inhibiting accurate incorporation of shrub effects into climate models. Here, we use dendroecology to elucidate the role of soil moisture in modifying the relationship between climate and growth for a dominant deciduous shrub, Salix pulchra, on the North Slope of Alaska, USA. We improve upon previous modeling approaches by using ecological theory to guide model selection for the relationship between climate and shrub growth. Finally, we present novel dendroecology-based estimates of shrub biomass change under a future climate regime, made possible by recently developed shrub allometry models. We find that S. pulchra growth has responded positively to mean June temperature over the past 2.5 decades at both a dry upland tundra site and an adjacent mesic riparian site. For the upland site, including a negative second-order term in the climate–growth model significantly improved explanatory power, matching theoretical predictions of diminishing growth returns to increasing temperature. A first-order linear model fit best at the riparian site, indicating consistent growth increases in response to sustained warming, possibly due to lack of temperature-induced moisture limitation in mesic habitats. These contrasting results indicate that S. pulchra in mesic habitats may respond positively to a wider range of temperature increase than S. pulchra in dry habitats. Lastly, we estimate that a 2°C increase in current mean June temperature will yield a 19% increase in aboveground S. pulchra biomass at the upland site and a 36% increase at the riparian site. Our method of biomass estimation provides an important link toward incorporating dendroecology data into coupled vegetation and climate models.

AB - The circumpolar expansion of woody deciduous shrubs in arctic tundra alters key ecosystem properties including carbon balance and hydrology. However, landscape-scale patterns and drivers of shrub expansion remain poorly understood, inhibiting accurate incorporation of shrub effects into climate models. Here, we use dendroecology to elucidate the role of soil moisture in modifying the relationship between climate and growth for a dominant deciduous shrub, Salix pulchra, on the North Slope of Alaska, USA. We improve upon previous modeling approaches by using ecological theory to guide model selection for the relationship between climate and shrub growth. Finally, we present novel dendroecology-based estimates of shrub biomass change under a future climate regime, made possible by recently developed shrub allometry models. We find that S. pulchra growth has responded positively to mean June temperature over the past 2.5 decades at both a dry upland tundra site and an adjacent mesic riparian site. For the upland site, including a negative second-order term in the climate–growth model significantly improved explanatory power, matching theoretical predictions of diminishing growth returns to increasing temperature. A first-order linear model fit best at the riparian site, indicating consistent growth increases in response to sustained warming, possibly due to lack of temperature-induced moisture limitation in mesic habitats. These contrasting results indicate that S. pulchra in mesic habitats may respond positively to a wider range of temperature increase than S. pulchra in dry habitats. Lastly, we estimate that a 2°C increase in current mean June temperature will yield a 19% increase in aboveground S. pulchra biomass at the upland site and a 36% increase at the riparian site. Our method of biomass estimation provides an important link toward incorporating dendroecology data into coupled vegetation and climate models.

KW - arctic

KW - biomass

KW - climate change

KW - dendroecology

KW - shrub expansion

KW - tundra

UR - http://www.scopus.com/inward/record.url?scp=85017383526&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85017383526&partnerID=8YFLogxK

U2 - 10.1111/gcb.13677

DO - 10.1111/gcb.13677

M3 - Article

VL - 23

SP - 4294

EP - 4302

JO - Global Change Biology

JF - Global Change Biology

SN - 1354-1013

IS - 10

ER -