Long-term physiological and growth responses of Himalayan fir to environmental change are mediated by mean climate

Shankar Panthi, Ze Xin Fan*, Peter van der Sleen, Pieter A. Zuidema

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

High-elevation forests are experiencing high rates of warming, in combination with CO2 rise and (sometimes) drying trends. In these montane systems, the effects of environmental changes on tree growth are also modified by elevation itself, thus complicating our ability to predict effects of future climate change. Tree-ring analysis along an elevation gradient allows quantifying effects of gradual and annual environmental changes. Here, we study long-term physiological (ratio of internal to ambient CO2, i.e., Ci/Ca and intrinsic water-use efficiency, iWUE) and growth responses (tree-ring width) of Himalayan fir (Abies spectabilis) trees in response to warming, drying, and CO2 rise. Our study was conducted along elevational gradients in a dry and a wet region in the central Himalaya. We combined dendrochronology and stable carbon isotopes (δ13C) to quantify long-term trends in Ci/Ca ratio and iWUE (δ13C-derived), growth (mixed-effects models), and evaluate climate sensitivity (correlations). We found that iWUE increased over time at all elevations, with stronger increase in the dry region. Climate–growth relations showed growth-limiting effects of spring moisture (dry region) and summer temperature (wet region), and negative effects of temperature (dry region). We found negative growth trends at lower elevations (dry and wet regions), suggesting that continental-scale warming and regional drying reduced tree growth. This interpretation is supported by δ13C-derived long-term physiological responses, which are consistent with responses to reduced moisture and increased vapor pressure deficit. At high elevations (wet region), we found positive growth trends, suggesting that warming has favored tree growth in regions where temperature most strongly limits growth. At lower elevations (dry and wet regions), the positive effects of CO2 rise did not mitigate the negative effects of warming and drying on tree growth. Our results raise concerns on the productivity of Himalayan fir forests at low and middle (<3,300 m) elevations as climate change progresses.

Original languageEnglish
JournalGlobal Change Biology
DOIs
Publication statusE-pub ahead of print - 7 Nov 2019

Fingerprint

physiological response
growth response
environmental change
climate
warming
arid region
Drying
tree ring
Climate change
moisture
Moisture
dendrochronology
Carbon Isotopes
climate change
effect
temperature
Springs (water)
water use efficiency
vapor pressure
Vapor pressure

Keywords

  • central Himalaya
  • climate change
  • elevation gradients
  • high-elevation forests
  • Himalayan fir (Abies spectabilis)
  • intrinsic water-use efficiency (iWUE)
  • long-term growth trends
  • tree rings

Cite this

@article{e4e6bbff4be54086b86ec2de35c0736f,
title = "Long-term physiological and growth responses of Himalayan fir to environmental change are mediated by mean climate",
abstract = "High-elevation forests are experiencing high rates of warming, in combination with CO2 rise and (sometimes) drying trends. In these montane systems, the effects of environmental changes on tree growth are also modified by elevation itself, thus complicating our ability to predict effects of future climate change. Tree-ring analysis along an elevation gradient allows quantifying effects of gradual and annual environmental changes. Here, we study long-term physiological (ratio of internal to ambient CO2, i.e., Ci/Ca and intrinsic water-use efficiency, iWUE) and growth responses (tree-ring width) of Himalayan fir (Abies spectabilis) trees in response to warming, drying, and CO2 rise. Our study was conducted along elevational gradients in a dry and a wet region in the central Himalaya. We combined dendrochronology and stable carbon isotopes (δ13C) to quantify long-term trends in Ci/Ca ratio and iWUE (δ13C-derived), growth (mixed-effects models), and evaluate climate sensitivity (correlations). We found that iWUE increased over time at all elevations, with stronger increase in the dry region. Climate–growth relations showed growth-limiting effects of spring moisture (dry region) and summer temperature (wet region), and negative effects of temperature (dry region). We found negative growth trends at lower elevations (dry and wet regions), suggesting that continental-scale warming and regional drying reduced tree growth. This interpretation is supported by δ13C-derived long-term physiological responses, which are consistent with responses to reduced moisture and increased vapor pressure deficit. At high elevations (wet region), we found positive growth trends, suggesting that warming has favored tree growth in regions where temperature most strongly limits growth. At lower elevations (dry and wet regions), the positive effects of CO2 rise did not mitigate the negative effects of warming and drying on tree growth. Our results raise concerns on the productivity of Himalayan fir forests at low and middle (<3,300 m) elevations as climate change progresses.",
keywords = "central Himalaya, climate change, elevation gradients, high-elevation forests, Himalayan fir (Abies spectabilis), intrinsic water-use efficiency (iWUE), long-term growth trends, tree rings",
author = "Shankar Panthi and Fan, {Ze Xin} and {van der Sleen}, Peter and Zuidema, {Pieter A.}",
year = "2019",
month = "11",
day = "7",
doi = "10.1111/gcb.14910",
language = "English",
journal = "Global Change Biology",
issn = "1354-1013",
publisher = "Wiley",

}

Long-term physiological and growth responses of Himalayan fir to environmental change are mediated by mean climate. / Panthi, Shankar; Fan, Ze Xin; van der Sleen, Peter; Zuidema, Pieter A.

In: Global Change Biology, 07.11.2019.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Long-term physiological and growth responses of Himalayan fir to environmental change are mediated by mean climate

AU - Panthi, Shankar

AU - Fan, Ze Xin

AU - van der Sleen, Peter

AU - Zuidema, Pieter A.

PY - 2019/11/7

Y1 - 2019/11/7

N2 - High-elevation forests are experiencing high rates of warming, in combination with CO2 rise and (sometimes) drying trends. In these montane systems, the effects of environmental changes on tree growth are also modified by elevation itself, thus complicating our ability to predict effects of future climate change. Tree-ring analysis along an elevation gradient allows quantifying effects of gradual and annual environmental changes. Here, we study long-term physiological (ratio of internal to ambient CO2, i.e., Ci/Ca and intrinsic water-use efficiency, iWUE) and growth responses (tree-ring width) of Himalayan fir (Abies spectabilis) trees in response to warming, drying, and CO2 rise. Our study was conducted along elevational gradients in a dry and a wet region in the central Himalaya. We combined dendrochronology and stable carbon isotopes (δ13C) to quantify long-term trends in Ci/Ca ratio and iWUE (δ13C-derived), growth (mixed-effects models), and evaluate climate sensitivity (correlations). We found that iWUE increased over time at all elevations, with stronger increase in the dry region. Climate–growth relations showed growth-limiting effects of spring moisture (dry region) and summer temperature (wet region), and negative effects of temperature (dry region). We found negative growth trends at lower elevations (dry and wet regions), suggesting that continental-scale warming and regional drying reduced tree growth. This interpretation is supported by δ13C-derived long-term physiological responses, which are consistent with responses to reduced moisture and increased vapor pressure deficit. At high elevations (wet region), we found positive growth trends, suggesting that warming has favored tree growth in regions where temperature most strongly limits growth. At lower elevations (dry and wet regions), the positive effects of CO2 rise did not mitigate the negative effects of warming and drying on tree growth. Our results raise concerns on the productivity of Himalayan fir forests at low and middle (<3,300 m) elevations as climate change progresses.

AB - High-elevation forests are experiencing high rates of warming, in combination with CO2 rise and (sometimes) drying trends. In these montane systems, the effects of environmental changes on tree growth are also modified by elevation itself, thus complicating our ability to predict effects of future climate change. Tree-ring analysis along an elevation gradient allows quantifying effects of gradual and annual environmental changes. Here, we study long-term physiological (ratio of internal to ambient CO2, i.e., Ci/Ca and intrinsic water-use efficiency, iWUE) and growth responses (tree-ring width) of Himalayan fir (Abies spectabilis) trees in response to warming, drying, and CO2 rise. Our study was conducted along elevational gradients in a dry and a wet region in the central Himalaya. We combined dendrochronology and stable carbon isotopes (δ13C) to quantify long-term trends in Ci/Ca ratio and iWUE (δ13C-derived), growth (mixed-effects models), and evaluate climate sensitivity (correlations). We found that iWUE increased over time at all elevations, with stronger increase in the dry region. Climate–growth relations showed growth-limiting effects of spring moisture (dry region) and summer temperature (wet region), and negative effects of temperature (dry region). We found negative growth trends at lower elevations (dry and wet regions), suggesting that continental-scale warming and regional drying reduced tree growth. This interpretation is supported by δ13C-derived long-term physiological responses, which are consistent with responses to reduced moisture and increased vapor pressure deficit. At high elevations (wet region), we found positive growth trends, suggesting that warming has favored tree growth in regions where temperature most strongly limits growth. At lower elevations (dry and wet regions), the positive effects of CO2 rise did not mitigate the negative effects of warming and drying on tree growth. Our results raise concerns on the productivity of Himalayan fir forests at low and middle (<3,300 m) elevations as climate change progresses.

KW - central Himalaya

KW - climate change

KW - elevation gradients

KW - high-elevation forests

KW - Himalayan fir (Abies spectabilis)

KW - intrinsic water-use efficiency (iWUE)

KW - long-term growth trends

KW - tree rings

U2 - 10.1111/gcb.14910

DO - 10.1111/gcb.14910

M3 - Article

JO - Global Change Biology

JF - Global Change Biology

SN - 1354-1013

ER -