Increased photosynthesis offsets costs of allocation to sapwood in an arid environment

Eileen V. Carey, Ragan M. Callaway, Evan H Delucia

Research output: Contribution to journalArticle

Abstract

We assessed the effect that varying patterns of biomass allocation had on growth of ponderosa pine (Pinus ponderosa) growing in the desert climate of the Great Basin and the montane climate of the eastern Sierra Nevada. Prior work established that desert trees have lower leaf: sapwood area ratios than montane trees (0.104 and 0.201 m 2 /cm 2 , respectively) and proportionally greater stem respiration. Sapwood: leaf mass ratios are also greater and increase more as a function stem diameter in desert than in montane trees. We hypothesized that this increased allocation of carbon to stem sapwood and stem respiration in large trees could decrease growth rates in the desert compared to the montane environment, in addition to any growth reduction imposed by drought on physiology and growth processes. Trees of all diameters (dbh) in the desert environment had lower relative growth rates (RGRs) than montane trees (e.g., for a 30 cm dbh tree, RGR = 0.012 vs. 0.021 kg · kg -1 · yr -1 , respectively). However, growth rates of desert and montane trees declined similarly with increasing dbh and did not reflect diverging sapwood: leaf mass ratios. Alternatively, we hypothesized that desert trees may increase rates of photosynthetic carbon accumulation (per unit leaf area) with diameter, thereby compensating for increased sapwood respiration. Leaf nitrogen (N) concentration and stable-carbon isotope composition (δ 13 C) were measured to examine size-dependent and seasonally integrated photosynthetic capacity within desert and montane environments. Nitrogen concentration was correlated with photosynthetic capacity. Leaf nitrogen (N) concentration and δ 13 C values were greater in the desert (e.g., in 1-yr-old needles, desert = 1.11% and -22.96‰; montane = 0.94% and -24.20‰) and differed between desert and montane trees as a function of dbh. In desert trees, leaf nitrogen concentration in 1-yr-old through 5-yr-old needles increased with dbh, and carbon isotope composition in 1-yr-old needles increased with dbh, suggesting increased photosynthetic capacity and photosynthetic rates with increasing tree size. Needle nitrogen concentration and δ 13 C values decreased or remained constant with dbh in montane trees. Desert trees had greater light extinction coefficients and retained fewer needle cohorts. Our results suggest that increased allocation to heterotrophic stem tissue at the expense of photosynthetic tissue does not always incur a reduction in tree growth as predicted by current models of forest productivity.

Original languageEnglish (US)
Pages (from-to)2281-2291
Number of pages11
JournalEcology
Volume79
Issue number7
DOIs
StatePublished - Jan 1 1998

Fingerprint

dry environmental conditions
arid environment
sapwood
photosynthesis
deserts
desert
cost
stem
stems
breathing
nitrogen
leaves
mountain environment
carbon
respiration
Pinus ponderosa
allocation
leaf area
isotopes
carbon isotope

Keywords

  • Canopy light interception
  • Carbon isotope ratio
  • Forest productivity
  • Forest stand development
  • Leaf age
  • Leaf area index
  • Light extinction coefficient
  • Nitrogen
  • Photosynthetic capacity
  • Pinus ponderosa
  • Relative growth rate

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Cite this

Increased photosynthesis offsets costs of allocation to sapwood in an arid environment. / Carey, Eileen V.; Callaway, Ragan M.; Delucia, Evan H.

In: Ecology, Vol. 79, No. 7, 01.01.1998, p. 2281-2291.

Research output: Contribution to journalArticle

Carey, Eileen V. ; Callaway, Ragan M. ; Delucia, Evan H. / Increased photosynthesis offsets costs of allocation to sapwood in an arid environment. In: Ecology. 1998 ; Vol. 79, No. 7. pp. 2281-2291.
@article{c62358782c8f4d8cbc914104d406dcee,
title = "Increased photosynthesis offsets costs of allocation to sapwood in an arid environment",
abstract = "We assessed the effect that varying patterns of biomass allocation had on growth of ponderosa pine (Pinus ponderosa) growing in the desert climate of the Great Basin and the montane climate of the eastern Sierra Nevada. Prior work established that desert trees have lower leaf: sapwood area ratios than montane trees (0.104 and 0.201 m 2 /cm 2 , respectively) and proportionally greater stem respiration. Sapwood: leaf mass ratios are also greater and increase more as a function stem diameter in desert than in montane trees. We hypothesized that this increased allocation of carbon to stem sapwood and stem respiration in large trees could decrease growth rates in the desert compared to the montane environment, in addition to any growth reduction imposed by drought on physiology and growth processes. Trees of all diameters (dbh) in the desert environment had lower relative growth rates (RGRs) than montane trees (e.g., for a 30 cm dbh tree, RGR = 0.012 vs. 0.021 kg · kg -1 · yr -1 , respectively). However, growth rates of desert and montane trees declined similarly with increasing dbh and did not reflect diverging sapwood: leaf mass ratios. Alternatively, we hypothesized that desert trees may increase rates of photosynthetic carbon accumulation (per unit leaf area) with diameter, thereby compensating for increased sapwood respiration. Leaf nitrogen (N) concentration and stable-carbon isotope composition (δ 13 C) were measured to examine size-dependent and seasonally integrated photosynthetic capacity within desert and montane environments. Nitrogen concentration was correlated with photosynthetic capacity. Leaf nitrogen (N) concentration and δ 13 C values were greater in the desert (e.g., in 1-yr-old needles, desert = 1.11{\%} and -22.96‰; montane = 0.94{\%} and -24.20‰) and differed between desert and montane trees as a function of dbh. In desert trees, leaf nitrogen concentration in 1-yr-old through 5-yr-old needles increased with dbh, and carbon isotope composition in 1-yr-old needles increased with dbh, suggesting increased photosynthetic capacity and photosynthetic rates with increasing tree size. Needle nitrogen concentration and δ 13 C values decreased or remained constant with dbh in montane trees. Desert trees had greater light extinction coefficients and retained fewer needle cohorts. Our results suggest that increased allocation to heterotrophic stem tissue at the expense of photosynthetic tissue does not always incur a reduction in tree growth as predicted by current models of forest productivity.",
keywords = "Canopy light interception, Carbon isotope ratio, Forest productivity, Forest stand development, Leaf age, Leaf area index, Light extinction coefficient, Nitrogen, Photosynthetic capacity, Pinus ponderosa, Relative growth rate",
author = "Carey, {Eileen V.} and Callaway, {Ragan M.} and Delucia, {Evan H}",
year = "1998",
month = "1",
day = "1",
doi = "10.1890/0012-9658(1998)079[2281:IPOCOA]2.0.CO;2",
language = "English (US)",
volume = "79",
pages = "2281--2291",
journal = "Ecology",
issn = "0012-9658",
publisher = "Ecological Society of America",
number = "7",

}

TY - JOUR

T1 - Increased photosynthesis offsets costs of allocation to sapwood in an arid environment

AU - Carey, Eileen V.

AU - Callaway, Ragan M.

AU - Delucia, Evan H

PY - 1998/1/1

Y1 - 1998/1/1

N2 - We assessed the effect that varying patterns of biomass allocation had on growth of ponderosa pine (Pinus ponderosa) growing in the desert climate of the Great Basin and the montane climate of the eastern Sierra Nevada. Prior work established that desert trees have lower leaf: sapwood area ratios than montane trees (0.104 and 0.201 m 2 /cm 2 , respectively) and proportionally greater stem respiration. Sapwood: leaf mass ratios are also greater and increase more as a function stem diameter in desert than in montane trees. We hypothesized that this increased allocation of carbon to stem sapwood and stem respiration in large trees could decrease growth rates in the desert compared to the montane environment, in addition to any growth reduction imposed by drought on physiology and growth processes. Trees of all diameters (dbh) in the desert environment had lower relative growth rates (RGRs) than montane trees (e.g., for a 30 cm dbh tree, RGR = 0.012 vs. 0.021 kg · kg -1 · yr -1 , respectively). However, growth rates of desert and montane trees declined similarly with increasing dbh and did not reflect diverging sapwood: leaf mass ratios. Alternatively, we hypothesized that desert trees may increase rates of photosynthetic carbon accumulation (per unit leaf area) with diameter, thereby compensating for increased sapwood respiration. Leaf nitrogen (N) concentration and stable-carbon isotope composition (δ 13 C) were measured to examine size-dependent and seasonally integrated photosynthetic capacity within desert and montane environments. Nitrogen concentration was correlated with photosynthetic capacity. Leaf nitrogen (N) concentration and δ 13 C values were greater in the desert (e.g., in 1-yr-old needles, desert = 1.11% and -22.96‰; montane = 0.94% and -24.20‰) and differed between desert and montane trees as a function of dbh. In desert trees, leaf nitrogen concentration in 1-yr-old through 5-yr-old needles increased with dbh, and carbon isotope composition in 1-yr-old needles increased with dbh, suggesting increased photosynthetic capacity and photosynthetic rates with increasing tree size. Needle nitrogen concentration and δ 13 C values decreased or remained constant with dbh in montane trees. Desert trees had greater light extinction coefficients and retained fewer needle cohorts. Our results suggest that increased allocation to heterotrophic stem tissue at the expense of photosynthetic tissue does not always incur a reduction in tree growth as predicted by current models of forest productivity.

AB - We assessed the effect that varying patterns of biomass allocation had on growth of ponderosa pine (Pinus ponderosa) growing in the desert climate of the Great Basin and the montane climate of the eastern Sierra Nevada. Prior work established that desert trees have lower leaf: sapwood area ratios than montane trees (0.104 and 0.201 m 2 /cm 2 , respectively) and proportionally greater stem respiration. Sapwood: leaf mass ratios are also greater and increase more as a function stem diameter in desert than in montane trees. We hypothesized that this increased allocation of carbon to stem sapwood and stem respiration in large trees could decrease growth rates in the desert compared to the montane environment, in addition to any growth reduction imposed by drought on physiology and growth processes. Trees of all diameters (dbh) in the desert environment had lower relative growth rates (RGRs) than montane trees (e.g., for a 30 cm dbh tree, RGR = 0.012 vs. 0.021 kg · kg -1 · yr -1 , respectively). However, growth rates of desert and montane trees declined similarly with increasing dbh and did not reflect diverging sapwood: leaf mass ratios. Alternatively, we hypothesized that desert trees may increase rates of photosynthetic carbon accumulation (per unit leaf area) with diameter, thereby compensating for increased sapwood respiration. Leaf nitrogen (N) concentration and stable-carbon isotope composition (δ 13 C) were measured to examine size-dependent and seasonally integrated photosynthetic capacity within desert and montane environments. Nitrogen concentration was correlated with photosynthetic capacity. Leaf nitrogen (N) concentration and δ 13 C values were greater in the desert (e.g., in 1-yr-old needles, desert = 1.11% and -22.96‰; montane = 0.94% and -24.20‰) and differed between desert and montane trees as a function of dbh. In desert trees, leaf nitrogen concentration in 1-yr-old through 5-yr-old needles increased with dbh, and carbon isotope composition in 1-yr-old needles increased with dbh, suggesting increased photosynthetic capacity and photosynthetic rates with increasing tree size. Needle nitrogen concentration and δ 13 C values decreased or remained constant with dbh in montane trees. Desert trees had greater light extinction coefficients and retained fewer needle cohorts. Our results suggest that increased allocation to heterotrophic stem tissue at the expense of photosynthetic tissue does not always incur a reduction in tree growth as predicted by current models of forest productivity.

KW - Canopy light interception

KW - Carbon isotope ratio

KW - Forest productivity

KW - Forest stand development

KW - Leaf age

KW - Leaf area index

KW - Light extinction coefficient

KW - Nitrogen

KW - Photosynthetic capacity

KW - Pinus ponderosa

KW - Relative growth rate

UR - http://www.scopus.com/inward/record.url?scp=0031691866&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031691866&partnerID=8YFLogxK

U2 - 10.1890/0012-9658(1998)079[2281:IPOCOA]2.0.CO;2

DO - 10.1890/0012-9658(1998)079[2281:IPOCOA]2.0.CO;2

M3 - Article

AN - SCOPUS:0031691866

VL - 79

SP - 2281

EP - 2291

JO - Ecology

JF - Ecology

SN - 0012-9658

IS - 7

ER -