Growth responses to arbuscular mycorrhizae by rain forest seedlings vary with light intensity and tree species

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

Light intensity and root colonization by arbuscular mycorrhizal (AM) fungi are considered important factors affecting the performance of rain forest plants, yet few studies have examined how these two factors interact. Whether AM colonization promoted growth or caused shifts in biomass allocation in seedlings of four species of Australian rain forest tree (Flindersia brayleana, Acmena resa, Cryptocarya mackinnoniana and Cryptocarya angulata), grown in a glasshouse under light conditions that mimicked the shaded understory (3% PAR) and small light gaps (10% PAR), was examined. Seedlings were grown in sterilized field soil and either inoculated with AM fungi or provided sterile inoculum. Four major findings emerged. First, in all species, seedlings grown in small gap light intensities were larger than seedlings grown in understory light intensities. Second, when seedling biomass was included as a covariate, variation in light intensity was associated with significant shifts in biomass allocation. In all species, leaf area ratio was lower at 10% PAR than at 3% PAR, while root-to-shoot ratio showed the opposite pattern in one of the four species (C. mackinonniana). Third, although percentage root length colonized by AM fungi was greater at 10% PAR than 3% PAR in all species, this difference could be accounted for by variation in seedling size in all species except C. angulata. Fourth, growth and biomass allocation responses to AM colonization varied with light intensity and plant species. AM colonization promoted growth in both light regimes only in F. brayleana, while it had no effect on growth in C. mackinnoniana and C. angulata in either light regime and promoted growth only under high light in A. resa. AM colonization had no effect on leaf area ratio or root-to-shoot ratio in any of the species, and significantly altered specific root length in only one of the four species (C. mackinnoniana). These findings suggest that rain forest seedlings are highly variable in their growth responses to AM colonization and that some of this variability is related to the light intensity of the environment. Given that seedlings may spend many years in the shaded understory, these differences among species could have important effects on long-term seedling performance and seedling community dynamics.

Original languageEnglish (US)
Pages (from-to)127-139
Number of pages13
JournalPlant Ecology
Volume167
Issue number1
DOIs
StatePublished - 2003

Fingerprint

arbuscular mycorrhiza
growth response
mycorrhizae
light intensity
rain forests
seedling
photosynthetically active radiation
seedlings
colonization
biomass allocation
dry matter partitioning
Cryptocarya
understory
mycorrhizal fungi
fungus
root shoot ratio
interspecific variation
leaf area
Flindersia
shoot

Keywords

  • Arbuscular mycorrhizae
  • Biomass allocation
  • Light gap
  • Rain forest
  • Seedling
  • Shaded understory

ASJC Scopus subject areas

  • Forestry
  • Plant Science
  • Ecology

Cite this

Growth responses to arbuscular mycorrhizae by rain forest seedlings vary with light intensity and tree species. / Gehring, Catherine A.

In: Plant Ecology, Vol. 167, No. 1, 2003, p. 127-139.

Research output: Contribution to journalArticle

@article{e39e93bce9f74ce7bdc17fe2ef549867,
title = "Growth responses to arbuscular mycorrhizae by rain forest seedlings vary with light intensity and tree species",
abstract = "Light intensity and root colonization by arbuscular mycorrhizal (AM) fungi are considered important factors affecting the performance of rain forest plants, yet few studies have examined how these two factors interact. Whether AM colonization promoted growth or caused shifts in biomass allocation in seedlings of four species of Australian rain forest tree (Flindersia brayleana, Acmena resa, Cryptocarya mackinnoniana and Cryptocarya angulata), grown in a glasshouse under light conditions that mimicked the shaded understory (3{\%} PAR) and small light gaps (10{\%} PAR), was examined. Seedlings were grown in sterilized field soil and either inoculated with AM fungi or provided sterile inoculum. Four major findings emerged. First, in all species, seedlings grown in small gap light intensities were larger than seedlings grown in understory light intensities. Second, when seedling biomass was included as a covariate, variation in light intensity was associated with significant shifts in biomass allocation. In all species, leaf area ratio was lower at 10{\%} PAR than at 3{\%} PAR, while root-to-shoot ratio showed the opposite pattern in one of the four species (C. mackinonniana). Third, although percentage root length colonized by AM fungi was greater at 10{\%} PAR than 3{\%} PAR in all species, this difference could be accounted for by variation in seedling size in all species except C. angulata. Fourth, growth and biomass allocation responses to AM colonization varied with light intensity and plant species. AM colonization promoted growth in both light regimes only in F. brayleana, while it had no effect on growth in C. mackinnoniana and C. angulata in either light regime and promoted growth only under high light in A. resa. AM colonization had no effect on leaf area ratio or root-to-shoot ratio in any of the species, and significantly altered specific root length in only one of the four species (C. mackinnoniana). These findings suggest that rain forest seedlings are highly variable in their growth responses to AM colonization and that some of this variability is related to the light intensity of the environment. Given that seedlings may spend many years in the shaded understory, these differences among species could have important effects on long-term seedling performance and seedling community dynamics.",
keywords = "Arbuscular mycorrhizae, Biomass allocation, Light gap, Rain forest, Seedling, Shaded understory",
author = "Gehring, {Catherine A}",
year = "2003",
doi = "10.1023/A:1023989610773",
language = "English (US)",
volume = "167",
pages = "127--139",
journal = "Plant Ecology",
issn = "1385-0237",
publisher = "Springer Netherlands",
number = "1",

}

TY - JOUR

T1 - Growth responses to arbuscular mycorrhizae by rain forest seedlings vary with light intensity and tree species

AU - Gehring, Catherine A

PY - 2003

Y1 - 2003

N2 - Light intensity and root colonization by arbuscular mycorrhizal (AM) fungi are considered important factors affecting the performance of rain forest plants, yet few studies have examined how these two factors interact. Whether AM colonization promoted growth or caused shifts in biomass allocation in seedlings of four species of Australian rain forest tree (Flindersia brayleana, Acmena resa, Cryptocarya mackinnoniana and Cryptocarya angulata), grown in a glasshouse under light conditions that mimicked the shaded understory (3% PAR) and small light gaps (10% PAR), was examined. Seedlings were grown in sterilized field soil and either inoculated with AM fungi or provided sterile inoculum. Four major findings emerged. First, in all species, seedlings grown in small gap light intensities were larger than seedlings grown in understory light intensities. Second, when seedling biomass was included as a covariate, variation in light intensity was associated with significant shifts in biomass allocation. In all species, leaf area ratio was lower at 10% PAR than at 3% PAR, while root-to-shoot ratio showed the opposite pattern in one of the four species (C. mackinonniana). Third, although percentage root length colonized by AM fungi was greater at 10% PAR than 3% PAR in all species, this difference could be accounted for by variation in seedling size in all species except C. angulata. Fourth, growth and biomass allocation responses to AM colonization varied with light intensity and plant species. AM colonization promoted growth in both light regimes only in F. brayleana, while it had no effect on growth in C. mackinnoniana and C. angulata in either light regime and promoted growth only under high light in A. resa. AM colonization had no effect on leaf area ratio or root-to-shoot ratio in any of the species, and significantly altered specific root length in only one of the four species (C. mackinnoniana). These findings suggest that rain forest seedlings are highly variable in their growth responses to AM colonization and that some of this variability is related to the light intensity of the environment. Given that seedlings may spend many years in the shaded understory, these differences among species could have important effects on long-term seedling performance and seedling community dynamics.

AB - Light intensity and root colonization by arbuscular mycorrhizal (AM) fungi are considered important factors affecting the performance of rain forest plants, yet few studies have examined how these two factors interact. Whether AM colonization promoted growth or caused shifts in biomass allocation in seedlings of four species of Australian rain forest tree (Flindersia brayleana, Acmena resa, Cryptocarya mackinnoniana and Cryptocarya angulata), grown in a glasshouse under light conditions that mimicked the shaded understory (3% PAR) and small light gaps (10% PAR), was examined. Seedlings were grown in sterilized field soil and either inoculated with AM fungi or provided sterile inoculum. Four major findings emerged. First, in all species, seedlings grown in small gap light intensities were larger than seedlings grown in understory light intensities. Second, when seedling biomass was included as a covariate, variation in light intensity was associated with significant shifts in biomass allocation. In all species, leaf area ratio was lower at 10% PAR than at 3% PAR, while root-to-shoot ratio showed the opposite pattern in one of the four species (C. mackinonniana). Third, although percentage root length colonized by AM fungi was greater at 10% PAR than 3% PAR in all species, this difference could be accounted for by variation in seedling size in all species except C. angulata. Fourth, growth and biomass allocation responses to AM colonization varied with light intensity and plant species. AM colonization promoted growth in both light regimes only in F. brayleana, while it had no effect on growth in C. mackinnoniana and C. angulata in either light regime and promoted growth only under high light in A. resa. AM colonization had no effect on leaf area ratio or root-to-shoot ratio in any of the species, and significantly altered specific root length in only one of the four species (C. mackinnoniana). These findings suggest that rain forest seedlings are highly variable in their growth responses to AM colonization and that some of this variability is related to the light intensity of the environment. Given that seedlings may spend many years in the shaded understory, these differences among species could have important effects on long-term seedling performance and seedling community dynamics.

KW - Arbuscular mycorrhizae

KW - Biomass allocation

KW - Light gap

KW - Rain forest

KW - Seedling

KW - Shaded understory

UR - http://www.scopus.com/inward/record.url?scp=0038718751&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0038718751&partnerID=8YFLogxK

U2 - 10.1023/A:1023989610773

DO - 10.1023/A:1023989610773

M3 - Article

VL - 167

SP - 127

EP - 139

JO - Plant Ecology

JF - Plant Ecology

SN - 1385-0237

IS - 1

ER -