High-frequency fire alters soil and plant chemistry but does not lead to nitrogen-limited growth of Eucalyptus pilularis seedlings

Orpheus M. Butler, Mehran Rezaei Rashti, Tom Lewis, James J. Elser, Chengrong Chen

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

Background and aims: Vegetation fire often raises levels of soil phosphorus (P) relative to those of nitrogen (N), while long-term fire exclusion is associated with accumulation of soil N and depletion of soil available P. Thus, high-frequency fire regimes might trigger N-limited plant growth in otherwise P-limited plant communities. Methods: We used soils from a long-term prescribed burning trial to grow Eucalyptus pilularis under several nutrient amendment conditions. We measured seedling growth, soil and plant chemistry, and root enzyme activities to assess nutrient status. Results: Biennially-burned (2yB) soils had higher labile P concentrations than long-unburned (NB) soils, and lower total and labile N:P ratios. This did not correspond to N-limited growth or stimulate seedling N demand. Seedlings grown with addition of N, P and micro-nutrients in combination (μMax treatment) attained 68% more biomass than unfertilised seedlings. Addition of P resulted in higher total biomass than addition of N, and similar biomass to the μMax treatment, suggesting partially P-limited growth. Plants grown in 2yB soils tended to be enriched with P, K, Ca and Mg compared to those grown in NB or 4yB soils. Conclusions: High-frequency prescribed burning depletes soil N relative to P, but this does not trigger a shift toward N-limited growth of E. pilularis seedlings. Instead, E. pilularis seedlings appear to grow under partial P-limitation which persists regardless of their soil’s fire history.

Original languageEnglish (US)
Pages (from-to)191-205
Number of pages15
JournalPlant and Soil
Volume432
Issue number1-2
DOIs
StatePublished - Nov 1 2018

Keywords

  • Ash deposition
  • Chitinase
  • Phosphatase
  • Prescribed burning
  • Stoichiometry

ASJC Scopus subject areas

  • Soil Science
  • Plant Science

Fingerprint Dive into the research topics of 'High-frequency fire alters soil and plant chemistry but does not lead to nitrogen-limited growth of Eucalyptus pilularis seedlings'. Together they form a unique fingerprint.

  • Cite this