CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Functional Plant Biology   
Functional Plant Biology
Journal Banner
  Plant Function & Evolutionary Biology
 
blank image Search
 
blank image blank image
blank image
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Board
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Reviews
Evolutionary Reviews
Sample Issue
For Authors
General Information
Notice to Authors
Submit Article
Open Access
For Referees
Referee Guidelines
Review Article
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter youtube

red arrow PrometheusWiki
blank image
PrometheusWiki
Protocols in ecological and environmental plant physiology

 

Article << Previous     |     Next >>   Contents Vol 33(7)

Potential organic and inorganic N uptake by six Eucalyptus species

C. R. Warren

School of Forest and Ecosystem Science, The University of Melbourne, Water Street, Creswick, Vic. 3363, Australia. Email: crwarren@unimelb.edu.au
 
PDF (149 KB) $25
 Export Citation
 Print
  


Abstract

There are no published studies of organic N uptake by species of south-eastern Australia (e.g. Eucalyptus) despite several studies of ecosystem N cycling. This study examines uptake of nitrate, ammonium and glycine (an amino acid) by six species of 16-year-old Eucalyptus growing at two plantations (‘common gardens’). By using two plantations, one xeric / oligotrophic and one mesic / eutrophic, I was able to disentangle genotypic from phenotypic differences in preference for N forms. Measurements were made on three separate occasions during spring. N uptake was examined in situ with attached roots placed in uptake solutions containing equimolar 100 μmol L–1 concentrations of 15N-nitrate, 15N-ammonium and 2-13C215N-glycine. Water and KCl extracts were used to determine the relative abundances of nitrate, ammonium and amino acids at the two plantations. Nitrate dominated at the eutrophic site, but was nearly absent at the oligotrophic site. N at the oligotrophic site was dominated by ammonium and amino acids which were present in similar concentrations. The rate of uptake of ammonium (6.3 ± 0.4 μmol g h–1; mean ± s.e., n = 108), was faster than glycine (3.4 ± 0.2), which was faster than nitrate (0.62 ± 0.07). Plant ‘preference’ for N forms did not vary between sites despite large differences in the relative abundances of N forms (nitrate v. ammonium v. amino acids). Hence, there was little evidence for acclimation of Eucalyptus species to differences in the relative availability of N forms. This study suggests the possibility for considerable organic N uptake in the field. Previous studies of ecosystem N cycling in south-eastern Australia have only examined inorganic N. The N cycle in south-eastern Australia needs to be revisited with a new perspective, one that considers inorganic N and organic N.

Keywords: amino acid, ammonium, common garden, Eucalyptus, glycine, nitrate, nitrogen, organic N, plantation, uptake.


   
Subscriber Login
Username:
Password:  

    
Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2014