Meny

Javascript verkar inte påslaget? - Vissa delar av Lunds universitets webbplats fungerar inte optimalt utan javascript, kontrollera din webbläsares inställningar.
Du är här

Plant and microbial uptake and allocation of organic and inorganic nitrogen related to plant growth forms and soil conditions at two subarctic tundra types

Författare:
  • P L Sørensen
  • K E Clemmensen
  • A Michelsen
  • S Jonasson
  • Lena Ström
Publiceringsår: 2008
Språk: Engelska
Sidor: 171-180
Publikation/Tidskrift/Serie: Arctic, Antarctic and Alpine Research
Volym: 40
Nummer: 1
Dokumenttyp: Artikel
Förlag: Institute of Arctic and Alpine Research, University of Colorado at Boulder

Sammanfattning

In order to follow the uptake and allocation of N in different plant functional types and microbes in two tundra ecosystems differing in nutrient availability, we performed a 15N-labeling experiment with three N forms and followed the partitioning of 15N label among plants, microorganisms and soil organic matter. At both sites the deciduous dwarf shrub Betula nana and the evergreen Empetrum hermaphroditum absorbed added 15N at rates in the order: NH4+ > NO3− > glycine, in contrast to the graminoid Carex species which took up added 15N at rates in the order NO3− > NH4+ > glycine. Carex transported a high proportion of 15N to aboveground parts, whereas the dwarf shrubs allocated most 15N to underground storage. Enhanced 13C in Betula nana roots represents the first field evidence of uptake of intact glycine by this important circumpolar plant. Plant and microbial uptake of label was complementary as plants took up more inorganic than organic N, while microbes preferred organic N. Microbes initially took up a large part of the added label, but over the following four weeks microbial 15N decreased by 50% and most 15N was recovered in soil organic matter, while a smaller but slowly increasing proportion was retained in plant biomass.

Disputation

Nyckelord

  • Earth and Environmental Sciences

Övriga

Published
Yes
  • ISSN: 1523-0430

Box 117, 221 00 LUND
Telefon 046-222 00 00 (växel)
Telefax 046-222 47 20
lu [at] lu [dot] se

Fakturaadress: Box 188, 221 00 LUND
Organisationsnummer: 202100-3211
Om webbplatsen