Favorable effect of mycorrhizae on biomass production efficiency exceeds their carbon cost in a fertilization experiment

Research output: Contribution to journalArticle

Abstract

Biomass production efficiency (BPE), the ratio of biomass production to photosynthesis, varies greatly among ecosystems and typically increases with increasing nutrient availability. Reduced carbon partitioning to mycorrhizal fungi (i.e., per unit photosynthesis) is the hypothesized underlying mechanism, as mycorrhizal abundance and plant dependence on these symbionts typically decrease with increasing nutrient availability. In a mesocosm experiment with Zea mays, we investigated the effect of nitrogen (N) and phosphorus (P) addition and of mycorrhizal inoculation on BPE. Photosynthesis and respiration were measured at mesocosm scale and at leaf scale. The growth of arbuscular mycorrhizal fungi (AMF) was assessed with ingrowth bags while also making use of the difference in δ13C between C4 plants and C3 soil. Mesocosms without AMF, that is, with pasteurized soil, were used to further explore the role of AMF. Plant growth, photosynthesis, and BPE were positively affected by P, but not by N addition. AMF biomass also was slightly higher under P addition, but carbon partitioning to AMF was significantly lower than without P addition. Interestingly, in the absence of AMF, plants that did not receive P died prematurely. Our study confirmed the hypothesis that BPE increases with increasing nutrient availability, and that carbon partitioning to AMF plays a key role in this nutrient effect. The comparison of inoculated vs. pasteurized mesocosms further suggested a lower carbon cost of nutrient uptake via AMF than via other mechanisms under nutrient rich conditions.

Details

Authors
  • Melanie S. Verlinden
  • Arne Ven
  • Erik Verbruggen
  • Ivan A. Janssens
  • Håkan Wallander
  • Sara Vicca
Organisations
External organisations
  • University of Antwerp
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Ecology
  • Botany

Keywords

  • arbuscular mycorrhizae, biomass production efficiency, carbon allocation, carbon use efficiency, mesocosm experiment, nitrogen, nutrient availability, phosphorus
Original languageEnglish
Pages (from-to)2525-2534
JournalEcology
Volume99
Issue number11
Early online date2018 Sep 14
Publication statusPublished - 2018
Publication categoryResearch
Peer-reviewedYes