What controls variation in carbon use efficiency among Amazonian tropical forests?

Research output: Contribution to journalArticle

Abstract

Why do some forests produce biomass more efficiently than others? Variations in Carbon Use Efficiency (CUE: total Net Primary Production (NPP)/ Gross Primary Production (GPP)) may be due to changes in wood residence time (Biomass/NPPwood), temperature, or soil nutrient status. We tested these hypotheses in 14, one ha plots across Amazonian and Andean forests where we measured most key components of net primary production (NPP: wood, fine roots, and leaves) and autotrophic respiration (Ra; wood, rhizosphere, and leaf respiration). We found that lower fertility sites were less efficient at producing biomass and had higher rhizosphere respiration, indicating increased carbon allocation to belowground components. We then compared wood respiration to wood growth and rhizosphere respiration to fine root growth and found that forests with residence times <40 yrs had significantly lower maintenance respiration for both wood and fine roots than forests with residence times >40 yrs. A comparison of rhizosphere respiration to fine root growth showed that rhizosphere growth respiration was significantly greater at low fertility sites. Overall, we found that Amazonian forests produce biomass less efficiently in stands with residence times >40 yrs and in stands with lower fertility, but changes to long-term mean annual temperatures do not impact CUE.

Details

Authors
  • Christopher E. Doughty
  • Gregory R. Goldsmith
  • Nicolas Raab
  • Cecile A. J. Girardin
  • Filio Farfan Amezquita
  • Walter Huaraca Huasco
  • Javier E. Silva Espejo
  • Alejandro Araujo-Murakami
  • Antonio C. L. da Costa
  • Wanderley Rocha
  • David Galbraith
  • Patrick Meir
  • Dan B. Metcalfe
  • Yadvinder Malhi
Organisations
External organisations
  • Northern Arizona University
  • University of Oxford
  • Universidad de La Serena
  • University of Leeds
  • University of Edinburgh
  • Paul Scherrer Institute
  • Chapman University
  • National University of Saint Anthony the Abbot in Cuzco
  • Gabriel René Moreno Autonomous University
  • Federal University of Pará
  • Amazon Environmental Research Institute (IPAM)
  • Australian National University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Ecology
  • Botany

Keywords

  • CUE, GPP, NPP, Amazonia, Temperature
Original languageEnglish
Pages (from-to)16-25
JournalBiotropica
Volume50
Issue number1
Early online date2017 Oct 10
Publication statusPublished - 2018 Jan
Publication categoryResearch
Peer-reviewedYes