Carbon isotope compositions (δ13C) of leaf, wood and holocellulose differ among genotypes of poplar and between previous land uses in a short‐rotation biomass plantation

• Published in: Plant, cell and environment Vol. 38; no. 1; pp. 144 - 156
• Main Authors: VERLINDEN, M. S, FICHOT, R, BROECKX, L. S, VANHOLME, B, BOERJAN, W, CEULEMANS, R
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Scientific Publications 01-01-2015; Wiley Subscription Services, Inc
• Subjects: bioenergy; biomass; carbon; carbon isotope discrimination; correlation; cropland; genotype; genotypic variations; growing season; growth; isotopes; land use; leaves; outreach; pasture; pastures; phenology; photosynthesis; plantations; Populus; Populus spp; trees; water relations; water use efficiency; wood
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.12383

The efficiency of water use to produce biomass is a key trait in designing sustainable bioenergy‐devoted systems. We characterized variations in the carbon isotope composition (δ¹³C) of leaves, current year wood and holocellulose (as proxies for water use efficiency, WUE) among six poplar genotypes in a short‐rotation plantation. Values of δ¹³Cwₒₒdand δ¹³Cₕₒₗₒcₑₗₗᵤₗₒₛₑwere tightly and positively correlated, but the offset varied significantly among genotypes (0.79–1.01‰). Leaf phenology was strongly correlated with δ¹³C, and genotypes with a longer growing season showed a higher WUE. In contrast, traits related to growth and carbon uptake were poorly linked to δ¹³C. Trees growing on former pasture with higher N‐availability displayed higher δ¹³C as compared with trees growing on former cropland. The positive relationships between δ¹³Cₗₑₐfand leaf N suggested that spatial variations in WUE over the plantation were mainly driven by an N‐related effect on photosynthetic capacities. The very coherent genotype ranking obtained with δ¹³C in the different tree compartments has some practical outreach. Because WUE remains largely uncoupled from growth in poplar plantations, there is potential to identify genotypes with satisfactory growth and higher WUE.