Abstract
Growing Miscanthus species and hybrids has received strong scientific and commercial support, with the majority of the carbon (C) modelling predictions having focused on the high-yield, sterile and noninvasive hybrid Miscanthus x giganteus. However, the potential of other species with contrasting phenotypic and physiological traits has been seldom explored. To better understand the mechanisms underlying C allocation dynamics in these bioenergy crops, we pulse-labelled (13CO2) intact plant-soil systems of Miscanthus x giganteus (GIG), Miscanthus sinensis (SIN) and Miscanthus lutarioriparius (LUT) and regularly analysed soil respiration, leaves, stems, rhizomes, roots and soils for up to 190 days until leaf senescence. A rapid isotopic enrichment of all three species was observed after 4 h, with the amount of 13C fixed into plant biomass being inversely related to their respective standing biomass prior to pulse-labelling (i.e., GIG < SIN < LUT). However, both GIG and LUT allocated more photoassimilates in the aboveground biomass (leaves+stems = 78% and 74%, respectively) than SIN, which transfererred 30% of fixed 13C in its belowground biomass (rhizomes+roots). Although less fixed 13C was recovered from the soils (<1%), both rhizospheric and bulk soils were signficantly more enriched under SIN and LUT than under GIG. Importantly, the soils under SIN emitted less CO2, which suggests it could be the best choice for reaching C neutrality. These results from this unique large-scale study indicate that careful species selection may hold the success for reaching net GHG mitigation.
Original language | English |
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Article number | 164003 |
Number of pages | 13 |
Journal | Science of the Total Environment |
Volume | 887 |
Early online date | 9 May 2023 |
DOIs | |
Publication status | Published - 20 Aug 2023 |
Bibliographical note
This work was supported by Energy Technologies Institute (ETI) Ecosystem Land Use Modelling project. NPM and DMOE were also supported by the Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme delivering National Capability. Additionally, KF and ID were supported by the Biotechnology and Biological Sciences Council (BBSRC) through the Core Strategic Programme in Resilient Crops: BBS/E/W/0012843A. We thank Kate Rolt, Rebecca Rowe, Rachel Marshall and Jonathan Oxley for field and laboratory support. Authors also acknowledge funding for open access charge from Universidade de Vigo/CISUG.Data Availability Statement
Data will be made available on request.Keywords
- 13CO2 pulse labelling
- carbon storage
- Miscanthus x giganteus
- Miscanthus sinensis
- Miscanthus lutarioriparius
- soil respiration