Using Plant Functional Traits to Define the Biomass Energy Potential of Invasive Alien Plant Species

Abstract

The eradication of invasive alien plant species (IAPS) is mandatory worldwide, but the resulting biomass is still considered waste. The energy use of biomasses obtained from IAPS eradication may represent ecological and economic benefits, creating synergies with restoration projects. We evaluated whether the growth forms and functional types identified using the functional space of 63 IAPS corresponded to a possible bioenergy use through multivariate analysis techniques. We extracted leaf and nutrient traits and Grime’s CSR plant strategies from an existing database. We calculated the carbon-to-nitrogen ratio (C:N) and gross heating value (GHV) as indicators of biochemical or thermal processes, respectively. For 10 species, we measured the above-ground biomass C:N and GHV (including leaves, stems and branches) and correlated them with those of leaves and with plant adaptive strategies. We identified four groups of IAPS indicative of the main trade-offs between plant economics and size variation, which respectively correlated with C:N and GHV. Herbaceous IAPS were better suited to biochemical processes, and woody IAPS to thermal ones. Overall, Grime’s CSR strategies were the best tool to define the IAPS bioenergy potential. In the long term, competitive and ruderal IAPSs can represent a reusable feedstock until their complete eradication.

Woody and herbaceous invasive alien plant species‐derived biochars are potentially optimal for soil amendment, soil remediation, and carbon storage

“…The eradicated biomass is considered a waste to be disposed of, but its valorization could help cut these costs. Nonetheless, since IAPS produces a large amount of readily available biomass, avoiding land conversion and competition with food, its biomass may represent a sustainable feedstock for different applications, ranging from bioenergy production to bio-based materials (Carson et al, 2018;Ceriani et al, 2023;Mathew & Saravanakumar, 2022;Monteiro & Ferreira, 2022;Nackley et al, 2013;Velvizhi et al, 2022). This concept is crucial within the EU's "Next Generation EU" project (https:// next-gener ation -eu.…”