Growth and competition between a native leguminous forb and an alien grass from the Cerrado under elevated CO₂

Abstract

The increase in atmospheric CO 2 concentration ([CO 2 ]) due to climate change may alter the composition of communities and the functioning of ecosystems. Owing to greater nitrogen use efficiency, leguminous plants present more effective responses to increasing [CO 2 ] than non-legumes. The objective of this study was to evaluate the morphophysiological and growth responses of two species from the Cerrado, a native C 3 herbaceous legume (Stylosanthes capitata Vogel.) and an invasive C 4 grass (Melinis minutiflora P. Beauv) growing alone or in competition, in ambient (350 ppm) and high (1000 ppm) [CO 2 ]. Competition with S. capitata reduced leaf development and dry matter production in M. minutiflora individuals, regardless of [CO 2 ]. Stylosanthes capitata increased root system growth under high [CO 2 ] and competition. This change allows greater soil exploitation, decreasing nutrient limitation to S. capitata development. The leguminous species S. capitata showed advantages in the competition for resources under high [CO 2 ] concerning the invasive grass. Although invasive C 4 species are initially better in the colonisation of the invaded areas, the C 3 native species of Cerrado may adjust morphophysiological traits when growing at high [CO 2 ] and develop strategies that enable it to more effectively compete for resources.

Influence of multiple global change drivers on plant invasion: Additive effects are uncommon

“…Increased CO 2 could also increase the advantages of invasive plants over native plants. High CO 2 may increase the primary productivity of native and invasive plants at the same time, but the aboveground biomass and rhizome size of invasive plants may increase more than native plants ( Nackley et al., 2017 ; Oliveira et al., 2021 ). However, our results also suggest that the competitiveness of invasive species tended to be more impacted than native species.…”

Nitrogen niche partitioning between tropical legumes and grasses conditionally weakens under elevated CO2

“…Atmospheric CO 2 concentrations have increased by 50% since the industrial revolution (IPCC, 2022). There are many ecosystem consequences associated with this change, including an increase in plant productivity (de Graaff et al, 2006;Gill et al, 2002), altered plant community composition and diversity (Reich, 2009;Zelikova et al, 2014), and modified plant interactions within a community that impact ecosystem scale processes (Blumenthal et al, 2013;Gonçalves de Oliveira et al, 2021;Maschler et al, 2022). However, some of these patterns may only occur when water is limiting, nutrients are abundant (Reich et al, 2014;Rogers et al, 2009;Soussana & Lüscher, 2007) or when plant diversity is high (Reich et al, 2001;Shaw et al, 2002).…”