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

Abstract

AbstractThe increase in atmospheric CO2 concentration ([CO2]) 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 [CO2] than non‐legumes. The objective of this study was to evaluate the morphophysiological and growth responses of two species from the Cerrado, a native C3 herbaceous legume (Stylosanthes capitata Vogel.) and an invasive C4 grass (Melinis minutiflora P. Beauv) growing alone or in competition, in ambient (350 ppm) and high (1000 ppm) [CO2]. Competition with S. capitata reduced leaf development and dry matter production in M. minutiflora individuals, regardless of [CO2]. Stylosanthes capitata increased root system growth under high [CO2] 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 [CO2] concerning the invasive grass. Although invasive C4 species are initially better in the colonisation of the invaded areas, the C3 native species of Cerrado may adjust morphophysiological traits when growing at high [CO2] and develop strategies that enable it to more effectively compete for resources.