Functional and evolutionary responses to resource availability among native and invasive grasses in the Cerrado

Abstract

Invasive species are a major restoration challenge and it is important to build functional plant communities resistant to invasions. However, invasive species often show functional attributes highly favourable to invasion and higher phenotypic plasticity than native species, either due to their past evolutionary history or local adaptation. African grasses often dominate the Cerrado herbaceous layer and hamper its restoration, so it is crucial to identify functional attributes favourable to native grasses under contrasting levels of resource availability, as well as the role of phenotypic plasticity and adaptive evolution on invasion success. In this study, I plan to assess the effect of the hydrological regime on the dominance by African grasses and on the taxonomic, phylogenetic and functional structure of Cerrado grass communities in the Parque Nacional da Chapada dos Veadeiros. I will also experimentally assess competitive ability and phenotypic plasticity to soil P and N content among African and Cerrado grasses and perform experiments comparing plasticity and performance under contrasting P levels among South African and Cerrado populations of African grasses. We predict that communities of native grasses occurring under more distinct hydrological regimes will show greater taxonomic, phylogenetic and functional differences. We also expect higher phenotypic plasticity and competitive ability among African than Cerrado grasses and evidence of adaptive evolution for species with long introduction history. Our findings will contribute with the efficiency of Cerrado restoration and shed light on the role of evolutionary processes on the success of African grasses in Neotropical savannas. (AU)