Can an invasive African grass affect carbon and nitrogen stocks in open habitats of the Brazilian Cerrado?

In a site open cerrado site invaded by the African Urochloa decumbens and in an adjacent uninvaded cerrado site in the Itirapina Ecological Station (SP-Brazil), we sampled the aboveground biomass and root biomass (10 cm layers) up to a 50 cm depth. In the same sites we obtained the content and stock (corrected for differences in soil bulk density) of C and N in the soil, as well as the soil level of 13C and 15N, up to a 1m depth (at 5 cm layers up to 20 cm and then at 10 cm layers).