This dataset contains records for vegetation in 49 plots across 14 fragmented forest sites and 4 continuous forest sites in Sabah, Malaysian Borneo. Living vegetation and deadwood were surveyed in two or three 0.28-ha plots in each of the eighteen sites. In addition to vegetation data, the dataset contains topsoil parameters, measurements of forest structure, and metrics of the degree of forest fragmentation in the landscape surrounding the plots. These data were collected in order to conduct studies examining (1) the factors supporting invasion of exotic plant species into fragmented forest areas; and (2) the value of conservation set-asides for carbon storage and associated plant diversity in oil palm plantations.