Complex sentence: Fire-stick farming had the long-term effect of turning scrub into grassland, increasing the population of nonspecific grass eating species like the kangaroo and the ecological disturbance caused by fire-stick farming has been implicated in the extinction of the Australian megafauna.
Split into simpler sentences: Fire-stick farming had the long-term effect of turning scrub into grassland, increasing the population of nonspecific grass eating species like the kangaroo. The ecological disturbance caused by fire-stick farming has been implicated in the extinction of the Australian megafauna.