When farmers use a controlled burn to prevent forest fires, the first plants to return would most likely be grasses. Grasses have a high resilience to fire and their seeds are often able to survive underground or in the soil after a fire. This allows them to quickly sprout and grow once the conditions become favorable after a controlled burn.
Shrubs may also return relatively quickly after a controlled burn, especially if the roots are not completely damaged by the fire. Mosses, on the other hand, may take longer to reestablish after a controlled burn due to their delicate nature and slower growth rate compared to grasses and shrubs.
While trees are important in forest ecosystems, they typically take longer to regenerate after a fire as they often rely on seeds that may need specific conditions to germinate and grow. So, in the case of a controlled burn, grasses are likely to be the first plants to return due to their resilience and quick regrowth.