Guinea grass adds wildfire fuel in Hawaii's unmanaged landscapes

Guinea grass can add fuel to fires in Hawaii when dense growth dries during drought. The Hawaii Invasive Species Council rates the species as posing a high fire risk. Its stands can build up in unmanaged areas, particularly where grazing or other vegetation management is absent.

According to the Hawaii Invasive Species Council, the perennial grass can reach 9 feet tall, and a single plant can produce up to 9,000 seeds. Wind and animal droppings can disperse those seeds. The grass is naturalized and common across all of Hawaii's main islands.

Fire can also help the grass spread. It can regenerate quickly after burning and expand into burned areas, gaining an advantage over vegetation that recovers more slowly. That new growth can occupy ground opened by fire and reinforce the grass's presence in the landscape.