Non-native grasses ignited last week's wildfires in Maui County

Preventable grass fire

A July 2021 report published by the County of Maui revealed that upon investigating the 2019 wildfire season, scientists foresaw a rising threat from wild/brush/forest fires to citizens, properties, and sacred sites. 

Researchers recommended expanding the existing prevention strategies led by the Maui County Fire Chief within State law. The report stated, “Most ​​wild/brush/forest fires are caused by human action and should be preventable.”

The state has already produced videos and prevention education programs for visitors to view at airports, hotels, and public service sections. The report further recommended reducing alien plant life that serves as fuel, “grasses serve as tinder and rapidly invade roadside shoulders.”

Combustible sugarcane fields

Additionally, they stressed addressing the functioning of abandoned sugarcane field growth as the lack of maintenance and periods of drought increases the combustibility of grasses and sugarcane. Other overgrown properties have also been named potential fire hazards.

Clay Trauernicht, an ecosystems and fire specialist at the University of Hawaii at Mānoa, alluded to the HC&S sugarcane mills in Hawaii that closed down in 2016 which covered 4,570 hectares (36,000 acres) on Maui told The Guardian:

“The lands around Lahaina were all sugarcane from the 1860s to the late 1990s. Nothing’s been done since then – hence the problem with invasive grasses and fire risk.”  

Despite addressing the concerns, the grasses that envelop parts of Hawaii fuelled wildfires that broke out last week in the region. The grasses growing on these lands included guinea grass, molasses grass, and buffel grass — which originated in Africa and were introduced to Hawaii as livestock forage — now occupy nearly a quarter of Hawaii’s landmass, The New York Times emphasized. These greens grow rapidly and are drought resistant.

Unmanaged non-native grass

According to The Guardian, Trauernicht said that any form of “land use or land care would have made the situation safer,” given that the grasses were “completely left unmanaged” when asked about the non-native grasses.

Although, Pacific Fire Exchange (PFX) factsheet indicated that the non-native grass species including – fountaingrass (Cenchrus setaceus) and Guinea grass (Megathyrsus maximus), “adapted to thrive with fire”. These greens were originally grown to feed cattle and provide ornamentation.

Melissa Chimera, coordinator of the Pacific Fire Exchange, a Hawaii-based project sharing fire science among Pacific island governments, told The New York Times:

“These grasses are highly aggressive, grow very fast, and are highly flammable. That’s a recipe for fires that are a lot larger and a lot more destructive.” 

Man-made GHGs

Human-driven greenhouse gas emissions (GHGs) are another factor that contributed to the devastating fires. Camilo Mora, an environment professor at the University of Hawaii, Mānoa, said that the failure to tackle the climate crisis contributed to the crisis.

“Yes, the grasses were a disaster waiting to happen, but … the silver bullet [solution] is reducing GHG [greenhouse gas] emissions. These people in Lahaina did not deserve to die. For a smart species like us to let this happen … as a scientist, I feel like crying,” he said.

Mora explained that grasses benefit from CO2 emissions as invasive grasses grow faster than native plants. “The more CO2 that’s in the air. It’s like more food for the plants. CO2 feeds photosynthesis of these grasses, and that helps them grow.”

While the investigation into the fire’s origin is still ongoing, experts caution that the warming planet is making it evident that even a tropical place such as Hawaii, known for its jungle-like rainforests and verdant hills, is increasingly susceptible to wildfires.