This year, like many years, Tucson put on a 4^th of July fireworks display over A Mountain. This would not be a problem for a typical Sonoran Desert landscape that has natural open space among its scattered trees, shrubs, and cacti and thus a very low potential to burn. However, this hill that lies nestled in the heart of the city is largely covered with the invasive plant— buffelgrass. Buffelgrass is an excellent fuel, capable of producing hotter fires that move faster and further than any our native vegetation could possibly produce.

On this 4th of July, I had just flown in from a family member’s wedding. Driving home from the airport we noticed that the hillside was on fire. One (or more) of the fireworks had set fire to some of the bone-dry grass, and the fire was rapidly spreading across the hill. We saw saguaros engulfed in flames.

As part of my work with the Desert Museum and the University of Arizona, I went out over the subsequent weeks to map the fire and study the mortality of the saguaros and other perennial plants on the hillside. I worked with Ben Wilder, Interim Director of UA’s Tumamoc Hill, to assess each saguaro cactus for height and burn extent. We will return to see how many of the burned cactus actually died. This will give us a better understanding of how the saguaro cactus withstands fire. From initial observations, the younger cacti are hit especially hard. Many of these will surely not survive.

Buffelgrass grows faster after fire. Photo: ASDM/Julia Rowe

Buffelgrass growing around a badly burned saguaro. Photo: ASDM/Julia Rowe

Another saguaro that had been badly burned. Photo: ASDM/Julia Rowe

We will not know the exact number of saguaros lost for some time, but more than 250 were burned in the fire.

So how can you help?

• Remove any buffelgrass that you see around your homes or neighborhoods.
• Volunteer to help remove buffelgrass in Tucson.
• Donate to help fight buffelgrass!

Written by Julia Rowe, Invasive Species Research Specialist.