Sunday, September 11, 2016

Scrub-Steppe Fire Near Kennewick

A scrub-steppe fire burned just south of Kennewick yesterday morning. The abrupt appearance of a plume of smoke in otherwise very clear sky was a bit of a surprise.

Scrub-steppe fires are common as this is a land with a long stretch of dry season. However, the grasses in this ecosystem have changed such that it is thought that the fires burn with a greater frequency and greater intensity than in the past. This past summer has seen several very large scrub-steppe fires in eastern Washington including one west of Prosser and another large one controlled with a large back fire on the Hanford Reach. These fires can cover huge swaths of land in very short periods.

The fire was contained and burned a bit short of one square mile. The fire burned during the morning when temperatures were mild and there was little wind. I went up the ridge above the burned area in the late afternoon. If the fire had burned then, it would have been a different story as the wind was blowing about 40 mph and the temperature was in the mid 80s.
A mix of dust and smoke coming off the burned area

Roots of sage brush and rabbit brush were still smoldering and dust was kicking up from the disturbed dirt roads around the perimeter of the burn. The cause of the fire is not yet known.

Sharp edged lines around the burn area along dirt roads
The lack of wind during the fire made a big difference
If the wind had been blowing this slope would have burned and posed a threat to the homes on the ridge crest.


Hollis said...

Are fires considered important for regeneration? as in chaparral?

Dan McShane said...

I am not the best person to answer that question. It is a really good question. What I can say is that fire intensity due to cheat grass has increased and is thought to be detrimental to the previously existing plant mix and particularly hard on sage brush and other brush plants. Periodic burning of sage and other brush must play a role in grass systems as very old sage stands or juniper can become rather mono culture. The edge habitat and impacts to riparian areas must also be important.

Hollis said...

Interesting. Based on where I am at the moment--Grand Jct area--I can see how cheatgrass could do that! We don't have much in the Laramie area, but here there are huge stands of cheatgrass with scattered shrubs.