Fighting the invasion in the Boise Foothills

BOISE, Idaho — The Boise Foothills are like a paradise in our backyard, but there’s a lot more going on up there than meets the eye.

“The city of Boise owns over 5,000 acres and these areas encompass diverse ecological sites so everything from wetlands all the way to forested areas around stack rock,” said Martha Brabec, an ecologist for the City of Boise.

Brabec is in charge of monitoring the ecology in the foothills. While there is beautiful scenery everywhere you look, there are also threats hiding in plain sight.

“The understory here is a mish-mash of invasive species. There are two grasses here that are really visible which include Cheat Grass as well as Medusa Head Rye. Both of these are annual grasses that came over from Europe. The problem with Medusa Head Rye is it has a high silica content and it forms a really dense layer of thatch on the soil’s surface which is highly flammable and so the Cheat Grass and Medusa Head Rye and a variety of other invasive grasses are the primary reason the fire return intervals have increased more fire means more disturbance and the means the wildlife habitat has been degraded,” Brabec said.

The threats come in all sizes. In addition to grasses, invasive trees are a menace to The Foothills environment as well.

“Russian Olives are really prolific all over the great basin desert and you can find them anywhere there’s water. You can see these are in a drainage so there’s probably a little bit of extra water in here. Birds love to spread them, birds love to eat them however Russian Olive consumes three to four times the amount of water than a native Cottonwood or Willow and the leaves are not easily biodegradable by all of the macroinvertebrates in the soil so when the leaves fall off they don’t feed the food pyramid from the bottom up I refer to them as biological garbage,” Brabec said.

And there are other invasive species as well. The reality, weeding out the invaders won’t happen overnight managing the biology in such a vast area takes decades.

“I’m the first person looking at long term management of these open spaces which goes beyond cutting down trees and walking away. Open space is committed to long term management, not just a one and done restoration planting some shrubs and walking away we’re utilizing science to guide management,” Brabec said.