Spatial patterns of tree cover change at a dry forest margin are driven by initial conditions, water balance and wildfire

How will cheatgrass respond to projected changes in future climate?

Increasing temperatures and reduced summer precipitation are projected to favor expansion of cheatgrass (Bromus tectorum) at higher elevations.  The greater the change in summer conditions, the greater the expected shift in cheatgrass (Bradley et al. 2016).  Although cheatgrass will probably decline at lower elevations, red brome (B. rubens) already present throughout the Great Basin will…

Does elevated atmospheric CO2 favor cheatgrass?

Several studies found that increased atmospheric CO2 concentrations resulted in increased cheatgrass (Bromus tectorum), when soil water and nutrients were not limiting establishment and growth (Hungate et al. 1996; Larigauderie et al. 1988; Nowak et al. 2004).

Will cheatgrass dominate a site in the first growing season following fire where native perennial grasses are depleted?

Response of cheatgrass (Bromus tectorum) the first growing season on a depleted site following fire depends on seed source.  Abundance of post-fire cheatgrass seed is directly related to: the amount of seed in the seed-pool prior to the fire the amount seed combusted by fire, which is largely related to the abundance and types of…

What are the optimal seasonal patterns of precipitation and temperature that favor cheatgrass?

Locations with relatively warm fall temperatures (examples are the Columbia, Snake, and Humboldt basins) are especially susceptible to cheatgrass (Bromus tectorum) dominance, while those with cooler fall seasons and relatively wet winters and springs are more resistant to cheatgrass (Bradley et al. 2016; Cline et al. 2018).

Why does cheatgrass do so well following fire?

In the first few growing seasons fire results in: 1) reduced competition, 2) increased available nitrogen, and 3) warmer soil surface temperatures in the fall and early spring. Cheatgrass (Bromus tectorum) has higher nitrogen absorption rates than many native plants, where soils are warm and moist in the fall and spring (Roundy et al. 2020;…