Climate change, snow mold and the invasion: mixed evidence for release from cold weather pathogens.

Climate change is reducing the depth and duration of winter snowpack, leading to dramatic changes in the soil environment with potentially important ecological consequences. Previous experiments in the Intermountain West of North America indicated that loss of snowpack increases survival and population growth rates of the invasive annual grass ; however, the underlying mechanism is unknown. We hypothesized that reduced snowpack might promote population growth by decreasing damage from snow molds, a group of subnivean fungal pathogens.