Altered snowfall and soil disturbance influence the early life stage transitions and recruitment of a native and invasive grass in a cold desert

摘要: Climate change effects on plants are expected to be primarily mediated through early life stage transitions. Snowfall variability, in particular, may have profound impacts seedling recruitment, structuring plant populations and communities, especially mid-latitude systems. These water-limited frequently invaded environments experience tremendous variation snowfall, species these systems must contend with harsh winter conditions frequent disturbance. In this study, we examined the mechanisms driving of snowpack depth soil disturbance germination, emergence, establishment native Pseudoroegnaria spicata invasive Bromus tectorum, two grass that widely distributed across cold deserts North America. The absence snow exposed seeds an increased frequency intensity freeze–thaw cycles greater fungal pathogen infection. A shallower promoted formation a frozen surface crust, reducing emergence both (more so for P. spicata). Conversely, deeper recharged improved by creating higher more stable levels moisture availability following spring thaw. Across several treatments, experimental served decrease cumulative survival species. Furthermore, observed that, regardless treatment, most seed mortality (70–80 %) occurred between germination (November–March), suggesting other wintertime factors or just general limited survival. Our results suggest legacy influence but might not facilitate invasion deserts.