Diversity Post-Wildfire of Vegitabel Understory in Rocky Mountain Ponderosa Pine Woodland and Montane Sagebrush Steppe

Abstract

In Montana, big sagebrush steppe, montane sagebrush steppe and rocky mountain ponderosa pine woodland take up over 16% of Montana’s 380,832 km2 (16.45%). Studies have shown that habitats dominated by graminoids depend on species abundance and richness to regulate invasion (Tilman 1997). The invasion process can be facilitated by the removal of native perennial species and the accumulation of seed banks of invasive annual grasses (Melgoza et al. 1990). Wildfire can contribute to these factors. A wildfire near Big Saw-Mill Gulch on September 1st 2016 offers an opportunity to compare diversity and richness in burned areas compared to unburned areas in rocky mountain ponderosa pine and montane sagebrush steppe. It is hypothesized that burned habitats will have lower values of diversity when compared to unburned habitats of the same ecosystem. Habitats with lower diversity are expected to have larger compositions of invasive species compared to habitats with higher diversity.