Warming temperatures associated with climate change have increased wildfire intensity and frequency, which can especially impact Ponderosa pine (Pinus ponderosa P. & C. Lawson) ecosystems in the Western United States. Ponderosa pine regeneration post high-severity wildfire is limited in mid-elevation, lower montane, xeric forests in the Rocky Mountain region due to reduction of seed supplies from living trees, warm temperatures, and limited precipitation. Ponderosa pine forests susceptibility to high-severity wildfire increased the need for better restoration practices. Our study aims to determine the most effective restoration of pine ecosystems through implementation of a combination of three treatments; 1) pine introduction through seeding, planting or natural regeneration, 2) dead wood removal; no cut/leave all, cut and leave slash, or cut and remove slash , and 3) erosion treatment through seeding of native grasses or no seeding. Restoration treatments were set up in 2015 at the Rogers Research Station in the Laramie Mountains of Wyoming, where a high-severity wildfire burned approximately 39,700 ha in 2012. In 2017, ponderosa pine seedling counts were performed in all treatment plots as well as vegetation species composition using Daubenmire quadrats along 50 m transects.
Results/Conclusions
Pine seedling density was highest in the planted seedling treatment at 84 stems ha -1 compared to 2 and 1 stem ha -1 for natural regeneration and hand-seeded treatments, respectively. Hand-planted and cut/remove slash combination treatment resulted in the highest stem density at 137 stems ha -1. Vegetation relative cover percent was dominated by perennial forb lifeforms for all cut treatments. Sub-shrubs and shrub lifeforms had the second highest relative cover in cut/remove slash and no cutting/leave all dead treatments; whereas perennial grasses and sub-shrub lifeforms had the second highest relative cover in the cut/leave slash treatment. Cheatgrass (Bromus tectorum (L.)) was the most abundant invasive species present in all cut treatments. Canada thistle (Cirsium arvense (L.) Scop.) was most abundant in the cut/leave slash treatment compared to the other cut treatments. Higher pine stem density in the cut/remove slash treatment plots may be due to ponderosa pine seedling’s intolerance to shade. If habitat restoration is the ultimate management goal, more research is needed regarding the viability of hand planting seedlings for habitat restoration purposes. There is a trend towards no significance regarding native grass seeding reducing invasive species abundance.