Ponderosa pine regeneration in the Southern Rocky Mountains has become a concern for forest management as fires increase in their intensity and duration, leaving behind homogeneous landscapes that lack seed sources and promote changes in its primary species. To address this problem, I partnered with The Nature Conservancy to map areas where traditional planting and direct seeding would be possible in fire scars, based off certain criteria (distance to roads, slope, and burn severity) used by the US Forest Service (USFS). In areas deemed possible to direct seed, we created treatments for ponderosa pine seeds collected in 2019, including: clay seedballs, chili coating, partial stratification, and direct seeding during different seasons of the year; they were then placed in plots and observed in a year-old and a two-decade old fire scar. After cyclic observation, it was found that the germination rate of ponderosa pine seeds in both fire scars were below average (less than 2%). However, 25.8% of seedlings established themselves in the two-decade old burn scar and 37.8% were established in the year-old fire scar till the end of the research period. Through a three-way ANOVA test, it was determined that the most significant treatment was the season: Spring for direct seeding; the treatments that had the most success was instead seeds with no seedball and no coating. More so, we found that there were abundances of seedlings (19) in a few of the micro-transects, which created outliers in the data that had mostly 0’s. Because ponderosa pine is an adaptable species, their seeds will germinate in burn scars and create heterogeneity on the landscape if they can find some source for their needs. What is also notable is that recent burn scars are more successful in establishing seedlings, even after moderate and high severity burns. It is important that this research emphasizes that direct seeding can become a cost efficient and more successful way to reforest, compared to traditional planting; ponderosa pine seeds only need carefully planned times to be spread, rather than expensive treatments and large groups of people to plant. As of right now, one quarter of the Southern Rocky Mountains is suitable to directly seed in moderate and severe fire scars. This is important in a hydrologic standpoint because trees are known to prevent erosion that would end up in water systems and have the capability to alter local hydrology. As summers continue to have record breaking forest fires, it is time to begin implementing more management practices to offset the major losses of ponderosa pine trees.
Geography Undergraduate Student, CU Boulder