On Sunday, February 16, 2025, at 2:00pm, around 60 people gathered at the Beaver Meadows Visitor Center Auditorium in Rocky Mountain National Park for the Winter Speaker Series and an opportunity to learn about post-wildfire plant communities. Chris Maienza, a PhD student at Idaho State University, presented an overview of his dissertation research, Arboreal Armageddon: Post-fire Plant Communities, through a virtual meeting.
With an academic and professional background in botany, forestry and ecology, Maienza said his primary research aim was to “conduct plant surveys to evaluate early post-fire plant community composition and diversity.”
During the summer of 2024, Maienza spent 12 weeks in the backcountry of Rocky Mountain National Park to conduct research for his dissertation through the Rocky Mountain Conservancy Scholar–in–Residence Program.
Despite facing challenges in the field such as overhead hazards, harsh conditions, and frequent moose encounters, Maienza sampled 120 plots across three forest types within the 2020 Cameron Peak Fire and East Troublesome Fire burn areas: lodgepole pine below 9500 feet, lodgepole pine above 9500 feet, and subalpine mixed conifer, which was spruce and fir dominated. Each plot type was split between burned and unburned areas, as well as between the two different fire areas. Maienza also recorded 1674 observations of vascular plant taxa, identified 170 unique taxa (distinct species), inventoried 1668 individual trees and counted 2096 seedlings.
Over the past 6000 years, the historical fire regime of high elevation forests across Western North America has been “characterized by high intensity, stand replacing fires every couple 100 years,” said Maienza. A stand replacing fire entails a complete tree mortality and forest reset after a wildland fire.
While total tree mortality is typical for high elevation plant communities, they have seen a greater increase in burned areas in the Western United States. Maienza identified the problem of a departure from historical fire conditions and patterns and sought out to highlight changes in species composition and biodiversity within post-fire plant communities.
The 2020 East Troublesome Fire and Cameron Peak Fire are the two largest fires in Colorado State history. The map shows the fires and their burn areas. Maienza’s plot samples were located within the dark red areas.
An important portion of Maienza’s research in the park was documenting community composition and biodiversity. High elevation plant communities can contain incredible biodiversity, unique species and ecosystem services. “Diversity can be thought of as having two components, richness and evenness,” said Maienza. “Richness is the number of species present, and evenness relates to the relative abundances of species.”
Plant biodiversity not only contributes to the beauty of a natural area, but it is also an important indicator of ecosystem resilience. “The more diverse an ecosystem is, the more able it is to respond to changing environmental conditions,” said Maienza. This includes resilience to altered disturbance regimes such as fire, invasive species, forest pathogens, and land use changes.
The preliminary results from Maienza’s research showed an overall higher understory vascular plant diversity in the burned plots from the Cameron Peak and East Troublesome fires. “Diversity is only one metric, and it’s important to evaluate things in multiple ways in order to better understand the effects of the process like fire,” said Maienza. Wildfire’s effects on Rocky’s ecosystems are complex and nuanced, so Maienza also considered vegetation composition and species lost to fire.
For the remainder of Maienza’s research, he will focus on the genetics of subalpine fir in the context of fire, examining its response to fire and looking for any associations between genetic diversity, fire history and frequency. Maienza predicts that the genetic diversity of subalpine fir will decrease with increasing fire frequency. His findings emphasize the need for further study on fire’s impact on subalpine fir regeneration.
We would like to thank Chris Maienza for his time and providing research that can be used by Rocky Mountain National Park managers to help guide conservation strategies and post-fire recovery efforts. To learn more about post-fire plant communities, NPS.gov has resources that can be accessed at Plant Communities Under a Changing Wildfire Regime (U.S. National Park Service).
The Winter Speaker Series and Scholar-in-Residence programs are made possible by the Rocky Mountain Conservancy. Each year, Rocky Mountain Conservancy funds a scholar, researcher, or scientist to live and conduct scholarly work in Rocky Mountain National Park throughout a 10-week residency.