PSU Study Will Explore How Fire and Human Activity Can Push Forests to the Breaking Point

A Portland State University professor recently received a $350,000 federal grant to study how high-intensity fires, re-burns, and human activity could result in the collapse of forest ecosystems.

The National Science Foundation awarded PSU College of Liberal Arts and Sciences geography professor Andrés Holz the grant in support of work that aims to assess the topographic and environmental factors that promote or inhibit wildfires. The study will take place across a swath of forests and woodlands near the Argentinian and Chilean border in the Patagonian region of South America. The grant also funds a series of field and laboratory experiments that will inform regional post-fire forest restoration efforts under conditions that may result from climate change.

The study will answer questions about factors (e.g., shifts in vegetation, climate variability, fire intensity, frequency, and the introduction of invasive species) that can result in forests becoming less resilient to wildfires and more prone to devastating burns and ecological collapse. Holz and his research team will use satellite data and computer modeling to predict fire occurrence and the potential for new, more fire-prone species of plants to spread through protected natural reserves on the Chilean and Argentinian slopes of the Andes. The team will also plant the seeds and seedlings of native species, including the iconic Monkey Puzzle tree (Araucaria araucana), at sites on both sides of the border to evaluate growing conditions in the field and at a lab facility in Argentina where they will simulate potential effects of climate change.

"As forests experience higher-intensity and higher-frequency fires, they become susceptible to changes that can result in ecological tipping points," Holz said. "Combined with the introduction of invasive species like pines and highly-flammable native shrubs, fires can limit a forest's ability to regenerate, and regeneration is the lynchpin of forest resilience."

While on the other side of the world, the Patagonian forests and woodlands Holz studies bear a striking resemblance to the Cascade Range that runs through Oregon and Washington. Given the similarities between the two regions, the three-year project results will be shared with forestland managers in North and South America. Holz anticipates the findings will support post-fire forest restoration efforts in Chile and Argentina. Here in the U.S., land-use managers will be able to take the lessons Holz learns and apply them to identifying assessment and management decisions that could prevent forest ecosystem collapse due to wildfire activity.