Are forests regenerating after fire?

Session: Fire impacts and lessons learnt

Presenter: Camille S Stevens-Rumann (Forest and Rangeland Stewardship, Colorado State University)

Contact email: C.Stevens-Rumann@colostate.edu

We focus on post-disturbance recovery. Our research focus is on the challenges facing disturbed lands, ecosystem responses and how to improve future ecosystem management.

Link: people.warnercnr.colostate.edu/?Camille.StevensRumann

ABSTRACT: Increasing disturbance activity and declining tree regeneration with warming climate, have lead to concerns about forest resilience. We used a multi-regional dataset of 52 wildfires from the U.S. Rocky Mountains to ask if and how changing climate over the last several decades impacted post-fire tree regeneration and use climate models to predict where forests are most at risk for faltering regeneration in the coming decades. Results highlight significant decreases in tree regeneration in the 21st century. Increasingly unfavorable post-fire growing conditions, as shown by increasing moisture deficits, corresponding to significantly lower seedling densities and increased regeneration failure. On sites burned in the 21st century >70% of dry forest sites did not achieve similar pre-fire densities, while >40% did not have any tree regeneration. This indicates these dry forests that occur at the edge of climatic tolerance for supporting forest cover are most prone to non-forest conversion after wildfires. Forest structures and associated ecosystem services will continue to change wildfire and climate change influence forest recovery.