Controlled burns are a powerful tool in the fight against non-native species, but are they the best way to promote oak regeneration? In short — it's complicated. In a 2015 study in Daniel Boone National Forest (eastern KY), researchers looked at how tree health and stand structure responded in frequently burned (4 times in 8 years), infrequently burned (2 times in 8 years), and fire-excluded study areas. What they found at the stand level was that effects of fire can be influenced by other environmental factors. In this case, drought and defoliating insect infestations led to higher tree mortality in the burnt areas regardless of the burn frequency. The researchers found support for the use of controlled burns to reduce non-native species such as sugar maple, but there was also evidence that repeated burning reduced oak sprout survival. Previous studies support the idea that a single burn would increase oak sprouts, but what this study showed is that if environmental stressors are also present, the oaks may not be able to benefit from post-burn conditions like increased light availability after a fire.