Higher Fire Frequency Impaired Woody Species Regeneration in a South-Eastern Amazonian Forest

Background:

The more and more common forest fires in the Amazon rainforest, caused after fire escape from pasture or deforested lands, cause unpredictable changes to the forest structure. Therefore, it is essential to assess the resilience of these ecosystems after being impacted by fire events and the likelihood of maintaining forest tree species and not being replaced by savanna species.

Goals:

The authors asked the following questions to elucidate how increasing fire frequency affects forest regeneration: (1) Is the diversity of regenerating tree species still altered two years after fire exclusion? (2) What is the contribution of resprouting for persistence of native tree species? (3) Is there an increased recruitment of Savanna or liana species after several fires? (4) Is there an increase in grass cover, associated fire frequency and/or edge effects?

Takeaway:

The number and frequency of fire events influence the regeneration of a forest stand. A higher number of fire events (six per year) led to a strong decline in forest regeneration ability, resulting in the loss of 77% of seedlings and 45% of resprout-based regeneration species. However, the authors emphasize the need for long-term studies to understand to what extent forest resilience was reduced.