How can fire suppression change Mediterranean scrubland into woodland?

Fire is a natural and essential component of scrubland ecosystems, serving to maintain their composition by killing young trees or keeping them in a shrub form.1

When fire suppression—the human activity of making wildfires less frequent—is introduced to these environments, it removes this critical control mechanism. Without periodic burning to clear competing vegetation and suppress tree growth, the community structure can shift from scrubland to woodland.

In many fire-adapted ecosystems, the absence of fire allows fuels to accumulate and enables woody plants to establish themselves where they would otherwise be inhibited. By preventing the natural fire regime, the landscape undergoes a transition as tree species are no longer periodically destroyed, eventually leading to the development of tree-dominated vegetation.12