Short-term post-fire structural and compositional habitat resilience in pine plantations

Fire plays a key role in structuring biotic communities around the world. In fire-prone regions, many plant species have acquired adaptive traits such as obligate seeders and resprouters that help them to survive, reproduce, and persist after fire disturbances. Seeder and resprouting species have different short-term responses to fire. Obligate seeders have faster growth rates, greater carbon allocation to reproduction, shorter life cycles, and lower shade tolerance than resprouters. A few years after fire, obligate seeders are expected to be more abundant than resprouter species within post-fire plant communities. We examined this hypothesis in burned pine plantations located along the African rim of the Western Mediterranean Basin. In this region, pine plantation is the commonest forestry practice, and such woodlands have undergone frequent fires during the last decades. Here, we describe habitat structure and plant species composition in burned and unburned plots located in four independently burned sites. Burned and unburned plots were structurally different, with the shrub and grass covers expanding after fire. In terms of functional plant composition, obligate seeders were more abundant than resprouters in burned pine plantations. The stronger short-term response of obligate seeders compared to resprouters can be related to the faster capacity of obligate seeders to respond to fire. Contrast in fire response between the two functional plant groups needs to be addressed in conservation planning to ensure the preservation of biodiversity in a future scenario of change in fire regime.