Post-fire structural and compositional habitat resilience in pine plantations woodland types

Abstract

Fire plays a key role in structuring biotic communities around the world. In fire-prone regions, many plant species have acquired adaptive traits (seeders and resprouters) that help them to survive, reproduce, and persist after fire disturbances. Seeder and resprouter species have different short-term responses to fire. Obligate seeders have faster growth rates, greater 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 burnt 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 burnt and unburnt plots located in four independent burnt sites. Burnt and unburnt plots were structurally different, with the shrub and grass covers expanding after fire. In terms of functional plant composition, seeders were more abundant than resprouters in burnt pine plantations. The stronger short-term resilience of obligate seeders compared to resprouters was found to 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.