No abstract

Fire plays a key role in structuring biotic communities around the world. In re-prone regions, many plant species have acquired adaptive traits (seeders and resprouters) that help them to survive, reproduce, and persist after re disturbances. Seeder and resprouter species have different short-term responses to re.Obligate seeders have faster growth rates, greater allocation to reproduction, shorter life cycles, and lower shade tolerance than resprouters. A few years after re, obligate seeders are expected to be more abundant than resprouter species within post-re 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 res 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 re. 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 re. Contrast in re 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 re regime.

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.

In recent decades, forest fires in the Mediterranean basin have been increasing in frequency, intensity, and the area burnt. Simultaneously, insects, a group with extraordinary biodiversity that provides vital ecosystem services such as pollination and decomposition, are undergoing a precipitous decline. Unfortunately, the impact of fire on arthropod communities has been poorly addressed despite the high diversity of taxonomic and functional arthropod groups. Responses to fire can differ considerably, depending on the life history and functional traits of the species. In the present study, we investigate the short-term impact of fire (three years after a blaze) on the abundance and species composition of soil arthropods in a burnt pine forest located in Ceuta (Spain, northwestern Africa). Soil arthropods were collected from pitfall traps in burnt and unburnt pine forest sampling points. In terms of total abundance per taxonomic order, Blattodea and Diptera were the only orders seemingly affected by the fire, whereas other arthropod groups (e.g., Araneae, Coleoptera, and Isopoda) showed no differences. In terms of species composition, Coleoptera and Formicidae (Hymenoptera) communities differed between burnt and unburnt sampling points, having more species associated with burnt areas than with unburnt ones. In burnt areas, some species from open areas built nests, fed in/on the ground, and dispersed over longer distances. Within the unburnt plots, we found more species in vegetated habitats, particularly those with shorter dispersal distances. We conclude that arthropod communities differ between burnt and unburnt sites and that the response of each taxon appears to be related to particular functional traits such as habitat preference (from open to forested landscapes) and ecological specialization (from generalist to specialist species).