Are pine plantations valid tools for restoring Mediterranean forests? An assessment along abiotic and biotic gradients

摘要: The ecological impacts of forest plantations are a focus intense debate, from studies that consider as "biological deserts" to showing positive effects on plant diversity and dynamics. This lack consensus might be influenced by the scarcity examine how characteristics vary along abiotic biotic gradients. Here we conducted large-scale assessment regeneration in southern Spain. Tree seedling sapling density, species richness, Shannon's (Hf) index were analyzed 442 pine plantation plots covering wide gradient climatic conditions, stand distance natural forests act seed sources. Pronounced variation was found understories gradients explored. Low- mid-altitude showed diverse abundant bank dominated Quercus ilex, whereas high-altitude virtually monospecific seeding Pinus sylvestris. Regeneration null with densities exceeding 1500 pines/ha. Moderate (500-1000 pines/ha) promoted recruitment comparison low or canopy cover, suggesting existence facilitative interactions. ilex diminished exponentially nearest Q. forest. Richness H' values hump-shaped distribution altitudinal radiation decreased monotonically density gradient. From management perspective, different strategies will necessary depending where lies Active required high- arrested succession diversity. Thinning could redirect toward more facilitation predominates. Passive recommended for low- moderate-density active successional dynamics (e.g., oak pine-oak at mid altitudes). Enrichment planting overcome limitation, especially far forests. We conclude should perceived dynamic systems trajectories levels determined constraints, complex balances competitive interactions, spatial configuration native sources, life-history traits.