Seed Origin and Protection Are Important Factors Affecting Post-Fire Initial Recruitment in Pine Forest Areas

Initial seedling recruitment is one of the most critical stages for plants in the Mediterranean basin. Moreover, wildfires and post-fire environmental conditions might deteriorate regeneration success, which can lead to problems for sustainable forest restoration and forest persistence. On this context, different seed origins and pine species may be better adapted to new environmental conditions remaining after forest fires and seed protection might modulate seedling initial recruitment. This study evaluates the effects of seed origin (Pinus nigra Arn. subsp. salzmannii Dunal (Franco) from lowland, midland and upland distribution areas), pine species (Pinus pinaster Aiton, Pinus sylvestris L. and Pinus nigra Arn. subsp. salzmannii Dunal (Franco)) and seed protection on seed emergence and early seedling survival after forest fires in the Cuenca Mountains. In addition, a greenhouse experiment was set up under controlled conditions to test seedling performance and to compare initial seedling growth of different P. nigra seed origins growing in field and greenhouse conditions. Results showed that wetter spring seasons and P. nigra seed origins from midland and upland distribution growing in their natural habitat distribution perform better that P. sylvestris and P. pinaster. Seed protection is an important factor modulating the above-mentioned trend. P. nigra seeds growing at the greenhouse experiment showed differences in growth for extreme (upland or lowland) P. nigra distribution.