Direct Seeding of Pinus halepensis Mill. for Recovery of Burned Semi-Arid Forests: Implications for Post-Fire Management for Improving Natural Regeneration

Abstract

Background: In order to maximize the resiliency of Pinus halepensis in semiarid forests, we analyzed direct seeding methods to recover burned stands by simulating post-fire soil treatments. Methods: Seeding was done by installing spot seeding (100 seeds in a 50 × 50 cm plot), using five methods: (1) covering seeding with wood chips; (2) seeding in branch piles; (3) seeding along trunks on contour-felled logs (on the shaded side); (4) seeding next to grass (Stipa tenacissima); and (5) seeding on the bare ground (control). The experiment was replicated according to aspect (northern and southern aspects). The response variables were seed germination (%), and seedling survival after the summer (measured in autumn 2015 and 2016). Direct seeding was carried out in 32 plots with 160-spot seeding, and data were analyzed using general linear models, including nested random effects. Results: Wood chips as a surface-covering material represented the only treatment that significantly improved seed germination and seedling survival (by 12.4%, and 17.4 seedlings m −2 in year 2, respectively) compared with the control in the two topographic aspects. Conclusions: Covering seeding with wood chips, and thus chipping wood within the burned stand, form a recommended post-fire treatment to improve regeneration in Pinus halepensis semiarid stands.

Post-Fire Regeneration and Diversity Response to Burn Severity in Pinus halepensis Mill. Forests

“…The dry period extends from June to September, during which relative humidity is less than 50%. According to Garcia-Morote et al [32], the total precipitation values recorded in the study area from early 2014 to late 2016 were slightly higher than the average values.…”

“…According to the Spanish Soil Map and following the USDA Soil Classification [33], the studied soils were classified as Aridisols (Lithic Haplocalcids), and as calcic soils with long periods (>90 days) of water not available for plants. According to Garcia-Morote et al [32], they are alkaline soils with a clay content above 30% with a high cation exchange capacity (CEC) and low available P. The predominant landform is composed of dolomitic limestones forming rocky slopes that range from 500 to 700 m a.s.l.…”

Towards better practices of salvage logging for reducing the ecosystem impacts in Mediterranean burned forests

“…Part of the publications assessed experimental treatments especially devoted to the study, including restoration techniques like direct seeding (García-Morote et al 2017). However, few studies have analysed practices designed to reduce the environmental impact of post-fire salvage logging.…”

The burn severity and plant recovery relationship affect the biological and chemical soil properties of Pinus halepensis Mill. stands in the short and mid-terms after wildfire

“…The dry period occurs from June to September (relative humidity < 50%). According to the averaging data from 1990 to 2014 (provided by the Spanish Meteorological Agency), the annual precipitation and temperature are 278.50 mm and 15.85 °C, respectively, although annual rainfall was slightly higher from 2012 to 2017 (García-Morote et al, 2017).…”