Burning season does not affect post-fire regeneration but fire alters the balance of the dominant species in a seeder-dominated Mediterranean shrubland

Authors


Abstract

Question

In a seeder-dominated shrubland, does burning season affect post-fire regeneration? Are herbs and shrubs similarly affected? Is the dominance of the main species modified by burning and its timing?

Location

Los Puntales, Sierra Morena (Córdoba, southern Spain).

Methods

The shrubland was 12 yr old, dominated by several species of Cistus, among the main seeders. Four blocks, each containing plots of 25 × 25 m, were burned in late May (early season, ES) and late September (late season, LS) with similar fire intensity. Woody plant density and woody and herbaceous cover and richness were monitored during the first three post-fire years and compared to pre-fire using ANOVA and ordination techniques.

Results

Burning season did not affect cover of the herbaceous or woody species in general, nor cover of the main groups (monocots, dicots, annuals and perennials) or density of the main woody species 3 yr after fire. Fire, however, differentially affected the relative abundance of the main shrub species. Ordination analysis showed that, while succession of herbaceous species was on track to convergence with the pre-fire vegetation, this was not the case for the woody species.

Conclusions

Burning season was not a significant factor in altering the post-fire regeneration in this seeder-dominated shrubland. Thus, the temporal window for prescribed fires is large, and both seasons could equally be used for management purposes. However, changes in the relative dominance of species due to fire indicate that managers should be alert when this shrubland burns.

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