Prescribed burning lowers the initial recruitment rates of three pine species that inhabit a mid-altitude Mediterranean mountain

Abstract

Prescribed burnings have been generally used for fuel reduction in Mediterranean forest ecosystems and in fire-prone areas. It is usually held that prescribed fire may alter microsite conditions, but very little is known about the impact of prescribed burning on Mediterranean pine species’ natural regeneration. In this study, we aim to know the effect of prescribed burning, soil preparation (scalping) and seed protection on the initial recruitment of Spanish black pine (Pinus nigra Arn. ssp salzmannii), maritime pine (Pinus pinaster Ait.) and Aleppo pine (Pinus halepensis M.) in the Cuenca Mountains (central-eastern Spain) after a 1 year of experiments. Our results indicated that the seed emergence rate was higher in the scalped plots for Maritime pine and Aleppo pine. In the case of Spanish black pine, differences comparing treatments for the emergence rate were weaker. Scalped and protected plots showed the highest seedling survival rate for Aleppo pine and Spanish black pine whereas protected and control plots perform better in the case of Maritime pine. Thus, seed protection is a crucial factor for ensuring seedling survival after the first growing season. By considering our results about early pine species recruitment, prescribed burning must be carefully planned when the natural regeneration of Spanish black pine, maritime pine and Aleppo pine is the aim.